The issue of stochastic reconstruction of chalk samples containing appreciable amount of vuggy porosity in the form of foraminifer shells using a conditional simulated annealing (SA) technique is addressed. A new indicator function suitable for the algorithm is defined to represent chalk microstructures. Most of the chalk samples consist of vuggy porosity associated with large cavities found in...

Fossil foraminiferal shells are utilized in paleoceanography to extract information about environmental conditions of the past ocean. Based on several assumptions, the ratio of C and C preserved in their shells is used to reconstruct, for example, the paleoproductivity or the oceanic pCO . Metabolism of the living organism and the sea water chemistry, 2 however, can influence the incorporation ...

A total of 38 box cores were collected from the Amerasian Basin, Arctic Ocean during the U.S. Geological Survey 1992 (PI92-AR) and 1993 (PI93-AR) Arctic Cruises aboard the U.S. Coast Guard Icebreaker Polar Star. In addition, the cruises collected geophysical data, piston cores and hydrographic data to address the geologic and oceanographic history of the western Arctic Ocean. This paper reports...

—Foraminiferal tests are a common component of many marine sediments. The oxygen isotope ratio (δ18O) of test calcite is frequently used to reconstruct aspects of their life environment. The δ18O depends mainly on the isotope ratio of the water it is precipitated from, the temperature of calcification, and, to a lesser extent, the carbonate ion concentration. Foraminifera and other organisms ca...

We report here the results of a multi-proxy study to reconstruct surface water pCO2 concentrations in the northern Arabian Sea. Our results show that δB and Mg/Ca measurements of the planktonic foraminifer Globigerinoides sacculifer yield consistent pCO2 values with those reconstructed from the δC of alkenones when used in

The Paleocene–Eocene Thermal Maximum (PETM), ca. 56 Ma, was a major global environmental perturbation attributed to a rapid rise in the concentration of greenhouse gases in the atmosphere. Geochemical records of tropical sea-surface temperatures (SSTs) from the PETM are rare and are typically affected by post-depositional diagenesis. To circumvent this issue, we have analyzed oxygen isotope rat...