This document summarizes Alyssa Lopez's geology field assignment on the Upper Truckee River and Trout Creek watersheds. The landforms in the area were shaped by tectonic and glacial processes, forming basin-filled deposits and steep mountain slopes. Early settlers beginning in the 1870s logged the area, altering stream flows, causing erosion, and modifying habitats. The document also describes the angiosperm and plant species found in the watersheds such as lupine, potentilla, ponderosa pine, and the igneous rock types granite and andesite.

1. Geology 103
Field Assignment
Alyssa Lopez

2. Upper Truckee River and Trout Creek
Watersheds
● The landform was shaped
primarily by tectonic and glacial
processes.
● Present-day landforms were the
result of:
– Basin-and-range, fault-
bounded blocks
– Glacial erosional/
depositional action
(USGS, 2000)

3. Glaciation
● Deep, basin filled deposits
● Steep mountain slopes
● Large, lateral moraines that divide the Trout Creek
watershed from the Upper Truckee River watershed
● Basin filled deposits of Trout Creek include stream and
glacial deposits (USGS, 2000)

4. Deterioration
● 1870- Early settlers began logging resulting in:
– Stream flow alteration
– Erosion
– Loss of native flora and fisheries
– Modified habitats
● For the past 8,000 years, little is known about
Native American impact on the environment
(Elliott-Fisk, n.d.)

5. Lupine
● Angiosperm
● From the Fabaceae family/ Plantae
kingdom
● Highly common in South and Western
North America
● Genus consists of 280 species
● Great companion plant:
– crops that need significant
amounts of nitrogen
● Located in North America, New
Zealand, parts of Australia, secondary
centers of Mediterranean region, and
Africa (Lupinus, 2013)

6. Potentilla
● Angiosperm
● Also known as Cinquefoil
● Plantae kingdom/ Rosaceae
Family
● Usually yellow, but can be pink or
white
● Grow in cool or cold regions
● Most creeping or erect shrubs,
others can be weeds or garden
plants
● Usually found throughout
Northern continents of the world
(Potentilla, 2013)

7. Angiosperms
● Flowering plants
● During the Early Cretaceous, the dominance of seedless plants and
gymnosperms ended.
● Early Cretaceous, possibly Late Jurassic, angiosperms replaced dominant
plants
● Closely related to gymnosperms, but precise ancestry of angiosperms is
still unclear
● Since evolution, angiosperms have adapted to nearly every terrestrial
habitats including shallow, coastal waters (Monroe, 2009, p.593)
● Continued to diversify throughout the Cenozoic Era along with seedless
vascular plants and gymnosperms (Monroe, 2009, P.632)

8. Ponderosa Pine
● Pinaceae- Pine family
● Found in mountainous areas
● Largely distributed through
North America
● Pollinates and is flowering
● Seeds largely consumed by
smaller animals
– Birds, quirrels,
chipmumnks, etc
(Oliver, n.d.)

9. Igneous Granite
● Light colored with large grains
● Slow crystallization of magma
underneath Earth's crust
● Mineral composition gives light
color
● Uplifted, overlying sedimentary
rocks were possibly eroded
● Composed mainly of quartz and
feldspar with minor amounts of
mica, amphiboles and other
minerals (King, 2013)

10. Igneous Andesite
● Fine Grained
● Extrusive
● Composed mainly of:
– Plagioclase
– Hornblende
– Pyroxene
– Biotite (Geology.com,
2013)

11. References
Elliott-Fisk, D.L. (n.d.) Lake Tahoe Case Study. Retrieved from
http://nature.berkeley.edu/stephens-lab/Publications/Elliot%20Fisk%20et
%20al%20Tahoe%20SNEP%20Tahoe%2096.pdf
Geology.com. (2013). Andesite. Retrieved from
http://geology.com/rocks/andesite.shtml
King, H. (2013). Granite. Retrieved from
http://geology.com/rocks/granite.shtml

12. Lupinus. (2013, May 31). en.Wikipedia.org. Retrieved from
http://en.wikipedia.org/wiki/Lupin
Monroe, J., & Wicander, R. (2009). The Changing Earth: Exploring Geology
and Evolution. Belmont: CA: Brooks/ Cole, Cengage Learning.
Oliver, W.W., & Ryker, R.A. (n.d.). Ponderosa Pine. Retrieved from
http://www.na.fs.fed.us/SPFO/PUBS/SILVICS_MANUAL/Volume_1/pinus/
ponderosa.htm

13. Potentilla. (2013, May 29). en.Wikipedia.org. Retrieved from
http://en.wikipedia.org/wiki/Potentilla
USGS. (2000, April 12). Surface and Ground Water Characteristics in the
Upper Truckee River and Trout Creek Watersheds. Retrieved from
http://pubs.usgs.gov/wri/wri004001/Text/description.htm
* All pictures taken by author, Alyssa Lopez