T H E G E O L O G Y O F T H E L A K E TA H O E B A S I N

F I E L D A S S I G N M E N T P R O J E C T B Y J O H N Q U I N N

G E O L O G Y 1 0 3

Satellite photo courtesy of NASA

O B S E R VAT I O N S

• In June of 2014 I made two observation trips in the South Lake Tahoe area.

• One observation trip was made along the southern edge of Lake Tahoe on the Rubicon Trail between D.L. Bliss State Park and Emerald Bay.

• One observation trip was made from the Eagle Falls trailhead to Eagle Lake in Desolation Wilderness.

• I was able to observe numerous rocks and rock formations, several plants, bushes, trees, and few birds and animals.

• All observations and findings were made by me.

• All photos take were by Hailey Quinn unless otherwise noted.

R U B I C O N T R A I L

A R E A O F O B S E R VA T I O N

F O R M AT I O N O F T H E TA H O E B A S I N

1. Plate Movement

2. Volcanic Activity

3. Glaciation

4. Glacier Melt

H O W W A S L A K E TA H O E F O R M E D ?

“ A B O U T 2 4 M I L L I O N Y E A R S A G O T H E S I E R R A N E VA D A B L O C K

WA S F O R M E D B Y T R E M E N D O U S U P L I F T I N G .   T W O P R I N C I PA L

FA U LT S E V O LV E D : T H E E A S T E R N M A R G I N C R E AT E D T H E C A R S O N

R A N G E , W H I L E T H E S I E R R A N E VA D A D E V E L O P E D O N T H E

W E S T E R N S I D E .   F R O M T H E " U P T H R O W N " FA U LT B L O C K S , T H E

H I G H E S T P E A K S I N T H E R E G I O N O R I G I N AT E D W H I L E T H E ‘ D O W N

T H R O W N ’ B L O C K S A N K C R E AT I N G A L A R G E VA L L E Y. ”

- ( U S D A N . D . ) !

U S G S . M AY 2 1 , 2 0 1 4

H O W W A S L A K E TA H O E F O R M E D ?

“ L AVA F L O W I N G F R O M M T. P L U T O O N T H E N O R T H S H O R E , T H E N F O R M E D A B A R R I E R O R

D A M A C R O S S T H E B A S I N ' S A N C E S T R A L O U T L E T, T H E

T R U C K E E R I V E R .   WAT E R F R O M S N O W FA L L A N D S T R E A M S

F L O W I N T O T H E B A S I N , G R A D U A L LY C R E AT I N G A L A K E

S E V E R A L H U N D R E D F E E T H I G H E R T H A N T H E P R E S E N T L A K E .   E V E N T U A L LY A N E W

O U T L E T WA S E R O D E D F R O M T H E L AVA D A M C R E AT I N G T H E P R E S E N T PAT H O F T H E L O W E R

T R U C K E E R I V E R . ” - ( U S D A N . D . )

Seasonal stream running into

the Lake Tahoe Basin

H O W W A S L A K E TA H O E F O R M E D ?

“ F O L L O W I N G T H E FA U LT I N G A N D V O L C A N I C P E R I O D O F T H E B A S I N ,

A N I C E A G E D E V E L O P E D .   H U G E G L A C I E R S F O R M E D A N D M O V E D

D O W N T H E V- S H A P E D C A N Y O N S O N T H E W E S T E R N S I D E O F T H E L A K E .   T H E S E G L A C I E R S S C O U R E D AWAY L O O S E R O C K A N D R E S H A P E D T H E C A N Y O N S I N T O B R O A D U - S H A P E D VA L L E Y S .   T H E R O C K A N D G R AV E L

L E F T B E H I N D AT T H E S I D E S A N D E N D O F T H E S E M E LT I N G G L A C I E R S A R E C A L L E D M O R A I N E S .   A S T H E S E

G L A C I E R S M E LT E D AWAY, T H E Y A L S O L E F T B E H I N D B R I L L I A N T

B AY S , J A G G E D P E A K S , G L A C I A L P O L I S H E D R I D G E S A N D C R Y S TA L

C L E A R L A K E S . ” - ( U S D A N . D . )

E V I D E N C E O F G L A C I AT I O N

I N T H E A R E A .

L A R G E G R A N I T E S L A B P O L I S H E D F L A T B Y G L A C I A T I O N

L A R G E G R A N I T E S L A B S S M O O T H E D B Y G L A C I A L M O V E M E N T

S E D I M E N TA R Y R O C K

• Breccia

• Piled up pieces of broken rock held together by quartz and compressed together.

S E D I M E N TA R Y R O C K

• Sandstone

• Eroded rock particles into sand.

• The sand is accumulated and compressed.

I G N E O U S R O C K

• Granite

• Forms deep in the earths crust from cooling magma.

S U G A R P I N E T R E E

• P I N U S L A M B E R T I A N A !

• M E M B E R O F T H E W H I T E P I N E G R O U P !

• K N O W N F O R I T S L O N G D O W N WA R D G R O W I N G C O N E S

L A R G E M A N Z A N I TA F I E L D

• Manzanita (species)

• Arctostahpylos (genus)

• “There are 106 species of manzanita, 95 of which are found in the Mediterranean climate and colder mountainous regions of California, ranging from ground-hugging coastal and mountain species to small trees up to 20 feet (6m) tall. Manzanitas bloom in the winter to early spring and carry berries in spring and summer.[1] The berries and flowers of most species are edible.” (wiki, june. 8. 2014)

R E F E R E N C E S

• Tahoe Adventure Sports (2000). D.L. Bliss Rubicon Trail. Retrieved from http://www.tahoeadventuresports.com/hikeindex/west/rubiconmapandprofile.htm

• USDA (no date). Geology of the Lake Tahoe Basin. Retrieved from http://www.fs.usda.gov/detail/ltbmu/learning/?cid=stelprdb5109570

• USGS (May 22, 2014). Lake Tahoe Faults, Shaded Relief Map. Retrieved from http://gallery.usgs.gov/photos/05_21_2012_dhx3Bnm00U_05_21_2012_1#.U6TL2BboYb2

• en.wikipedia (May 3, 2014). Pinus Lambertiana Retrieved from http://en.wikipedia.org/wiki/Pinus_lambertiana

• en.wikipedia (June 8, 2014). Manzanita Retrieved from http://en.wikipedia.org/wiki/Manzanita