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...

The appearance of permanent El Niño-like conditions prior to 3 million years ago is founded on sea-surface temperature (SST) reconstructions that show invariant Pacific warm pool temperatures and negligible equatorial zonal temperature gradients. However, only a few SST records are available, and these are potentially compromised by changes in seawater chemistry, diagenesis, and calibration lim...

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...

Abstract Diagenesis can have a major impact on sedimentary mineralogy. Primary magnetic mineral assemblages be modified significantly by dissolution or formation of new minerals during early late diagenesis. At International Ocean Discovery Program Site C0023, which was drilled in the protothrust zone Nankai Trough Expedition 370, offshore Shikoku Island, Japan, non‐steady state conditions prod...

This paper presents a mineralogical and chemical investigation of shale deposits from the U.S. Gulf coast in order to document the mechanisms and reactions involved in the diagenetic conversion of smectite into illite. Cuttings from the 1,250 to 5,500 m stratigraphic interval of a well were sorted by grain size and analzyed by x-ray diffraction to assess chemical and mineralogical trends with d...

We have studied the REE distribution in shallow marine continental platform carbonates belonging to two late Neoproterozoic basins of India. Their REE abundance patterns normalized by chondrite display well defined W-type tetrad effect. Based on chondrite-normalized Gd/Ho, La/Nd ratios, the REE abundance patterns have been classified into three groups. (Y/Ho) and (Y/Dy) concentration ratios ref...

Abstract Calcium isotopes (δ 44/40 Ca) are particularly useful in palaeo‐environmental studies due to the key role of carbonate minerals continental weathering and their formation seawater. The calcium isotope ratio can provide hints on past changes fluxes, environmental shifts, ecological factors alternatively diagenesis rocks. investigation Late Triassic record offers a great opportunity eval...