Melligan field assignment

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Transcript of Melligan field assignment

The Anza-Borrego Desert

A Living Laboratory

Scott C Melligan

Anza-Borrego Desert State Park (CA)

• Two hours northeast of downtown San Diego, away from the ocean and foothills, you’ll find a living laboratory of earths evolution.

• It is the largest state park in California covering 600,000 acres.

• 20,000 feet of sediment has been deposited in the course of 7 million years

(Anza Borrego Travel Blog, 2012)

Anza-Borrego Desert State Park

32°57’18.96’’N 116°17’51.86’’W

Courtesy of Google™ Earth

A Link to the Past

• This Desert Chuckwalla lizard lives in the ABDSP.

• This species of reptile is native to the desert regions of southern California and Arizona.

• In it’s natural setting it bears a passing resemblance for it’s extinct cousin, the dinosaur.

(Desert Gazette, 2012) http://en.wikipedia.org/wiki/File:0703Chuckwalla.JPG

Split Mountain

The magnificent badlands in the park look like a moonscape but function as a measurable demonstration of how the earth was formed with both a visible rift valley and continental plate boundary.

http://www.backroadswest.com/anza/2011/11/split-mountain/

Clam Shell Fossils

• Some 20,000 feet of sediment has been deposited in 7 million years, leaving a ripe fossil bed for academic study.

• Over 500 types of fossils have been discovered in the park.

(Jefferson, 2012) http://tinyurl.com/brdemga

Stromatelite

Stromatelites are formed when sediments are trapped within photosynthesizing cyanobacteria- also called blue/green algae- in areas of high salinity concentrations as you’d find in the Salton Sea. (Monroe, 2009). http://www.abdnha.org/pages/12brag/co_stromatelite.htm

Fulgurite

When lightning greater than 1800° strikes sand- which is in abundance in the desert- it can form a hollow glass tube called a Fulgurite.(What is a Fulgurite, 2012)

http://www.abdnha.org/pages/12brag/co_fulgurite.htm

Gone Today, Here Tomorrow

• The geologic activity along the many fault lines in southern California means that on a regular basis new features are revealed in the desert.

• In fact, a 3.4 magnitude tremor occurred just one month ago only 9 miles from Borrego Springs.

(Phys, 2012) http://www.anzaborregopaleo.org/PARK_GEOLOGY.html

Conclusion

Several years ago I had the “pleasure” of living in the ABDSP- the town of Borrego Springs- when I worked at the now defunct La Casa del Zorro Resort. It is a beautiful but unforgiving place which demonstrates how small man is compared to the earths magnificence. In fact, fewer and fewer men choose to live there but the evolution continues unabated.

ReferencesAnza Borrego Travel Blog, (2012)http://www.backroadswest.com/anza

Desert Gazette (2012). Chuckwallahttp://digital-desert.com/wildlife/chuckwalla.html

Jefferson, George T. (2012) Fossil Treasures of the Anza Borrego Deserthttp://www.borregospringschamber.com/abdsp/fossils.htm

Monroe, James S. (2009). The Changing Earth, 5th EditionBelmont, CA: Brooks/Cole

Phy, Melissa (2012). 3.4 Magnitude Earthquake Near Borrego Springs Felt in RamonaRamona Patch http://ramona.patch.com/articles/3-4-magnitude-earthquake-near-borrego-springs

What is a Fulgurite (2012)http://wiki.answers.com/Q/What_is_a_Fulgurite