Diatoms are one of the most important eukaryotic primary producers in lower ecosystem; understanding their evolutionary history is therefore also important. Throughout Cenozoic hydrosphere, diatoms have flourished. However, as a result progressive diagenesis and dissolution opaline silica that forms frustules, early evolution during Cretaceous unclear, so fossil record incomplete. Largely becau...

Abstract The sandstone units of the Early Cretaceous Lower Goru Formation are significant reservoir for gas, oil, and condensates in Indus Basin Pakistan. Even though these sandstones rocks hydrocarbon exploration, diagenetic controls on properties poorly documented. For effective production, appraisal a promising reservoir, diagenesis must be comprehensively analyzed first. this study, core sa...

The Berriasian-Valanginian Fahliyan Formation forms one of the giant reservoirs in the subsurface of the Abadan plain, onshore Iran. A detailed petrographical analysis of the available cores and thin sections revealed that the different diagenetic parameters influenced the reservoir quality of the Fahliyan Formation in this field. The Fahliyan Formation has been influenced by three diagenetic e...

As an unconventional oil and gas reservoir, the diagenesis evolution of continental shale controls formation occurrence inorganic organic pores. In order to quantitatively characterize pore characteristics a reservoir their influence on stage, types in Da’anzhai section lower Jurassic Ziliujing Formation were identified by means X-ray diffraction mineral composition analysis argon ion polishing...

the source of cement in oilfields is critical to the prediction of the distribution of cements in the reservoirs and also prediction of reservoir quality. the source of mineral forming cements has been determined for the storrington oolitic carbonate reservoir (middle jurassic great oolite formation, weald basin, onshore uk) using a combination of petrography, electron microscopy, fluid inclusi...

[1] Restricted zones of recent dissolution and secondary aragonite infilling were identified in a coral core collected in 1986 from a living massive Porites colony from the central Great Barrier Reef, Australia. Secondary aragonite needles, 20 mm long, cover skeletal surfaces deposited from 1972 to late 1974 and increase bulk density by 10%. Dissolution is observed above this zone, whereas olde...

The chemical taxonomic relationship of microorganisms has been studied through the hydrocarbon fraction of their chemical constituents. The diagenesis and biological transformations of some hydrocarbons in sediments is suggested, as a result of this information.

We have performed U-Th isotope analyses on pure aragonite samples from the upper sections of Leg 166 cores to assign each aragonite-rich sediment package to the correct sea-level highstand. The uppermost sediment package from each of the four sites investigated (Sites 1003, 1005, 1006, and 1007) yielded a Holocene U-Th age. Sediment packages from deeper in the cores have suffered diagenesis. Th...