Fallen Leaf Lake

Rochelle MillerProfessor LawlerGeology 103Spring 2014

Photo by author

Content

• Geological summary• Map and location• Plant examples• Native animals• Rocks and landscape• Fallen Leaf Lake facts

Geological Summary

-Fallen Leaf Lake was formed by glacial moraines.

-The east and west sides of the three-mile-long lake are bounded by lateral moraines and thelake is separated from Lake Tahoe by a series of recessional moraines.

-Fallen Leaf Lake is 150 feet above Lake Tahoe and drains into LakeTahoe through Taylor Creek, which cuts through these recessional moraines.

-If there were no lateral and recessional moraines, there would be no Fallen Leaf Lake. (http://www.geologictrips.com/sn/snttlt.pdf)

Photo by author

• The south end of Fallen Leaf Lake lies at the base of one of the large faults along which the Tahoe block was downfaulted several thousand feet.

• The lake sits in a pile of glacial debris that was carried down the scarp of this fault by Pleistocene glaciers.

• This glacial debris fills in much of the southern part of the Tahoe

basin. • As the lake was filled in, the glaciers rode over the older glacial

material and continued to dump their debris into the lake. (http://www.geologictrips.com/sn/snttlt.pdf)

http://www.fishsniffer.com/locations/lakes/fallen-leaf-lake/

Manzanita plant (Arctostaphylos species)(http://www.laspilitas.com/groupsmanzanita_arctostaphylos/Manzanita.htmlhttp://).

The genus evolution was likely centered in the far western part of North America, where fossil ancestors dating to the Middle Miocene are apparent. The genus was likely even more diversified as it evolved into the Early Tertiary. Evolution of genus Arctostaphylos likely shares a similar timeline with that of Ceanothus, which is another western North America genus that exhibits fire regenerative properties. Extensive use of the fruit and leaves were made by prehistoric peoples for culinary, medicinal and ceremonial purposes.

Photo by author

Jeffrey Pine (Pinus jeffreyi)

Photo credit- http://www.laspilitas.com/plants/fragrant.htm

• Jeffrey pine (Pinus jeffreyi) was discovered in 1852 in the Shasta Valley of California by John Jeffrey, a Scottish botanical explorer. Partly overlapping ponderosa pine (Pinus ponderosa) in range and superficially resembling it, Jeffrey pine was first classified as a variety of ponderosa pine (28,45). These western yellow pines produce wood of identical structure and quality and are closely related taxonomically (10). Jeffrey pine is distinct chemically, ecologically, and physiologically and is readily distinguished from ponderosa pine on the basis of bark, leader, needle, bud, and cone morphology (23).

• The Jeffrey pine may live 400 to 500 years and can attain immense size. It typically grows to 4 to 6 feet in diameter, and 170 to 200 feet in height. To date, the largest Jeffrey pine recorded in the western Sierra Nevada had a diameter of 7.5 feet, and a height of 175 feet.

• Jeffrey pine is found primarily in California extending north through the Klamath Mountains into southwestern Oregon, across the Sierra Nevada into western Nevada, and south to the Transverse and Peninsular Ranges and into northern Baja California. In the northeast, central, and southern portions of its range, climate and elevation determine its distribution, rather than soil type. (http://eol.org/pages/999712/details).

• Lahontan Cutthroat Trout• Historically, only a few species of fish lived in Lake Tahoe. The Lahontan

Cutthroat Trout was the dominant fish. Large and long-lived, it grew to an impressive 50 inches in length and weighed 40 pounds. Native people throughout the Great Basin depended on the trout for their livelihood.

• However, the Lahontan cutthroat’s fate changed dramatically during the 19th and 20th centuries. The fish were caught in high numbers to sustain the towns and mining camps of the growing West. Dams and development destroyed habitat. By 1970, the fish were listed as an endangered species. In 1975, that classification was lowered to “threatened.”

• Extensive efforts are underway to restore the Lahontan cutthroat to its traditional range. (http://keeptahoeblue.org/abouttahoe/animals -plants/)

Dark-eyed Junco

Photo credit- http://blog.nwf.org/2011/01/bird-of-the-week-dark-eyed-junco/

Photo by author

Among the most variable of all North American birds, the dark-eyed junco features several distinct color forms, five of which were once considered separate species. Today six groups of subspecies—or types—of a single species, Junco hyemalis, are accepted by ornithologists. The two most widespread are the “slate-colored junco” of the eastern United States and most of Canada and the “Oregon junco,” which inhabits much of the West. (http://blog.nwf.org/2011/01/bird-of-the-week-dark-eyed-junco/).

Photo by author

Igneous rock- Granite

Granite rock is the result of magma or lava crystallizing

As it cools, the resulting rock is characterized by interlocking mineral grains.

Magma that cools beneath the surface produces intrusive igneous rocks such as Granite (Monroe, Wicander 17). Felsic - "light" rocks, contain light colored minerals

(Also low temp minerals See Bowen's Below) (quartz, Potassium feldspar, micas). (http://www.dinojim.com/Geology/GeoBasics/igneous.html#Types

Basalt rock- extrusive Igneous

Photo by author

Extrusive igneous rocks cool at the surface unlike intrusive igneous rocks. Both igneous rocks are formed when magma or lava crystallizes (Monroe, Wicander 17).

Phyllite-Metamorphic rock

Photo by author

Metamorphic grade is a term that generally characterizes the degree to which a rock has undergone a metamorphic change.

Photo by author

Phyllite is a foliate metamorphic rock that is made up mainly of veryfine-grained mica. The surface of phyllite is typically lustrous and sometimes wrinkled. It is intermediate in grade between slate and schist(http://geology.com/rocks/phyllite.shtml).

Fallen Leaf Lake Facts

• Fallen leaf is 3 miles wide, 1 mile long, and 400 feet deep.• In the winter of 1951-52, Fallen Leaf

got over 12 feet of snow!• 4000 years ago, Washoe Indians used

Fallen Leaf for summer camp.(Courtesy of Tahoe Heritage Foundation)

References

"Geologic Trips." . N.p., n.d. Web. 22 June 2014. <http://www.geologictrips.com/sn/snttlt.pdf>.

Hogan, C. "The Encyclopedia of Earth." . N.p., 12 June 2012. Web. 22 June 2014. <http://www.eoearth.org/view/article/150218/>.

"A voice for lake Tahoe." . N.p., n.d. Web. 22 June 2014. <http://www.trpa.org/wp-content/uploads/Tree-ID-tip-sheets_2012-version-MS.pdf>.

Jenkison, James . "Encycopedia of Life." . N.p., n.d. Web. 22 June 2014. <http://eol.org/pages/999712/details>.

Tangley, Laura. "Bird of the Week: Dark-eyed Junco." Wildlife Promise Bird of the Week Darkeyed Junco Comments. Wildlife Promise, 31 Jan. 2011. Web. 22 June 2014. <http://blog.nwf.org/2011/01/bird-of-the-week-dark-eyed-junco/>.

Lehame, Jim . "Dinojim.com - Geology Stage 1.4: Igneous Rocks." Dinojim.com - Geology Stage 1.4: Igneous Rocks. N.p., n.d. Web. 22 June 2014. <http://www.dinojim.com/Geology/GeoBasics/igneous.html#Types>.

"Phyllite." : Metamorphic Rock. N.p., n.d. Web. 22 June 2014. <http://geology.com/rocks/phyllite.shtml>.

Monroe, James S., and Reed Wicander. The changing earth: exploring geology and evolution. 6th ed. Belmont, CA: Brooks/Cole, 2001. Print.

Wilson, Bert. "Manzanitas of California, (Arctostaphylos species)." . N.p., 11 Dec. 2013. Web. 22 June 2014. <http://www.laspilitas.com/groupsmanzanita_arctostaphylos/Manzanita.htmlhttp://).>.