Field assignment

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Transcript of Field assignment

Cold Creek Trail & High Meadow

Lake Tahoe, California

Patrick RuloProfessor Mark LawlerGeology 103June 18,2015

Photo by P. RuloHigh Meadow

LocationCold Creek Trail is located in South Lake Tahoe

and is a popular mountain biking trail. The trail

starts up a moderate grade through a pine

forest and goes through different zones as

elevation changes. At the top of the trail is

High Meadow and then the trail follows Cold

Creek back to the start.

Methodology• During May and June I hiked and rode Cold

Creek trail a couple of times, taking pictures and collecting samples, while familiarizing myself with the area.

• Plant ID was performed with Wildflowers of the Tahoe Sierra

• Rock ID was performed with Rocks & Minerals

Off to Collect Samples on Cold Creek Trail

Photo P. Rulo Collection

Overview of Geological History of Lake Tahoe & Sierra Nevada

Mountain Range.

• According to the Geological Society of America, evidence suggest that the Sierra Nevada are a result of an uplift from the crust becoming thicker during the Late Cretaceous or Early Cenozoic Period.(GSA)

• A rain shadow east of the Sierra Nevada has been around since the middle Miocene Period. (GSA)

Overview of Geological History of Lake Tahoe & Sierra Nevada

Mountain Range.

• Lake Tahoe Basin was the result of block faulting 2-3 million years ago. (USGS)

• Around 2.5 years ago glaciation eroded many parts of the Sierra Nevada. (Wikipedia)

• Uplifting of the Sierra Nevada is on ongoing process that is still occurring.

Rocks found around Cold Creek Trail & Lake Tahoe

Photo by P. Rulo

Rocks found around Cold Creek Trail & Lake Tahoe

• The oldest rocks in the Sierra Nevada are metamorphic rocks such as schists and slates.(wikipedia)

• Granite was formed as early as the Jurassic Period.

• Much of the course soil and rocks are a result of glaciation and erosion.

• Quartz is common in surface rocks and igneous rocks such as granite.

GraniteIgneous Rock

Sialic- Silica Rich

BasaltIgneous Rock

SchistMetamorphic Rock

Milky QuartzSilicate

Rose QuartzSilicate

Flora & Fauna

Mountain Mule EarsWythea mollis

Photo By P.Rulo

Mountain Mule EarsWythea mollis

• Member of the Sunflower Family

• Common in Lake Tahoe from 6250’ to 8500

• Broad leaves covered with white silky hairs

to lessen evaporation.

• One plant can be reproduced if only one

flower is pollinated.

• Range:Sierra Nevada to Oregon.

Rosy SedumSedum roseum

Photo by P.Rulo

Rosy SedumSedum roseum

• Member of Stonecrop family

• Found in Rocky areas

• Range in Tahoe: 7,000’ to 10,500’

Snow PlantSarcodes sanguinea

Snow PlantSarcodes sanguinea

• Member of the Wintergreen Family

• Resembles an asparagus and is edible, although, it is protected.

• Does not photosynthesize, but is mycotrophic.

• Found on forest floors up to 8,000’.

• Appears in spring in shaded areas.

Black BearUrsus Americanus

Photo from Google

Black BearUrsus Americanus

• The American Black Bear is the most common bear species in the world.

• Despite being called black bears, they can have brown, blonde and cinnamon colored coats.

• Black bears are omnivorous.

• Bears live in various habitats and can be found from elevations at 1,300’ to 9,800’.

• Black Bears are highly efficient at hibernating through the lean months of the year.

• Bears live from 18 to 23 years.

Invasive SpeciesCanis Familiarus Daisy

Invasive SpeciesCanis Familiarus Daisy

• Introduced to Tahoe in 2012.

• Member of Canis rulo family.

• Likes to run in packs with mountain bikes.

• Omnivore, prefers kibble and cookies.

High Meadow

High Meadow and how meadows form

• Meadows form when sediment fills lakes and ponds and over a long period of time,water becomes earth. Grasses and other sun dependent plants form the meadow. An example of this process is Mirror Lake in Yosemite Valley.

• Meadows serve as a wetland for the mountains by filtering water.

• As time goes by, the meadow is invaded by various pine trees.

• The pine trees eventually block the sunlight making the meadow disappear.

High Meadow

High Meadow

High Meadow

Cold Creek TrailRiparian Area

Cold Creek

Cold Creek

Cold Creek

• Boulders have the appearance of being pushed into a pile, like a moraine at the snout of a glacier that I have seen from mountaineering.

• This appears to be evidence of glaciation from the last ice age, when the Sierra Nevada’s had significant glaciers.

Conclusion• Geologic Processes have formed the

mountains that we love and those processes will constantly change them.

References• Baker, Elna, An Island Called California, University of

California Press, Berkeley, 1972

• Blackwell, Laird R. Wildflowers of the Tahoe Sierra, Lone Pine Publishing, 1997

• Unknown, Rocks & Minerals, St Martins Press,1973

• wikipedia.org Black Bear & Geology of the Sierra Nevada

• USGS.Gov Lake Tahoe Geology overview

• geology.gsapubs.org Henry, Christopher,Uplift of the Sierra Nevada, Viewed on June 19, 2015