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Karkhanis, Suresh N.
- Chemical Studies on Insoluble Carbonaceous Matter from Precambrian Sediments from Onverwacht Group of South Africa by Electron Spin Resonance and X-Ray Diffraction Techniques
Authors
1 1400, Limberlost Road, London, Ontario, N6G 2V6, CA
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 19, No 6 (1978), Pagination: 233-239Abstract
Electron spin resonance and X-ray diffraction techniques are used to study insoluble carbonaceous matter from Precambrian sediments. Techniques for sample preparation are described. The ESR data when correlated with XRD data show striking parallelism between carbonisation of coal and organic matter during incipient metamorphism. The method is potentially applicable to studies of diagenesis and low rank metamorphism of organic matter in sediments and could be extended to study the levels of organic metamorphism to determine the thermal history of sedimentary basins.- Palaeobiology and Organic Geochemistry of Archean Helen Iron formation, Michipicoten Area
Authors
1 Department of Geology, University of Toronto, Toronto, Ont., M5S IAI, CA
2 Laboratory of Chemical Evolution, Department of Chemistry, University of Maryland, College Park, Maryland 20742, US
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 21, No 1 (1980), Pagination: 1-9Abstract
Diamond Drill Core (D. D. H. U-2-647) samples of approximately 2.75 b.y. old Helen Iron Formation of Michipicoten area in the Superior Province of the Canadian Shield have been examined for morphological and molecular fossils. Evidence shows two types of bioforms - simple micron-sized filamentous microstructures resembling present day iron bacteria and laminated structures designated as cryptalgal mats.
Organic geochemical studies have shown that a variety of organic compounds is present. These include n alkanes, isoprenoid hydrocarbons pristane and phytane and fatty acids. The exact syngenetic nature of these compounds will be evaluated in the future by appropriate control experiments such as permeability measurements, diffusion studies, etc.
Presence of pristane and phytane is indicative of high photosynthetic activity. Predominance of n-C16 (palmitic) acid is significant in view of it being the major constituent of the cell membrane of an organism.
The morphological and molecular evidence and previously reported carbon and sulphur isotope data further substantiate the existence of autotrophic organisms and reducing bacteria in Archean times and they were operative during accumulation of these ancient Precambrian chemical sediments.
- Natural Graphite from Neoproterozoic Psammitic Gneiss, Inanalo Mountain, Southern Madagascar
Authors
1 Analytical Research Laboratory, Department of Polymer and Petroleum Engineering, MIT Engineering College, Kothrud, Pune - 4 11 038, IN
2 NGRI, Hyderabad - 500 007, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 69, No 4 (2007), Pagination: 865-866Abstract
No Abstract.- Shock Basaltic Glasses from Lonar Lake, Maharashtra: a Potential Natural Analogue of Nuclear Waste Glasses
Authors
1 Analytical Research Laboratory, Department of Petroleum and Polymer Engineering, MAEER's Maharashtra Institute of Technology, S No 124, Ex-Servicemen Colony, Kothrud, Pune - 41 1 038, IN
2 Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085, IN