Total organic carbon content and redox-sensitiv trace metal concentrations of selected late Cenoman claystones from DSDP Hole 93-603B

The Cenomanian/Turonian (C/T) intervals at DSDP Sites 105 and 603B from the northern part of the proto-North Atlantic show high amplitude, short-term cyclic variations in total organic carbon (TOC) content. The more pronounced changes in TOC are also reflected by changes in lithology from green claystones (TOC<1%) to black claystones (TOC>1%). Although their depositional history was different, the individual TOC cycles at Sites 105 and 603B can be correlated using stable carbon isotope stratigraphy. Sedimentation rates obtained from the isotope stratigraphy and spectral analyses indicate that these cycles were predominately precession controlled. The coinciding variations in HI, OI, delta13Corg and the abundance of marine relative to terrestrial biomarkers, as well as the low abundance of lignin pyrolysis products generated from the kerogen of the black claystones, indicate that these cyclic variations reflect changes in the contribution of marine organic matter (OM). The cooccurrence of lamination, enrichment of redox-sensitive trace metals and presence of molecular fossils of pigments from green sulfur bacteria indicate that the northern proto-North Atlantic Ocean water column was periodically euxinic from the bottom to at least the base of the photic zone (<150 m) during the deposition of the black claystones. In contrast, the green claystones are bioturbated, are enriched in Mn, do not show enrichments in redox-sensitive trace metals and show biomarker distributions indicative of long oxygen exposure times, indicating more oxic water conditions. At the same time, there is evidence (e.g., abundance of biogenic silica and significant 13C-enrichment for OC of phytoplanktic origin) for enhanced primary productivity during the deposition of the black claystones. We propose that increased primary productivity periodically overwhelmed the oxic OM remineralisation potential of the bottom waters resulting in the deposition of OM-rich black claystones. Because the amount of oxygen used for OM remineralisation exceeded the amount supplied by diffusion and deep-water circulation, the northern proto-North Atlantic became euxinic during these periods. Both Sites 105 and 603B show trends of continually increasing TOC contents and HI values of the black claystones up section, which most likely resulted from both enhanced preservation due to increased anoxia and increased production of marine OM during oceanic anoxic event 2 (OAE2).

Interaction of waves and currents /

This report presents an overview of wave-current interacion, including comprehensive review of references to significant U.S. and foreign literature available through December 1981. Specific topics under review are the effects of horizontally and vertically varying currents on waves, wave refraction by currents, dissipation and turbulence, small- and medium-scale currents, caustics and focusing, and wave breaking. The results of the review are then examined for engineering applications. The most appropriate general-purpose computer program to include wave-current interaction is the Dutch Rijkswaterstaat program CREDIZ, which is based on a parabolic wave equation. Further applications include wave and current forces on structures and possibly sediment transport. The report concludes with a brief state-of-the-art review of wave-current interaction and a list of topics needing further research and development.

Annotated bibliography on wave-current interaction /

This annotated bibliography discusses 60 key publications dealing with wave-current interaction. Each entry includes a bibliographic identification, keywords, a discussion of contents, and a statement of coastal engineering significance. An index of the entries by keywords is provided in an appendix. The recent growth of the wave-current interaction field is indicated by the fact that more than 30 percent of the selected publications were published in 1978 and 1979. (Author).

Upplandsmaalet : eit lite uppkast til ei overgansform aat landsmaalet.

Cover-title.

Monographie der arktischen Acariden /

Blank leaves bound between each leaf.

Norske ordsprog...

Mode of access: Internet.

Eusebius Werke /

Original Greek texts, some supplemented or accompanied by Latin versions; texts preserved in other languages, and editorial matter, in German.

Register til en del Norske tidsskrifter.

Vol. 1 mainly compiled by Ivar Sæter; edited by Arne Arnesen. cf. Pref.

Rococonoveller.

Mode of access: Internet.

Industri- och slöjdutställningen i Gefle 1901 : officiell berättelse /

Includes one folded map.

Ortnamnen i Älvsborgs län.

Issued in 25 pts. Pt. 1: Inledning, by Ivar Lundahl, issued by Kungl. Ortnamnskommissionen; pts. 2-25, by Kungl. Ortnamnskommittén.

Samlede værker /

Bd. 1. Arne. Synnøve Sølbakken. En glad gut. Jærnbanen og kirkegården. -- Bd. 2. Fiskerjænten. Brudeslåtten. Småstykker. Kaptejn Mansana. -- Bd. 3. Magnhild. Støv. Mors Hænder. Én dag. Et styggt barndomsminne. Ivar Bye. Absalons hår. -- Bd. 4. Det flager i byen og på havnen. -- Bd. 5. På Guds veje. Mary. -- Bd. 6. Mellem slagene. Halte-Hulda. Sigurd Slembe. Maria Stuart. Sigurd Jorsalfar. -- Bd. 7. De nygifte. Redaktøren. En fallit. Kongen. Leonarda. Det ny system. -- Bd. 8. Over ævne I-II. Geografi og kjærlighed. Paul Lange og Tora Parsberg. En hanske. -- Bd. 9. Laboremus. På Storhove. Daglannet. Når den ny vin blomstrer. -- Bd. 10. Digte og sange. Arnljot Gelline. Lyset.

La Galerie de tableaux de la Reine Christine de Suéde ayant appartenu anparavent à l'Enpersur Rodolphe II, plus tard aux ducs d'Orléans. Recherche historique et critique par ...

Mode of access: Internet.