The long-term goal of this study is to develop a better mechanistic and quantitative understanding of the effects of biologically-enhanced transport, mineralogy, sediment fabric, and particle surface chemistry on biogeochemical reactions occurring in coastal sediments. Specifically, we plan to provide quantitative expressions of biogeochemical processes from field and laboratory studies and to ...

Abstract Surficial sediments on the seafloor from passive continental margins can provide insight into recent Late Quaternary sedimentary dynamics acting over offshore systems. This work focuses study of some particular ferruginous tubular structures resembling bioforms (FTB) located in distal Galician Continental Margin (NW Iberian Margin) at water depths between ~ 1550 and 2200 m. The charact...

The different types of elements that occurred together in conodont apparatuses are not recovered from the fossil record in the expected numbers. The causes of this are complex and difficult to study. Numerous complete articulated skeletons of Ozarkodina excavata (Branson and Mehl) have been recovered from the Eramosa Member at Hepworth, Ontario, and as a consequence, several of the potential bi...

Detailed magnetostratigraphic studies of Late Neogene siliciclastic sediments of the Awatere Group, South Island, New Zealand (41°45'S, 174°05'E) have revealed a wide range of palaeomagnetic behaviour. Examination of rock magnetic properties was undertaken using conventional palaeomagnetic techniques and thermomagnetic, X-ray diffraction and electron microprobe analyses. These analyses indicate...

Stable isotope analysis of skeletal tissues is widely used in archeology and paleoanthropology to reconstruct diet. In material that is poorly preserved or very old, the tissue of choice is frequently tooth enamel, since this is less susceptible to diagenesis. The relationships between carbon isotope ratios in tooth enamel (δ(13) C(enamel) ), bone collagen (δ(13) C(collagen) ), and bone apatite...

Mathematical modeling of sediment early diagenesis always involves choosing and describing a set of chemical reactions and processes that is both self-consistent and sufficient for the problem at hand. This critical choice is always a compromise between describing the system’s complexity in all details and using a manageable set of reactions with known or obtainable parameters such as equilibri...

A previous study of strontium/calcium (Sr/Ca) ratios in Paranthropus suggested that it consumed more animal foods than was previously believed. However, that study looked at Sr/Ca in fossil bone, which is known to be highly susceptible to diagenesis. Enamel, in contrast, is resistant to post-mortem alteration making it a more appropriate material for Sr/Ca analysis of Plio-Pleistocene fossils. ...

Early diagenetic modification of magnetic properties is an important process in marine sediments, but temporal and spatial variability of diagenetic processes have rarely been reported for recent coastal sediments. The magnetic properties of sediments from the Ria de Vigo (NW Spain) define a marked three-part zonation with depth. The uppermost zone is magnetically dominated by (titano-)magnetit...

Prehistoric cave sediments are often subjected to severe mechanical and chemical alteration, making it difficult to interpret aspects of their archaeology. Theopetra cave offers unique opportunities to resolve aspects of this problem, particularly in relation to chemical changes, because it has a relatively well defined stratigraphy and its older deposits have been subjected to unusually severe...