CGpaleozoic
PALEOZOIC OF CALIFORNIA
I. Overwhelmingly Marine deposition
Seas encroached from the West extended into Great Basin
e.g. Cambrian--oldest and thickest
II. Areas for Exposures
1. Great Basin-Mojave Desert
2. Sierra Nevada- (N.W Belt)
3. Klamath Mountains
III. All connected at one time
IV. Paleozoic-Paleogeography
1. Shallow Marine environment-Early Paleozoic
Extended inland to areas now occupied by Rocky Mts. Western Cordillera
2. Geosynclinal Environment
a.
Shallow-Miogeosyncline
Deep water-Eugeosyncline
b. Existed about 400 million years (Entire Paleozoic)
3. Over most of continent (Not in Death Valley), an unconformity exists between the earliest
Cambrian and P-C Rocks
4. Seas were warm and shallow (Fossil Evidence)
e.g. Tabulate corals and Rugosa (Tetracorals)
*Uniformitarianism: The present is the key to the past (Processes occurring on the Earth Today did so in
the past)
5. Sediments were dominantly Carbonates
Limestone=CaCO3
Dolomite=CaMg(CO3)2
6. Oldest Paleozoic rocks (Cambrian) in North America
a. Waucoba District in Inyo Mts and Southern Death Valley
(1) Boundary between P-C and Cambrian in middle of Wood Canyon
(2) Basin Subsidence (8000' thick)
b. Early Cambrian-shoreline North and South through California-Nevada-Arizona
Junction
c. Mid-Cambrian-shoreline near eastern Border of Arizona
e.g. Wood Canyon (Death Valley)
d. Late Cambrian-further to east to central New Mexico (as far east as Southern
Wisconsin)
7. Geosyncline was deepest in Basin and Range in Inyo-Panamint-Death Valley area
CGpaleozoic
8. Ordovician
a. Same areas
b. dolomite and light gray Mid-Ordovican Eureka Quartzite--widespread easily
recognized; found in California and Western Nevada
c. Best exposures found in isolated remnants in Sierra Nevada and Klamaths mts.
9. Silurian and Devonian
e.g. limestones and dolomites
10. Mississippean (Mitchell Caverns in Providence mountains)
e.g. limestones
11. Late Miss.--Pennsylvanian seas become shallower and more muddy (shales)
-uplift of land to east --mountain building=Orogenic activity
12. Penn.--Permian
coarser sediments along with increasing Volcanism and unconformities
a. indicated orogenic activity in Basin-Range, Sierra Nevada and Klamaths Areas
b. Granites in Area dated as Permian
13. Coast ranges and Peninsula Range areas--Paleozoic sediments were eugeosynclinal but little
history preserved
CGpaleozoic
14. Eastern Mojave Desert
a. Only find Cambrian and late Paleozoic sediments and strata
Ordovician and Silurian rocks are absent
15. South Western Mojave
a. no lower Paleozoic and Devonian
b. Mississippean and Permian represented
16. Gaps
a. Land above sea level
b. uplift and erosion (remove sediments)
17. Coast, Transverse and Peninsular Ranges
a. Scant fossil remains
b. Quartzites, schists, marbles
c. Furnace limestone
marble---San Bernardino mountains about 4500ft thick
brachiopods, horn corals, and Foraminifera (Miss-Penn in age)
d. Sur Series-marbles, schist, quartzsites in coast ranges late Paleozoic sediments
(Metamorphosed in Mesozoic)
e. Remnants of Paleozoic materials around Point Reyes west side of San Andreas fault
f. San Gabriel mountains
Granite about 245 million years old
18. Sierra Nevada (N.W. Belt)
a. mostly granite batholiths (Mesozoic in age)
b. left over Paleozoic rocks called remnants--isolated rocks are called Roof Pendants
e.g. Schists, limestones, quartizites, slate
c. Mount Morrison Area thickest and best known section
-about 32,000 ft
(1) Lower portion-Ordovician rocks
(2) upper portion fossiliferous--Penn and Permian strata
d. Calaveras Formation
Western foothills of Sierra Nevada
East of Mother Lode Fault zone
(1) all metamorphosed but they were, shales, dark sandstones, chert,
minor limestone and submarine volcanic rock
(2) Northern end--metamorphosed strata
Silurian-Permian in age (fossil beds)
(3) Angular unconformities found between
a. Silurian and Devonian
b. Permian and Triassic
**uplift and erosion--orogenic activity
CGpaleozoic
19. Klamath Mountains
a. abundant Paleozoic strata
b. Three Arc--shaped zones
Eastern Klamaths
25,000 ft. of Marine Sedimentary rock (Ordovician--Permian) Rocks are
metamorphosed but were originally graywacke, cherts, conglomerates,
rhyolites and basalts
c. Two periods of orogenic activity (unconformities)
(1) first in Devonian
(2) Lake Penn.throughTriassic implies emergence of land and mountain building