Fallen Leaf LakeMike CashaField AssignmentM. LawlerGeology 1036/23/13

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Fallen Leaf LakeLocated in South Lake Tahoe, Ca

- Fallen Leaf Lake is located approximately 1.5 miles from Lake Tahoe on the plain of Lake Valley. This lake was formed by two glaciers that traveled from Glen Alpine Valley in the direction of Lake Tahoe. As the glaciers descended onto the flat plain of Lake Valley, they created the lake basin where Fallen Leaf Lake is today (James, n.d, para. 1).

- If the glaciers that formed Fallen Leaf Lake had continued traveling towards Lake Tahoe rather than stopping where they did, Fallen Leaf Lake would have been a bay, much like Emerald Bay is (Fallen Leaf Lake,n.d, para. 1).

- Glen Alpine Creek flows into Fallen Leaf Lake. Water then flows out to Lake Tahoe via Taylor Creek.

- Tallac Mountain borders the western side of the lake.

Glen Alpine Valley

Lake Tahoe to the NE

Tallac Mountain

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Rocks Types Near Fallen Leaf Lake:

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IGNEOUS - GRANITE - Very common in the Lake Tahoe area.

- Granite is formed in the Earth’s crust by cooling magma. The slowly cooling magma contains a substantial amount of silica and the “slow cooling produces the large crystals in granite” (Peck, n.d).

- Igneous Granite is typically white or light grey, but its also sometimes yellowish or even pink. These rocks usually have dark specks of biotite and sometimes hornblende on them (Peck, n.d).

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IGNEOUS - PEGMATITE ?

- This rock was especially difficult to identify due to the oxidation and weathering on its cortex.

- The lower left side appears to have relatively large crystals, indicative of a Pegmatite (King, n.d, para. 1).

- Considered an “extreme igneous rock”, pegmatites “form during the final stage of magma’s crystallization” (King, n.d, para 1)

- They are considered “extreme” due to their larger than average crystals. Also, pegmatites sometimes contain more rare minerals than most other rocks (King, n.d, para 1)

- Pegmatites tend to have a similar composition to granite, consisting of quartz, feldspar, and mica (King, n.d, para 3)

- Frequently referred to as “granite pegmatites” because of its similarities to granite (King, n.d, para 3).

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Plant life near Fallen Leaf Lake:

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Quaking Aspen(Populus Tremuloides)

- Named and described by Michaux in 1803 (Harper, Shane, Jones, n.d, p. 1).

- Trees with a likeness to the Quaking Aspen have been around since the middle Miocene time (nearly 15 million years ago) (Harper, et al., n.d, p. 1).

- Researchers speculate that the modern Quaking Aspen was “strongly influenced by episodes of hybridization during the late Cenozoic era” between P. Tremuloides and P. Grandidentata (Harper, et al., n.d, p. 1).

- The Quaking Aspen can be found all over North America and its easily recognized by it’s white bark and seasonal color change.

- Closely related to the Eurasian Aspen (Populus Tremula)

- Quaking Aspens can be found at any elevation in the north-central part of North America, whereas, they can only be found in higher elevations in the southern parts of the US and Mexico (Grant, Mitton, 2010, para. 2).

- The white bark is living tissue that carries out photosynthesis - something that sets it apart from other North American trees (Grant, Mitton, 2010, para. 3).

- Aspens lose their leaves in the winter.

- Aspen groves have interconnected root systems that allow for genetically identical clones to grow nearby. This shared root system is the reason that Aspens are generally growing in large patches and not just by themselves (Grant, Mitton, 2010, para. 4).

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Snow Plant(Sarcodes Sanguinea)

- Snow Plant is thought to be closely associated with “at least three distantly related groups of fungi” (Bruns, Bidartondo, Taylor, 2002)

- The snow plant, also known as Monotropoideae, is part of the Ericaceae family (Bidartondo, 2005, p. 8).

- The Snow Plant is the only member of the Ericaceae family that is non-photosynthetic (with the possible exception of a few Pyroloideae) (Bidartondo, 2005, p. 8).

- ”All nonphotosynthetic plants with monotropoid mycorrhizas” (like the Snow Plant) “evolved from photosynthetic plants that formed mycorrhizas where otherwise ectomycorrhizal fungi actually penetrated epidermal root cells” (Bidartondo, 2005, p. 5).

- Snow Plant is a parasitic plant that gets its nutrients via fungi that attaches to the roots of trees (Sarcodes, n.d, para.1).

- Snow Plant is native to western North America and it generally grows in the early spring or summer shortly after the snow has mostly melted away (Sarcodes, n.d, para. 3).

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Fauna near Fallen Leaf Lake:

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Pale Swallowtail Butterfly(Papilio Eurymedon)

- The earliest recorded butterfly fossils are from the mid Eocene epoch (between 40-50 million years ago (Butterfly, n.d, para. 1).

- Because butterflies and caterpillars feed on flowering plants, “their development is closely linked to the evolution of flowering plants” (Butterfly, n.d, para. 1).

- Some researchers theorize that butterflies originated sometime during the Cretaceous period (Butterfly, n.d, para. 6).

- Pale Swallowtails are part of the Papilionidae family, descendants of the Papilionoidea family (Butterfly, n.d, para. 3).

- The Pale Swallowtail is a commonly found butterfly in a large portion of the western United States (Papilio, n.d, para. 1).

- Pale Swallowtails are generally found living in open woodland areas near bodies of water (Papilio, n.d, para. 1).

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REFERENCESBidartondo, M. I. (2005). The evolutionary ecology of myco-heterotrophy. New Phytologist, 167(2), 335-352.

Bruns, T. D., Bidartondo, M. I., & Taylor, D. L. (2002). Host specificity in ectomycorrhizal communities: what do the exceptions tell us?. Integrative and Comparative Biology, 42(2), 352-359.

Butterfly Evolution. (n.d.). In Wikipedia. Retrieved June 20, 2013, from http://en.wikipedia.org/wiki/Butterfly_evolution

Fallen Leaf Lake (California). (2013, June 2). In Wikipedia . Retrieved June 20, 2013, from http://en.wikipedia.org/wiki/Fallen_Leaf_Lake_(California)

Grant, M., & Mitton, J. (2010). Case Study: The Glorious, Golden, and Gigantic Quaking Aspen. In The Nature Education. Retrieved June 20, 2013, from http://www.nature.com/scitable/knowledge/library/case-study-the-glorious-golden-and-gigantic-13261308

Harper, K. T., Shane, J. D., & Jones, J. R. (n.d.). Taxonomy. In US Forest Service. Retrieved June 20, 2013, from http://www.fs.fed.us/rm/pubs_rm/rm_gtr119/rm_gtr119_007_008.pdf

James, G. W. (n.d.). The Lake of the Sky - Lake Tahoe. In Exploration.net. Retrieved June 20, 2013, fromhttp://explorion.net/lake-sky-lake-tahoe/chapter-viii-glacial-history-lake-tahoe?page=4

King, H. (n.d.). Pegmatite. In News and Information About Geology and Earth Science. Retrieved June 20, 2013, from http://geology.com/rocks/pegmatite.shtml

Papilio eurymedon. (n.d.). In Wikipedia. Retrieved June 20, 2013, from http://en.wikipedia.org/wiki/Papilio_eurymedon

Peck, D. (n.d.). In The Rock Identification Key. Retrieved June 20, 2013, from http://www.rockhounds.com/rockshop/rockkey/

Sarcodes. (n.d.). In Wikipedia. Retrieved June 20, 2013, from http://en.wikipedia.org/wiki/Sarcodes

*All photos were taken by Author*

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