GAS HYDRATES AND MAGNETISM: COMPARATIVE GEOLOGICAL SETTINGS FOR DIAGENETIC ANALYSIS ...
Geochemical processes associated with gas hydrate formation lead to the growth of iron sulphides which have a geophysically-measurable magnetic signature. Detailed magnetic investigation, complemented by petrological observations, were undertaken on cores from a permafrost setting, the Mackenzie Del...
| Main Authors: | , , |
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| Format: | Text |
| Language: | English |
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The University of British Columbia
2008
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.14288/1.0040993 https://doi.library.ubc.ca/10.14288/1.0040993 |
| Summary: | Geochemical processes associated with gas hydrate formation lead to the growth of iron sulphides which have a geophysically-measurable magnetic signature. Detailed magnetic investigation, complemented by petrological observations, were undertaken on cores from a permafrost setting, the Mackenzie Delta (Canadian Northwest Territories) Mallik region, and two marine settings, IODP Expedition 311 cores from the Cascadia margin off Vancouver Island and the Indian National Gas Hydrate Program Expedition 1 from the Bengal Fan. Stratigraphic profiles of the fine scale variations in bulk magnetic measurements correspond to changes in lithology, grain size and pore fluid geochemistry which can be correlated on local to regional scales. The lowest values of magnetic susceptibility are observed where iron has been reduced to paramagnetic pyrite, formed in settings with high methane and sulphate or sulphide flux, such as at methane vents. High magnetic susceptibility values are observed in sediments which contain ... |
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