Christmas Valley•and the South Upper Truckee River

Vanessa YochheimGeology 103Spring 2015

Christmas Valley

Christmas Valley lies south of Lake Tahoe on highway 89. The South Upper Truckee River flows through this valley and provides a beautiful landscape of flora. Granite outcrops mark the mountainous edges of the valley on either side. This valley was formed in the Plio-Pleistocene during the Sierra Nevada mountain building. Faulting formed the Carson Range on the eastern side and the Sierra Nevada on the western side of the Tahoe Basin. (http://www.fs.usda.gov/detail/ltbmu/learning/?cid=stelprdb5109570 )

As the mountains were built, a deep valley formed between the two mountain ranges. Lava from Mt. Pluto on the North shore blocked the only river outlet, the Upper Truckee. Glacier events followed which created small lakes and steep valley walls. Glaciers deposited rock material on the western and southern parts of the lake. When the Truckee River outlet became blocked, the lake would rise up to 600 feet and covered much of South Lake Tahoe and Meyers. Christmas Valley serves as a gateway to Meyers, carved between walls of granite, allowing the Upper Truckee River to flow to Lake Tahoe. (Konigsmark, 2002)

Geologic map of Christmas Valley

Image courtesy of California Department of Conservation

The Christmas Valley area is mostly comprised of Till deposits from the Pleistocene and Talus deposits from the Holocene and a smaller area of Alluvium from both.

Plant Evolution

Image courtesy of Brittanica.com

Snow PlantSarcodes Sanguinea

The Snow Plant is a non-green flowering plant from the Monotropaceae family. It is a parasitic plant that feeds off of the fungus that infects it and has no chlorophyll. Snow plants emerge from the soil once the snow has melted, looking like a giant red asparagus top before it blooms. This type of plant has it’s origins in the Subkingdom Tracheobionta which are known as vascular plants that contain the tissues xylem and phloem. These plants evolved their vascular tissues to increase photosynthesis in a terrestrial environment. Vascular plants first appeared in the Silurian period. Angiosperms arose from these vascular plants in the Late Mesozoic. (http://botany.org/Parasitic_Plants/Sarcodes_sanguinea.php)

Wavy-leaf Indian Paintbrush Castilleja Applegati

• The Indian Paintbrush is from the Scrophulariaceae family and is native to the western part of the United States. This family is derived of the seed bearing vascular plants, angiosperms. The flowers of these plants are edible and sweet but the green parts and roots can be highly toxic. Native Americans were known to eat these flowers and use them for medicinal and hygenic purposes. (http://www.theplantencyclopedia.org/wiki/Castilleja)

The Indian Paintbrush is a hemi-parasitic plant that feed off the roots of grasses and forbs. These plants have high transpiration rates that require open, sunny areas. Hemiparasitic plants may have evolved due to competition in dense ground covered areas. (Nickrent and Musselman, 2010)

Plant Classifications

Images courtesy of plant.usda.gov

Wavyleaf Indian PaintbrushCastilleja Applegatei

Snowplant Sarcodes Sanguinea

Bird EvolutionBirds evolved from small carnivorous dinosaurs called theropods that lived during the late Jurassic. Fossils found mostly in China show evidence that these small dinosaurs had primitive feathers. As they evolved further, their claws turned to wings and their tails shortened to a stump. They lost their teeth and developed a beak. (http://evolution.berkeley.edu/evolibrary/article/evograms_06)

American RobinTurdus Migratorius

The American Robin is from the Aves class of the Animalia Kingdom. It comes from the family Trudidae (thrushes) which includes other songbirds such as the bluebird. The Trudidae family belongs to the order Passeriformes. They are thought to have diversified in the late Cretaceous before the break up of Gondwana. The oldest passerine fossils have been found in Australia and are from the early Eocene. (Ericson et al., 2014)

South Upper Truckee Riverbed This riverbed contains a small variety of Granite, Quartz, Diorite, and clongomerate rocks. The beach is made of fine sand, silt, and gravel particles. Many of the rocks I found here looked similar and had smooth surfaces, making them more difficult to identify. I took them home, dried them off and even cut some open.

Conglomerate

I believe this rock to be a conglomerate. It has a coarse texture and is made up of smaller rocks cemented together with sand. It broke easily when struck with an axe. It has some shiny dark pieces inside which may be horneblend and quartz. Conglomerates are a clastic sedimentary rock that are bound together with smaller particles and cement. (geology.com/rocks/conglomerate.shtml)

Welded Tuff

I had some difficulty identifying these rocks. They have a smooth exterior but are rough inside and broke apart easily. They are composed of smaller shiny black and white rocks(horneblend and quartz?) cemented together with a red-tinted sand. At first I thought they were Breccia but now I believe them to be Welded Tuff, an igneous rock that forms from the debris that is ejected during volcanic eruptions. The ejected material falls to earth and is cemented into a rock. (geology.com/rocks/tuff.shtml)

Granite

These rocks have rough exteriors and are mostly white with speckled black shiny pieces and some translucent white pieces. The black shiny rocks may be feldspar crystals and the white shiny rocks are probably quartz. The exterior has some light brown discoloring that isn’t present on the interior so I believe it is caused from sitting in the riverbed. I believe that these rocks are granite. Granite is an igneous plutonic rock that is found in most of the earths crust. (geology.com/rocks/granite.shtml)

Quartz

These rocks have a smooth texture and are a milky white and slightly pink color. There are flecks of gold shiny pieces which may be Mica embedded in the right piece. I believe they are a type of quartz. Quartz is a metamorphic silicate that is abundant throughout the world. It can be found in igneous, sedimentary and metamorphic rocks. It can form at all temperatures and is the dominant mineral of mountain areas and sandy beaches. (geology.com/minerals/quartz.shtml)

Shale

These rocks have a coarse texture and a dark gray and brown exterior. They break into smooth flat pieces and are lighter colored on the inside. They feel slightly chalky to the touch. Shale is a sedimentary rock with fined grain that forms when silt and mud are compacted. It splits into thin pieces along laminations easily and is found in riverbeds and near lakes. (geology.com/rocks/shale.shtml)

Resources• Konigsmark, T. (2002). Geologic trips Sierra Nevada. Gualala, CA:

GeoPress.

 • Lake Tahoe Basin Mgt Unit - Learning Center. (n.d.). Retrieved June

11, 2015, from http://www.fs.usda.gov/detail/ltbmu/learning/?cid=stelprdb5109570

•  • Saucedo, G. (n.d.). California Geological Survey - Geologic Map of the

Lake Tahoe Basin. Retrieved June 9, 2015, from http://www.quake.ca.gov/gmaps/RGM/tahoe/tahoe.html

• Ericson, G., Klopfstein, S., Irestedt, M., Nguyen, J., & Nylander, J. (2014). Dating the diversification of the major lineages of Passeriformes (Aves). BMC Evol Biol BMC Evolutionary Biology, 14(8), 8-8. doi:10.1186/1471-2148-14-8

• American Robin. (n.d.). Retrieved June 10, 2015, from http://www.mbr-pwrc.usgs.gov/id/framlst/i7610id.html

 • BSA Parasitic Plant Pages. (n.d.). Retrieved June 6, 2015, from http://

botany.org/Parasitic_Plants/Sarcodes_sanguinea.php

 • Plant Life. (n.d.). Retrieved June 13, 2015, from

http://lifeofplant.blogspot.com/2011/01/tracheobionta.html

 • Plants Profile for Sarcodes sanguinea (snowplant). (n.d.). Retrieved

June 10, 2015, from http://plants.usda.gov/core/profile?symbol=SASA5

Resources ContinuedPlants Profile for Castilleja Applegati (indian paintbrush).(n.d.). Retrieved June 9, 2015, from http://plants.usda.gov/core/profile?symbol=CAAPA2 (n.d.). Retrieved June 10, 2015, from http://www.theplantencyclopedia.org/wiki/Castilleja Nickrent, D., & Musselman, L. (2004). Introduction to Parasitic Flowering Plants. PHI The Plant Health Instructor. doi:10.1094/PHI-I-2004-0330-01 The origin of birds. (n.d.). Retrieved June 9, 2015, from http://evolution.berkeley.edu/evolibrary/article/evograms_06 Evolution. (n.d.). Retrieved June 10, 2015, from http://www.britannica.com/science/evolution-scientific-theory/images-videos Natural History Museum of Los Angeles County. (n.d.). Retrieved June 13, 2015, from http://www.nhm.org/site/research-collections/dinosaur-institute/dinosaurs/birds-late-evolution-dinosaurs Tuff. (n.d.). Retrieved June 16, 2015, from http://geology.com/rocks/tuff.shtml Conglomerate. (n.d.). Retrieved June 16, 2015, from http://geology.com/rocks/conglomerate.shtml Shale. (n.d.). Retrieved June 16, 2015, from http://geology.com/rocks/shale.shtml Quartz. (n.d.). Retrieved June 16, 2015, from http://geology.com/minerals/quartz.shtml Granite. (n.d.). Retrieved June 16, 2015, from http://geology.com/rocks/granite.shtml Peck, D. (n.d.). Rock Key. Retrieved June 16, 2015, from http://www.rockhounds.com/rockshop/rockkey/