NATURAL GAS HYDRATES UP CLOSE: A COMPARISON OF GRAIN CHARACTERISTICS OF SAMPLES FROM MARINE AND PERMAFROST ENVIRONMENTS AS REVEALED BY CRYOGENIC SEM
Using cryogenic SEM, we investigated the physical states of gas-hydrate-bearing samples recovered by drill core from several localities including the SE India margin (NGHP Expedition 01), Cascadia margin (IODP Leg 311), Gulf of Mexico (RV Marion Dufresne 2002), and Mackenzie River Delta (Mallik site...
Main Authors: | , |
---|---|
Other Authors: | , |
Format: | Conference Object |
Language: | English |
Published: |
2008
|
Subjects: | |
Online Access: | http://hdl.handle.net/2429/1109 |
id |
ftunivbritcolcir:oai:circle.library.ubc.ca:2429/1109 |
---|---|
record_format |
openpolar |
spelling |
ftunivbritcolcir:oai:circle.library.ubc.ca:2429/1109 2023-05-15T17:09:40+02:00 NATURAL GAS HYDRATES UP CLOSE: A COMPARISON OF GRAIN CHARACTERISTICS OF SAMPLES FROM MARINE AND PERMAFROST ENVIRONMENTS AS REVEALED BY CRYOGENIC SEM Stern, Laura A. Kirby, Stephen H. University of British Columbia. Department of Chemical and Biological Engineering International Conference on Gas Hydrates (6th : 2008 : Vancouver, B.C.) Mackenzie River Delta (N.W.T. and Yukon) India Mexico, Gulf of 2008-07 5380134 bytes application/pdf http://hdl.handle.net/2429/1109 eng eng Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ CC-BY-NC-ND Gas hydrates Scanning electron microscopy Grain characteristics Cascadia Gulf of Mexico Mallik Text Conference Paper 2008 ftunivbritcolcir 2019-10-15T17:43:35Z Using cryogenic SEM, we investigated the physical states of gas-hydrate-bearing samples recovered by drill core from several localities including the SE India margin (NGHP Expedition 01), Cascadia margin (IODP Leg 311), Gulf of Mexico (RV Marion Dufresne 2002), and Mackenzie River Delta (Mallik site, well 5L-38). Core material with a significant fraction of preserved hydrate has only been obtained for cryogenic SEM investigation from relatively few sites worldwide to date, yet certain consistent textural characteristics, as well as some clear differences between sites have been observed. Gas hydrate in cores recovered from Cascadia, Gulf of Mexico, and Mallik often occurs as a dense substrate with typical grain size of 30 to as large as 200 μm. The hydrate often contains a significant fraction of isolated macropores that are typically 5–100 μm in diameter and occupy 10-30 vol. % of the domain. In fine-grained sediment sections of marine samples, gas hydrate commonly forms small pods or lenses with clay platelets oriented sub-parallel around them, or as thin veins 50 to several hundred microns in thickness. In some sections, hydrate grains are delineated by a NaCl-bearing selvage that forms thin rinds along hydrate grain exteriors, presumably produced by salt exclusion during original hydrate formation. Preliminary assessment of India NGHP-01 samples shows some regions consistent with the observations described above, as well as other regions dominated by highly faceted crystals that line the walls or interior of cavities where the hydrate grows unimpeded. Here, we focus on gas hydrate grain morphology and microstructures, pore characteristics and distribution, and the nature of the hydrate/sediment grain contacts of the recovered samples, comparing them to each other and to laboratory-produced gas hydrates grown under known conditions. Non UBC Unreviewed Conference Object Mackenzie river permafrost Yukon University of British Columbia: cIRcle - UBC's Information Repository Mackenzie River Yukon |
institution |
Open Polar |
collection |
University of British Columbia: cIRcle - UBC's Information Repository |
op_collection_id |
ftunivbritcolcir |
language |
English |
topic |
Gas hydrates Scanning electron microscopy Grain characteristics Cascadia Gulf of Mexico Mallik |
spellingShingle |
Gas hydrates Scanning electron microscopy Grain characteristics Cascadia Gulf of Mexico Mallik Stern, Laura A. Kirby, Stephen H. NATURAL GAS HYDRATES UP CLOSE: A COMPARISON OF GRAIN CHARACTERISTICS OF SAMPLES FROM MARINE AND PERMAFROST ENVIRONMENTS AS REVEALED BY CRYOGENIC SEM |
topic_facet |
Gas hydrates Scanning electron microscopy Grain characteristics Cascadia Gulf of Mexico Mallik |
description |
Using cryogenic SEM, we investigated the physical states of gas-hydrate-bearing samples recovered by drill core from several localities including the SE India margin (NGHP Expedition 01), Cascadia margin (IODP Leg 311), Gulf of Mexico (RV Marion Dufresne 2002), and Mackenzie River Delta (Mallik site, well 5L-38). Core material with a significant fraction of preserved hydrate has only been obtained for cryogenic SEM investigation from relatively few sites worldwide to date, yet certain consistent textural characteristics, as well as some clear differences between sites have been observed. Gas hydrate in cores recovered from Cascadia, Gulf of Mexico, and Mallik often occurs as a dense substrate with typical grain size of 30 to as large as 200 μm. The hydrate often contains a significant fraction of isolated macropores that are typically 5–100 μm in diameter and occupy 10-30 vol. % of the domain. In fine-grained sediment sections of marine samples, gas hydrate commonly forms small pods or lenses with clay platelets oriented sub-parallel around them, or as thin veins 50 to several hundred microns in thickness. In some sections, hydrate grains are delineated by a NaCl-bearing selvage that forms thin rinds along hydrate grain exteriors, presumably produced by salt exclusion during original hydrate formation. Preliminary assessment of India NGHP-01 samples shows some regions consistent with the observations described above, as well as other regions dominated by highly faceted crystals that line the walls or interior of cavities where the hydrate grows unimpeded. Here, we focus on gas hydrate grain morphology and microstructures, pore characteristics and distribution, and the nature of the hydrate/sediment grain contacts of the recovered samples, comparing them to each other and to laboratory-produced gas hydrates grown under known conditions. Non UBC Unreviewed |
author2 |
University of British Columbia. Department of Chemical and Biological Engineering International Conference on Gas Hydrates (6th : 2008 : Vancouver, B.C.) |
format |
Conference Object |
author |
Stern, Laura A. Kirby, Stephen H. |
author_facet |
Stern, Laura A. Kirby, Stephen H. |
author_sort |
Stern, Laura A. |
title |
NATURAL GAS HYDRATES UP CLOSE: A COMPARISON OF GRAIN CHARACTERISTICS OF SAMPLES FROM MARINE AND PERMAFROST ENVIRONMENTS AS REVEALED BY CRYOGENIC SEM |
title_short |
NATURAL GAS HYDRATES UP CLOSE: A COMPARISON OF GRAIN CHARACTERISTICS OF SAMPLES FROM MARINE AND PERMAFROST ENVIRONMENTS AS REVEALED BY CRYOGENIC SEM |
title_full |
NATURAL GAS HYDRATES UP CLOSE: A COMPARISON OF GRAIN CHARACTERISTICS OF SAMPLES FROM MARINE AND PERMAFROST ENVIRONMENTS AS REVEALED BY CRYOGENIC SEM |
title_fullStr |
NATURAL GAS HYDRATES UP CLOSE: A COMPARISON OF GRAIN CHARACTERISTICS OF SAMPLES FROM MARINE AND PERMAFROST ENVIRONMENTS AS REVEALED BY CRYOGENIC SEM |
title_full_unstemmed |
NATURAL GAS HYDRATES UP CLOSE: A COMPARISON OF GRAIN CHARACTERISTICS OF SAMPLES FROM MARINE AND PERMAFROST ENVIRONMENTS AS REVEALED BY CRYOGENIC SEM |
title_sort |
natural gas hydrates up close: a comparison of grain characteristics of samples from marine and permafrost environments as revealed by cryogenic sem |
publishDate |
2008 |
url |
http://hdl.handle.net/2429/1109 |
op_coverage |
Mackenzie River Delta (N.W.T. and Yukon) India Mexico, Gulf of |
geographic |
Mackenzie River Yukon |
geographic_facet |
Mackenzie River Yukon |
genre |
Mackenzie river permafrost Yukon |
genre_facet |
Mackenzie river permafrost Yukon |
op_rights |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_rightsnorm |
CC-BY-NC-ND |
_version_ |
1766065822359355392 |