Carbonate, organic carbon, pyrolysis and composition of the extracts at DSDP Holes 76-534A and 44-391

The geochemical studies of Sites 534 and 391 and their comparison allow us to improve the chemical characterization of different geological formations dating from the early Callovian to the Maestrichtian along the continental margin of eastern North America. Three of the formations are favorable for the preservation of organic matter: (1) the unnamed formation (middle Callovian to Oxfordian), (2) the Blake-Bahama Formation (Berriasian to Barremian), and (3) the Hatteras Formation (Aptian to Cenomanian). The organic matter is mainly detrital, except for a few organic-rich layers where a contribution of aquatic material occurs. In these organic-rich layers, the petroleum potential is medium to good. Maturation has not quite reached the beginning of the oil window even for the deepest organic material.

Thickness and duration of biostratigraphic zones, assemblages, ages and sedimentation rates at DSDP Sites 76-534 and 44-391

In this Initial Report of the Deep Sea Drilling Project, detailed studies of Sites 533 (gas hydrates) on the Blake Outer Ridge and 534 (oldest ocean history) in the Blake-Bahama Basin have provided answers to many geological and geophysical questions posed over the decade that deep drilling has been undertaken in this part of the western North Atlantic. The history of drilling and a historical review of key scientific accomplishments have been presented in the Introduction (Gradstein and Sheridan, this volume). In this final chapter we review highlights of new geological, geophysical and paleoceanographic interpretations presented in this volume, and offer a critical review of this information. We conclude with a listing of some outstanding problems and recommendations for future research, including data collection.

(Table 2) Physical properties at DSDP Holes 44-391 and 76-534

Laboratory measurements on sediment samples and density well logs run at DSDP Site 534 in the Blake-Bahama Basin were used to establish an in situ velocity and density structure. Synthetic seismograms were generated for comparison to reprocessed seismic reflection data in the vicinity of the Site. Uncertainties in the relative positions of the hole and seismic reflection data, velocity corrections, and the composition of the unrecovered section were evaluated. In light of the errors and compressed section, no unique correlation of the seismic reflection data to the drill hole is completely defensible either in this chapter or elsewhere. The preferred correlation resulting from this exercise is as follows, with the Site 534 report correlation shown in parentheses where different. Horizon beta', 887 m; Horizon beta, 950 m (975 m); Horizon C , 1202 m (1250 m); Horizon C, 1268 m (1340 m); Horizon D', 1342 m (1432 m); Horizon D, 1550 m (1552 m). The major differences in these correlations arise from the use of slightly different velocities and hole location relative to the seismic profiles. The Site 534 report results rely on hole placement on a basement flank, whereas in this chapter we locate it within a basement depression still within the uncertainty of the navigation. The Site 534 report also uses drilling rates, CDP velocity analyses, sonobuoy data, and previous similar drilling correlation methods used at Site 391, along with other geologic considerations in arriving at differing results. Although the correlation method used in this investigation is more objective and the hole location uncertainties better defined, in order to have confidence in any results we will require drilling in areas where reflections are either more widely spaced or where we have better vertical velocity control in the hole.

Mineral and chemical compositions of sedimentary and volcano-sedimentary rocks drilled in DSDP Legs 43 and 44

Sedimentary cover on the bottom of the Northwest Atlantic Ocean is underlain by Late Jurassic - Cretaceous tholeiite-basalt formation. It consists of come sedimentary formations with different lithologic features and age. Their composition, stratigraphic position and, distribution are described on materials of deep-sea drilling. Mineralogical and geochemical studies of DSDP Leg 43 and Leg 44 holes lead to new ideas about composition and genesis of some sediment types of and their associations. High metal contents in the chalk formation of black clays on the Bermuda Rise probably result from exhalations. Connection of red-colored and speckled deposits with hiatuses in sedimentation is shown. Main stages of geological history of the North American Basin are reflected in accumulation of the followed formations: ancient carbonate formation (Late Jurassic - Early Cretaceous), formation of black clays rich in organic matter (Cretaceous), formation of speckled clays (Late Cretaceous), siliceous-clayey turbidite formation (Eocene), hemipelagic and pelagic clayey formation (Neogene), and terrigenous turbidite formation (Pleistocene).

Haplotype frequency distribution and linkage disequilibrium analysis of single nucleotide polymorphisms at the human FMO3 gene locus

We analyzed flavin-containing monooxygenase 3 (FMO3) polymorphisms, haplotype structure, and linkage disequilibrium (LD) in 256 Han Chinese and 50 African-American individuals to compare their haplotype frequencies and LD with other world populations. For

(Table 5) Quaternary paleoproductivity of organic carbon in oceans based on DSDP cores

By analogy with the present-day ocean, primary productivity of paleoceans can be reconstructed using calculations based on content of organic carbon in sediments and their accumulation rates. Results of calculations based on published data show that primary productivity of organic carbon, mass of phosphorus involved in the process, and content of phosphorus in ocean waters were relatively stable during Cenozoic and Late Mesozoic. Prior to precipitation on the seafloor together with biogenic detritus, dissolved phosphorus could repeatedly be involved in the biogeochemical cycle. Therefore, only less than 0.1% of phosphorus is retained in bottom sediments. Bulk phosphorus accumulation rate in ocean sediments is partly consistent with calculated primary productivity. Some epochs of phosphate accumulation also coincide with maxima of primary productivity and minima of the fossilization coefficient of organic carbon. The latter fact can testify to episodes of acceleration of organic matter mineralization and release of phosphorus from sediments leading to increase in the phosphorus reserve in paleoceans and phosphate accumulation in some places.