Tiger Creek Field AssignmentMatt SavoieProfessor LawlerGel 103, Spring 2013June 20, 2013

Content● Background & Method● Brief Geological History● River Geology● Rock Examples● Plant Examples● Geological Features

Background & Method● In late June, i visited an area of Tiger Creek

near the reservoir. ● The photos and rock samples included in

this report are from this field trip● 3D map images were prepared using Google

Earth● Identification of rocks done using: Geology

of the Sierra Nevada, by Mary Hill (2006)● Identification of plants done using: The Laws

Field Guide To The Sierra Nevada, by John Muir Laws (2007)

Site Location● Near Pioneer,

California● Take Tiger Creek Rd

from Hwy 88, Eventually turning right onto Salt Springs Rd.

● Coordinates 38.447973, -120.493616

Tiger Creek Terrain

View of terrain, elevation, and shrubbery that has been carved from the river flow. (Google Earth)

Quick Geological History & Overview● Sierra Nevada Range is a 400 mile long tilted

fault block.● 250 million years ago the pacific plate began to

fall below the north american plate causing subduction.

● Plutonic rock began to rise from the collison causing the mountain to begin to rise 80 million years ago.

(Resendes, M. A.)

Geology of Tiger Creek● Deep granite canyon, expert-only river rapids below

Highway 26

● Large boulders in the river; massive granite domes near

Salt Springs Powerhouse

● Steep, granitic river gorge downstream; the Devil’s

Nose

● Healthy trout fishery

● Important mid-elevation wildlife and bird habitat

(Tiger Creek to Elektra)

Rock Sample: ShaleI I believe this to be the

sedimentary rock shale. Formed by particles of clay and mud compressed by the pressure and weight of what is above.

(Peck, D)(Hill 2006)

Rock Sample: GraniteI believe this to be a sample of the Igneous rock Granite. Formed when a magma rapidly cools and crystallizes deep underground. The course crystals are pressed together and form this rock.

(Peck,D)(Hill 2006)

Plant Sample: Himalayan Blackberry

● I believe this to be a Himalayan Blackberry bush (Rubus Armeniacus)

● This bush is of the family Rosacea, under the order Rosales.

● Descended from early angiosperms.

● introduced for cultivation, but then spread due to birds and other animals

(Laws 2007)(Rubus Armeniacus)

Plant Sample: White Fir● I believe this to be a White Fir

(Abies Concolor)● This tree is from the family

Pinaceae, under the order Pinales● It is a cone bearing tree most likely

evolving from early non-flowering vascular plants.

● It is native to the Great Basin Mountains, and generally lives at altitudes of 1700-3400 m

(laws 2007)(Abies Concolor)

Plant Sample: White Alder● I believe this to be White Alder (Alnus Rhombifolia)● This tree is from the family Betulaceae, under theorder Fagales.● This has evolved from early vascular, flower-bearingplants.● This tree is native to the southern sierra

nevadas, 100-2,400 m(laws 2007)(Alnus Rhombifolia)

Additional Photos

References● 38.447973,-120.493616. (n.d.). In Google Maps. Retrieved June 23, 2013,

from https://maps.google.com/maps?hl=en&tab=wl● Abies Concolor. (n.d.). In Ask.com. Retrieved June 23, 2013, from http:

//www.ask.com/wiki/Abies_concolor?o=2801&qsrc=999● Alnus Rhombifolia. (n.d.). In Ask.com. Retrieved June 23, 2013, from http:

//www.ask.com/wiki/Alnus_rhombifolia?o=2801&qsrc=999● Laws, J. M. (2007). The Laws Field Guide To The Sierra Nevada

(Illustrated ed.). N.p.: Heyday.● Peck, D. (n.d.). The Rock Identification Key. In Rock Hounds. Retrieved

June 23, 2013, from http://www.rockhounds.com/rockshop/rockkey/● Resendes, M. A. (n.d.). Geology of the Sierra Nevada. In Sierra Historical.

Retrieved June 23, 2013, from http://www.sierrahistorical.org/geology-sierra-nevadas

● Rubus Armeniacus. (n.d.). In Ask.com. Retrieved June 23, 2013, from http://www.ask.com/wiki/Rubus_armeniacus?o=2801&qsrc=999

● Tiger Creek to Elektra. (n.d.). In Foothill Conservancy. Retrieved June 23, 2013, from http://www.foothillconservancy.org/pages/ws_tiger.cgi

The End