1. Sources of Beach Sand Beach sands are derived from the breakdown of rocks (or reefs, etc.) in the surrounding region. THEREFORE, whatever is nearby will create what is on the beach OR, what is in the beach sand MUST also be in the rocks nearby

2. Sources of Beach Sand In California lots of rocks = lots of broken rock bits = lots of bits of minerals = lots of mineral beach sands Near Coral Reefs Lots of organic material = lots of broken bits of organic material + closer to beach than other eroded particles = beach full of coral reef fragments

3. Heavy Mineral Sand Some minerals heavier than others Magnetite, pyrite, galena Takes energy to move particles Larger particles = more energy

4. Oolitic Sands Ooites (aka ooids) Formation: CaCO 3 precipitates out of water Forms a CaCO 3 (lime) mud on bottom of the sea floor Pieces of mud get ripped up by wave action Ripped up pieces get rolled into balls by the gentle waves Eventually harden into ooites

5. Beach sands Location: Cabo, Baja Mexico Composition: Shells Source: http://www.microscope-microscope.org lots of shells (kelp bed, tide pool) just offshore.

6. Beach sands Location: Waianapanapa, Maui Composition: Basalt Source: http://www.microscope-microscope.org Erosion of basaltic lava flows which comprise the island of Maui

7. Basalt = Black Sand Beaches Black Sand Beach, Hawai’i http://www.hawaiipictures.com Basalt Waianapanapa, Maui http://www.microscope-microscope.org

8. Green Sand Olivine common in basalt Crystals can easily fall out during weathering Creates a beach of green sand

9. Beach sands Location: Guam Composition: Olivine Source: http://www.microscope-microscope.org Erosion of basaltic lava flows containing lots olivine

10. Olivine = Green Sand Beaches Green Sand Beach Papakolea, Hawai’i http://www.hawaiipictures.com Olivine Guam http://www.microscope-microscope.org

11. Beach sands Location: Huahini, Tahiti Composition: Coral Source: http://www.microscope-microscope.org Breakdown of coral reefs just offshore

12. Beach sands Location: Ventura, California Composition: Minerals Source: http://www.gly.uga.edu/railsback/sands/sandsmain.html Breakdown of rocks in surrounding area

13. Minerals = “Tan” Sand Beaches Cabrillo Beach San Pedro, CA S. Leyva 2005 Minerals (quartz, feldspar, hornblend) Ventura, California http://www.gly.uga.edu/railsback/sands/sandsmain.html