Equations are developed for the calculation of the simultaneous variations in trace element concentrations and radiogenic and stable isotopic compositions that occur during water-rock interaction. The equations are of general use for modeling chemical and isotopic variations in porous media and are applied here to the diagenesis of carbonate rocks and sediments. The variables which control the ...

The redeposition of pristine phosphorite plays an important role in phosphorus accumulation, which created reworked extensively on the continental shelf. This paper, using geochemical analysis combined with data from petrology and diagenesis, focuses reconstruction formation processes Late Cretaceous Thaniyat deposition northwestern Saudi Arabia, is a part famous large Neo-Tethys Ocean’s deposi...

Investigation of modern and fossil teeth from northern and central Kenya, using the ion microprobe, electron microprobe, and transmission electron microscope, confirms that fossil tooth chemistry is controlled not only by the diagenetic precipitation of secondary minerals but also by the chemical alteration of the biogenic apatite. Increases in the concentrations of Fe, Mn, Si, Al, Ba, and poss...

[1] We present molybdenum isotope and concentration data from 14 sites in the eastern Pacific from the central California to the Peru margin. The environments studied have been chosen to represent a broad range in oxidation-reduction (redox) potential, which provide a framework for the behavior of this redoxsensitive element. Manganese-rich hemipelagic sediments from the eastern tropical Pacifi...

Introduction Conclusions References

The sediment of a highly productive lake (Priest Pot, UK) contains the biosynthesised hopanoid bacteriohopanetetrol (BHT) and a series of hopanediols and triols. These polyols represent intermediate stages in the conversion of biologically produced hopanoids to the diagenetic products, hopanes. Two of these geohopanoids, assigned as trishomohopane-32,33-diol and bishomohopane-30,31,32-triol hav...