Week 3

• Native Elements• Oxides• Hydroxides• Halides• Carbonates• Sulfates• Phosphates

Objectives

(Mg,Fe)O, a possible phase in Earth’s mantleFeO, a possible component of Earth’s core

Mg,Fe,Al-PV FP

Ca-PV

0 80 95 100%

Dzeiwonski & Anderson 1981Fei & Bertka 1999

Life on Mars?

hematite&olivine

Goethite - Fe(OH)3

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Johann Wolfgang Goethe, 1749-1832

A German polymath: poet, novelist, scientist, painter, etc.

The Sorrows of Young Werther

Gibbsite - Al(OH)3

George Gibbs, 1776-1833

An American mineralogist, who donated a collection of 12,000 specimens to Yale University

• Carbonates cover 7% land surface

• Greater than 50% oil and gas reservoirs worldwide are contained in carbonate rocks

• Major economic importance as industrial "mineral" (agriculture stone, cement)

Carbonate minerals are useful

Stromatolites living fossils

Coral reef

Carbonates are born, not made

Pacific reef

Red Sea reef

Florida reef

Caribbean reef

Carbonate cavern

Stalactites & Stalagmites, NM, USA

Sinkholes

Winter Park, Florida

Sinkholes, FL, USA

Karst terrain

Guilin, China

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Munching microbes could cleanse arsenic-contaminated groundwater Sulfate-reducing bacteria will consume sulfate and reduce it into sulfide. The sulfide then reacts to precipitate arsenic, leaving little in solution.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture. 2005

U. of I. finds solution to arsenic in wells

When the scientists analyzed water from 21 wells, all fed by the Mahomet aquifer in central Illinois, they noticed that the more sulfate they found, the less arsenic there was.

Well-water bacteria that are harmless to humans but death on arsenic were responsible, said geology professor Craig Bethke, an author of a paper to be published next month in the journal Geology. "They breathe in sulfate and breathe out sulfide," he said. The sulfide reacts with arsenic, causing it to settle out and never reach the surface.Just add salts

That suggests owners of wells with unhealthy levels of arsenic can simply add sulfate, Bethke said. Sulfate salts are inexpensive, readily soluble and easy to find.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

How do our bones and teeth grow?The earliest mineral formed in bone growth is in the nanometer size-range. Previous studies were unable to identify the phase because they relied on traditional methods like X-Ray Diffraction which work best in the micrometer size-range. Identifying the earliest mineral phase that eventually becomes bone (apatite) can help in the development of treatments for osteoporosis and other bone-diseases. Determining the mechanism for heterogeneous apatite precipitation also has environmental applications in remediation of pollutant phosphate.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Nita Sahai