Los Penasquitos Canyon?

Question

hi! I really need help!!! i have tried researching but there is nothing. does anyoneknow the rock formation. rock name, how the rock was formed, the enviroment of the rock, how the formation ties intop the san diego history adnd hte absolute dating of the rock. any links are fine to. but please i have searched everywhere adn I really need help. you'll get 10 points!!!!!!!!!!

Answer 1

http://www.sandiego.gov/park-and-recreat...

The western portion of the watershed is underlain by Eocene sands, shales and conglomerate of the Poway and La Jolla group. The flat ridge tops of many areas within the western watershed are overlain by thin layers of red-colored Quaternary marine terrace deposits of the Linda Vista Formation in. The eastern portion of the watershed, near the City of Poway, is underlain by uplifting granitic rock of the Southern California Batholith, the Santiago Peak Volcanics, and non-marine Eocene Poway conglomerates.  Within the lower watershed, subsurface units are characterized by thick layers of marine and non-marine sedimentary rocks. The oldest formation is the Delmar Formation, which is exposed along the bluffs near the Los Penasquitos Creek's mouth. Above, is the Torrey Sandstone, a white sand deposit, which weathers into distinctive hollows and is susceptible to landslides and slope failure

Soil characteristics within the upper watershed are characterized as having severe erodibility. Approximately 76 percent of the soil hydrologic groups mapped within the upper watershed have the highest potential for runoff. These ratings are based upon the properties of the soil slope, texture, water infiltration rates, natural drainage or wetness, depth to material that restricts water permeability, and grade of structure in surface layer) and not other physical factors, such as vegetative cover, climate, and physiological features. For a more detailed description of soil types and their limitations see the Los Peñasquitos Canyon Preserve Natural Resource Management Plan, 1998.

The sediments underlying the Los Penasquitos Lagoon basin range from greenish and grayish sand near the lagoon entrance to blue and gray sand shale and thin beds of limestone upstream in the Soledad Valley. The surface sediments are comprised predominantly of fine silty clays which form the sticky, gray-brown mud found in most of the lagoon channels and salt marsh areas. These salt marsh sediments are relatively thin and are underlain by marine or fluvial deposited sand to depths of more than 50 feet. Almost all of the soils in the lagoon area are highly saline. The soils in the upper watershed consist of Anderson gravelly sandy soils, Cieneba Fallbrook rocky sandy soils, to Friant rocky sandy loams.