[1] In recent years it has become apparent that the ‘‘cool tropic paradox’’ of Paleogene and Cretaceous ‘‘greenhouse’’ climates arises because of the diagenetic alteration of tropical planktic foraminiferal calcite near the seafloor, yielding artificially high dO values. Because the Mg/Ca compositions of foraminiferal and inorganic calcite are thought to be quite different, Mg/Ca measurements s...

-Illite polytype quantification allows the differentiation of diagenetic and detrital illite components. In Paleozoic shales from the Illinois Basin, we observe 3 polytypes: 1M d, 1M and 2M~. 1M d and 1M are of diagenetic origin and 2M1 is of detrital origin. In this paper, we compare experimental X-ray diffraction (XRD) traces with traces calculated using WILDFIRE 9 and quantify mixtures of al...

The significant degradation that fossilized biomolecules may experience during burial makes it challenging to assess the biogenicity of organic microstructures in ancient rocks. Here we investigate the molecular signatures of 1.88 Ga Gunflint organic microfossils as a function of their diagenetic history. Synchrotron-based XANES data collected in situ on individual microfossils, at the submicro...

This study investigates stable isotope signatures of five species of Silurian and Devonian deep-water, ahermatypic rugose corals, providing new insights into isotopic fractionation effects exhibited by Palaeozoic rugosans, and possible role of diagenetic processes in modifying their original isotopic signals. To minimize the influence of intraskeletal cements on the observed signatures, the ana...

The Ediacaran Doushantuo biota has yielded fossils that include the oldest widely accepted record of the animal evolutionary lineage, as well as specimens with alleged bilaterian affinity. However, these systematic interpretations are contingent on the presence of key biological structures that have been reinterpreted by some workers as artefacts of diagenetic mineralization. On the basis of ch...

The acoustic properties of heterozoan and photozoan carbonates are compared interpreted in the light their distinct patterns diagenetic evolution. combined role depositional processes on petroacoustic signatures both has been assessed basis a multi-disciplinary multi-scale study Oligo-Miocene limestone outcrops from Cape Range peninsula (NW Australia). This integrates detailed analysis (using s...

The experiences of developing engineering geological models in karst areas for designing and construction purposes prove the necessity of considering at least three basic submodels: sedimentological, structural-tectonic and the weathering one. The research presented here deals with very important and frequently neglected segments in each of the submodels. Therefore, particular attention should ...

Oxygen isotope records of planktonic foraminifera indicate that Late Eocene and Oligocene tropical sea surface temperatures were as much as 88C lower than present at a time when high latitude sea surface temperatures were higher than present. Using a numerical model which describes oxygen isotope exchange during burial and recrystallization of deep sea carbonate, the effects of diagenesis on bu...