South Lake Tahoe

Formation

• Lake Tahoe is 4-5 million years old it formed by two parallel fractures in the earth’s crust causing the basin to sink. The mountains on each side began to rise while the valley slowly filled with water forming the lake.

• 2-3 million years ago volcano eruptions blocked the north side of the lake causing the valley to fill up with water hundreds of feet above the current elevation today.

• The west side of Lake Tahoe was covered by large pieces of glacial ice.

• The Large Leaf Lupine

• scientific name is Lupinus polyphyllus

• Pea family

• color varies from purple to blue violet.

• This flower grows about 3-5 ft

• It is also very toxic to livestock

• All lupines have compound leaves meaning that each leaflet originates from the same point. They form large enlongated clusters on the top of each stout.

• This plant is native to western North America

• Often found in moist habitats along side river beds, sage brush, pine forests, and meadows.

Picture by: Audriana Oniell

Black Bears

• The bears found in Lake Tahoe are known as the Northwestern black bear also called Ursus Americana Altifrontalis.• Lake Tahoe is populated with tons of Black Bears despite their name they can be found in other colors ex; cinnamon,

brown, blonde, blue-grey and white. • Due to increased fires over the years and humans leaving food out and littering the bears are prone to dumpster

diving and coming into town at any given time. Pictures By :Audriana Oniell

Jeffrey Pine (Pinus Jeffreyi)

• The most common pine tree in Lake Tahoe

• They live 400-500 yrs

• Jeffrey Pines are very well adapted to fires in the areas, the bark is thick and fairly fire resistant.

Photo by Audriana Oniell

Granodiorite

• Medium to coarse grained intermediate to acid igneous rock with essential quartz. >20% It also has minor mafic minerals. The fine grained equivalent of a granodiorite is a dacite.

Photo by :Audriana Oniell

Quartz• The second most common mineral found in the earth’s crust.• It is made up of silicon, oxygen and tetrahedra with each oxygen

being shared between two tetrahedra.

Photo by Audriana Oniell

Basalt

• Very common extrusive igneous volcanic rock • Formed by rapid cooling of basaltic lava exposed near the surface of the earth.• It has a glassy matrix look with a mix of minerals.• Basalt is usually seen as dark color but can be found with a mixture of colors from

weathering.

Conglomerate • Coarse grained

sedimentary rock made up of substantial fraction of pebbles, cobble stones, granule and boulders.

• They are often cemented together by hardened clay, silica, calcium carbonate, iron oxide.

Diorite

• Grey to dark grey intrusive igneous rock.

• The salt and pepper texture is due to the random distribution of the medium sized grains of white albite and black amphibole as well as pyroxene crystals, minor glints of biotite.

Photo by: Audriana Oniell

Sources

• Lake Tahoe Fast Facts. (n.d.). Retrieved June 22, 2015. • Lake tahoe fault lines - Google Search. (n.d.). Retrieved June 22, 2015. • Sierra Wild Flowers | Large-Leaf Lupine | Info & Photos. (n.d.). Retrieved June 22,

2015.

• Black Bear Color Phases. (n.d.). Retrieved June 22, 2015.

• (n.d.). Retrieved June 22, 2015.

• Glossary: Granodiorite. (n.d.). Retrieved June 22, 2015.

• (n.d.). Retrieved June 22, 2015, from https://en.wikipedia.org/wiki/Quartz

• (n.d.). Retrieved June 22, 2015, from https://en.wikipedia.org/wiki/Diorite

• (n.d.). Retrieved June 22, 2015, from https://en.wikipedia.org/wiki/Basalt

• (n.d.). Retrieved June 22, 2015, from https://en.wikipedia.org/wiki/Conglomerate_(geology)

• By :Audriana Oniell