Davidson Field Trip Travel Journal - Week 6 Entry

This week I visited the Death Valley region of Southern California where the geology is quite complex. The three pieces of information I requested were the geologic map of California available at http://www.consrv.ca.gov to understand what was known, radioactivity to determine the absolute age of rocks, and the Fundamental Principles of Relative Dating to understand the geology and to account for what was missing.
Fundamental Principles of Relative Dating:
1.   Superposition- in a sequence of sedimentary rock, layers get younger from bottom to top
2.   Original horizontality- layers of sediment deposited in water are approximately horizontal; if not horizontal, tilted after deposition.
3.   Lateral continuity- sediment extends laterally in all directions until it thins and pinches out or terminates against the edge of basin.
4.   Cross-cutting relations- disrupted rocks are older than the cause of disruption (figs. 8.3, 8.4).
5.   Inclusions- fragments (inclusions) of rock within a layer of rock are older than the rock layer itself
6.   Fossil succession- fossil assemblages (groups) succeed one another through time in a regular and predictable order (any period of geol. time can be recognized by fossils present)

References
California Department of Conservation. (n.d.). Retrieved from http://www.consrv.ca.gov

Chapter 8. (n.d.). Retrieved from http://quake.ualr.edu/mahdiwebpage/physical-geology/ch8.htm

Retrieved from: Death Valley National Park. (2018, March 21). Retrieved from https://www.audubon.org/climate/national-parks/death-valley-national-park

Retrieved from: https://maps.conservation.ca.gov/cgs/gmc/

Retrieved from: https://maps.conservation.ca.gov/cgs/gmc/