Carbonates

Carbonates in the Martian meteorite

Despite evidence for liquid water at the surface of Mars during the Noachian epoch, the temperature of early aqueous environments has been impossible to establish, raising questions of whether the surface of Mars was ever warmer than today. We address this problem by determining the precipitation temperature of secondary carbonate minerals preserved in the oldest known sample of Mars’ crust—the...

Paleoelevation Reconstruction using Pedogenic Carbonates

Paleoelevation reconstruction using stable isotopes, although a relatively new science, is making a signifi cant contribution to our understanding of the recent growth of the world’s major orogens. In this review we examine the use of both light stable isotopes of oxygen and the new “clumped-isotope” (Δ47) carbonate thermometer in carbonates from soils. Globally, the oxygen isotopic composition...

Seismic Wave Attenuation in Carbonates

Gold-catalyzed efficient formation of alkenyl enol esters/carbonates from trimethylsilylmethyl-substituted propargyl esters/carbonates.

A gold-catalyzed efficient method for the preparation of alkenyl enol esters/carbonates is developed. Besides the mild reaction conditions and high catalytic efficiency, the excellent E-selectivity of the nonenolic double bond is remarkable.

Carbon isotopes in mollusk shell carbonates

Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell δC reflects the local mix of C3 and C4 plants consumed. S...