Hydrocarbon Generation by the Rocks of the Bremer Formation in Adjacent Areas of the Nonvolcanic Passive Margins of Australia and Antarctica

This paper analyzes differences in the history of hydrocarbon (HC) generation by the rocks of the Bremer 1–6 formations in adjacent areas of the nonvolcanic passive continental margins of Australia and Antarctica. The problem is examined by the example of the numerical reconstruction of the burial and thermal history of two sedimentary sequences of approximately equal thicknesses: the section of well 19–2012 in the Bremer sub-basin of the southwestern margin of Australia and the section of pseudowell 2 in the adjacent area of the passive margin of Antarctica on seismic profile 5909 across the Mawson Sea. The asymmetry of Gondwana rifting in the region of interest resulted in asymmetry in the tectonic structure and development of adjacent areas of passive margins and, as a consequence, significantly different histories of HC generation by the rocks of the Bremer 1–6 formations in these areas. Modeling indicates that the rocks of the Bremer 1 and 2 formations are mainly gas-prone in the Bremer basin and can become oil-prone in the Mawson Sea region of the Antarctic margin. In contrast, according to modeling, the rocks of the Bremer 4 and 5 formations generate a minor amount of HC in the well 19–2012 area of the Bremer sub-basin and considerable amounts of heavy and light oil in the adjacent Antarctic margin area at pseudowell 2 in the Mawson Sea.     

Platinum Group Element Geochemistry in Ferromanganese Crust of the Detroit Guyot,Pacific Ocean

Oceanology - Abstract—Hydrogenetic Fe–Mn crusts in the ocean are enriched in platinum but do not accumulate palladium. The mechanism of platinum input into the crusts remains debatable....     

Evolution of the Kerguelen plume and its impact upon the continental and oceanic magmatism of East Antarctica

Petrological–geochemical study showed that the alkaline-ultramafics of the Jetty Oasis (rift zone of the Lambert glacier, East Antarctica) are similar in the age (117–110 Ma) and geochemistry to the ultrapotassic alkali basalts of eastern India (Jharia and Raniganj intrusions). Alkaline magmatism in India and Antarctica is related to the activity of the Kerguelen plume, which significantly affected the evolution of the entire eastern Indian Ocean, in particular, determined geodynamic peculiarities of the ocean opening (existence of non-spreading blocks, fragments of the Gondwana lithosphere in oceanic areas) and geochemical characteristics of erupted tholeiitic magmas. Enriched magma sources related to the Kerguelen plume were formed by melting of ancient Gondwana-derived continental fragments, which experienced multiple transformations during its evolution up to the formation of metasomatized mantle under the impact of the Kerguelen plume on the Antarctic and India margins.     

Determination of the platinum-group elements and gold in ferromanganese nodule reference material NOD-A-1

The concentrations of Ru, Pd, Ir, Pt, and Au were determined in a ferromanganese nodule reference sample NOD-A-1 by inductively coupled plasma mass-spectrometry. Sample preparation procedures include acid digestion and anion exchange preconcentration. Standard addition method was used to eliminate losses of the analyte during the chromatographic separation. The results are in agreement with previously published data. The low level of intermediate precision for Au between different subsamples of the same sample probably originates from the heterogeneous distribution of Au in ferromanganese nodules. The accumulation of PGE in ferromanganese nodules was studied using international reference samples.