1. Geology of Lake Tahoe
By Jennifer Kline
Satellite Pictures, NASA
Lake Tahoe Community College 2012 Research
Presentation,Geology 103

2. Table of Content
○ Observations
○ Lake Tahoe Basin Formation
○ Lake Tahoe Faults
○ Rocks found in Lake Tahoe Basin
○ Fauna of the Lake Tahoe Basin
○ Crawfish Fossil Records
○ Lake Tahoe's Ecosystem
○ Flora of the Lake Tahoe Basin
○ References

3. Observation
July 2012 I hiked to Granite Lake in
Desolation Wilderness on the South end
of the Lake Tahoe Basin.
I observed many types of birds including,
Bald Eagle, Woodpeckers,Styler Jays,
Robins, and a Humming Bird.
I also saw a freshwater crawfish and a
marmot.

4. Lake Tahoe Basin Formation
Sierra Nevadas
○ Basin was under a shallow sea on
Pangea
○ North American Continental
Plate broke off from Pangea (210
mya)
○ Pacific Ocean Plate drifted east
○ Pacific Plate was pushed under
North America Plate.
○ during the next 130 million years
plate tectonic pressure and
magma chamber caused uplift
creating the Sierra Nevada
Mountain Range

5. Lake Tahoe Basin Formation
(continued)
○ uplifting formed parallel faults
○ Sierra Crest rose in the west
○ Carson Range dropped in the east
○ lava flow dammed the Carson
Valley and the Basin was formed
○ glaciers carved and polished rock
○ snow run off eventually filled Lake
Tahoe
(Investigating The Sierra Nevada
Mountains and Lake Tahoe, (NASA)

6. Lake Tahoe Major Faults
Northern portion of
Tahoe is tectonically
active with three major
faults:
● Incline Fault
● Stateline Fault
● West Tahoe Fault
Picture (Sacramento Bee, 2006)

7. Rocks found in Lake Tahoe Basin
Igneous intrusive rocks (typically
granodiorite) and igneous extrusive
rocks (typically andesitic lahar). Small
amounts of metamorphic rock occur
in the Spooner Summit and
Desolation Wilderness areas (NRCS
2007).

8. Rocks found in Lake Tahoe Basin
Granite formed from increased pressure
and temperature from the colliding plates
caused rock to melt then the cooling
process allowed crystals to form and create
the granitic rock seen in the Sierra Nevada.
Granite forms in plutonic environments and
contains potassium feldspar, plagioclase
feldspar, quartz, biotite and/or amphibole
Granite
Igneous rock with coarse grain
classification acid

9. Rocks found in Lake Tahoe Basin
Metamorphic rock forms when heat, pressure
and/or chemical activity transform rock such
as sedimentary or igneous rock.Metamorphic
rock is much harder than the original
sedimentary rock and can still be seen today
in many areas as caps on top of the Sierra
granitic rock.
Metamorphic Rock
Metamorphic rock is an igneous rock
containing minerals such as olivines,
pyroxenes, amphiboles, micas,feldspars
and quartz.

10. Fauna of Lake Tahoe Basin
Crayfish,(also called crawfish or
crawdads)were introduced into the
Lake Tahoe Basin's ecosystem in
the 1960s
○ members of Astacidae and Parastacidae
families
○ freshwater crustaceans
○ evolved from Decapoda order
○ lives in freshwater shallows in Lake
Tahoe, surrounding rivers and streams
○ feeds on aquatic plants and animal life

11. Crawfish Fossil Records
○ Crawfish evolve from the Decapoda order
○ oldest fossil record are the Albian fossils found
in Victoria, Australia
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Infraorder:Astacidea
Superfamily: Parastacoidea
Family: Parastacidae
(Rodney A. Feldmann, Carrie E. Schweitzer & John Leahy 2011)

12. Lake Tahoe Basin Ecosystems
Elements of Tahoe's Ecosystem
○ soil ○ trees
○ incects ○ water
○ wildlife ○ people
○ plants
All elements must find a way to coexist in the same
environment to keep Lake Tahoe's Ecosystem health.

13. Flora of Lake Tahoe Basin
Lupinus perennis grows all over the basin and flowers in the
spring blooms lasting into the summer. There are about 280
species of this genus.
Kingdom: Plantae Order: Fabales
Family: Fabales Subfamily: Faboidese
Tribe: Genisteae Genus: Lupinus

14. Reference
WEBSITE:
Lake Tahoe, From Wikipedia, the free encyclopedia, last update 2012
http://en.wikipedia.org/wiki/Lake_Tahoe#Geology
NASA Investigating The Sierra Nevada Mountains and Lake Tahoe, 2012
https://earthkam.ucsd.edu/ek-images/investigating_images/lake_tahoe
U.S.Geological Survey, Lake Tahoe, 2004
http://tahoe.usgs.gov/pictures.html
The Sacramento Bee, Lake Tahoe Fault Could Deliver Massive
Earthquake, 2006
http://www.standeyo.com/NEWS/06_Earth_Changes/061226.Lake.Tahoe.Fault.html
United States Department of Agriculture, Forest Service, Lake Tahoe
Basin Management Unit, 2012
United States Department of Agriculture, Natural Resources Conservation
Services, 2007
Rodney A. Feldmann, Carrie E. Schweitzer & John Leahy (2011). "New
Eocene crayfish from the McAbee Beds in British Columbia: First record of
Parastacoidea in the Northern Hemisphere