scholarly journals Organic geochemistry of continental margin and deep ocean sediments

1992 ◽  
Author(s):  
J.K. Whelan ◽  
J.M. Hunt ◽  
J.M. Seewald ◽  
L.B. Eglinton ◽  
M. Zawoysky ◽  
...  
Keyword(s):  
Continental Margin ◽  
Organic Geochemistry ◽  
Deep Ocean

scholarly journals Organic geochemistry of continental margin and deep ocean sediments. Progress report, 1 March 1991--28 February 1993

1992 ◽  
Author(s):  
J.K. Whelan ◽  
J.M. Hunt ◽  
J.M. Seewald ◽  
L.B. Eglinton ◽  
M. Zawoysky ◽  
...  
Keyword(s):  
Continental Margin ◽  
Organic Geochemistry ◽  
Deep Ocean ◽  
Progress Report

scholarly journals Organic geochemistry of continental margin and deep ocean sediments

1990 ◽  
Author(s):  
J.K. Whelan ◽  
J.M. Hunt ◽  
T. Eglinton ◽  
P. Dickinson ◽  
C. Johnson ◽  
...  
Keyword(s):  
Continental Margin ◽  
Organic Geochemistry ◽  
Deep Ocean

scholarly journals Neoproterozoic Nafun Group Sediments from Oman Affected by an Active Continental Margin

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 511
Author(s):  
Liang Yue ◽  
Veerle Vandeginste
Keyword(s):  
Continental Margin ◽  
Water Oxidation ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Trace Element Analysis ◽  
Deep Ocean ◽  
Geochemical Data ◽  
Ocean Water ◽  
Element Analysis ◽  
Deep Ocean Water

The Neoproterozoic era is a time of major environmental change in Earth history. The Ediacaran period (635–541 Ma), the uppermost division of Precambrian time, is characterized by the remarkable Shuram excursion (largest C isotope negative excursion), a deep ocean water oxidation event, and Ediacaran biota. The Nafun Group of Oman provides a well-preserved and mostly continuous section of an Ediacaran succession. Based on geochemical data from the Nafun Group, the Shuram excursion (SE) and deep ocean oxidation hypotheses were proposed. Now, we sampled this section at high stratigraphic resolution, and present here the petrographical and geochemical analysis of the Khufai, Shuram and Buah Formations. The major and trace element analysis of shales from the Shuram Formation indicates that northern Oman was an active continental margin environment in Neoproterozoic times. The provenance of the Shuram Formation was primarily mafic and intermediate igneous rocks. With the unsteady tectonic setting, the development of the Nafun Group was influenced by hydrothermal supply and volcaniclastic input. Based on the V/Cr and U/Th ratio of the samples from the Nafun Group, our study reveals the transition of the ocean water redox environment, which is connected to the rise and fall of the Ediacaran biota. Our study constrains the tectonic setting of northern Oman and the petrography and geochemical data from the Nafun Group for the hydrothermal and volcaniclastic supply. Thus, our study acknowledges more factors for the explanation of the Ediacaran conundrums.

Scientific aspects of well logging in deep ocean drill sites on Leg 48 - Biscay and Rockall areas

1980 ◽  
Vol 294 (1409) ◽  
pp. 105-119
Keyword(s):  
Continental Margin ◽  
Deep Ocean ◽  
Well Logging ◽  
Core Material ◽  
Seismic Record ◽  
Additional Information ◽  
The Core ◽  
Continuous Record ◽  
The Future ◽  
Tools And Techniques

Downhole logging techniques are already widely used in the petroleum and mining industries. Despite strong recommendations, no logging has been attempted before in holes drilled on the continental margin areas where such techniques might reasonably be expected to produce worthwhile results. These logs will ideally be a complete and continuous record of the interval surveyed, will provide valuable correlative information against cores, back-up information for the seismic record, and will suggest general lithologies where no core exists. This paper highlights and comments on the degree to which these logs succeed in their objectives and suggests alternative tools and techniques that might be used in the future. Recording the logs digitally at the well site has enabled the full interplay of computer techniques to be used to help in the analysis. Valuable additional information from the logs suggests re-examination and further analyses of the core material.

scholarly journals Organic geochemistry of continental margin sediments

1979 ◽  
Author(s):  
J.M. Hunt ◽  
J.K. Whelan ◽  
A.Y. Huc ◽  
M. Pratt
Keyword(s):  
Continental Margin ◽  
Organic Geochemistry

DEPOSITIONAL ENVIRONMENTS AND GEOTECTONIC FRAMEWORK: SOUTHERN AUSTRALIAN CONTINENTAL MARGIN

1976 ◽  
Vol 16 (1) ◽  
pp. 25 ◽  
Author(s):  
I. Deighton ◽  
D.A. Falvey ◽  
D.J. Taylor
Keyword(s):  
Continental Margin ◽  
Rift Valley ◽  
Upper Cretaceous ◽  
Deep Ocean ◽  
Ocean Basin ◽  
Depositional Environments ◽  
Ocean Current ◽  
Spreading Ridge ◽  
Marine Influence ◽  
Sea Floor Spreading

Three principal phases occurred in the development of the basins of the southern Australian continental margin: epi-continental, marginal continental and oceanic. These correspond generally to the phases of margin development proposed by Falvey (1974): pre-rift, rift valley, and post-breakup; but tectonic and depositional transitions are not necessarily contemporaneous.Prior to the Upper Cretaceous, the region of the present day southern Australian margin lay well within the Eastern Gondwanaland continent, essentially barred from deep ocean basins. During the Upper Cretaceous the series of epicontinental basins was increasingly subjected to marine breakthroughs. Thus marine ingressive horizons were deposited along an incipient rift valley between the primitive Indian Ocean and Tasman Sea. Rift valley subsidence, possibly related to deep crustal metamorphism, was most significant on the flanks of the rift zone. Further marine influence during the Paleocene ('infra-breakup') and early Eocene corresponded to the onset of seafloor spreading between Australia and Antarctica. The neo-breakup phase is dominated by shelf and plateau subsidence and spreading ridge development, with topography influencing ocean current. The changing palaeogeography can be accurately illustrated by computer-derived reconstructions based on quantitative sea-floor spreading data. Quantitative thermal uplift/subsidence models can be used to estimate post-breakup water depth of the subsiding ocean basin and the continental margin. A complex pattern of transgressive continental deposition and submarine erosion diminished with the gradual widening of the Southern Ocean and the establishment of circumpolar ocean current paths. Oceanic basins dominated the margin through the Neogene.

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