field lab assignment geology 103 professor Lawler

1. South Lake
Tahoe, CA
Lab Field Project
Geology 103
By Andrea Mateo
June 24, 2018

2. History of Lake Tahoe
• Introduction
• Land formations
• Fauna
• Rocks
• Steno’s Law

3. South
Lake Tahoe
• The basin of Lake Tahoe
is an excellent area to
find evidence of many
different types of
geology events. During
this field project I was
able to identify
magmatic intrusion,
volcanism, glacial
sourcing, fauna, uplifting
and extension of plate
tectonics.
Photos credits in this presentation are mine, unless noted

4. How was the lake
formed?
• This beautiful lake was created about
twenty-four million years ago. By the
rise and fall of landscapes due to
faulting.
• Following the faulting and volcanic
period was an ice age where huge
glaciers formed.
• As the glaciers melted away clear
lakes were formed, brilliant bays and
jagged peaks.

5. Fun Facts about the
Lake
• Third deepest lake in North America
• Twenty-two miles in length
• Twelve miles wide
• Greatest depth measured 1,654 feet
• The lake has thirty-seven trillion
gallons of water
• Sixty-three streams flow into Lake
Tahoe and only one flows out the
Truckee River
http://tolhurstj.faculty.go
columbia.edu/ESGIS/Earth_Science/ESC_35_Field_Geology/Lake_Tahoe/Lake_Tahoe_
Home2.htm

7. Lovers Peak
• Lovers peak is located in the Sierra
Nevada Mountain. This part of the
mountain experienced major erosion
about twelve thousand years ago.
There was a huge glacier that split
this peak in half causing permeant
reshaping of the landscape. This
happened because this area was
fully glaciated during the glacial
cycles and then deglaciated during
the interglacial times (Ulmer, 2012).
• https://phys.org/news/2012-02-mountain-ranges.html#jCp

9. Fauna of
Lake
Tahoe

11. Bald Eagles
• Birds are ancestor of dinosaurs.
• Living birds are also known as avian dinosaurs.
• There is evidence that birds evolved from a small group
called theropods
• Birds share an evolutionary foundation with reptiles
• During the Mesozoic era, the first birds began to appear
• Thirty-six million years ago, the first sea eagles descended
http://www.pbs.org/wnet/nature/american-eagle-bald-eagles-evolutionary-ancestors/4274/
http://www.summitside.com/p742432617/h12627BEA#h12627bea

12. Lupines
Lupines are a native flowering plant in
this area. There different types of
lupine species. The most common in
Lake Tahoe are silvery lupine and
broadleaf lupine. The ones in the
picture are broadleaf lupines.
The evolution of flowering plants goes
all the way back to the Late Paleozoic.
Frist there was Gymnosperms a large
seeded ferns that became extinct in
the Early Cretaceous. Angiosperm
started to appear during this time. This
flowering plant was able to adapt in
almost all terrestrial habits from
mountains, deserts, to sea level
(Wicander. Pg.593).

13. Jeffery Pine
• “Early pine evolution was concentrated
between 31° and 50° in the Northern
Hemisphere on the Laurasian super-
continent. During this period, pines
radiated widely, and by the end of the
Cretaceous, they were distributed in the
west from what is presently North America
“(Keeley, 2012, pg. 445).
• This is the most common type of tree in
South Lake Tahoe.
• These trees live for about 400 to 500 years
in high elevations
• Grow over 170 feet tall
• Native to California but ranges through
Oregon and Nevada
• Adaptive to stressful environments
Droughts
Fire
Climate changes
https://link.springer.com/article/10.1007/s13595-012-0201-8#Sec9

16. This picture is
an example of
Steno’s law
superposition
where the
older rocks
are on the
bottom and
the younger
rocks on top