neal lacroix geology presentation

Death Valley

Photo by Neal Lacroix

History● Death Valley is actually a graben● A graben is a depressed block of

land bordered by parallel faults● Oldest rocks are extensively

metamorphosed and at least 1.7 billion years old

● Death Valley is the hottest and driest place in North America

● On July 10. 1913 the hottest temperature on earth was recorded in Death Valley, 134* F

● Annual average rainfall is 1.5 inches

USGS

Geology● Salt Pan● Covers more than 200

square miles● Forty miles long● More than five miles wide

Photo by Neal Lacroix

Plants● Prickly pear● Opuntia Polycantha● Desert flowering succulent● Conservation status-secure● Joshua tree● Yucca brevafolia● Native to the southwestern

United States● Consevation status-could be

threatened by climate change

Photos by Neal Lacroix

Animals● Great-tailed Grackle● Quiscalus mexicanus● Native to North and South

America● Medium size passerine bird

Photo by Neal Lacroix

Rock 1● Shale● Sedimentary rock● Coated with sand and fused

together

Photo by Neal Lacroix

Rock 2● Sandstone● Sedimentary ● Carved with lines of an

unknown nature

Photo by Neal Lacroix

Rock 3● Igneous rock● Basalt with quartz streaks

Photo by Neal Lacroix

Rock 4● Layered sedimentary rock

Photo by Neal Lacroix

Rock 5● Sand dunes● The sand dunes are

comprised of very fine particles of silica and other rocks that have been ground up over time by the forces of nature.

Photo by Neal Lacroix

Changes 1● Over the course of millions of

years these rocks were moved to a vertical position and then formed into a curve by the extreme forces of nature.

Photo by Neal Lacroix

Changes 2● The plants had to adapt to

the lack of water. They did this by sending roots deep into the earth or by spreading out a vast network of roots that were shallow in depth.

Photo by Neal Lacroix

Changes 3● Sand bee● These small bees burrow into

the sand dunes to create a home

● They appear to be the sole resident of the hole

● This is most likely an adaptation to escape the oppressive summer heat in Death Valley

Photo by Neal Lacroix

References● Retrieved from Wikipedia:

http://www.en.wikipedia.org/wiki/graben● Retrieved from National Park Service:

http://www.nps.gov/deva/naturescience/cacti.htm● Retrieved from The Cornell Lab of Ornithology:

http://www.allaboutbirds.org/guide/great-tailed_grackle/id ● Retrieved from Wikipedia:

http://www.en.wikipedia.org/wiki/Death_Valley_National_Park● All photographs taken by Neal Lacroix