Geology Field assignment

1. Cold Creek Trail & High
Meadow
Lake Tahoe, California
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Patrick Rulo
Professor Mark Lawler
Geology 103
June 18,2015
Photo by P. Rulo
High Meadow

2. Location
Cold 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.
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3. 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
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4. 4
Off to Collect Samples on
Cold Creek Trail
Photo P. Rulo Collection

5. 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)
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6. 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.

7. Rocks found around Cold
Creek Trail & Lake Tahoe
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Photo by P. Rulo

8. 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.
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9. Granite
Igneous Rock
Sialic- Silica Rich
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10. Basalt
Igneous Rock
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11. Schist
Metamorphic Rock
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12. Milky Quartz
Silicate
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13. Rose Quartz
Silicate
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14. Flora & Fauna
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15. Mountain Mule Ears
Wythea mollis
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Photo By P.Rulo

16. Mountain Mule Ears
Wythea 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.
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17. Rosy Sedum
Sedum roseum
17 Photo by P.Rulo

18. Rosy Sedum
Sedum roseum
• Member of Stonecrop family
• Found in Rocky areas
• Range in Tahoe: 7,000’ to 10,500’
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19. Snow Plant
Sarcodes sanguinea
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20. Snow Plant
Sarcodes 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.
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21. Black Bear
Ursus Americanus
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Photo from Google

22. Black Bear
Ursus 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.
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23. Invasive Species
Canis Familiarus Daisy
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24. Invasive Species
Canis 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.
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25. High Meadow
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26. 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.
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27. High Meadow
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28. High Meadow
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29. High Meadow
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30. Cold Creek Trail
Riparian Area
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31. Cold Creek
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32. Cold Creek
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33. 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.
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34. Conclusion
• Geologic Processes have formed the mountains
that we love and those processes will constantly
change them.
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35. 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
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