Open File Report OF-AR-26
New Mexico Bureau of Geology and Mineral Resources
A division of
New Mexico Institute of Mining and Technology
Data Repository for 40Ar/39Ar Age
Constraints on the Duration of Resurgence
at the Valles Caldera, New Mexico
Prepared By:
Erin H. Phillips1,2, Fraser Goff3, Philip R. Kyle1,2, William C. McIntosh1,2,
Nelia W. Dunbar2
1
Department of Earth and Environmental Science, New Mexico Institute of Mining and
Technology, Socorro, NM 87801 USA
2
New Mexico Bureau of Geology and Mineral Resources, New Mexico Institute of
Mining and Technology, Socorro, NM 87801 USA
3
Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque,
NM 87131 USA
Data Repository for:
Journal of Geophysical Research
Volume XX, Issue XX
SOCORRO 2006
Summary of 40Ar/39Ar ages for the first Valles caldera ring fracture rhyolite, post-collapse intracaldera units, Bandelier Tuff, and selected megabreccia blocks.a
Rock type
nb
MSWDc
Age (± 2 σ)
Final age determination (± 2 σ)
rhyolite lava
rhyolite lava
28
34
0.31
1.95
1.210 ± 0.023 Ma
1.239 ± 0.028 Ma
Pooled age: 1.229 ± 0.017 Maf
Redondo Creek Member
Redondo Creek Member
Redondo Creek Member
Redondo Creek Member
pumiceous rhyolite lava
rhyolite lava
rhyolite lava
rhyolite lava
20
14
12
23
0.95
0.14
0.22
0.91
1.208 ± 0.017 Ma
1.227 ± 0.020 Ma
1.235 ± 0.028 Ma
1.239 ± 0.017 Ma
Deer Canyon Member
Deer Canyon Member
Deer Canyon Member
Deer Canyon Member
Deer Canyon Member
Deer Canyon Member
Deer Canyon Member
Deer Canyon Member
lithic tuff
lithic tuff
rhyolite lava
lithic tuff
rhyolite lava
lithic tuff
lithic tuff
rhyolite lava
12
9
13
14
11
25
14
31
1.42
0.46
0.14
0.70
0.87
1.27
2.23
1.69
1.229 ± 0.013 Ma
1.245 ± 0.027 Ma
1.254 ± 0.025 Ma
1.257 ± 0.022 Ma
1.262 ± 0.023 Ma
1.274 ± 0.022 Ma
1.274 ± 0.022 Ma
1.283 ± 0.017 Ma
plinian fall deposit
ignimbrite
welded ignimbrite
welded ignimbrite
8
33
18
24
1.82
1.07
3.37
3.56
1.232 ± 0.017 Ma
1.256 ± 0.010 Ma
1.262 ± 0.016 Ma
1.300 ± 0.031 Ma
clast of welded ignimbrite
clast of welded ignimbrite
14
13
3.96
2.85
1.654 ± 0.059 Ma
1.699 ± 0.038 Ma
dacitic lava
dacitic tuff
na
9
2.01
1.3
2.004 ± 0.018 Ma
8.205 ± 0.083 Ma
Sample
Unit
Ring-fracture Rhyolite
EP-42
Cerro del Medio (Valle Grande Member)
EP-39
Cerro del Medio (Valle Grande Member)
Resurgent Dome Rhyolites
EP-7
F03-52
F03-53
EP-10HF
EP-14
EP-15
F03-14b
EP-31
EP-34
EP-2
EP-29
EP-32
Upper Bandelier Tuff
EP-43
upper Bandelier Tuff
EP-44
outflow facies upper Bandelier Tuff
EP-1
intracaldera upper Bandelier Tuff
EP-28
intracaldera upper Bandelier Tuff
Lower Bandelier Tuff
EP-13
lower Bandelier Tuff megabreccia block
EP-12
lower Bandelier Tuff megabreccia block
Tertiary Volcanic Rocks
F03-04-2d
dacitic lava megabreccia block (Polvadera Group)
EP-18e
dacitic tuff megabreccia block (Keres Group)
Age range: 1.208 ± 0.017 to
1.239 ± 0.017 Mag
Age range: 1.229 ± 0.013 to
1.283 ± 0.017 Mag
Preferred age: 1.256 ± 0.010
Ma (EP-44)h
Pooled age: 1.682 ± 0.034 Maf
a
All analyses are by single crystal laser fusion of sanidine exept EP-18 (laser step heating of biotite) and F03-04-2 (laser step heating of groundmass concentrate).
b
Number of analyses used to calculate weighted mean age
c
Mean square of weighted deviates; a goodness of fit parameter
d
Analyzed by laser step heating of groundmass concentrate (heated in 8 heating steps). Six heating steps used to calculate plateau age.
e
Analyzed by laser step heating of biotite separate in two heating steps. Age is weighted mean age of B steps only.
f
Pooled ages: a weighted mean age is calculated for all crystals from multiple samples from the same geologic unit, by the same methods used to calculate individual weighted
mean ages. Used if ages from multiple samples are statistically indistinguishable at the 2σ confidence interval and are of the same lithology and eruptive history.
g
Age ranges: a range of ages for a geologic unit from the youngest to the oldest. Used if a geologic unit is physically variable and occurs in multiple isolated localities,
or if field evidence shows the unit was erupted over a span of time.
h
Preferred age: the age of a single sample from a geologic unit that is found to be the most precise. Used if the 40Ar/39Ar age of one sample is clearly more precise than ages
for other samples within the unit.
40
AR/39AR SINGLE CRYSTAL SANIDINE DATA
ID
40
Age
(%)
(Ma)
(Ma)
EP-44san,K1:160, single crystal sanidine; J=0.0007306±0.10%; D=1.00743±0.00124; NM-160; Lab#=53781
*EP-44san,D5:165, single crystal san; J=0.0016275±0.10%; D=1.00484±0.00092; NM-165; Lab#=54037
09
1.093
0.0090
0.5956
9.791
56.6
84.0
* 14
0.4972
0.0074
0.2110
0.000
68.8
87.0
13
1.929
0.0089
3.415
11.769
57.3
47.7
* 10
0.5026
0.0084
0.2214
0.000
60.7
86.5
15
1.648
0.0099
2.435
9.422
51.5
56.4
* 05
0.4697
0.0086
0.0949
0.000
59.3
93.9
02
1.342
0.0089
1.379
11.093
57.3
69.7
10
1.214
0.0082
0.9408
10.669
62.1
77.1
03
1.244
0.0098
1.041
10.865
52.2
75.3
* 21
0.4859
0.0082
0.1412
0.000
62.5
91.1
14
1.150
0.0088
0.7128
7.688
57.7
81.7
* 12
0.5016
0.0094
0.1903
0.000
54.2
88.4
11
1.307
0.0088
1.231
7.163
58.1
72.2
* 24
0.4595
0.0085
0.0423
0.000
60.1
97.3
12
2.427
0.0099
5.008
11.298
51.6
39.1
* 06
0.4646
0.0082
0.0551
0.000
62.5
96.5
* 15
0.4630
0.0081
0.0468
0.000
62.9
97.0
* 19
0.4809
0.0103
0.1054
0.000
49.7
93.4
06
2.719
0.0139
5.979
10.223
36.8
35.1
* 16
0.4882
0.0089
0.1260
0.000
57.5
92.2
04
1.749
0.0087
2.683
13.173
58.5
54.7
* 11
0.4704
0.0087
0.0592
0.000
58.7
96.2
* 13
0.5274
0.0087
0.2517
0.000
58.8
85.4
* 22
0.4798
0.0085
0.0853
0.000
59.8
94.6
07
3.952
0.0091
10.11
5.545
55.9
24.4
* 20
0.5409
0.0082
0.2824
0.000
62.4
84.0
* 25
0.4922
0.0090
0.1170
0.000
56.8
92.8
* 23
0.4769
0.0083
0.0537
0.000
61.6
96.7
* 04
0.5468
0.0092
0.2900
0.000
55.6
83.8
* 09
0.4836
0.0092
0.0721
0.000
55.6
95.5
05
4.706
0.0086
12.57
10.744
59.0
21.1
08
2.293
0.0085
4.381
13.065
59.7
43.6
* 07
0.5073
0.0083
0.1166
0.000
61.2
93.0
*# 08
20.70
-1.0650
5.647
0.000
91.5
Mean age ± 2σ
n=33
MSWD=1.07
57.7 ±10.8
1.209
1.210
1.212
1.217
1.225
1.230
1.231
1.234
1.234
1.238
1.239
1.241
1.243
1.246
1.249
1.250
1.252
1.254
1.256
1.258
1.261
1.263
1.264
1.268
1.272
1.277
1.277
1.287
1.288
1.291
1.308
1.316
1.322
54.7
1.256
0.027
0.057
0.027
0.067
0.031
0.033
0.025
0.025
0.025
0.017
0.033
0.034
0.036
0.018
0.030
0.020
0.015
0.022
0.033
0.024
0.024
0.019
0.019
0.048
0.061
0.022
0.024
0.031
0.029
0.027
0.043
0.026
0.022
143.7
0.010
EP-43san,K6:160, single crystal sanidine; J=0.0007304±0.10%; D=1.00743±0.00124; NM-160; Lab#=53780
10
1.819
0.0089
3.069
11.364
57.4
50.2
15
1.258
0.0083
1.142
9.732
61.4
73.2
06
1.426
0.0084
1.701
10.157
60.6
64.8
14
1.597
0.0085
2.241
11.861
60.3
58.6
13
1.485
0.0083
1.861
14.191
61.4
63.0
12
1.271
0.0087
1.091
11.444
58.4
74.7
05
3.576
0.0086
8.861
10.910
59.2
26.8
09
2.155
0.0094
3.968
6.818
54.4
45.6
04
3.188
0.0090
7.311
4.212
57.0
32.3
08
2.239
0.0085
4.082
9.073
59.9
46.2
03
7.620
0.0092
22.18
4.378
55.7
14.0
07
3.809
0.0104
9.153
3.064
48.9
29.0
11
3.799
0.0108
8.897
5.953
47.0
30.8
02
14.35
0.0124
42.75
2.854
41.2
12.0
Mean age ± 2σ
n=8
MSWD=1.82
59.1 ±4.8
1.202
1.214
1.216
1.232
1.233
1.251
1.262
1.294
1.355
1.362
1.406
1.455
1.542
2.26
1.232
0.019
0.015
0.017
0.015
0.015
0.014
0.032
0.027
0.046
0.023
0.075
0.058
0.038
0.13
0.017
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(x 10 )
39
ArK
(x 10-15 mol)
K/Ca
Ar*
±1σ
UPPER BANDELIER TUFF
#
#
#
#
#
#
#
#
EP-1san,H8:160, single crystal sanidine; ID#<20: J=0.000734±0.10%, D=1.0052±0.00172; ID#≥20: J=0.0007293±0.10%, D=1.00737±0.00192; NM-160;
29
1.089
0.0224
0.5786
4.944
22.7
84.5
1.210
0.020
07
1.057
0.0195
0.4866
8.701
26.2
86.5
1.211
0.017
20
0.9629
0.0157
0.1177
6.186
32.4
96.5
1.222
0.014
03
1.091
0.0276
0.5403
6.129
18.5
85.6
1.236
0.024
36
1.019
0.0264
0.2714
5.223
19.3
92.3
1.238
0.016
34
1.047
0.0167
0.3305
5.248
30.6
90.8
1.250
0.017
27
1.095
0.0258
0.4961
5.925
19.8
86.8
1.250
0.015
23
0.9703
0.0189
0.0385
5.784
26.9
99.0
1.263
0.015
15
1.008
0.0363
0.1767
4.265
14.1
95.1
1.269
0.033
25
1.073
0.0229
0.3645
8.059
22.3
90.1
1.272
0.012
33
1.133
0.0671
0.5582
2.733
7.6
85.9
1.280
0.031
11
1.083
0.0276
0.3908
4.024
18.5
89.5
1.284
0.035
13
1.108
0.0225
0.4529
10.672
22.6
88.1
1.292
0.015
30
1.074
0.0556
0.3217
4.972
9.2
91.6
1.293
0.018
24
1.091
0.0189
0.3152
6.061
26.9
91.6
1.314
0.015
10
1.104
0.0223
0.3786
3.323
22.9
90.0
1.316
0.042
14
1.033
0.0462
0.1397
2.808
11.0
96.4
1.317
0.050
09
1.725
0.0581
2.459
5.896
8.8
58.1
1.327
0.030
28
1.349
0.0693
1.013
3.706
7.4
78.2
1.387
0.025
26
1.116
0.0421
0.1762
8.231
12.1
95.6
1.403
0.011
Lab#=53755
40
AR/39AR SINGLE CRYSTAL SANIDINE DATA
ID
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(x 10 )
#
#
#
#
#
#
#
#
#
#
#
#
#
#
22
1.476
0.0606
1.376
35
2.147
0.0735
3.474
21
1.552
0.0317
1.384
05
1.348
0.0536
0.7197
31
2.025
0.0704
2.966
06
1.337
0.0502
0.4844
32
1.505
0.0697
0.5993
08
1.384
0.0515
0.1797
02
1.853
0.1000
1.348
04
2.091
0.0664
1.843
12
1.901
0.1107
0.8336
Mean age ± 2σ
n=18
MSWD=3.37
39
ArK
K/Ca
(x 10-15 mol)
3.257
3.184
5.580
5.106
5.011
10.799
6.718
5.992
3.746
5.785
1.649
8.4
6.9
16.1
9.5
7.2
10.2
7.3
9.9
5.1
7.7
4.6
20.0 ±14.9
40
Age
(%)
(Ma)
(Ma)
72.8
52.5
73.8
84.5
57.0
89.6
88.6
96.5
78.9
74.2
87.5
1.412
1.481
1.506
1.508
1.517
1.586
1.754
1.767
1.936
2.053
2.202
1.262
0.033
0.038
0.020
0.029
0.029
0.016
0.015
0.024
0.041
0.029
0.086
0.016
Ar*
±1σ
EP-28san,H10:160, single crystal sanidine; ID#<20: J=0.0007334±0.10%, D=1.0052±0.00172; ID#≥20: J=0.00007287±0.10%, D=1.00737±0.00192; NM-160;
02
0.9506
0.0184
0.1929
3.158
27.8
94.2
1.184
0.041
08
0.9462
0.0187
0.1670
3.660
27.3
94.9
1.188
0.035
22
1.139
0.0262
0.7260
1.859
19.5
81.4
1.22
0.13
09
1.068
0.0259
0.4950
3.066
19.7
86.5
1.221
0.042
14
0.9713
0.0084
0.1570
4.888
60.4
95.3
1.224
0.026
32
1.086
0.0214
0.5018
4.802
23.8
86.5
1.234
0.049
11
1.044
0.0224
0.3481
4.013
22.8
90.3
1.247
0.033
13
0.9866
0.0172
0.1296
3.829
29.7
96.3
1.256
0.034
29
1.017
0.0172
0.1976
2.405
29.6
94.4
1.261
0.097
23
1.320
0.1077
1.221
2.254
4.7
73.3
1.27
0.10
21
1.372
0.0226
1.353
7.044
22.6
71.0
1.280
0.036
04
1.010
0.0189
0.1433
2.074
26.9
96.0
1.282
0.062
26
0.9988
0.0150
0.0755
3.361
34.1
97.9
1.285
0.069
10
1.061
0.0192
0.2786
4.720
26.6
92.4
1.296
0.028
15
1.062
0.0158
0.2763
4.102
32.3
92.4
1.298
0.031
27
1.626
0.0076
2.089
6.749
67.2
62.1
1.326
0.038
31
1.735
0.0314
2.449
4.537
16.2
58.4
1.332
0.056
28
1.109
0.0191
0.2999
6.038
26.7
92.1
1.342
0.039
25
1.146
0.0213
0.3962
4.545
23.9
89.9
1.354
0.052
05
1.058
0.0159
0.1117
3.043
32.2
97.0
1.357
0.046
03
1.061
0.0231
0.0826
2.871
22.1
97.9
1.374
0.046
12
1.061
0.0212
0.0228
3.720
24.1
99.5
1.396
0.037
20
1.212
0.0213
0.5068
5.632
23.9
87.8
1.398
0.043
30
2.132
0.0344
3.602
6.141
14.8
50.2
1.407
0.045
06
1.538
0.0265
1.549
5.613
19.2
70.4
1.431
0.029
07
1.312
0.0507
0.6362
3.643
10.1
86.0
1.491
0.037
24
1.914
0.0445
2.210
2.828
11.5
66.1
1.661
0.086
Mean age ± 2σ
n=24
MSWD=3.56
28.1 ±24.2
1.300
0.031
Lab#=53757
DEER CANYON MEMBER
#
#
#
EP-34san,H2:160, single crystal sanidine; J=0.0007365±0.10%; D=1.0052±0.00172; NM-160; Lab#=53749
13
1.080
0.0199
0.5490
2.436
25.7
85.1
11
0.9695
0.0141
0.1546
7.749
36.1
95.4
07
1.059
0.0134
0.4432
7.338
37.9
87.7
14
0.9953
0.0126
0.2134
5.648
40.6
93.8
02
0.9523
0.0147
0.0375
4.992
34.7
99.0
08
1.241
0.0186
0.9934
2.864
27.4
76.5
09
1.125
0.0167
0.5840
3.606
30.5
84.8
10
0.9751
0.0151
0.0706
3.695
33.8
98.0
15
1.016
0.0188
0.1629
4.235
27.1
95.4
06
1.115
0.0178
0.4522
8.473
28.7
88.1
12
1.077
0.0155
0.2360
3.033
32.9
93.6
03
1.832
0.0392
2.601
4.115
13.0
58.2
04
1.290
0.0155
0.4420
3.774
33.0
90.0
05
1.371
0.0167
0.2100
4.044
30.5
95.6
Mean age ± 2σ
n=11
MSWD=0.87
32.3 ±9.7
1.222
1.228
1.234
1.239
1.251
1.260
1.267
1.269
1.287
1.306
1.340
1.416
1.541
1.739
1.262
EP-32san,H9:160, single crystal sanidine;
16
0.9795
0.0136
09
0.9962
0.0143
06
0.9829
0.0171
10
1.006
0.0130
05
0.9683
0.0150
15
1.012
0.0164
13
0.9705
0.0126
04
1.053
0.0181
28
0.9852
0.0152
17
0.9606
0.0143
08
0.9922
0.0104
12
0.9973
0.0121
14
1.038
0.0194
37
1.009
0.0123
26
1.035
0.0172
07
0.9975
0.0175
1.171
1.19
1.195
1.198
1.205
1.209
1.210
1.228
1.228
1.231
1.233
1.236
1.242
1.247
1.249
1.251
0.078
0.025
0.028
0.039
0.038
0.067
0.053
0.051
0.050
0.023
0.064
0.052
0.053
0.066
0.023
ID#<20: J=0.0007335±0.10%, D=1.0052±0.00172; ID#≥20: J=0.0007289±0.10%, D=1.00737±0.00192; NM-160; Lab#=53756
0.3228
0.3376
0.2743
0.3423
0.1965
0.3345
0.1907
0.4275
0.1757
0.1048
0.2048
0.2150
0.3409
0.2082
0.2913
0.1790
3.998
2.605
3.678
4.977
3.384
4.454
4.733
6.823
5.737
4.925
6.616
5.775
3.093
3.790
5.504
4.030
37.5
35.7
29.8
39.1
34.1
31.1
40.6
28.2
33.6
35.6
49.1
42.1
26.3
41.5
29.7
29.1
90.4
90.1
91.9
90.1
94.1
90.4
94.3
88.1
94.9
96.9
94.0
93.7
90.4
94.0
91.8
94.8
0.068
0.10
0.074
0.055
0.081
0.061
0.058
0.041
0.023
0.055
0.041
0.047
0.089
0.035
0.024
0.068
40
AR/39AR SINGLE CRYSTAL SANIDINE DATA
ID
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(x 10 )
#
#
#
#
#
#
#
#
#
#
#
#
#
#
#
#
33
1.114
0.0185
0.5512
30
1.001
0.0136
0.1347
20
1.190
0.0205
0.7658
35
1.183
0.0158
0.7276
23
1.026
0.0126
0.1720
38
1.025
0.0103
0.1662
39
1.059
0.0113
0.2764
22
1.089
0.0146
0.3160
21
1.061
0.0205
0.2117
32
1.368
0.0576
1.236
24
1.154
0.0196
0.5004
31
1.093
0.0142
0.2742
25
1.117
0.0175
0.3395
29
1.198
0.0158
0.6095
36
1.068
0.0132
0.1559
34
1.057
0.0133
0.1187
27
1.584
0.0345
1.830
11
1.139
0.0196
0.1979
Mean age ± 2σ
n=31
MSWD=1.69
39
ArK
K/Ca
(x 10-15 mol)
4.688
2.999
4.261
3.904
3.776
2.923
2.942
6.611
5.539
1.927
3.411
6.254
3.707
6.435
2.614
3.763
3.311
5.777
27.5
37.6
24.9
32.2
40.6
49.7
45.3
34.9
24.9
8.9
26.0
35.8
29.2
32.3
38.7
38.5
14.8
26.0
34.9 ±13.4
40
Age
(%)
(Ma)
(Ma)
85.5
96.1
81.1
81.9
95.1
95.3
92.4
91.5
94.3
73.6
87.3
92.7
91.1
85.1
95.8
96.8
66.0
95.0
1.252
1.265
1.268
1.274
1.283
1.283
1.286
1.310
1.314
1.324
1.324
1.331
1.339
1.339
1.345
1.345
1.375
1.431
1.283
0.031
0.042
0.032
0.034
0.034
0.046
0.044
0.021
0.025
0.068
0.038
0.021
0.035
0.022
0.049
0.035
0.043
0.048
0.017
1.112
1.200
1.213
1.224
1.230
1.241
1.242
1.257
1.260
1.261
1.285
1.289
1.298
1.310
1.314
1.257
0.055
0.046
0.035
0.043
0.074
0.030
0.042
0.032
0.034
0.042
0.046
0.037
0.063
0.050
0.038
0.022
Ar*
EP-31san,H15:160, single crystal sanidine; J=0.0007354±0.10%; D=1.00743±0.00124; NM-160; Lab#=53762
04
1.929
0.0193
3.694
3.271
26.4
43.5
08
1.168
0.0221
0.8949
3.615
23.0
77.5
02
1.974
0.0135
3.586
5.633
37.9
46.4
11
2.465
0.0193
5.224
4.845
26.5
37.4
03
0.9910
0.0157
0.2186
2.182
32.5
93.6
14
1.250
0.0157
1.066
5.767
32.6
74.9
15
1.041
0.0168
0.3585
3.938
30.4
90.0
10
1.361
0.0194
1.403
5.582
26.3
69.7
05
1.089
0.0112
0.4733
4.931
45.6
87.2
09
1.634
0.0236
2.319
4.813
21.6
58.2
01
2.670
0.0193
5.761
4.553
26.4
36.3
06
2.504
0.0205
5.192
5.901
24.9
38.8
07
3.875
0.0193
9.806
3.796
26.5
25.3
12
3.821
0.0172
9.591
5.227
29.6
25.9
13
1.800
0.0140
2.740
4.905
36.3
55.1
Mean age ± 2σ
n=14
MSWD=0.70
30.0 ±13.0
±1σ
EP-2san,H7:160, single crystal sanidine; ID#<20: J=0.0007345±0.10%, D=1.0052±0.00172; ID#≥20: J=0.0007295±0.10%, D=1.00737±0.00192; NM-160;
09
1.597
-0.0414
56.65
0.014
-948.2
-20.2
16.8
08
0.9503
0.0147
0.2323
8.393
34.8
92.9
1.169
0.027
03
0.9699
0.0215
0.2005
4.714
23.7
94.1
1.208
0.047
06
0.9598
0.0177
0.0987
3.970
28.9
97.1
1.234
0.056
20
1.051
0.0494
0.3786
4.444
10.3
89.7
1.240
0.051
14
0.9754
0.0232
0.1096
5.870
22.0
96.9
1.251
0.038
39
1.064
0.0211
0.3669
2.726
24.1
90.0
1.259
0.081
29
1.068
0.0194
0.3544
4.664
26.3
90.3
1.269
0.048
10
0.9960
0.0182
0.1317
5.824
28.1
96.2
1.269
0.038
21
1.398
0.0144
1.468
3.230
35.3
69.0
1.270
0.071
31
0.9655
0.0180
-0.0008
4.417
28.3
100.2
1.272
0.050
07
1.196
0.0378
0.7845
3.682
13.5
80.9
1.281
0.061
38
0.9919
0.0115
0.0515
5.213
44.3
98.6
1.286
0.043
33
0.9994
0.0189
0.0671
5.226
26.9
98.2
1.290
0.042
35
1.034
0.0230
0.1598
4.755
22.2
95.6
1.301
0.047
27
1.166
0.0240
0.6041
5.714
21.3
84.9
1.301
0.040
30
1.169
0.0212
0.5990
3.748
24.1
85.0
1.308
0.060
28
1.016
0.0288
0.0692
2.192
17.7
98.2
1.31
0.10
12
1.179
0.0666
0.6478
2.015
7.7
84.2
1.31
0.11
24
1.091
0.0096
0.3070
3.396
53.0
91.8
1.317
0.065
41
1.114
0.0188
0.3763
2.886
27.2
90.2
1.321
0.077
11
1.048
0.0175
0.1693
7.246
29.2
95.4
1.323
0.031
02
1.051
0.0206
0.1711
3.409
24.7
95.3
1.327
0.065
26
1.214
0.0268
0.6393
3.893
19.0
84.6
1.351
0.058
40
1.154
0.0179
0.4114
4.288
28.6
89.6
1.360
0.053
37
1.125
0.0260
0.2771
3.341
19.6
92.9
1.375
0.067
34
1.063
0.0264
-0.0475
4.746
19.3
101.5
1.419
0.046
25
1.199
0.0202
0.3603
5.577
25.3
91.3
1.439
0.041
16
1.419
0.0181
1.100
2.193
28.2
77.2
1.45
0.10
04
1.222
0.0267
0.2651
2.954
19.1
93.8
1.517
0.075
36
1.731
0.0463
1.922
2.367
11.0
67.4
1.535
0.095
32
1.415
0.0202
0.8205
4.826
25.3
83.0
1.545
0.047
15
1.270
0.0175
0.3536
5.794
29.1
91.9
1.545
0.040
13
1.373
0.0301
0.5075
5.688
17.0
89.3
1.622
0.040
23
1.945
0.0459
2.022
4.245
11.1
69.5
1.778
0.056
22
1.937
0.1063
1.829
2.822
4.8
72.5
1.848
0.082
05
27999.4
-0.1450
777.3
0.002
99.2
5526.1
1032.1
Mean age ± 2σ
n=25
MSWD=1.27
25.6 ±19.3
1.274
0.022
Lab#=53754
40
AR/39AR SINGLE CRYSTAL SANIDINE DATA
ID
40
Age
(%)
(Ma)
(Ma)
EP-29san,J2:160, single crystal sanidine; J=0.0007319±0.10%; D=1.00743±0.00124; NM-160; Lab#=53765
02
1.098
0.0076
0.5895
5.995
67.0
84.2
09
1.074
0.0085
0.4889
4.972
60.3
86.6
06
1.016
0.0084
0.2183
6.412
60.9
93.7
14
1.119
0.0090
0.5558
4.727
57.0
85.4
11
0.9931
0.0195
0.1089
4.500
26.2
96.9
08
0.9532
0.0082
-0.0464
2.993
61.9
101.5
03
0.9805
0.0075
0.0275
4.744
67.9
99.2
15
1.072
0.0074
0.3240
3.175
69.1
91.1
13
1.050
0.0077
0.2292
3.359
66.3
93.6
10
0.9675
0.0070
-0.0535
2.889
72.7
101.7
07
1.001
0.0076
0.0500
2.878
67.3
98.6
12
0.9670
0.0079
-0.0744
4.607
64.6
102.3
04
1.631
0.0310
2.070
3.738
16.5
62.7
05
1.072
0.0080
0.1607
6.123
63.4
95.6
01
1.311
0.0169
0.3377
4.298
30.2
92.5
Mean age ± 2σ
n=14
MSWD=2.23
58.7 ±32.9
1.220
1.227
1.256
1.261
1.270
1.277
1.284
1.288
1.297
1.298
1.303
1.306
1.349
1.353
1.601
1.274
0.020
0.023
0.019
0.025
0.025
0.037
0.026
0.035
0.033
0.038
0.039
0.025
0.038
0.027
0.027
0.022
EP-14san,H1:160, single crystal sanidine; J=0.0007364±0.10%; D=1.0052±0.00172; NM-160; Lab#=53748
07
0.9671
0.0160
0.2091
6.734
31.9
93.7
03
1.144
0.0087
0.7921
6.375
58.8
79.6
05
1.013
0.0101
0.3403
6.209
50.5
90.2
04
0.9397
0.0088
0.0783
5.486
57.8
97.6
11
1.137
0.0137
0.7255
6.048
37.3
81.2
15
0.9703
0.0093
0.1557
5.887
54.7
95.3
10
0.9790
0.0089
0.1762
6.077
57.5
94.8
13
0.9802
0.0092
0.1330
4.699
55.5
96.1
12
0.9971
0.0091
0.1643
3.237
56.2
95.2
06
1.305
0.0088
1.203
5.370
58.1
72.8
09
0.9943
0.0119
0.1195
3.493
43.0
96.5
02
1.008
0.0114
0.1606
3.221
44.7
95.4
14
1.160
0.0131
-0.0131
4.837
39.0
100.4
08
1.813
0.0184
2.183
5.482
27.7
64.5
Mean age ± 2σ
n=12
MSWD=1.42
50.5 ±18.3
1.204
1.209
1.213
1.218
1.226
1.228
1.232
1.250
1.260
1.262
1.275
1.276
1.547
1.553
1.229
0.015
0.017
0.017
0.018
0.017
0.017
0.016
0.021
0.030
0.020
0.027
0.030
0.020
0.026
0.013
EP-15san,H3:160, single crystal sanidine; J=0.0007364±0.10%; D=1.0052±0.00172; NM-160; Lab#=53750
02
4.754
0.0089
13.30
4.988
57.4
17.3
11
0.9842
0.0103
0.2512
3.823
49.8
92.5
03
1.237
0.0084
1.044
5.201
61.0
75.1
07
1.076
0.0101
0.5007
4.993
50.4
86.3
06
0.9522
0.0244
0.0785
2.072
20.9
97.8
10
0.9836
0.0145
0.1695
5.637
35.2
95.0
05
0.9963
0.0101
0.1991
4.149
50.4
94.2
13
0.9976
0.0275
0.1101
2.735
18.6
97.0
14
1.062
0.0081
0.3162
2.949
63.1
91.3
12
1.003
0.0077
0.0441
2.660
66.3
98.8
15
1.522
0.0131
1.668
5.275
39.1
67.7
09
1.953
0.0116
3.069
6.551
44.1
53.6
08
2.107
0.0151
3.053
4.142
33.8
57.2
04
289.9
-0.1406
659.9
0.001
32.7
Mean age ± 2σ
n=9
MSWD=0.46
46.2 ±35.2
1.094
1.210
1.233
1.234
1.236
1.241
1.246
1.284
1.287
1.315
1.369
1.391
1.601
121.9
1.245
0.064
0.040
0.032
0.032
0.074
0.028
0.038
0.057
0.053
0.058
0.032
0.032
0.044
173.0
0.027
1.217
1.230
1.232
1.239
1.241
1.242
1.246
1.257
1.262
1.262
1.267
1.275
1.32
1.417
2.381
1.254
0.073
0.058
0.051
0.036
0.059
0.066
0.083
0.038
0.028
0.032
0.033
0.063
0.12
0.036
0.070
0.025
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(x 10 )
#
#
#
#
#
#
#
#
#
#
39
ArK
K/Ca
(x 10-15 mol)
F03-14b san,N5:172, single crystal sanidine, J=0.0007527±0.10%, D=1.005±0.001, NM-172, Lab#=54479
10
1.820
0.0165
3.128
6.853
30.9
01
1.428
0.0338
1.774
8.485
15.1
14
1.074
0.0212
0.5691
9.550
24.1
11
1.082
0.0134
0.5767
13.654
38.1
04
1.523
0.0245
2.068
8.387
20.8
03
1.016
0.0173
0.3451
7.359
29.5
13
1.443
0.0161
1.782
5.961
31.6
07
1.620
0.0238
2.354
13.656
21.4
09
1.739
0.0176
2.746
20.725
29.0
06
1.640
0.0151
2.407
16.235
33.8
05
1.119
0.0133
0.6313
15.242
38.3
12
6.459
0.0540
18.69
11.489
9.5
15
1.045
0.0131
0.2394
4.177
39.0
02
3.252
0.0755
7.494
17.428
6.8
08
2.140
0.0242
1.311
7.055
21.1
Mean age ± 2σ
n=13
MSWD=0.14
27.8 ±18.3
Ar*
49.3
63.5
84.5
84.4
60.0
90.1
63.6
57.2
53.4
56.7
83.4
14.5
93.3
32.1
82.0
±1σ
REDONDO CREEK MEMBER
#
EP-10HFsan,H11:160, single crystal sanidine; ID#<20: J=0.0007334±0.10%, D=1.0052±0.00172; ID#≥20: J=0.0007285±0.100%, D=1.00737±0.00192; NM-160;
10
0.9324
0.0218
0.5415
1.678
23.4
83.0
1.02
0.15
05
0.9624
0.0211
0.4017
2.655
24.2
87.8
1.118
0.093
08
1.011
0.0198
0.5078
2.988
25.7
85.3
1.141
0.083
14
1.002
0.0170
0.4125
2.648
30.1
88.0
1.166
0.094
12
0.9457
0.0225
0.2188
5.240
22.7
93.4
1.168
0.048
11
0.9725
0.0214
0.2997
6.825
23.9
91.1
1.171
0.037
Lab#=53758
40
AR/39AR SINGLE CRYSTAL SANIDINE DATA
ID
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(x 10 )
#
#
#
#
#
#
#
#
#
#
#
#
09
0.9577
0.0209
0.2129
23
0.9921
0.0124
0.2839
02
0.9538
0.0127
0.1440
13
0.9996
0.0162
0.2948
15
0.9663
0.0140
0.1147
25
1.046
0.0247
0.3393
04
1.086
0.0166
0.4849
30
1.134
0.0147
0.6126
21
1.036
0.0209
0.2770
31
0.9736
0.0221
0.0573
06
1.044
0.0213
0.3101
24
1.358
0.1151
1.374
26
1.026
0.0203
0.2212
03
1.074
0.0149
0.4002
33
1.025
0.0108
0.1928
27
1.013
0.0190
0.1432
07
1.103
0.0177
0.4427
20
1.460
0.0541
1.627
32
1.015
0.0186
0.0950
29
1.398
0.0214
1.373
22
1.222
0.0107
0.5195
34
1.415
0.0188
1.075
28
7.088
2.209
10.10
Mean age ± 2σ
n=23
MSWD=0.91
39
ArK
K/Ca
(x 10-15 mol)
6.326
2.572
4.008
6.579
7.780
3.641
2.282
9.391
2.302
3.050
2.974
1.287
2.850
3.193
1.745
2.642
2.515
2.036
3.079
1.767
1.566
1.625
0.179
24.4
41.2
40.2
31.4
36.6
20.7
30.8
34.8
24.4
23.1
24.0
4.4
25.2
34.1
47.0
26.9
28.8
9.4
27.4
23.9
47.7
27.1
0.23
29.2 ±13.8
40
Age
(%)
(Ma)
(Ma)
93.6
91.6
95.6
91.4
96.6
90.6
86.9
84.1
92.3
98.4
91.4
70.8
93.8
89.1
94.5
96.0
88.3
67.4
97.4
71.1
87.5
77.7
60.5
1.186
1.194
1.206
1.208
1.235
1.246
1.25
1.253
1.256
1.259
1.261
1.263
1.264
1.265
1.272
1.277
1.287
1.292
1.299
1.306
1.405
1.443
5.63
1.239
0.040
0.044
0.062
0.038
0.041
0.031
0.11
0.015
0.049
0.037
0.083
0.094
0.041
0.078
0.065
0.043
0.099
0.058
0.037
0.065
0.078
0.074
0.65
0.017
Ar*
±1σ
EP-7san,H14:160, single crystal sanidine; ID#<20: J=0.0007348±0.10%, D=1.00743±0.00124; ID#≥20: J=0.0007285±0.10%, D=1.00737±0.00192; NM-160;
07
0.9237
0.0194
0.2232
2.164
26.2
93.0
1.139
0.053
12
0.9323
0.0214
0.1937
3.613
23.9
94.0
1.162
0.031
23
1.033
0.0136
0.4933
4.325
37.6
86.0
1.166
0.030
25
1.057
0.0159
0.5360
2.980
32.1
85.1
1.182
0.044
04
1.007
0.0174
0.3729
2.512
29.4
89.2
1.191
0.045
22
1.070
0.0148
0.5573
3.709
34.4
84.7
1.191
0.036
24
1.086
0.0171
0.6102
2.678
29.8
83.5
1.191
0.049
13
1.113
0.0286
0.7271
3.288
17.9
80.9
1.193
0.037
11
1.142
0.0203
0.8175
4.368
25.1
79.0
1.196
0.028
05
1.903
0.0216
3.381
3.535
23.6
47.6
1.200
0.038
01
1.042
0.0214
0.4643
4.933
23.9
87.0
1.201
0.025
28
1.080
0.0314
0.5547
2.258
16.2
85.1
1.207
0.058
08
0.9971
0.0178
0.2361
2.144
28.7
93.1
1.231
0.056
20
1.039
0.0139
0.3282
2.872
36.8
90.8
1.239
0.046
03
0.9816
0.0193
0.1590
4.091
26.4
95.4
1.241
0.028
02
1.113
0.0203
0.5965
2.386
25.2
84.3
1.243
0.049
14
1.077
0.0295
0.4768
1.770
17.3
87.1
1.243
0.065
27
1.007
0.0292
0.2092
2.111
17.5
94.1
1.244
0.061
26
1.089
0.0143
0.4291
3.789
35.6
88.5
1.266
0.035
15
1.068
0.0209
0.3201
3.113
24.4
91.3
1.292
0.037
06
1.488
0.0264
1.562
4.877
19.3
69.1
1.362
0.026
10
1.206
0.0242
0.4447
4.062
21.1
89.3
1.426
0.030
09
1.286
0.0146
0.2342
2.502
35.0
94.7
1.614
0.046
29
7.221
2.414
5.881
0.333
0.21
78.7
7.46
0.41
21
12.82
1.760
13.65
0.438
0.29
69.7
11.71
0.34
Mean age ± 2σ
n=20
MSWD=0.95
26.6 ±13.0
1.208
0.017
F03-52 san,N2:172, single crystal sanidine, J=0.0007539±0.10%, D=1.005±0.001, NM-172, Lab#=54477
03
0.9289
0.0206
0.1969
13.216
24.7
13
0.9701
0.0179
0.2832
8.224
28.5
08
1.045
0.0171
0.5303
13.907
29.8
10
0.9253
0.0229
0.0915
23.886
22.3
04
0.9396
0.0180
0.1313
28.833
28.3
06
0.9457
0.0208
0.1489
22.495
24.5
01
0.9476
0.0226
0.1535
13.584
22.6
05
0.9501
0.0162
0.1577
17.453
31.5
15
0.9955
0.0184
0.3120
3.352
27.7
12
0.9544
0.0205
0.1683
9.527
24.9
07
0.9519
0.0196
0.1591
22.316
26.0
09
0.9549
0.0205
0.1467
17.227
24.9
02
0.9668
0.0154
0.1338
9.914
33.0
14
1.008
0.0177
0.2720
8.082
28.9
11
1.507
0.0191
1.761
4.857
26.8
Mean age ± 2σ
n=14
MSWD=0.14
27.0 ±6.5
F03-53 san,N4:172, single crystal sanidine, J=0.0007532±0.10%, D=1.005±0.001, NM-172, Lab#=54478
14
0.9372
0.0173
0.3036
2.392
29.5
02
0.9403
0.0190
0.1846
7.841
26.9
04
0.9363
0.0213
0.1638
11.329
24.0
07
0.9274
0.0192
0.1310
10.060
26.5
12
0.9376
0.0184
0.1652
6.320
27.8
08
0.9424
0.0141
0.1562
11.804
36.1
93.9
91.5
85.1
97.3
96.0
95.5
95.4
95.2
90.9
95.0
95.2
95.6
96.0
92.2
65.6
1.186
1.207
1.210
1.224
1.226
1.228
1.229
1.230
1.23
1.232
1.232
1.241
1.262
1.263
1.34
1.227
0.047
0.075
0.044
0.026
0.022
0.027
0.046
0.035
0.18
0.065
0.028
0.036
0.062
0.076
0.13
0.020
90.6
94.4
95.0
96.0
95.0
95.2
1.15
1.205
1.208
1.209
1.209
1.219
0.19
0.059
0.041
0.046
0.074
0.040
Lab#=53761
40
AR/39AR SINGLE CRYSTAL SANIDINE DATA
ID
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(x 10 )
#
#
13
0.9831
0.0223
0.2749
09
2.149
0.0344
4.193
15
1.015
0.0203
0.3394
11
1.245
0.0182
1.104
06
1.132
0.0190
0.7128
01
1.047
0.0279
0.4045
10
0.9624
0.0187
0.1039
03
1.101
0.0232
0.4376
05
1.819
0.0259
2.782
Mean age ± 2σ
n=12
MSWD=0.22
39
ArK
K/Ca
(x 10-15 mol)
4.144
13.656
5.793
4.421
17.178
8.271
9.134
7.091
17.173
22.8
14.8
25.1
28.0
26.8
18.3
27.3
22.0
19.7
25.4 ±10.5
40
Age
(%)
(Ma)
(Ma)
91.9
42.5
90.3
73.9
81.5
88.8
97.0
88.4
54.9
1.23
1.240
1.244
1.25
1.253
1.262
1.267
1.323
1.357
1.235
0.11
0.038
0.080
0.11
0.028
0.057
0.051
0.066
0.030
0.028
Ar*
±1σ
CERRO DEL MEDIO
#
#
#
#
EP-42san,J8:160, single crystal sanidine; ID#<20: J=0.0007303±0.10%, D=1.00743±0.00124; ID#≥20: J=0.0007394±0.10%, D=1.00737±0.00192; NM-160;
20
4.920
0.0154
13.92
2.483
33.2
16.4
1.08
0.10
05
1.208
0.0261
1.244
2.640
19.5
69.8
1.110
0.070
08
1.024
0.0190
0.4789
2.768
26.9
86.3
1.164
0.066
11
1.094
0.0194
0.7151
3.043
26.3
80.8
1.165
0.060
03
0.9404
0.0158
0.1746
2.405
32.2
94.6
1.172
0.076
06
1.364
0.0192
1.605
3.842
26.6
65.3
1.174
0.049
10
0.9617
0.0231
0.2300
3.403
22.1
93.1
1.179
0.053
07
0.9267
0.0203
0.0890
2.289
25.2
97.3
1.188
0.079
33
1.006
0.0130
0.3882
5.051
39.3
88.7
1.189
0.039
36
1.011
0.0163
0.4038
2.733
31.2
88.3
1.190
0.069
04
0.9723
0.0200
0.2310
3.264
25.6
93.1
1.193
0.056
22
1.309
0.0173
1.402
4.456
29.5
68.5
1.194
0.045
01
0.9463
0.0161
0.1333
3.921
31.6
96.0
1.196
0.046
26
1.050
0.0153
0.5221
4.263
33.3
85.4
1.196
0.045
09
0.9647
0.0170
0.1883
1.862
30.0
94.4
1.199
0.099
24
2.820
0.0160
6.499
2.876
31.9
31.9
1.201
0.080
13
1.241
0.0216
1.112
3.343
23.6
73.7
1.204
0.055
21
1.041
0.0191
0.4216
2.830
26.7
88.2
1.224
0.067
12
1.453
0.0296
1.776
2.364
17.2
64.1
1.226
0.079
25
1.079
0.0151
0.5394
3.870
33.8
85.3
1.227
0.050
15
1.000
0.0226
0.2195
2.474
22.5
93.7
1.234
0.073
27
1.101
0.0203
0.5821
2.775
25.2
84.5
1.240
0.070
02
1.111
0.0232
0.5670
3.005
22.0
85.1
1.245
0.061
35
1.101
0.0309
0.5693
2.979
16.5
85.0
1.247
0.064
30
1.300
0.0341
1.207
3.179
15.0
72.8
1.262
0.061
34
1.092
0.0163
0.4763
3.276
31.4
87.2
1.269
0.059
14
1.245
0.0368
0.9540
1.471
13.9
77.6
1.27
0.12
23
1.389
0.0159
1.470
2.301
32.0
68.8
1.274
0.085
32
1.113
0.0162
0.5371
1.947
31.4
85.9
1.274
0.098
29
1.173
0.0271
0.7366
3.033
18.8
81.6
1.276
0.063
31
1.312
0.0202
1.027
3.367
25.2
77.0
1.346
0.058
28
2.174
0.0438
3.719
2.413
11.7
49.6
1.438
0.087
Mean age ± 2σ
n=28
MSWD=0.31
26.5 ±12.6
1.210
0.023
EP-39san,J9:160, single crystal sanidine;
09
0.9121
0.0160
06
1.706
0.0176
05
0.9922
0.0216
07
0.9178
0.0160
25
0.9406
0.0260
15
1.541
0.0366
38
2.275
0.0316
23
1.072
0.0146
14
0.9576
0.0216
11
0.9379
0.0172
20
1.024
0.0210
36
0.9754
0.0140
02
3.145
0.0223
37
1.084
0.0158
04
0.9680
0.0258
10
0.9481
0.0269
26
1.004
0.0274
08
1.095
0.0170
22
1.119
0.0375
24
1.011
0.0291
35
1.152
0.0251
27
0.9849
0.0203
31
1.012
0.0190
01
1.063
0.0257
21
1.267
0.0126
30
1.027
0.0139
32
0.9628
0.0152
34
1.125
0.0156
03
1.068
0.0332
33
1.654
0.0346
Lab#=53771
ID#<20: J=0.0007306±0.10%, D=1.00743±0.00124; ID#≥20: J=0.0007377±0.10%, D=1.00737±0.00192; NM-160; Lab#=53772
0.2175
2.880
0.4640
0.0628
0.1655
2.169
4.672
0.5766
0.1566
0.0853
0.4008
0.2305
7.536
0.5894
0.1628
0.0939
0.3048
0.5597
0.6641
0.2674
0.7175
0.1092
0.1176
0.2482
0.9623
0.1327
-0.0877
0.4552
0.1811
2.164
5.043
5.576
2.962
4.782
4.079
3.982
3.135
2.551
2.205
2.599
2.836
2.895
2.950
1.587
2.575
3.573
2.564
3.964
3.494
2.670
3.295
2.338
2.906
2.433
2.580
3.558
2.728
2.484
2.325
1.624
31.9
29.1
23.6
32.0
19.6
13.9
16.2
34.9
23.6
29.6
24.3
36.5
22.8
32.4
19.8
19.0
18.7
29.9
13.6
17.5
20.3
25.1
26.8
19.9
40.6
36.8
33.6
32.8
15.3
14.7
93.1
50.2
86.4
98.1
95.0
58.6
39.4
84.2
95.4
97.5
88.6
93.1
29.2
84.0
95.3
97.3
91.3
85.0
82.7
92.4
81.8
96.9
96.7
93.3
77.6
96.3
102.8
88.2
95.2
61.5
1.119
1.128
1.129
1.186
1.189
1.190
1.193
1.201
1.203
1.204
1.207
1.208
1.211
1.211
1.215
1.215
1.219
1.226
1.232
1.242
1.253
1.269
1.302
1.306
1.308
1.315
1.317
1.319
1.340
1.354
0.041
0.040
0.068
0.043
0.038
0.053
0.061
0.062
0.092
0.078
0.057
0.054
0.080
0.097
0.079
0.057
0.060
0.052
0.045
0.058
0.050
0.066
0.054
0.084
0.062
0.044
0.058
0.063
0.087
0.099
40
AR/39AR SINGLE CRYSTAL SANIDINE DATA
ID
40
Age
(%)
(Ma)
(Ma)
74.3
84.5
71.9
61.8
1.355
1.359
1.413
1.430
1.239
0.068
0.069
0.070
0.051
0.028
EP-12san,H13:160, single crystal sanidine; J=0.0007343±0.10%; D=1.00743±0.00124; NM-160; Lab#=53760
05
21.75
0.0161
69.85
4.467
31.7
5.1
07
1.499
0.0160
1.238
1.600
32.0
75.7
15
1.545
0.0153
1.115
2.376
33.4
78.8
03
1.377
0.0125
0.4550
3.810
41.0
90.3
01
1.891
0.0185
2.163
2.354
27.6
66.3
10
1.679
0.0158
1.421
4.143
32.3
75.1
04
1.335
0.0145
0.1630
1.627
35.2
96.5
09
1.471
0.0160
0.6260
3.288
32.0
87.5
14
1.518
0.0164
0.7632
4.335
31.1
85.2
02
5.276
0.0103
13.41
1.583
49.4
24.9
08
3.283
0.0188
6.616
3.467
27.2
40.5
12
2.109
0.0098
2.629
1.407
52.3
63.2
13
1.970
0.0080
2.089
5.210
63.5
68.7
11
3.749
0.0147
8.026
1.891
34.7
36.8
06
3.074
0.0138
0.1876
2.375
37.1
98.2
Mean age ± 2σ
n=13
MSWD=2.85
37.8 ±21.7
1.47
1.502
1.611
1.646
1.659
1.669
1.705
1.705
1.712
1.741
1.761
1.764
1.792
1.826
3.996
1.699
0.18
0.065
0.047
0.028
0.051
0.029
0.062
0.033
0.031
0.097
0.047
0.079
0.028
0.079
0.046
0.038
EP-13san,J3:160, single crystal sanidine; J=0.0007315±0.10%; D=1.00743±0.00124; NM-160; Lab#=53766
12
46.81
0.0179
154.6
3.837
28.5
2.4
07
2.781
0.0163
5.480
3.805
31.3
41.8
06
4.240
0.0140
10.37
3.617
36.3
27.7
08
8.896
0.0150
26.08
2.412
34.0
13.4
13
2.289
0.0133
3.709
3.953
38.5
52.2
04
2.390
0.0182
4.008
2.340
28.1
50.5
01
1.362
0.0169
0.5101
2.840
30.1
89.0
05
2.713
0.0186
4.997
5.907
27.4
45.6
10
1.360
0.0159
0.3315
1.764
32.0
92.9
11
2.379
0.0173
3.647
3.723
29.5
54.8
03
2.173
0.0169
2.840
1.652
30.1
61.4
15
2.720
0.0114
4.631
2.126
44.7
49.7
02
2.081
0.0142
2.428
1.951
35.9
65.6
14
1.837
0.0124
1.414
1.930
41.2
77.3
09
3.046
0.0121
5.341
1.957
42.0
48.2
Mean age ± 2σ
n=14
MSWD=3.96
34.4 ±11.1
1.48
1.534
1.551
1.57
1.575
1.592
1.600
1.632
1.666
1.719
1.760
1.783
1.800
1.872
1.937
1.654
0.35
0.044
0.059
0.11
0.043
0.066
0.046
0.035
0.072
0.041
0.083
0.073
0.073
0.073
0.075
0.059
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(x 10 )
12
1.384
0.0233
1.211
13
1.221
0.0174
0.6438
28
1.478
0.0249
1.415
29
1.738
0.0383
2.255
Mean age ± 2σ
n=34
MSWD=1.95
39
ArK
K/Ca
(x 10-15 mol)
3.023
2.939
2.267
3.625
21.9
29.3
20.5
13.3
24.7 ±15.3
Ar*
±1σ
MEGABRECCIA BLOCKS
#
#
#
Notes:
Isotopic ratios corrected for blank, radioactive decay, and mass discrimination, not corrected for interferring reactions.
Errors quoted for individual analyses include analytical error only, without interferring reaction or J uncertainties.
Mean age is weighted mean age of Taylor (1982). Mean age error is weighted error
of the mean (Taylor, 1982), multiplied by the root of the MSWD where MSWD>1, and also
incorporates uncertainty in J factors and irradiation correction uncertainties.
Decay constants and isotopic abundances after Steiger and Jaeger (1977).
# symbol preceding sample ID denotes analyses excluded from mean age calculations.
Ages calculated relative to FC-2 Fish Canyon Tuff sanidine interlaboratory standard at 28.02 Ma
Decay Constant (LambdaK (total)) = 5.543e-10
Samples and monitors from irradiation NM-160 were analyzed during two different time intervals, resulting in two
different J-factors for some samples. The two J-factors were not averaged because of possible variations in the actual
discrimination values between the two analysis periods and/or variations in the geometry of crystals in irradiation disks.
Correction factors:
(39Ar/37Ar)Ca = 0.0007 ± 2e-05 (NM-160)
0.00075 ± 5e-05 (NM-165)
0.0007 ± 2e-05 (NM-172)
(36Ar/37Ar)Ca = 0.00028 ± 5e-06 (NM-160)
0.00028 ± 1e-05 (NM-165)
0.00028 ± 5e-06 (NM-172)
(40Ar/39Ar)K = 0.0002 ± 3e-04 (NM-160)
0.0232 ± 9e-04 (NM-165)
0.0002 ± 3e-04 (NM-172)
40
AR/39AR STEP HEATED BIOTITE DATA
ID
Power
40
Ar/39Ar
37
Ar/39Ar
Ar/39Ar
-3
(Watts)
(x 10 )
EP-18 bi, J4:160, 3-5 xtals bi,
A
2
57.89
B
6
15.44
Integrated age ± 2σ
Plateau ± 2σ
36
39
ArK
(x 10
-15
K/Ca
Plateau ± 2σ
0.0110
0.0044
n=2
n=2
174.3
30.29
MSWD=0.02
0.241
0.44
0.68
46.4
115.1
0.68
90.7
steps A-B
n=2
MSWD=0.35
3.39
0.6443
0.7158
n=2
steps A-B
n=2
286.8
17.38
MSWD=3.65
0.203
0.54
0.74
0.79
0.71
0.74
0.73
steps A-B
n=2
MSWD=9.05
1.75
steps A-B
steps A-B
EP-18 bi, J4:160, 3-5 xtals bi,
A
2
34.84
B
6
15.86
Integrated age ± 2σ
Plateau ± 2σ
n=2
MSWD=0.14
1.55
n=2
MSWD=0.04
0.47
18.7
71.8
7.5
68.7
71.4
75.0
133.4
(Ma)
(Ma)
35.5
100.0
8.41
8.54
8.50
0.87
0.31
0.76
100.0
8.53
0.58
7.3
100.0
8.81
8.262
8.30
0.93
0.053
0.18
100.0
8.26
0.11
27.5
100.0
10.6
8.28
8.92
1.2
0.25
0.77
100.0
8.38
0.93
48.0
100.0
9.20
8.03
8.59
0.36
0.13
0.39
100.0
8.17
0.76
31.2
100.0
8.38
8.07
8.17
0.79
0.13
0.55
100.0
8.08
0.25
52.9
100.0
8.72
8.85
8.78
0.43
0.48
0.64
100.0
8.78
0.64
35.0
100.0
7.70
8.38
8.14
0.34
0.15
0.35
100.0
8.26
0.51
36.5
100.0
7.36
8.05
7.80
0.47
0.12
0.39
100.0
8.00
0.33
13.1
100.0
8.75
8.151
8.23
0.64
0.089
0.23
100.0
8.16
0.18
±1σ
J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-32
steps A-B
0.0128
0.0351
n=2
n=2
98.09
32.16
MSWD=3.33
0.82
1.53
2.35
39.8
14.5
2.35
23.4
steps A-B
n=2
MSWD=1.99
1.79
steps A-B
n=2
MSWD=0.84
1.55
16.8
40.1
13.2
72.8
72.3
EP-18 bi, J4:160, 3-5 xtals bi, J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-35
A
2
16.73
0.0236
34.11
0.203
21.6
B
6
6.722
0.0164
1.791
1.35
31.2
Integrated age ± 2σ
n=2
1.55
Plateau ± 2σ
8.7
55.3
180.1
EP-18 bi, J4:160, 3-5 xtals bi, J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-33
A
2
42.43
0.0032
124.7
0.66
160.1
B
6
8.404
0.0234
7.756
1.14
21.8
Integrated age ± 2σ
n=2
1.79
Plateau ± 2σ
9.9
86.6
21.5
EP-18 bi, J4:160, 3-5 xtals bi, J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-30
A
2
9.280
0.0145
8.980
0.249
35.3
B
6
8.965
0.0021
7.578
0.222 243.8
Integrated age ± 2σ
n=2
0.47
Plateau ± 2σ
Age
J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-24
EP-18 bi, J4:160, 3-5 xtals bi, J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-28
A
2
85.07
0.0032
266.3
0.48
158.2
B
6
8.930
0.0027
9.462
1.07
190.1
Integrated age ± 2σ
n=2
1.55
Plateau ± 2σ
11.0
42.1
16.9
EP-18 bi, J4:160, 3-5 xtals bi, J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-26
A
2
37.35
0.0210
102.7
0.84
24.4
B
6
8.499
0.0271
8.121
0.91
18.8
Integrated age ± 2σ
n=2
1.75
Plateau ± 2σ
Ar
(%)
39
J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-20
steps A-B
EP-18 bi, J4:160, 3-5 xtals bi,
A
2
92.73
B
6
11.37
Integrated age ± 2σ
Ar*
(%)
mol)
EP-18 bi, J4:160, 3-5 xtals bi, J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-22
A
2
67.74
0.0617
206.6
0.248
8.3
B
6
7.252
0.0289
3.302
3.14
17.6
Integrated age ± 2σ
n=2
3.39
Plateau ± 2σ
40
29.9
39.8
92.1
40
AR/39AR STEP HEATED BIOTITE DATA
ID
Power
40
Ar/39Ar
37
Ar/39Ar
Ar/39Ar
-3
(Watts)
(x 10 )
EP-18 bi, J4:160, 3-5 xtals bi,
A
2 147.6
B
6
11.54
Integrated age ± 2σ
Plateau ± 2σ
36
39
ArK
(x 10
-15
K/Ca
40
Ar*
(%)
mol)
Ar
Age
(%)
(Ma)
(Ma)
22.6
100.0
9.1
8.23
8.44
1.3
0.12
0.66
100.0
8.24
0.23
39
±1σ
J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767-37
steps A-B
0.0131
0.0160
n=2
n=2
475.9
17.89
MSWD=0.49
0.44
1.51
1.94
39.1
32.0
1.94
33.6
4.7
54.2
B STEP DATA
ID
Power
(watts)
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(x 10 )
39
ArK
(x 10
-15
mol)
K/Ca
40
Age
(%)
(Ma)
(Ma)
8.03
8.05
8.07
8.151
8.23
8.262
8.28
8.38
8.54
8.85
8.205
0.13
0.12
0.13
0.089
0.12
0.053
0.25
0.15
0.31
0.48
0.083
Ar*
EP-18 bi, J4:160, 3-5 xtals bi, J=0.0007311±0.10%, D=1.00743±0.00124, NM-160, Lab#=53767
26B
6
8.499
0.0271
8.121
0.908
18.8
71.8
33B
6
8.404
0.0234
7.756
1.139
21.8
72.8
28B
6
8.930
0.0027
9.462
1.067 190.1
68.7
35B
6
6.722
0.0164
1.791
1.349
31.2
92.1
37B
6
11.54
0.0160
17.89
1.506
32.0
54.2
22B
6
7.252
0.0289
3.302
3.142
17.6
86.6
# 24B
6
11.37
0.7158
17.38
0.536
0.71
55.3
32B
6
15.86
0.0351
32.16
1.527
14.5
40.1
20B
6
15.44
0.0044
30.29
0.437 115.1
42.1
30B
6
8.965
0.0021
7.578
0.222 243.8
75.0
Mean age ± 2σ
n=9
MSWD=1.30
76.1 ±173.3
±1σ
Notes:
Isotopic ratios corrected for blank, radioactive decay, and mass discrimination, not corrected for interfering reactions.
Errors quoted for individual analyses include analytical error only, without interfering reaction or J uncertainties.
Integrated age calculated by summing isotopic measurements of all steps.
Integrated age error calculated by quadratically combining errors of isotopic measurements of all steps.
Plateau age is inverse-variance-weighted mean of selected steps.
Plateau age error is inverse-variance-weighted mean error (Taylor, 1982) times root MSWD where MSWD>1.
Plateau error is weighted error of Taylor (1982).
Decay constants and isotopic abundances after Steiger and Jäger (1977).
Weight percent K2O calculated from 39Ar signal, sample weight, and instrument sensitivity.
Ages calculated relative to FC-2 Fish Canyon Tuff sanidine interlaboratory standard at 28.02 Ma
Decay Constant (LambdaK (total)) = 5.543e-10/a
Correction factors:
(39Ar/37Ar)Ca = 0.0007 ± 2e-05
(36Ar/37Ar)Ca = 0.00028 ± 5e-06
(40Ar/39Ar)K = 0.0002 ± 3e-04
For B step data, mean age is weighted mean age of Taylor (1982).
Mean age error is weighted error of the mean (Taylor, 1982), multiplied by the root of the MSWD where MSWD>1,
and also incorporates uncertainty in J factors and irradiation correction uncertainties.
# symbol preceding sample ID denotes analyses excluded from mean age calculations.
40
Ar/39Ar GROUNDMASS CONCENTRATE DATA
ID
Power
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(Watts)
(x 10 )
39
ArK
(x 10
-15
K/Ca
steps B-G
n=6
MSWD=2.01
2464.5
Age
±1s
(%)
(Ma)
(Ma)
6.7
12.3
60.9
56.5
54.4
84.3
31.4
93.5
21.8
96.5
17.6
97.8
15.2
98.6
17.7 100.0
K2O=15.41%
2.68
2.001
1.996
2.036
2.111
2.057
1.943
2.583
2.097
0.16
0.009
0.010
0.027
0.041
0.070
0.086
0.070
0.059
86.3
2.004
0.018
Ar*
(%)
mol)
F03-04-2wr,M5:172, 95.22 mg wr, J=0.0007474±0.10%, D=1.005±0.001, NM-172, Lab#=54474-01
# A
5
29.73
0.1477
93.92
351.0
3.5
B
8
2.437
0.1408
3.261
1261.4
3.6
C
12
2.725
0.1408
4.248
794.9
3.6
D
16
4.819
0.1883
11.25
260.8
2.7
E
20
7.184
0.2844
19.09
85.7
1.8
F
23
8.675
0.4005
24.31
37.5
1.3
G
27
9.469
0.5405
27.32
24.2
0.94
# H
30
10.85
1.082
30.53
39.3
0.47
Integrated age ± 2σ
n=8
2854.8
3.0 ±0.0
Plateau ± 2σ
Ar
40
3.4 ±2.3
39
Notes:
Isotopic ratios corrected for blank, radioactive decay, and mass discrimination, not corrected for interfering reactions.
Errors quoted for individual analyses include analytical error only, without interfering reaction or J uncertainties.
Integrated age calculated by summing isotopic measurements of all steps.
Integrated age error calculated by quadratically combining errors of isotopic measurements of all steps.
Plateau age is inverse-variance-weighted mean of selected steps.
Plateau age error is inverse-variance-weighted mean error (Taylor, 1982) times root MSWD where MSWD>1.
Plateau error is weighted error of Taylor (1982).
Decay constants and isotopic abundances after Steiger and Jäger (1977).
# symbol preceding sample ID denotes analyses excluded from plateau age calculations.
Weight percent K2O calculated from 39Ar signal, sample weight, and instrument sensitivity.
Ages calculated relative to FC-2 Fish Canyon Tuff sanidine interlaboratory standard at 28.02 Ma
Decay Constant (LambdaK (total)) = 5.543e-10/a
Correction factors:
(39Ar/37Ar)Ca = 0.0007 ± 2e-05
(36Ar/37Ar)Ca = 0.00028 ± 5e-06
(40Ar/39Ar)K = 0.0002 ± 3e-04
40
AR/39AR STEP HEATED SANIDINE DATA
ID
Power
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
(x 10-3)
(Watts)
EP-44san crushed and etched,M1:165, 27.8mgsan,
# A
3
0.9907
0.0116
B
6
0.4769
0.0093
C
9
0.4520
0.0092
D
12
0.4565
0.0090
E
15
0.4562
0.0089
F
20
0.4653
0.0089
G
25
0.4628
0.0101
# H
30
0.4789
0.0089
# I
35
0.4894
0.0133
# J
40
0.5312
0.0123
# K
45
0.5801
0.0114
Integrated age ± 2σ
n=11
Plateau ± 2σ
steps B-G
n=6
EP-44san surface etched,A5:165, 35.93mgsan,
# A
3
8.982
0.0155
B
6
1.271
0.0098
C
8
0.8597
0.0094
D
10
0.7380
0.0089
E
12
0.7567
0.0087
F
15
0.7939
0.0089
G
20
0.7290
0.0092
H
25
0.7083
0.0093
I
30
0.7289
0.0092
# J
35
0.7244
0.0090
# K
40
0.8187
0.0079
# L
45
1.499
0.0095
Integrated age ± 2σ
n=12
Plateau ± 2σ
steps B-I
n=8
steps C-G
n=5
EP-31san surface etched,C1:165, 33.35mgsan,
# A
3
5.621
0.0232
B
6
1.023
0.0197
C
8
0.7410
0.0199
D
10
0.6715
0.0196
E
12
0.6559
0.0197
F
15
0.6644
0.0196
# G
20
0.6799
0.0181
# H
25
0.7262
0.0190
# I
30
0.8025
0.0186
# J
35
0.9859
0.0192
# K
40
1.265
0.0184
# L
45
3.227
0.0187
Integrated age ± 2σ
n=12
Plateau ± 2σ
steps B-F
n=5
ArK
K/Ca
40
Ar*
(%)
Ar
Age
(%)
(Ma)
(Ma)
39
±1σ
J=0.0016419±0.10%, D=1.00484±0.00092, NM-165, Lab#=54041-01
1.986
0.1195
0.0636
0.0481
0.0537
0.0790
0.0930
0.0964
0.2129
0.7371
0.5724
MSWD=3.03
8.7
212.5
366.0
125.2
83.6
25.3
19.8
7.1
5.0
3.57
3.94
860.6
44.1
54.7
55.4
56.9
57.5
57.2
50.6
57.0
38.3
41.4
44.9
39.4
1.0
92.4
25.7
95.8
68.2
96.9
82.8
96.5
92.5
94.9
95.4
93.9
97.7
93.9
98.5
86.7
99.1
57.3
99.5
69.8 100.0
K2O=7.24 %
1.13
1.241
1.216
1.243
1.237
1.242
1.223
1.267
1.197
0.86
1.15
1.227
0.13
0.005
0.005
0.006
0.008
0.020
0.025
0.070
0.094
0.14
0.12
0.009
832.3
55.6
96.7
1.234
0.010
J=0.0016281±0.10%, D=1.00484±0.00092, NM-165, Lab#=54040-01
28.77
2.808
1.429
0.9747
1.058
1.230
0.9856
0.8400
0.8090
0.9273
1.071
3.124
MSWD=3.66
EP-31san crushed and etched,C3:165, 26.45mgsan,
# A
3
4.268
0.0295
# B
6
0.5535
0.0218
C
8
0.4643
0.0201
D
10
0.4669
0.0197
E
12
0.4665
0.0193
F
15
0.4679
0.0188
G
20
0.4723
0.0197
# H
25
0.5686
0.0197
# I
30
0.5891
0.0259
# J
35
0.5860
0.0221
# K
40
0.6867
0.0221
# L
45
0.7788
0.0198
Integrated age ± 2σ
n=12
Plateau ± 2σ
39
(x 10-15 mol)
9.5
105.3
395.9
67.5
83.6
229.4
60.0
44.0
20.3
10.8
6.3
3.59
1036.3
33.0
52.2
54.0
57.4
58.3
57.5
55.4
55.1
55.4
56.7
64.4
53.9
5.1
0.9
33.6
11.1
49.6
49.3
59.8
55.8
57.5
63.9
53.0
86.0
58.8
91.8
63.9
96.0
66.2
98.0
61.0
99.0
60.3
99.7
37.5 100.0
K2O=6.80 %
1.35
1.229
1.218
1.255
1.238
1.198
1.219
1.285
1.372
1.256
1.41
1.63
1.229
0.24
0.020
0.011
0.019
0.016
0.011
0.020
0.025
0.045
0.084
0.15
0.30
0.018
1006.1
55.4
97.1
1.226
0.022
J=0.0016375±0.10%, D=1.00484±0.00092, NM-165, Lab#=54045-01
11.05
0.1953
0.0762
0.0502
0.0678
0.0453
0.0554
0.0505
0.1063
0.2064
0.3133
0.7318
MSWD=2.58
5.4
65.7
252.7
65.4
66.8
63.9
124.5
43.2
18.3
10.2
4.8
4.3
725.3
17.3
23.4
25.3
25.8
26.4
27.2
25.9
26.0
19.7
23.1
23.1
25.7
23.2
0.7
89.5
9.8
95.3
44.6
97.0
53.7
95.8
62.9
97.3
71.7
96.7
88.8
97.6
94.8
94.8
97.3
89.5
98.7
86.3
99.4
71.6 100.0
K2O=6.43 %
2.9
1.401
1.241
1.271
1.255
1.278
1.283
1.571
1.585
1.487
1.69
1.60
1.319
1.8
0.019
0.011
0.015
0.014
0.016
0.009
0.021
0.048
0.083
0.18
0.20
0.029
573.3
25.9
79.0
1.266
0.018
J=0.0016447±0.10%, D=1.00484±0.00092, NM-165, Lab#=54044-01
17.26
2.003
1.031
0.7626
0.6670
0.6645
0.4920
0.5949
0.7773
1.291
2.659
8.483
MSWD=9.22
10.7
122.5
318.6
176.8
102.5
118.6
32.9
28.9
11.1
5.7
7.9
5.1
941.4
22.0
25.9
25.6
26.0
25.9
26.0
28.2
26.8
27.4
26.6
27.7
27.3
8.9
1.1
41.0
14.2
57.8
48.0
65.5
66.8
69.1
77.7
69.6
90.3
78.1
93.8
75.2
96.8
70.7
98.0
60.5
98.6
36.9
99.5
21.8 100.0
K2O=6.59 %
1.48
1.216
1.230
1.259
1.297
1.324
1.521
1.568
1.635
1.73
1.36
2.07
1.290
0.20
0.019
0.010
0.010
0.015
0.016
0.034
0.041
0.094
0.19
0.15
0.25
0.017
839.0
25.8
89.1
1.261
0.034
Notes:
Isotopic ratios corrected for blank, radioactive decay, and mass discrimination, not corrected for interfering reactions.
Errors quoted for individual analyses include analytical error only, without interfering reaction or J uncertainties.
Integrated age calculated by summing isotopic measurements of all steps.
Integrated age error calculated by quadratically combining errors of isotopic measurements of all steps.
Plateau age is inverse-variance-weighted mean of selected steps.
Plateau age error is inverse-variance-weighted mean error (Taylor, 1982) times root MSWD where MSWD>1.
Plateau error is weighted error of Taylor (1982).
Decay constants and isotopic abundances after Steiger and Jäger (1977).
# symbol preceding sample ID denotes analyses excluded from plateau age calculations.
Weight percent K2O calculated from 39Ar signal, sample weight, and instrument sensitivity.
Ages calculated relative to FC-2 Fish Canyon Tuff sanidine interlaboratory standard at 28.02 Ma
Decay Constant (LambdaK (total)) = 5.543e-10/a
Correction factors:
(39Ar/37Ar)Ca = 0.00075 ± 5e-05
(36Ar/37Ar)Ca = 0.00028 ± 1e-05
(40Ar/39Ar)K = 0.0232 ± 9e-04
40
AR/39AR STEP HEATED QUARTZ DATA
ID
Power
40
Ar/39Ar
37
Ar/39Ar
36
Ar/39Ar
-3
(Watts)
(x 10 )
EP-44qtz,A1&A3:165, 240.75mg qtz,
A
350
5.097
B
400
54.05
C
450 -137.1069
D
625
2.808
E
750
-5.2965
F
900
2.426
G
1150
7.224
H
1450
9.987
I
1700
149.1
Integrated age ± 2σ
0.0292
-0.7519
6.944
-0.1404
0.0723
0.0322
0.0212
0.0226
0.0635
n=9
Plateau ± 2σ
n=9
steps A-I
39
ArK
(x 10
-15
steps A-I
Cl/K
40
Ar*
(%)
mol)
Ar
Age
(%)
(Ma)
(Ma)
4.13
86.1
-101.7
17.4
15.0
7.2
9.3
11.61
13.8
5.66
0.10
116.0
1072.9
18.5
27.1
4.9
1.5
0.53
4.4
0.43
39
±1σ
J=0.0016381±0.10%, D=1.00562±0.00081, NM-165, Lab#=54038-02
12.45
81.56
-349.4275
-10.6094
-35.2801
-0.1274
13.68
20.39
488.7
MSWD=26.21
46.8
0.035
-0.004
0.209
0.143
0.79
2.57
7.65
1.01
59.2
17.5
0.073
7.1
15.8
24.1
22.6
8.0
59.2
18.1
EP-31qtz,D1&D3:165, 235.13mg qtz, J=0.001639±0.10%, D=1.00562±0.00081, NM-165,
A
300
27.00
0.1424
66.60
2.03
B
400 1624.9
32.42
831.5
0.000
C
450 -147.4916
-3.0179
-302.3316
-0.002
D
625 -310.4206
-4.6782
-405.2176
-0.001
E
750 -1135.556
-0.4347
-169.3038
-0.001
F
900
97.28
0.9410
118.4
0.010
G
1150
35.49
0.0862
47.14
0.472
H
1450
27.11
0.0857
42.17
0.588
I
1700
392.2
0.1273
1264.1
0.250
Integrated age ± 2σ
n=9
3.34
Plateau ± 2σ
K/Ca
n=8
MSWD=48.51
3.34
0.09480
27.6
-0.24666
55.3
4.39375
24.3
-0.01296 212.2
0.08131
-96.1
0.07454 101.7
0.06096
43.9
0.08579
39.6
0.09195
3.1
K2O=0.06 %
75.4
75.5
75.5
75.3
75.3
77.3
82.4
97.9
100.0
100.0
4.4
1.0
Lab#=54035-01
3.6
0.016
0.54
5.9
6.0
4.0
4.4
0.02914
27.1
-1.68391
85.0
0.08406
39.6
0.19256
61.6
-0.82880
95.6
0.00830
64.1
0.06084
60.7
0.06947
54.0
0.06308
4.8
K2O=0.00 %
55.6
55.6
55.5
55.4
55.4
55.7
70.8
90.9
100.0
21.48
2165.5
-181.2
-674.9
175.6
62.6
42.7
54.4
35.2
0.79
37563
758.3
3708.0
-51922
144.7
2.4
1.9
7.7
2.4
100.0
27.8
9.7
Notes:
Isotopic ratios corrected for blank, radioactive decay, and mass discrimination, not corrected for interfering reactions.
Errors quoted for individual analyses include analytical error only, without interfering reaction or J uncertainties.
Integrated age calculated by summing isotopic measurements of all steps.
Integrated age error calculated by quadratically combining errors of isotopic measurements of all steps.
Plateau age is inverse-variance-weighted mean of selected steps.
Plateau age error is inverse-variance-weighted mean error (Taylor, 1982) times root MSWD where MSWD>1.
Plateau error is weighted error of Taylor (1982).
Decay constants and isotopic abundances after Steiger and Jäger (1977).
Weight percent K2O calculated from 39Ar signal, sample weight, and instrument sensitivity.
Ages calculated relative to FC-2 Fish Canyon Tuff sanidine interlaboratory standard at 28.02 Ma
Decay Constant (LambdaK (total)) = 5.543e-10/a
Correction factors:
(39Ar/37Ar)Ca = 0.00075 ± 5e-05
(36Ar/37Ar)Ca = 0.00028 ± 1e-05
(40Ar/39Ar)K = 0.0232 ± 9e-04
40
39
a) EP-44 age probability distribution diagram
8
4
0
100
50
K/Ca
100
0
10
30
20
10
0
1.256 ± 0.010 Ma
MSWD = 1.07
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-44 inverse isochron
0.0034
0.0032
0.003
0.0028
5
0.0026
7
0.0024
6
0.0022
12
8
0.002
0.0018
13
0.0016
4
0.0014
15
0.0012
2
0.001
0.0008
Isochron age = 1.254 ± 0.010 Ma
40Ar/36Ar Intercept = 297.1 ± 3.8
MSWD = 1.1, n = 33
0.0006
0.0004
11
3
10
14
420139
10
14
12
21
16
7 25
195
922
11
615
23
24
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for
outflow facies upper Bandelier Tuff (EP-44).
1.1
Analyses
1
36Ar/40Ar
% Radiogenic
Mol 39Ar x 10-14
AR/ AR PLOTS:
The following figures display 40Ar/39Ar data on age probability distribution diagrams, inverse isochrons, and age sprectra. Uncertainties are reported at the ± 2 sigma confidence level, unless otherwise noted. On age probability distribution diagrams, open circles denote analyses excluded from weighted mean age and gray probability curve represents the curve that results if these analyses
are included. On inverse isochron plots, pink points and numbers denote analyses excluded from isochron age and correspond to
analyses eliminated from weighted mean age displayed on age probability distribution diagrams. Red error envelope is the error on
the isochron and is displayed at the 1 sigma uncertainty level. Large tick on inside of y-axis marks the atmospheric 40Ar/36Ar ratio
of 295.5.
4
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-43 age probability distribution diagram
8
10
1
15
5
0
Analyses
10
1.232 ± 0.017 Ma
MSWD = 1.82
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0.9
1
2
Age (Ma)
b) EP-43 inverse isochron
0.0034
0.0032
2
0.003
3
0.0028
0.0026
5
7
11 4
0.0024
36Ar/40Ar
0.0022
0.002
89
0.0018
10
0.0016
14
0.0014
13
6
0.0012
0.001
15
12
0.0008
Isochron age = 1.221 ± 0.030 Ma
40Ar/36Ar Intercept = 299 ± 8
MSWD = 1.8, n = 8
0.0006
0.0004
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for basal Plinian
fall deposit of upper Bandelier Tuff (EP-43).
8
4
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-1 age probability distribution diagram
10
30
20
10
Analyses
1
0
1.262 ± 0.016 Ma
MSWD = 3.37
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-1 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
35
0.0016
31
0.0014
9
0.0012
0.001
21 22
4
0.0008
Isochron age = 1.246 ± 0.024 Ma 2
40Ar/36Ar Intercept = 328 ± 37
12
MSWD = 2.9, n = 18
0.0006
0.0004
28
5
32
0.0002
0
29
33327
13117
10 2534
2430 36
26 1415 20
23
6
8
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for intracaldera
upper Bandelier Tuff (EP-1).
4
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-28 age probability distribution diagram
8
10
1
10
0
Analyses
20
1.300 ± 0.031 Ma
MSWD = 3.56
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-28 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
30
0.0016
31
0.0014
0.0012
27
24
6
0.001
0.0008
21
Isochron age = 1.267 ± 0.037 Ma
40Ar/36Ar Intercept = 337 ± 28
MSWD = 2.4, n = 24
0.0006
0.0004
23
22
7
20
25
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
9
32
11
28 15
10
29
1428
4 13
35
26
12
1
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for intracaldera
upper Bandelier Tuff (EP-28).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-34 age probability distribution diagram
4
10
15
10
5
Analyses
1
0
1.262 ± 0.023 Ma
MSWD = 0.87
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-34 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
0.0016
3
0.0014
0.0012
0.001
0.0008
8
Isochron age = 1.23 ± 0.04 Ma
Intercept = 370 ± 100
MSWD = 0.68, n = 11
40Ar/36Ar
0.0006
0.0004
4
0.0002
0
9 13
6 7
12
5
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
14
15 11
102
1
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Deer Canyon
lava (EP-34).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-32 age probability distribution diagram
4
10
30
20
10
Analyses
1
0
1.283 ± 0.017 Ma
MSWD = 1.69
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-32 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
0.0016
0.0014
0.0012
27
0.001
32
0.0008
Isochron age = 1.226 ± 0.038 Ma
40Ar/36Ar Intercept = 430 ± 84
MSWD = 1.1, n = 31
0.0006
0.0004
20
35
29 33
24
4
10
9
141516
2531
2239
26 6
12
37
21 38
5
13
7828
11 36
23
34 30 17
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Deer Canyon
lava (EP-32).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-31 age probability distribution diagram
4
10
15
10
5
Analyses
1
0
1.257 ± 0.022 Ma
MSWD = 0.70
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-31 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
712
0.0024
36Ar/40Ar
0.0022
1 11
6
0.002
4
2
0.0018
0.0016
13
0.0014
9
0.0012
10
0.001
0.0008
14
Isochron age = 1.239 ± 0.032 Ma
40Ar/36Ar Intercept = 300 ± 6
MSWD = 0.57, n = 14
0.0006
0.0004
8
5
15
3
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Deer Canyon
tuff (EP-31).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-2 age probability distribution diagram
4
10
30
20
10
Analyses
1
0
1.274 ± 0.022 Ma
MSWD = 1.27
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-2 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
0.0016
0.0014
0.0012
23
22
0.001
0.0008
36
21
Isochron age = 1.236 ± 0.038 Ma
Intercept = 400 ± 80
MSWD = 0.88, n = 25
16
40Ar/36Ar
0.0006
0.0004
32
13
0.0002
0
5
0
0.1
0.2
0.3
0.4
0.5
0.6
39Ar/40Ar
0.7
7
2612
27
30
20
40 41 29
39
24
15 25 37
4
38
21135 1014
28
33
386
31
34
0.8
0.9
1
1.1
Age probability distribution diagram (a) and inverse isochron (b) for Deer Canyon
tuff (EP-2).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-29 age probability distribution diagram
4
10
15
10
5
Analyses
1
0
1.274 ± 0.022 Ma
MSWD = 2.23
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-29 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
0.0016
0.0014
4
0.0012
0.001
0.0008
Isochron age = 1.271 ± 0.028 Ma
Intercept = 305 ± 43
MSWD = 2.4, n = 14
0.0006
40Ar/36Ar
0.0004
142 9
1
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
15
13 6
5
711
3
8
10
12
1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Deer Canyon
tuff (EP-29).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-14 age probability distribution diagram
4
10
15
10
5
Analyses
1
0
1.229 ± 0.013 Ma
MSWD = 1.42
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-14 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
0.0016
0.0014
8
0.0012
0.001
6
0.0008
Isochron age = 1.224 ± 0.022 Ma
40Ar/36Ar Intercept = 306 ± 32
MSWD = 1.5, n = 12
0.0006
0.0004
3
11
5
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
14
0.9
7
10
212
15
913
4
1
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Deer Canyon
tuff (EP-14).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-15 age probability distribution diagram
4
10
15
10
5
Analyses
1
0
1.245 ± 0.027 Ma
MSWD = 0.46
0.2
0
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-15 inverse isochron
0.0034
0.0032
0.003
2
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
0.0016
8
0.0014
9
0.0012
15
0.001
0.0008
3
Isochron age = 1.249 ± 0.040 Ma
Intercept = 290 ± 60
MSWD = 0.51, n = 9
40Ar/36Ar
0.0006
0.0004
7
14
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
511
10
13 6
12
1
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Deer Canyon
tuff (EP-15).
2.0
1.0
0
100
50
0
K/Ca
100
% Radiogenic
Mol 39Ar x 10-14
a) F03-14b age probability distribution diagram
10
20
10
0
Analyses
1
1.254 ± 0.025 Ma
MSWD = 0.14
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Age (Ma)
b) F03-14b inverse isochron
0.0034
0.0032
0.0030
12
0.0028
0.0026
0.0024
2
36Ar/40Ar
0.0022
0.0020
0.0018
10
0.0016
9
67
0.0014
4
1
13
0.0012
0.0010
0.0008
8
0.0006
5 11
14
Isochron age = 1.251 ± 0.015 Ma
Intercept = 297 ± 3
MSWD = 0.14, n = 13
0.0004
3
15
40Ar/36Ar
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Deer Canyon
lava (F03-14b).
2
0
200
100
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-10HF age probability distribution diagram
4
10
1
30
20
10
Analyses
0.1
0
1.239 ± 0.017 Ma
MSWD = 0.91
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-10HF inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
0.0016
0.0014
0.0012
29
0.001
0.0008
Isochron age = 1.207 ± 0.038 Ma
Intercept = 360 ± 80
MSWD = 0.7, n = 23
0.0006
40Ar/36Ar
0.0004
30
743
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
8
14 5
11
625
13
23
21
912
26
33
2
27 15
32
31
1
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Redondo Creek
lava (EP-10HF). For clarity, only those analyses included in the weighted mean ages
are shown on inverse isochron.
2
0
200
100
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-7 age probability distribution diagram
4
10
1
20
10
Analyses
0.1
0
1.208 ± 0.017 Ma
MSWD = 0.95
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-7 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
5
0.0016
0.0014
0.0012
0.001
0.0008
Isochron age = 1.207 ± 0.022 Ma
Intercept = 297 ± 20
MSWD = 1, n = 20
0.0006
11
13
2 24
22
28
25
14 1 23
26
4
15 20
8
273
40Ar/36Ar
0.0004
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
7
12
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Redondo Creek
lava (EP-7). For clarity, only those analyses included in the weighted mean ages are
shown on inverse isochron.
2
1
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) F03-52 age probability distribution diagram
3
10
20
10
0
Analyses
1
1.227 ± 0.020 Ma
MSWD = 0.14
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Age (Ma)
b) F03-52 inverse isochron
0.0034
0.0032
0.0030
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.0020
0.0018
0.0016
0.0014
0.0012
11
0.0010
0.0008
0.0006
8
Isochron age = 1.23 ± 0.02 Ma
Intercept = 300 ± 90
MSWD = 0.15, n = 14
0.0004
40Ar/36Ar
0.0002
15
14 13
12
756
143
29
10
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Redondo Creek
Lava (F03-52).
1.0
0
100
50
0
K/Ca
100
% Radiogenic
Mol 39Ar x 10-14
a) F03-53 age probability distribution diagram
2.0
10
10
0
Analyses
20
1
1.235 ± 0.028 Ma
MSWD = 0.22
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Age (Ma)
b) F03-53 inverse isochron
0.0034
0.0032
0.0030
0.0028
0.0026
0.0024
36Ar/40Ar
0.0022
0.0020
9
0.0018
0.0016
5
0.0014
0.0012
0.0010
11
0.0008
6
0.0006
Isochron age = 1.231 ± 0.017 Ma
40Ar/36Ar Intercept = 298 ± 8
MSWD = 0.23, n = 12
0.0004
0.0002
3 1 15
13
14
4
8212
10 7
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for Redondo Creek
Lava (F03-53).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-42 age probability distribution diagram
4
10
30
20
10
Analyses
1
0
1.210 ± 0.023 Ma
MSWD = 0.31
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-42 inverse isochron
0.0034
0.0032
0.003
20
0.0028
0.0026
0.0024
24
36Ar/40Ar
0.0022
0.002
0.0018
28
0.0016
0.0014
12 6
23 22
5
30 13
31 14
29
0.0012
0.001
0.0008
Isochron age = 1.207 ± 0.030 Ma
Intercept = 298 ± 18
MSWD = 0.32, n = 28
0.0006
40Ar/36Ar
0.0004
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
11
27
35
22526 8
32
34 2136
33
1549103
17
0.9
1
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for southern flow
lobe of Cerro del Medio (EP-42).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-39 age probability distribution diagram
4
10
30
20
10
Analyses
1
0
1.239 ± 0.028 Ma
MSWD = 1.95
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Age (Ma)
b) EP-39 inverse isochron
0.0034
0.0032
0.003
0.0028
0.0026
2
0.0024
36Ar/40Ar
0.0022
38
0.002
0.0018
6
0.0016
0.0014
2933
0.0012
15
0.001
28
0.0008
Isochron age = 1.234 ± 0.034 Ma
40Ar/36Ar Intercept = 300 ± 17
MSWD = 2, n = 34
0.0006
0.0004
12
21
13
0.0002
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
3522
37
23
8
5
34
20
26
1 24 36 25 9
3 30 414
3127 10
117
0.9
1
32
1.1
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for southern flow
lobe of Cerro del Medio (EP-39).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-12 age probability distribution diagram
4
10
1
10
5
0
Analyses
15
1.699 ± 0.038 Ma
MSWD = 2.85
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
2.6
3
2.8
Age (Ma)
b) EP-12 inverse isochron
0.0034
5
0.0032
0.003
0.0028
0.0026
2
0.0024
36Ar/40Ar
0.0022
11
8
0.002
0.0018
0.0016
0.0014
12
0.0012
13
0.001
10
0.0008
Isochron age = 1.673 ± 0.046 Ma
40Ar/36Ar Intercept = 307 ± 12
MSWD = 2.4, n = 13
0.0006
0.0004
0.0002
0
1
7
15
14
9
4
6
0
0.1
0.2
0.3
3
0.4
0.5
0.6
0.7
0.8
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for clast from
lower Bandelier Tuff megabreccia block (EP-12).
2
0
100
50
K/Ca
100
0
% Radiogenic
Mol 39Ar x 10-14
a) EP-13 age probability distribution diagram
4
10
1
10
5
0
Analyses
15
1.654 ± 0.059 Ma
MSWD = 3.96
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
3
Age (Ma)
b) EP-13 inverse isochron
0.0034
12
0.0032
0.003
8
0.0028
0.0026
6
0.0024
36Ar/40Ar
0.0022
0.002
0.0018
9
0.0016
7
5
15
4
13
11
0.0014
3
0.0012
2
0.001
0.0008
14
Isochron age = 1.68 ± 0.08 Ma
40Ar/36Ar Intercept = 292 ± 12
MSWD = 4.1, n = 14
0.0006
0.0004
0.0002
0
0
0.1
0.2
0.3
0.4
1
10
0.5
0.6
0.7
0.8
39Ar/40Ar
Age probability distribution diagram (a) and inverse isochron (b) for clast from
lower Bandelier Tuff megabreccia block (EP-13).
0.4
0
100
50
K/Ca
1000
0
% Radiogenic
Mol 39Ar x 10-14
EP-18 age probability distribution diagram
0.8
10
0.1
10
0
Analyses
20
8.205 ± 0.083 Ma
MSWD = 1.30
4
5
6
7
8
9
10
11
12
Age (Ma)
Age probability distribution diagram for biotite from dacitic tuff megabreccia block
(EP-18). Black points and curve represent A-steps in laser step heating analysis and
red points and curve represent B-steps. Open circles and squares denote analyses
excluded from the weighted mean ages.
100
50
0
K/Ca
10
1
0.1
3.5
Apparent Age (Ma)
3
2.5
2.004 ± 0.018 Ma (MSWD = 2.01)
H
A
2
B
D
C
1.5
E
F
G
1
0.5
0
0
10
20
30
40
50
60
70
80
90
100
Cumulative 39Ar Released
Age spectra for dacitic lava megabreccia block (F03-04-2).
% Radiogenic
F03-04-2 Age Sprectra
100
50
K/Ca
60
0
40
20
0.02
2
Cl/K
0.01
Apparent Age (Ma)
% Radiogenic
a) EP-44
0
1.226 ± 0.022 Ma (MSWD = 3.66)
1.234 ± 0.010 Ma (MSWD = 3.03)
1.5
B
B
1
D
C
C
F D
E
H GI
F
EG
A
A
0.5
0
0
10
20
30
40
50
60
70
80
90
100
Cumulative 39Ar Released
100
50
K/Ca
40
0
% Radiogenic
a) EP-31
30
20
10
0.008
3
Cl/K
0.004
0
Apparent Age (Ma)
2.5
1.261 ± 0.034 Ma (MSWD = 9.22)
2
1.266 ± 0.018 Ma (MSWD = 2.58)
1.5
1
A
BB
D
C C
E
D
E
F
H I
G H
G F
L
0.5
A
0
0
10
20
30
40
50
60
70
80
90
100
Cumulative 39Ar Released
Age spectra for crushed and etched sanidine used in the excess argon study for (a)
upper Bandelier Tuff sample EP-44 and (b) Deer Canyon sample EP-31. Black spectra are for “crushed and etched” portion and red spectra are for “surface etched” portion. Labels for high temperature steps were removed for clarity. Each sample was
heated in 11 or 12 incremental heating steps.
100
50
K/Ca
40
0
% Radiogenic
a) EP-44
20
0
4
Cl/K
0
-4
Apparent Age (Ma)
20
15
Integrated Age = 5.66 ± 0.43 Ma
10
H
1500
G
1200
5
A
490
0
0
10
20
30
I
1750
F 950
40
50
Cumulative
39Ar
60
70
80
90
100
Released
100
50
K/Ca
40
0
% Radiogenic
b) EP-31
20
0
4
-4
80
Cl/K
0
Apparent Age (Ma)
60
G
1200
Integrated Age = 35.2 ± 2.4 Ma
40
H
1500
20
0
I
1750
A
345
0
10
20
30
40
Cumulative
50
39Ar
60
70
80
90
100
Released
Age spectra for step heated quartz used in the excess argon study for (a) upper
Bandelier Tuff sample EP-44 and (b) Deer Canyon sample EP-31. Heating steps that
did not release significant 39Ar are not shown. The integrated ages include these
steps, but their effect is negligible.
ELECTRON MICROPROBE ANALYTICAL METHODS:
Analyses were performed using the New Mexico Bureau of Geology and Mineral Resources Cameca SX-100 electron microprobe
with three wavelength dispersive spectrometers and high-speed backscattered electron detectors. Backscattered electron images
were obtained for mineral separates and polished thin sections and quantitative analyses were completed for phases of interest.
ELECTRON MICROPROBE DETECTION LIMITS
Oxide or Element Detection Limit
SiO2
TiO2
Al2O3
MgO
CaO
MnO
FeO
Na2O
K2O
Cl
F
SrO
BaO
Cr2O3
P2O5
SO2
ZrO2
0.07 wt.%
0.05 wt.%
0.05 wt.%
0.05 wt.%
0.09 wt.%
0.05 wt.%
0.05 wt.%
0.05 wt.%
0.07 wt.%
0.05 wt.%
0.1 wt.%
0.05 wt.%
0.05 wt.%
0.05 wt.%
0.04 wt.%
0.05 wt.%
0.07 wt.%
ELECTRON MICROPROBE STANDARD ANALYSES AND ACCEPTED VALUES
Orthoclase1
Number of Analyses:
16
Average
Standard Deviation Accepted Value
SiO2
TiO2
Al2O3
FeO
MnO
MgO
CaO
Na2O
K2O
P 2O 5
F
SO2
Cl
SrO
BaO
1
2
64.32
0.48
64.79
16.51
1.76
0.14
0.03
16.72
1.88
0.01
0.94
15.55
0.01
0.03
0.15
0.91
15.49
0.01
0.07
0.02
0.03
0.05
Average
76.38
0.07
11.96
1.12
0.03
0.04
0.43
3.64
5.13
0.02
0.20
0.02
0.11
VG-5682
8
Standard Deviation Accepted Value
0.21
0.03
0.10
0.08
0.02
0.05
0.03
0.14
0.08
0.02
0.09
0.03
0.02
76.71
0.12
12.06
1.23
0.03
0.50
3.75
4.89
Donovan, personal communication
Jarosewich E., Nelen, J.A., and Norberg, J.A., 1980, Reference samples for electron microprobe analyses, Geostandards Newsletter, v. 4, p. 43-47
ELECTRON MICROPROBE ANALYSES OF FELDSPAR
SiO2
Al2O3
FeO
CaO
Na2O
K2O
SrO
BaO
Total
Or
Ab
An
UPPER BANDELIER TUFF
EP-1-01
Qbt
EP-1-02
Qbt
EP-1-03
Qbt
EP-1-04
Qbt
EP-1-06
Qbt
EP-1-07
Qbt
EP-1-08
Qbt
EP-1-09
Qbt
EP-1-10
Qbt
EP-1-11
Qbt
EP-1-12
Qbt
EP-1-13
Qbt
EP-28-01
Qbt
EP-28-02
Qbt
EP-28-03
Qbt
EP-28-04
Qbt
EP-28-06
Qbt
EP-28-07
Qbt
EP-28-10
Qbt
EP-28-11
Qbt
EP-28-12
Qbt
EP-28-13
Qbt
EP-28-14
Qbt
EP-28-15
Qbt
EP-28-16
Qbt
EP-43-01
Qbt
EP-43-02
Qbt
EP-43-04
Qbt
EP-43-05
Qbt
EP-43-06
Qbt
EP-43-07
Qbt
EP-43-10
Qbt
EP-43-12
Qbt
EP-43-14
Qbt
EP-43-16
Qbt
EP-43-17
Qbt
EP-44-01
Qbt
EP-44-02
Qbt
EP-44-03
Qbt
EP-44-04
Qbt
EP-44-05
Qbt
EP-44-06
Qbt
EP-44-07
Qbt
EP-44-08
Qbt
EP-44-09
Qbt
EP-44-10
Qbt
66.09
66.62
66.27
66.04
66.22
66.07
66.40
66.55
66.60
66.43
66.79
66.33
66.73
66.62
67.20
66.62
66.65
66.78
66.46
66.35
66.33
66.42
65.47
65.77
66.72
67.08
66.93
66.74
66.69
67.14
66.87
66.95
66.72
66.95
66.62
67.11
66.74
66.52
66.94
65.83
66.99
65.40
67.18
66.71
66.52
66.60
19.28
19.29
19.36
19.30
19.38
19.09
19.13
19.27
19.22
19.14
19.46
19.38
19.60
19.30
19.29
19.71
19.95
19.38
19.29
19.79
19.65
19.77
19.38
19.02
19.30
19.35
19.43
19.34
19.35
19.36
19.36
19.23
19.37
19.34
19.10
19.35
19.20
19.11
19.50
18.98
19.30
19.02
19.47
19.38
19.24
19.02
0.13
0.22
0.22
0.16
0.17
0.18
0.19
0.19
0.19
0.18
0.17
0.19
0.18
0.14
0.19
0.18
0.19
0.18
0.20
0.18
0.21
0.15
0.19
0.19
0.17
0.18
0.21
0.17
0.21
0.19
0.21
0.21
0.23
0.19
0.19
0.20
0.21
0.20
0.22
0.21
0.28
0.22
0.18
0.19
0.24
0.22
0.27
0.30
0.32
0.33
0.33
0.22
0.24
0.22
0.37
0.29
0.32
0.28
0.42
0.23
0.34
0.60
0.58
0.36
0.25
0.58
0.49
0.48
0.44
0.22
0.22
0.13
0.14
0.12
0.15
0.14
0.13
0.14
0.17
0.17
0.14
0.12
0.12
0.14
0.16
0.15
0.14
0.16
0.14
0.16
0.15
0.14
6.42
6.61
6.68
6.82
6.73
6.36
6.34
6.40
6.54
6.43
6.74
6.61
6.78
6.35
6.47
7.09
7.11
6.66
6.34
7.33
6.91
6.93
6.75
6.31
6.33
6.54
6.63
6.58
6.54
6.51
6.51
6.49
6.45
6.61
6.51
6.69
6.49
6.25
6.67
6.27
6.45
6.66
6.53
6.43
6.43
6.26
7.32
7.26
7.02
6.92
7.21
7.56
7.54
7.71
7.25
7.40
7.23
7.25
6.77
7.48
7.33
6.01
5.95
7.14
7.38
5.98
6.52
6.57
6.63
7.62
7.64
7.72
7.53
7.52
7.50
7.71
7.57
7.70
7.48
7.41
7.49
7.52
7.26
7.47
7.11
7.56
7.43
7.24
7.47
7.38
7.32
7.63
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.07
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.05
nd
nd
nd
nd
0.08
0.08
0.10
nd
nd
nd
nd
nd
nd
0.05
0.11
nd
0.09
0.10
0.11
nd
0.06
0.09
0.12
0.10
0.11
nd
nd
nd
0.06
nd
nd
nd
nd
nd
nd
0.10
nd
nd
nd
nd
0.06
nd
nd
nd
nd
nd
nd
nd
99.52
100.31
99.93
99.64
100.14
99.47
99.85
100.34
100.17
99.87
100.72
100.09
100.59
100.11
100.91
100.29
100.55
100.50
100.03
100.28
100.23
100.42
98.96
99.13
100.37
100.99
100.93
100.47
100.44
101.06
100.64
100.71
100.41
100.76
100.05
100.99
100.01
99.70
100.66
98.98
100.58
98.70
100.97
100.31
99.90
99.86
42
41
40
39
41
43
43
44
41
42
41
41
39
43
42
35
35
41
43
34
37
38
38
44
44
43
42
43
43
44
43
44
43
42
43
42
42
44
41
44
43
41
43
43
43
44
56
57
58
59
58
56
55
55
57
56
58
57
59
56
56
62
63
58
56
63
60
60
59
55
55
56
57
57
57
56
56
56
56
57
57
57
57
56
58
55
56
58
57
57
57
55
1
1
2
2
2
1
1
1
2
1
2
1
2
1
2
3
3
2
1
3
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
DEER CANYON MEMBER
EP-2-01
Qvdc
EP-2-02
Qvdc
EP-2-03
Qvdc
EP-2-04
Qvdc
EP-2-05
Qvdc
EP-2-06
Qvdc
EP-2-08
Qvdc
EP-2-09
Qvdc
EP-2-11
Qvdc
EP-2-12
Qvdc
EP-2-13
Qvdc
EP-2-14
Qvdc
EP-2-15
Qvdc
EP-2ts-15
Qvdc
EP-14-01
Qvdc
EP-14-02
Qvdc
EP-14-03
Qvdc
EP-14-04
Qvdc
EP-14-05
Qvdc
EP-14-06
Qvdc
EP-14-07
Qvdc
EP-14-08
Qvdc
EP-14-09
Qvdc
EP-14-10
Qvdc
EP-15-01
Qvdc
EP-15-02
Qvdc
EP-15-03
Qvdc
EP-15-04
Qvdc
EP-15-05
Qvdc
EP-15-07
Qvdc
EP-15-08
Qvdc
EP-15-09
Qvdc
EP-15-10
Qvdc
EP-15-12
Qvdc
EP-15-13
Qvdc
EP-15-14
Qvdc
EP-15-15
Qvdc
EP-15-16
Qvdc
EP-29-01
Qvdc
66.45
66.65
67.09
66.81
67.74
66.77
67.18
67.27
66.83
66.84
66.69
67.00
67.56
65.57
67.00
66.56
66.71
65.57
66.16
66.97
65.60
65.84
66.94
66.53
65.54
66.61
67.35
67.00
66.61
65.09
66.39
65.76
66.53
66.56
66.37
66.58
66.80
67.25
66.68
19.75
19.78
19.60
19.43
19.82
19.66
19.42
19.46
19.55
19.79
19.38
19.58
19.78
19.52
19.11
19.16
19.27
19.32
19.15
19.42
19.36
19.30
19.25
19.10
19.40
19.43
19.31
19.32
19.45
19.10
19.30
19.44
19.34
19.24
19.20
19.42
19.38
19.26
19.47
0.19
0.20
0.19
0.22
0.16
0.12
0.22
0.12
0.23
0.21
0.18
0.19
0.20
0.16
0.20
0.16
0.14
0.20
0.12
0.16
0.20
0.18
0.21
0.21
0.16
0.17
0.23
0.18
0.16
0.13
0.09
0.09
0.12
0.18
0.24
0.20
0.19
0.21
0.22
0.58
0.49
0.21
0.29
0.30
0.36
0.28
0.15
0.37
0.59
0.16
0.37
0.48
0.40
0.24
0.14
0.18
0.28
0.22
0.21
0.16
0.12
0.17
0.19
0.20
0.21
0.13
0.14
0.28
0.23
0.24
0.29
0.22
0.21
0.16
0.14
0.13
0.14
0.18
7.06
7.05
6.85
6.48
6.72
5.99
6.56
6.62
6.74
7.34
6.51
6.72
7.05
6.16
6.43
6.31
6.08
6.62
5.75
5.76
6.54
6.58
6.48
6.60
6.49
6.39
6.37
6.47
5.96
5.84
5.90
5.40
5.85
6.39
6.45
6.49
6.53
6.40
6.77
6.35
6.52
7.12
7.39
7.25
8.07
7.45
7.43
7.09
6.13
7.64
7.12
6.63
8.06
7.38
7.53
7.95
7.08
8.26
8.45
7.29
7.17
7.37
7.00
7.60
7.52
7.57
7.24
8.44
8.20
8.27
8.88
8.54
7.52
7.40
7.34
7.47
7.61
7.29
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.06
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.06
0.07
0.08
nd
nd
nd
nd
0.05
0.15
nd
nd
nd
0.07
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.05
nd
nd
0.22
nd
0.07
nd
nd
nd
nd
nd
100.39
100.76
101.14
100.71
101.99
100.96
101.11
101.06
100.86
101.04
100.56
100.99
101.75
99.94
100.36
99.85
100.33
99.05
99.66
100.97
99.15
99.19
100.42
99.63
99.37
100.32
100.95
100.35
100.94
98.59
100.19
100.08
100.60
100.17
99.82
100.17
100.50
100.88
100.60
36
37
40
42
41
46
42
42
40
34
43
40
37
45
43
44
46
41
48
49
42
42
42
41
43
43
44
42
48
47
47
51
48
43
43
42
43
44
41
61
61
59
56
58
52
56
57
58
63
56
58
60
53
56
56
53
58
51
50
57
58
57
58
56
56
56
57
51
51
51
47
50
56
57
57
57
56
58
3
2
1
1
1
2
1
1
2
3
1
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Sample
Unit
ELECTRON MICROPROBE ANALYSES OF FELDSPAR
Sample
Unit
SiO2
Al2O3
FeO
CaO
Na2O
K2O
SrO
BaO
Total
Or
Ab
An
EP-29-03
EP-29-04
EP-29-05
EP-29-06
EP-29-07
EP-29-09
EP-29-10
EP-29-11
EP-29-13
EP-29-14
EP-31-02
EP-31-03
EP-31-05
EP-31-06
EP-31-07
EP-31-09
EP-31-10
EP-31-11
EP-31-12
EP-31-13
EP-31-14
EP-31-15
EP-31-16
EP-32-01
EP-32-02
EP-32-03
EP-32-04
EP-32-05
EP-32-06
EP-32-09
EP-32-10
EP-32-11
EP-32-12
EP-32-14
EP-34-01
EP-34-03
EP-34-06
EP-34-07
EP-34-08
EP-34-09
EP-34-10
EP-34-11
EP-34-12
EP-34-13
EP-34-14
EP-34-15
EP-34-16
EP-34-17
EP-34-18
EP-34ts-08
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
Qvdc
66.84
66.71
67.05
67.06
67.00
67.16
65.65
66.27
66.62
66.65
66.88
66.81
66.89
65.64
67.29
66.39
66.71
67.18
65.70
65.58
66.15
66.35
67.42
67.01
66.81
66.57
66.42
67.18
66.78
66.75
66.64
66.96
66.48
66.34
66.74
66.64
66.56
67.09
66.34
66.00
65.26
66.79
65.50
66.76
65.39
66.59
66.93
65.38
64.70
66.52
19.52
19.34
19.55
19.34
19.22
19.39
19.18
19.55
19.44
19.45
19.47
19.38
19.39
19.02
19.43
19.17
19.52
19.38
19.01
19.06
19.40
19.61
19.60
19.37
19.34
19.36
19.31
19.36
19.30
19.30
19.39
19.42
19.27
19.69
19.31
19.52
19.33
19.16
19.91
19.09
19.30
19.38
19.45
19.21
19.28
19.32
19.72
19.46
19.31
19.47
0.17
0.16
0.21
0.19
0.21
0.14
0.15
0.15
0.20
0.17
0.16
0.21
0.22
0.21
0.21
0.18
0.16
0.18
0.19
0.17
0.16
0.18
0.18
0.17
0.21
0.19
0.18
0.20
0.21
0.19
0.19
0.21
0.22
0.16
0.15
0.18
0.21
0.19
0.17
0.17
0.23
0.13
0.17
0.13
0.20
0.17
0.14
0.18
0.22
0.17
0.17
0.25
0.27
0.14
0.13
0.23
0.34
0.18
0.16
0.15
0.29
0.25
0.26
0.21
0.22
0.21
0.26
0.24
0.27
0.28
0.28
0.34
0.29
0.25
0.24
0.24
0.33
0.32
0.23
0.19
0.27
0.27
0.28
0.49
0.26
0.38
0.17
0.24
0.43
0.26
0.22
0.27
0.45
0.25
0.33
0.40
0.39
0.27
0.35
0.30
6.55
6.49
6.87
6.52
6.53
6.23
6.78
6.71
6.69
6.70
6.56
6.36
6.57
6.29
6.44
6.31
6.59
6.48
6.32
6.20
6.49
6.68
6.72
6.28
6.38
6.42
6.55
6.54
6.31
6.37
6.44
6.52
6.48
6.91
6.55
6.60
6.32
6.47
6.91
6.27
6.31
6.45
6.94
6.39
6.48
6.82
6.88
6.44
6.61
6.47
7.48
7.28
7.20
7.52
7.52
7.93
6.94
7.33
7.54
7.33
7.31
7.50
7.39
7.40
7.52
7.37
7.32
7.57
7.31
7.39
7.45
7.01
7.16
7.43
7.42
7.26
7.07
7.25
7.57
7.58
7.37
7.29
7.28
6.36
7.37
7.20
7.76
7.40
6.88
7.46
7.46
7.19
6.63
7.54
7.09
6.65
6.65
7.54
7.06
7.34
nd
0.12
0.11
nd
nd
0.08
0.05
nd
0.08
nd
nd
nd
nd
nd
nd
nd
nd
0.07
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.05
nd
nd
nd
nd
0.05
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.08
nd
nd
nd
nd
nd
nd
0.07
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.06
0.05
nd
0.09
0.05
0.06
nd
nd
0.07
nd
0.05
nd
0.08
nd
nd
0.09
nd
nd
nd
0.06
0.05
nd
nd
nd
0.07
nd
nd
0.07
0.08
nd
0.10
0.10
100.81
100.35
101.25
100.78
100.61
101.16
99.09
100.26
100.74
100.45
100.67
100.52
100.72
98.77
101.10
99.62
100.55
101.08
98.86
98.73
99.93
100.25
101.41
100.57
100.39
100.04
99.92
100.85
100.44
100.39
100.38
100.67
100.01
100.10
100.38
100.52
100.35
100.59
100.73
99.26
98.78
100.20
99.20
100.29
98.77
100.01
100.80
99.26
98.34
100.38
43
42
40
43
43
45
40
41
42
42
42
43
42
43
43
43
42
43
43
43
42
40
41
43
43
42
41
42
44
43
42
42
42
37
42
41
44
42
39
43
43
42
38
43
41
38
38
43
41
42
57
57
58
56
57
54
59
58
57
58
57
56
57
56
56
56
57
56
56
55
56
58
58
56
56
57
58
57
55
56
56
57
57
61
57
57
55
56
59
55
56
57
60
56
57
60
60
56
58
56
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
2
2
1
1
1
1
1
2
1
2
1
1
2
1
1
1
2
1
2
2
2
1
2
1
65.23
65.91
63.77
64.35
64.75
64.09
64.42
65.00
64.37
64.18
64.64
64.81
64.89
64.21
64.84
64.40
65.26
64.97
64.75
65.97
66.12
65.51
65.17
64.51
64.36
58.16
59.56
64.74
63.67
65.20
64.55
63.54
63.90
64.33
63.57
64.65
64.42
19.40
19.58
19.29
19.42
22.39
19.46
19.25
19.67
19.90
19.55
19.74
19.55
19.52
19.56
19.81
19.77
19.64
19.55
19.86
19.91
19.56
19.92
19.42
19.55
19.56
25.48
25.32
19.57
19.61
19.31
19.45
19.43
19.66
19.65
19.34
19.74
19.41
0.13
0.15
0.16
0.12
0.18
0.11
0.09
0.15
0.17
0.17
0.17
0.14
0.14
0.14
0.14
0.17
0.13
0.16
0.12
0.17
0.15
0.13
0.14
0.15
0.12
0.34
0.33
0.14
0.16
0.11
0.14
0.10
0.14
0.14
0.11
0.12
0.16
0.42
0.41
0.40
0.42
3.03
0.35
0.33
0.44
0.47
0.42
0.44
0.42
0.31
0.44
0.46
0.43
0.42
0.39
0.52
0.45
0.33
0.33
0.35
0.40
0.40
6.95
6.56
0.40
0.49
0.36
0.42
0.37
0.44
0.41
0.42
0.47
0.43
4.89
5.14
4.60
4.75
9.12
4.56
4.56
4.89
4.85
4.67
4.81
4.88
4.73
4.77
4.95
4.77
4.86
4.74
4.98
5.09
4.93
4.91
4.68
4.70
4.66
7.02
7.41
4.69
4.71
4.75
4.74
4.64
4.71
4.55
4.61
4.85
4.69
9.64
9.39
9.44
9.62
1.50
9.55
9.73
9.44
9.34
9.36
9.34
9.36
9.54
9.37
9.32
9.30
9.61
9.43
9.05
9.59
9.75
9.69
9.98
9.41
9.75
0.62
0.72
9.59
9.22
9.81
9.58
9.49
9.29
9.50
9.44
9.43
9.26
0.06
0.06
0.06
0.08
0.11
0.12
0.06
0.07
nd
0.08
nd
0.10
0.07
0.06
0.09
0.09
0.09
0.08
0.09
0.06
0.10
0.06
nd
0.07
0.08
0.18
0.18
0.11
0.11
0.07
0.06
nd
0.10
nd
0.13
0.08
0.09
0.36
0.27
1.17
1.07
0.09
1.37
0.78
1.04
1.37
1.09
1.26
0.98
0.82
1.22
1.22
1.19
0.91
1.08
1.17
0.96
0.36
0.88
0.40
1.05
1.03
0.15
0.12
0.94
1.32
0.36
0.91
1.09
1.27
1.59
0.98
0.99
1.27
100.13
100.92
98.88
99.84
101.16
99.60
99.20
100.70
100.48
99.52
100.41
100.23
100.02
99.77
100.83
100.12
100.91
100.38
100.53
102.18
101.29
101.42
100.14
99.84
99.97
98.88
100.19
100.19
99.29
99.98
99.85
98.65
99.50
100.18
98.60
100.33
99.73
55
54
56
56
8
57
57
55
55
56
55
55
56
55
54
55
55
56
53
54
56
56
57
56
57
4
4
56
55
57
56
56
55
57
56
55
55
43
45
42
42
77
41
41
43
43
42
43
43
42
43
44
43
43
42
44
44
43
43
41
42
41
62
64
42
43
42
42
42
43
41
42
43
43
2
2
2
2
14
2
2
2
2
2
2
2
2
2
2
2
2
2
3
2
2
2
2
2
2
34
32
2
2
2
2
2
2
2
2
2
2
REDONDO CREEK MEMBER
EP-7-01
Qvrc
EP-7-02
Qvrc
EP-7-03
Qvrc
EP-7-04
Qvrc
EP-7-06
Qvrc
EP-7-08
Qvrc
EP-7-09
Qvrc
EP-7-10
Qvrc
EP-7-11
Qvrc
EP-7-13
Qvrc
EP-7-14
Qvrc
EP-7-15
Qvrc
EP-7-16
Qvrc
EP-7-17
Qvrc
EP-7-18
Qvrc
EP-7-19
Qvrc
EP-7-20
Qvrc
EP-7-21
Qvrc
EP-7-22
Qvrc
EP-7-23
Qvrc
EP-7-24
Qvrc
EP-7-25
Qvrc
EP-7-26
Qvrc
EP-9-01
Qvrc
EP-9-02
Qvrc
EP-9-03
Qvrc
EP-9-04
Qvrc
EP-9-05
Qvrc
EP-9-06
Qvrc
EP-9-07
Qvrc
EP-9-08
Qvrc
EP-9-09
Qvrc
EP-9-10
Qvrc
EP-9-11
Qvrc
EP-9-12
Qvrc
EP-9-13
Qvrc
EP-9ts-07
Qvrc
ELECTRON MICROPROBE ANALYSES OF FELDSPAR
Sample
Unit
SiO2
Al2O3
FeO
CaO
Na2O
K2O
SrO
BaO
Total
Or
Ab
An
EP-9ts-08
EP-9ts-20
EP-9ts-23
EP-9ts-26
EP-9ts-29
EP-10-noHF-01
EP-10-noHF-03
EP-10-noHF-05
EP-10-noHF-06
EP-10-noHF-07
EP-10-noHF-08
EP-10-noHF-10
EP-10-noHF-11
EP-10-noHF-12
EP-10-noHF-14
EP-10-noHF-15
EP-10-noHF-16
EP-10-noHF-18
EP-10-noHF-20
EP-10-HF-01
EP-10-HF-02
EP-10-HF-03
EP-10-HF-04
EP-10-HF-05
EP-10-HF-06
EP-10-HF-07
EP-10-HF-08
EP-10-HF-09
EP-10-HF-10
EP-10-HF-11
EP-10-HF-12
EP-10-HF-13
EP-10-HF-14
EP-10-HF-15
EP-10-HF-16
EP-10-HF-17
EP-30-01
EP-30-02
EP-30-03
EP-30-04
EP-30-05
EP-30-06
EP-30-07
EP-30-08
EP-30-09
EP-30-10
EP-30-11
EP-30-12
EP-30-13
EP-30-14
EP-30-16
EP-30-17
EP-30-18
EP-30-19
EP-30-21
EP-30-25
EP-30-26
EP-30-28
EP-30-29
EP-30-30
EP-30-32
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
62.63
63.96
63.03
60.35
63.19
63.35
63.75
64.69
63.16
64.74
65.26
61.59
62.28
64.21
64.87
64.92
64.68
64.64
63.95
63.64
65.41
64.67
64.31
65.38
66.21
64.38
64.45
65.71
64.26
65.26
65.08
65.00
63.89
63.73
64.01
64.79
64.53
64.93
64.37
64.21
65.38
58.71
62.90
57.17
62.83
65.34
64.46
63.94
65.22
65.08
55.81
60.00
57.50
61.74
63.00
63.70
64.03
65.27
62.87
64.30
64.42
22.60
22.00
22.28
23.46
22.11
19.74
19.51
19.51
19.56
19.25
19.51
24.30
25.15
19.31
19.70
19.84
19.88
23.45
19.43
19.42
19.49
22.29
19.11
19.13
19.30
19.52
20.08
19.73
19.52
19.39
20.04
19.80
23.11
19.29
22.65
19.37
22.29
19.38
19.86
19.84
20.02
26.35
23.47
28.42
23.49
19.58
19.72
22.23
22.50
22.82
27.87
25.27
28.69
24.09
23.19
22.49
22.38
19.45
22.97
19.39
19.87
0.24
0.23
0.26
0.22
0.24
0.16
0.14
0.14
0.12
0.16
0.15
0.22
0.22
0.14
0.18
0.15
0.13
0.21
0.15
0.13
0.13
0.24
0.13
0.10
0.17
0.12
0.14
0.16
0.19
0.14
0.15
0.17
0.26
0.16
0.24
0.13
0.20
0.15
0.15
0.16
0.14
0.24
0.21
0.24
0.27
0.11
0.15
0.24
0.21
0.18
0.23
0.26
0.22
0.28
0.28
0.24
0.22
0.11
0.21
0.46
0.21
4.11
3.32
3.63
5.03
3.51
0.40
0.39
0.38
0.40
0.38
0.39
5.35
5.61
0.31
0.48
0.47
0.47
3.71
0.31
0.33
0.41
2.96
0.32
0.31
0.27
0.40
0.47
0.37
0.39
0.30
0.47
0.45
3.63
0.39
3.38
0.29
3.08
0.26
0.54
0.35
0.54
7.33
4.19
8.93
3.87
0.35
0.40
3.05
2.89
3.16
9.11
6.17
9.17
4.75
3.84
3.20
2.94
0.29
3.72
0.58
0.55
8.33
8.58
8.56
8.01
8.44
4.72
4.67
4.75
4.73
4.63
4.79
7.23
8.02
4.67
4.86
4.91
4.92
7.06
4.75
4.57
4.76
8.51
4.47
4.71
4.71
4.64
5.08
4.70
4.63
4.71
4.85
4.96
8.65
4.68
8.42
4.65
8.91
4.40
4.86
4.32
4.98
6.98
8.38
6.38
8.63
4.60
4.65
8.63
8.81
8.90
5.85
7.52
6.15
8.25
8.40
8.55
8.42
4.51
8.34
4.71
5.10
1.29
1.66
1.49
0.99
1.51
9.37
9.58
9.48
9.46
9.67
9.40
0.99
0.86
9.68
8.96
9.18
9.13
1.58
9.64
9.90
9.43
2.01
9.70
9.65
10.02
9.36
9.01
9.51
9.14
9.70
9.15
9.32
1.56
9.44
1.71
9.66
1.64
10.04
9.12
9.87
8.93
0.54
1.21
0.38
1.25
9.52
9.32
1.68
1.87
1.73
0.35
0.69
0.34
0.92
1.40
1.61
1.57
9.93
1.35
8.39
8.51
0.10
0.08
0.10
0.07
0.09
0.05
nd
0.06
0.08
0.06
0.07
0.07
0.13
0.05
0.08
nd
0.07
nd
nd
0.05
0.06
nd
nd
0.05
nd
0.08
0.09
0.06
0.08
0.06
0.09
0.06
0.10
nd
0.10
nd
0.07
nd
0.05
nd
0.08
0.13
0.12
0.12
0.09
nd
0.05
0.07
nd
0.07
0.17
0.10
0.12
0.15
0.11
0.06
0.10
nd
0.08
nd
0.11
0.17
0.12
0.12
0.09
0.18
1.21
0.89
0.76
0.80
0.80
0.77
0.08
0.10
0.42
1.35
1.33
1.31
0.17
0.44
0.85
0.62
0.09
0.53
0.46
0.06
1.15
1.08
0.76
1.24
0.61
1.41
1.35
0.09
0.99
0.10
0.54
0.11
0.58
1.20
1.10
0.99
0.06
0.09
0.08
0.10
0.68
0.88
nd
0.08
nd
0.07
0.09
0.07
0.06
0.18
0.22
0.16
0.32
0.16
1.33
0.92
99.48
99.95
99.47
98.22
99.28
99.00
98.93
99.76
98.33
99.69
100.35
99.82
102.38
98.79
100.47
100.81
100.57
100.81
98.67
98.89
100.31
100.78
98.57
99.79
100.74
99.66
100.40
100.98
99.45
100.18
101.23
101.10
101.30
98.68
100.61
99.42
100.81
99.74
100.14
99.85
101.05
100.36
100.57
101.71
100.52
100.17
99.63
99.84
101.58
101.94
99.45
100.08
102.25
100.25
100.40
100.07
99.80
99.89
99.71
99.14
99.69
7
9
8
6
9
56
56
56
56
57
55
6
5
57
54
54
54
10
56
58
55
12
58
57
58
56
53
56
55
57
54
54
9
56
10
57
9
59
54
59
53
3
7
2
7
57
56
10
11
10
2
4
2
5
8
9
9
58
8
52
51
73
75
74
70
74
43
42
42
42
41
43
67
69
42
44
44
44
70
42
41
43
74
41
42
41
42
45
42
43
42
44
44
74
42
74
42
76
39
44
39
45
61
73
55
74
42
42
76
76
76
53
66
54
72
73
75
76
40
74
45
46
20
16
17
24
17
2
2
2
2
2
2
27
27
2
2
2
2
20
2
2
2
14
2
2
1
2
2
2
2
1
2
2
17
2
16
1
15
1
3
2
3
36
20
43
18
2
2
15
14
15
45
30
44
23
19
16
15
1
18
3
3
CERRO DEL MEDIO
EP-39-01
Qvvf
EP-39-02
Qvvf
EP-39-03
Qvvf
EP-39-04
Qvvf
EP-39-05
Qvvf
EP-39-06
Qvvf
EP-39-07
Qvvf
EP-39-08
Qvvf
EP-39-09
Qvvf
EP-39-10
Qvvf
EP-39-11
Qvvf
EP-39-12
Qvvf
EP-39-13
Qvvf
EP-39-15
Qvvf
EP-39-16
Qvvf
EP-39-17
Qvvf
EP-39-18
Qvvf
EP-39-19
Qvvf
EP-39-21
Qvvf
EP-41-01
Qvvf
EP-41-02
Qvvf
EP-41-03
Qvvf
EP-41-04
Qvvf
EP-41-05
Qvvf
EP-41-06
Qvvf
EP-41-07
Qvvf
65.40
64.53
66.58
66.29
66.15
65.24
65.37
66.52
66.67
66.18
65.37
66.62
67.07
66.36
65.00
64.86
66.62
65.72
65.08
65.27
65.66
66.99
65.49
66.02
65.41
65.92
19.39
19.21
20.65
19.47
19.39
20.39
19.34
19.58
19.40
20.10
19.28
19.41
19.49
20.07
19.35
20.09
19.42
19.69
20.55
20.80
20.38
19.72
20.26
20.29
20.49
19.85
0.15
0.12
0.10
0.11
0.12
0.14
0.11
0.15
0.11
0.13
0.08
0.13
0.13
0.11
0.10
0.13
0.12
0.11
0.12
0.18
0.19
0.17
0.20
0.19
0.18
0.14
0.37
0.37
1.05
0.30
0.39
0.98
0.34
0.41
0.29
1.04
0.31
0.30
0.31
0.92
0.39
1.08
0.30
0.45
1.20
1.69
1.20
0.38
1.18
1.25
1.44
0.76
6.07
5.86
8.12
5.70
6.00
8.07
5.89
6.12
5.87
8.02
5.77
5.81
6.07
7.86
6.18
7.93
6.10
6.41
8.35
8.43
8.06
6.42
7.91
8.06
8.22
7.32
7.94
8.07
4.46
8.35
7.88
4.61
8.00
7.87
8.08
4.23
8.35
8.27
8.26
4.80
7.65
4.42
7.99
7.60
3.67
3.43
4.29
7.69
4.29
4.28
3.77
5.87
nd
0.05
nd
nd
nd
nd
nd
0.05
nd
nd
nd
nd
nd
nd
nd
0.05
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.05
0.10
nd
0.11
0.08
nd
nd
0.05
0.06
0.07
nd
0.06
0.06
0.06
0.07
nd
nd
0.09
nd
nd
nd
0.11
0.09
nd
0.08
0.06
99.36
98.30
100.96
100.34
100.01
99.43
99.05
100.74
100.48
99.78
99.16
100.59
101.40
100.17
98.73
98.56
100.54
100.07
98.99
99.81
99.78
101.49
99.41
100.10
99.58
99.92
45
47
25
48
45
26
46
45
47
24
48
48
47
27
44
25
46
43
21
19
24
43
25
24
22
33
53
52
70
50
53
69
52
53
52
70
50
51
52
68
54
69
53
55
73
73
70
55
69
70
71
63
2
2
5
1
2
5
2
2
1
5
2
1
1
4
2
5
1
2
6
8
6
2
6
6
7
4
ELECTRON MICROPROBE ANALYSES OF FELDSPAR
Sample
Unit
SiO2
Al2O3
FeO
CaO
Na2O
K2O
SrO
BaO
Total
Or
Ab
An
EP-41-08
EP-41-09
EP-41-10
EP-41-11
EP-41-12
EP-41-13
EP-41-14
EP-41-15
EP-41-16
EP-41-17
EP-41-18
EP-42-01
EP-42-02
EP-42-04
EP-42-05
EP-42-06
EP-42-08
EP-42-09
EP-42-10
EP-42-11
EP-42-12
EP-42-13
EP-42-14
EP-42-15
EP-42-16
EP-42-17
EP-42-18
EP-42-21
EP-42-22
EP-42-24
EP-42-25
EP-42-26
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
Qvvf
66.36
66.47
65.80
66.78
65.26
65.81
66.97
65.74
65.86
65.35
66.67
65.51
66.73
66.38
66.48
66.15
66.34
67.03
66.22
66.61
65.90
65.18
67.09
66.52
66.00
66.54
67.11
66.44
66.37
66.31
66.08
65.79
20.91
19.87
20.23
19.76
20.29
20.88
20.92
20.69
20.79
20.43
20.88
19.29
19.57
19.54
19.46
20.52
19.49
19.66
19.51
20.62
19.35
20.34
19.89
20.23
19.54
19.62
19.85
19.60
19.50
20.51
21.14
19.40
0.22
0.15
0.21
0.20
0.22
0.20
0.18
0.16
0.16
0.18
0.16
0.13
0.10
0.14
0.11
0.12
0.11
0.08
0.10
0.11
0.10
0.16
0.11
0.13
0.12
0.13
0.14
0.09
0.14
0.10
0.17
0.08
1.35
0.52
1.07
0.44
1.12
1.57
1.33
1.37
1.35
1.45
1.31
0.35
0.32
0.33
0.35
1.20
0.32
0.27
0.34
1.10
0.37
1.11
0.48
0.87
0.35
0.35
0.30
0.38
0.32
1.17
1.81
0.30
8.42
6.49
7.90
6.40
7.90
8.50
8.41
8.30
8.39
8.27
8.54
5.94
6.26
5.92
6.22
8.55
6.17
6.12
6.10
8.19
6.05
8.11
6.80
7.84
5.90
6.06
6.11
6.12
6.11
8.35
9.27
5.65
3.91
7.60
4.74
7.76
4.41
3.71
4.21
3.85
3.92
3.74
3.96
7.91
8.01
8.28
7.92
4.07
8.11
8.31
7.95
4.19
8.00
4.08
7.27
5.12
8.23
8.11
8.40
8.11
8.08
4.16
2.18
8.44
nd
nd
0.08
nd
nd
nd
nd
nd
nd
0.05
nd
nd
0.08
nd
0.05
0.06
nd
0.06
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.05
nd
0.07
nd
nd
nd
0.14
0.07
0.08
0.06
nd
nd
nd
nd
nd
0.07
nd
0.13
0.09
nd
0.08
0.06
nd
0.11
nd
nd
nd
0.12
0.08
0.13
nd
0.05
0.09
nd
nd
nd
0.11
101.17
101.25
100.09
101.41
99.25
100.66
102.00
100.12
100.47
99.47
101.59
99.13
101.19
100.68
100.59
100.74
100.60
101.53
100.33
100.81
99.77
98.98
101.76
100.78
100.26
100.80
101.96
100.87
100.51
100.68
100.64
99.78
22
42
27
43
25
21
23
22
22
21
22
46
45
47
45
23
46
47
45
24
46
24
40
29
47
46
47
46
46
23
12
49
72
55
68
54
69
72
71
72
72
72
72
52
54
51
53
72
53
52
53
71
53
71
57
67
51
52
52
52
53
71
79
50
6
2
5
2
5
7
6
7
6
7
6
2
1
2
2
6
2
1
2
5
2
5
2
4
2
2
1
2
2
6
9
1
LOWER BANDELIER TUFF MEGABRECCIA BLOCK
EP-12-01
Qmb
66.98
19.67
0.13
EP-12-02
Qmb
66.52
19.34
0.16
EP-12-03
Qmb
67.02
19.49
0.21
EP-12-04
Qmb
67.07
19.55
0.17
EP-12-05
Qmb
66.38
19.24
0.14
EP-12-06
Qmb
66.62
19.24
0.16
EP-12-07
Qmb
67.39
19.94
0.17
EP-12-09
Qmb
66.62
19.53
0.17
EP-12-10
Qmb
66.96
19.47
0.22
EP-12-11
Qmb
66.56
19.17
0.16
EP-12-12
Qmb
66.96
19.72
0.16
EP-12-13
Qmb
67.10
19.75
0.19
EP-12-14
Qmb
66.67
19.35
0.19
EP-13-01
Qmb
66.46
19.50
0.16
EP-13-02
Qmb
65.98
19.31
0.11
EP-13-03
Qmb
66.61
19.61
0.18
EP-13-04
Qmb
66.17
19.20
0.22
EP-13-05
Qmb
66.05
19.40
0.14
EP-13-06
Qmb
66.09
19.37
0.19
EP-13-07
Qmb
66.24
19.22
0.12
EP-13-08
Qmb
66.43
19.43
0.18
EP-13-10
Qmb
66.49
19.43
0.09
EP-13-11
Qmb
66.54
19.30
0.15
EP-13-12
Qmb
65.39
19.08
0.18
EP-13-13
Qmb
66.39
19.17
0.21
0.28
0.27
0.23
0.36
0.24
0.28
0.43
0.30
0.24
0.23
0.36
0.34
0.23
0.47
0.32
0.30
0.25
0.28
0.29
0.34
0.27
0.33
0.30
0.22
0.23
6.39
6.52
6.20
7.27
6.25
6.49
8.17
6.13
6.53
6.26
7.03
7.34
6.31
7.10
6.41
6.53
6.21
6.36
6.44
6.13
6.43
6.42
6.44
6.04
6.24
7.70
7.11
7.90
6.21
7.82
7.36
5.32
8.25
7.51
7.68
6.79
6.49
7.77
6.40
7.27
7.52
7.92
7.70
7.56
7.88
7.59
7.56
7.56
7.93
7.92
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.05
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.05
nd
0.05
0.05
0.07
nd
nd
nd
nd
nd
nd
nd
101.14
99.92
101.05
100.62
100.07
100.14
101.41
101.00
100.93
100.11
101.02
101.21
100.53
100.13
99.39
100.79
100.02
99.99
99.93
99.93
100.33
100.32
100.28
98.84
100.16
44
41
45
35
45
42
29
46
43
44
38
36
44
36
42
43
45
44
43
45
43
43
43
46
45
55
57
54
63
54
57
69
52
56
55
60
62
55
61
56
56
54
55
56
53
56
55
56
53
54
1
1
1
2
1
1
2
1
1
1
2
2
1
2
2
1
1
1
1
2
1
2
1
1
1
Qmb = Megabreccia Block (lower Bandelier Tuff)
Qbt = upper Bandelier Tuff
Qvdc = Deer Canyon Member
Qvrc = Redondo Creek Member
Qvvf = Cerro del Medio
nd = below detection limit
ELECTRON MICROPROBE ANALYSES OF GLASS
Sample
Unit
Feature
SiO2
TiO2
Al2O3
FeO
MnO
MgO
CaO
Na2O
K2O
P2O5
F
SO2
Cl
SrO
BaO
Total
EP-1-05
EP-1ts-12*
Qbt
Qbt
melt inclusion
melt inclusion
78.14
77.89
0.06
0.14
13.09
11.70
1.23
0.40
0.06
nd
nd
0.12
0.25
0.18
1.78
3.03
5.39
6.30
na
nd
na
0.14
na
0.06
na
nd
na
na
na
na
100
100
EP-1ts*
Qbt
matrix glass average (n=7)
matrix glass standard deviation
78.04
1.24
0.15
0.07
11.56
0.76
0.47
0.22
nd
-
nd
-
0.14
0.02
2.42
0.20
7.12
0.75
0.06
-
0.14
0.05
0.06
0.01
nd
-
na
-
na
-
100
EP-43-08
EP-43-13
EP-43-15
EP-44-13
Qbt
Qbt
Qbt
Qbt
melt inclusion
melt inclusion
melt inclusion
melt inclusion
78.59
79.18
78.32
81.38
na
na
na
0.06
12.08
12.46
12.42
13.01
1.34
1.50
1.49
1.54
na
na
na
0.13
na
na
na
nd
0.25
0.27
0.24
0.26
3.33
2.30
3.04
1.14
4.40
4.24
4.45
2.48
na
na
na
na
na
na
na
na
na
na
na
na
na
na
na
na
nd
nd
nd
na
nd
nd
nd
na
100
100
100
100
EP-44-11
Qbt
matrix glass
77.90
na
12.36
1.55
na
na
0.25
3.38
4.50
na
na
na
na
nd
nd
100
EP-43
Qbt
matrix glass average (n=4)
matrix glass standard deviation
78.39
0.48
na
-
12.38
0.17
1.39
0.06
na
-
na
-
0.26
0.01
3.09
0.43
4.46
0.19
na
-
na
-
na
-
na
-
nd
-
0.06
0.00
100
EP-2-07
EP-2ts-11
Qvdc
Qvdc
melt inclusion
melt inclusion
81.30
77.80
0.08
nd
13.01
11.43
0.95
1.38
nd
0.09
0.07
0.05
0.34
0.22
0.30
3.60
3.92
4.80
na
nd
na
0.30
na
nd
na
0.26
na
na
na
na
100
100
EP-29-12
Qvdc
melt inclusion
80.57
nd
12.47
1.37
0.10
nd
0.25
1.46
3.76
na
na
na
na
na
na
100
EP-2ts
Qvdc
matrix glass average (n=12)
matrix glass standard deviation
80.59
1.53
0.12
0.05
12.53
0.27
1.17
0.21
0.08
0.03
0.06
0.02
0.32
0.04
1.11
0.41
3.77
1.27
0.04
-
0.22
0.06
nd
-
0.15
0.06
na
-
na
-
100
EP-34ts-15*
Qvdc
melt inclusion
77.82
nd
12.03
0.44
nd
nd
nd
3.71
5.90
nd
nd
nd
nd
na
na
100
EP-34ts*
Qvdc
matrix glass average (n=5)
matrix glass standard deviation
78.26
0.69
0.10
0.02
12.19
0.29
0.34
0.08
nd
-
nd
-
0.12
0.02
5.12
0.39
3.76
0.73
0.06
-
0.19
0.03
nd
-
nd
-
na
-
na
-
100
EP-35-07
Qvdc
melt inclusion
80.59
0.07
12.91
0.78
0.08
0.11
0.39
1.23
3.85
na
na
na
na
na
na
100
EP-7-27
Qvrc
melt inclusion
77.12
0.13
13.85
1.51
0.08
nd
0.26
1.83
5.21
na
na
na
na
na
na
100
EP-10-noHF-19
EP-10-noHF-04
EP-10-HF-18
EP-10-noHF-02
EP-10-noHF-13
Qvrc
Qvrc
Qvrc
Qvrc
Qvrc
melt inclusion
melt inclusion
melt inclusion
melt inclusion
melt inclusion
80.24
76.96
77.29
76.88
80.19
0.19
na
na
na
na
13.52
13.89
13.62
13.59
11.61
1.09
1.16
0.94
1.00
1.06
nd
na
na
na
na
0.08
na
na
na
na
0.39
0.36
0.43
0.46
0.34
0.79
1.78
1.70
2.72
1.22
3.67
5.77
5.97
5.27
5.50
na
na
na
na
na
na
na
na
na
na
na
na
na
na
na
na
na
na
na
na
na
0.06
nd
0.07
nd
na
nd
nd
nd
0.05
100
100
100
100
100
EP-9ts
Qvrc
matrix glass average (n=6)
matrix glass standard deviation
77.16
0.98
0.15
0.02
12.79
0.11
0.92
0.06
0.05
0.00
0.07
0.01
0.42
0.05
2.72
0.95
5.65
0.21
0.05
-
nd/na
-
0.05
-
0.07
0.01
0.05
-
0.05
-
100
EP-40o
Qvvf
obsidian average (n=9)
obsidian standard deviation
76.81
0.09
0.08
0.02
12.41
0.09
0.93
0.07
0.06
0.02
0.06
0.00
0.35
0.03
4.25
0.07
4.84
0.09
nd
-
0.13
0.03
0.05
0.01
0.13
0.01
na
-
na
-
100
All analyses normalized to 100%. Multiple matrix glass analyses within a sample were averaged; standard deviation is also shown.
Qbt = upper Bandelier Tuff
Qvdc = Deer Canyon Member
Qvrc = Redondo Creek Member
Qvvf = Cerro del Medio
na = not analyzed
* denotes devitrified glass
nd = below detection limit
BaO Compositions in Feldspars
2.00
BaO (wt. %)
1.60
Upper Bandelier Tuff
1.20
Deer Canyon member
Redondo Creek member
0.80
Cerro del Medio
0.40
0.00
0
1
2
3
4
5
BaO composition in feldspars from the Upper Bandelier Tuff, Deer Canyon member,
Redondo Creek member, and Cerro del Medio.
Glass Compositions
Qbt melt inclus ions
1.60
Qbt matrixglas s
1.40
Qbt (intracaldera) melt
inclus ion
Qvdc melt inclus ions
FeO
1.20
Qvdc matrixglas s
1.00
Qvrc melt inclus ions
Qvrc matrixglas s
0.80
Qvvf obs idian
0.60
0.20
0.25
0.30
0.35
0.40
0.45
0.50
CaO
CaO vs. FeO plot of glass analyses (melt inclusions and matrix glass) for the Upper
Bandelier Tuff (Qbt), Deer Canyon member (Qvdc), Redondo Creek member (Qvrc), and
obsidian from Cerro del Medio (Qvvf). Multiple matrix glass analyses within samples
were averaged.