Version 10/03/2007
MOUNTAIN OCCUPATION PROJECT
MIRES OF THE AUSTRALIAN CAPITAL TERRITORY
Figure 1. Nursery Swamp: The Carex gaudichaudiana fen is often frozen in winter. Core collection by
Ben Keaney and Matiu Prebble May 2002.
Stratigraphy
Two main cores from the same site have been analysed, but dating samples also came
from an 1982 core.
Core 02/1 (prob same location as 82/2)
Depth cm
Material
0-4
Loose rootlet mat of Carex fen
4-36
Firm black fibrous mat with Carex roots and some clay-silt
36-94
Yellow brown fibrous sedge peat
94-185
Black clayer fibrous peat, possible Phragmites stems @ 95-110.
185-230
Black peaty clay
230-274
Dark grey compact fibrous peat with slight clay
274-280
Black sandy peaty clay
280-314
Grey clayey fine sand
314-317
Grey clayey fine sand
317-319
Grey clayey coarse sand with sedge stems
319-345
Dark grey clayey fine sand with sedge remains
345-365
Pale grey sandy clay with sedge roots
365-395
Green-grey medium sandy clay with very occ vertical sedge stems
10 March 2007 Coring and probing.
1.05km from head of swamp. Core 2007/1: GPS: 148° 57.966’E 35° 40.5997’S
Composite Core 2007/1 (28m from western edge- hole not completed below 250cm)
I have integrated the sed description for the two spots we sampled in 2007. I used the
description 0-150cm from core 1 and 150-450 from the second spot, which had deeper
inorganic sediments.
Core 2007/2 (15m from western edge) GPS: 148° 57.9593’E 35° 40.611’S
Depth cm
Material -Description
Colour
0-20cm
Sedge mat, fibrous peat
Brown
20-52cm
Black stiff clayey peat with fine rootlets
Black
52-61
Organic sands, gritty feel
Rusty brown grading to black
61-93
Fibrous sedge peat
Dark brown
93-97
Gritty, maybe charcoal/silt, mealy peat with roots
Black
97-110
Clayey peat, large amounts of clay
Dark brown
110-150
Darker brown peat, more clay
Dark brown
150-154
Fibrous peaty clay
Brown
154-157
Pale yellow clay
Yellow
157-161
Peaty clay
Dark brown
161-163
Medium brown peaty clay
Brown
163-189
Coarsening down from peaty clay
189-192
Sandy layer, fine sand, made of angular gravel
from 1mm-3mm
Black/grey
192-200
Slightly sandy clay with some root material
Black
185-215
Clay
Grey/Black
215-223
Coarse grey sand
223-250
Fibrous peat
250-275
Large sand grains, fibrous peat
275-277
Organic layer, more textured, mealy peat (sand
sized organic particles, more like inwashed
organics from a soil)
277-301
Clayey fibrous peat (at 289 and 293 there are
yellow clay bands)
Dark brown (with yellow bands)
301-305
Peaty clay
Black
305-340
Dark grey silty clay (black band at 330)
Dark grey
340-350
Sandy silty clay
Grey
343-400
Fine sandy clay
Very dark grey (Black)
400-420
Fine sandy clay, abundant mica
Grey/Black
420-450
Very sandy
Pale grey
SAMPLES
150-350 duplicate D Section, 225-325, 325-425,
420-450(Base) Livingstone.
Dark brown
Dating
Core
Depth cm
Date
Lab No
Cal Age BP
Cal
median
Material
82/1
25-30
100.5M ± 2.1%
ANU 3354A
M
82/1
25-30
240 ± 110
ANU 3354B
260-450
355
Fines <0.25mm
82/1
145-150
5610 ± 240
ANU 3355
6161- 6702
6430
Fines <0.25mm from organic clays
82/2
55-60
107.4 ± 2.4%M
ANU 3356A
M
Coarse sedge remains
82/2
55-60
99.1.4 ± 1.9%M
ANU 3356B
M
Fines <0.25mm
02/1
170-176
2910 ± 80
ANU 11640
2946- 3183
3065
Coarse peaty debris in clay
82/2
295-300
8200 ± 250
ANU 3357A
8908- 9464
9185
Coarse peaty debris in clay
82/2
295-300
8140 ± 340
ANU 3357B
8646- 9443
9045
Fines <0.25mm from fibrous peat
02/1
345
12300 ± 120
OZI 144
14009-14500
14255
Organic ABA insol in grey sandy cl
Coarse sedge remains
I have used the calibrated ages based on the dates given in red above together with the
advent of pine pollen at 15 cm= 50BP to create an age model for the diagrams. Note
that only two dates come from the pollen analysed core and none from our 2007 core.
To estimate the age of the 2007 core I presumed that the age at 345cm in core 02/1
applies to the deepest organic rich sandy clay in core 07/2 at ca 400cm. The transition
from sandy clay to significantly more organic –rich material occurs around 300cm in
all three cores, hence the date ANU 3357A is assumed to be valid for all. Note that
that level was dated on fines and on sedge debris, yielding identical ages, which
suggests that intrusion by younger sedge has been minimal.
A pollen diagram (Figure 4). at 20cm interval has been prepared from the 02/1
core (by John Rogers in 2003 using standard HF and acetolysis methods, with pollen
identification based on MacPhail. and Hope (2003). Macro-charcoal occurs at several
levels and carbonised particles are abundant throughout the deposit, with a noteable
peak at 25cm depth, again reflecting burning of the bog by leaseholders or recent
bushfires.
I have presented Johns and your results in several diagrams. Feel free to use
some in your reports. One is the analyses made on the 2007 cores. Then there are
three using pollen and extrapolated physical data. NURSALL1 has a complete set of
data. NURS-VEG has a summary diagram and data from plants that either do not
grow in the swamp itself or which (like some herbs and grass) often do not. NURSSWAMP repeats the data for Swamp margin herbs and ferns and the aquatics and
mosses.
The diagram has been zoned into five zones on the basis of a classification based on
the wetland and local plants. Note that the basal zone has very low pollen counts and
is not very reliable.
I have put the pollen data up as EMF files which you can paste into the report.
However TILIAGRAPH tgx files print much more clearly and you may wish to have
some special features added. Feel free to come over and we can prepare and print
these.
You have the class data as well.
Macphail, M. K. and Hope, G. S. 1985. Late Holocene mire development in montane southeastern
Australia: a sensitive climatic indicator, Search 15, 344-349.
Macphail, M.K. and Hope, G.S. 2003. Pollen flora for subalpine south eastern Australia. Department
ANH, Canberra.
Rogers, J. 2003. A pollen study at Nursery Swamp, ACT. Unpublished report.
Rosenfeld and Winston-Gregson 1983. Excavations at Nursery Swamp 2, Gudgenby Nature Reserve,
Australian Capital Territory. Australian Archaeology 17, 48-58