Geochemistry of gas hydrates of DSDP Hole 84-570
During Deep Sea Drilling Project (DSDP) Leg 84 a core 1 m long and 6 cm in diameter of massive gas hydrate was unexpectedly recovered at Site 570 in upper slope sediment of the Middle America Trench offshore of Guatemala. This core contained only 5-7% sediment, the remainder being the solid hydrate...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.763350 2023-05-15T17:11:55+02:00 Geochemistry of gas hydrates of DSDP Hole 84-570 Kvenvolden, Keith A Claypool, George E Threlkeld, Charles N Sloan, E Dendy LATITUDE: 13.285300 * LONGITUDE: -91.392800 * DATE/TIME START: 1982-02-17T00:00:00 * DATE/TIME END: 1982-11-30T00:00:00 1984-07-21 application/zip, 4 datasets https://doi.pangaea.de/10.1594/PANGAEA.763350 https://doi.org/10.1594/PANGAEA.763350 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.763350 https://doi.org/10.1594/PANGAEA.763350 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Kvenvolden, Keith A; Claypool, George E; Threlkeld, Charles N; Sloan, E Dendy (1984): Geochemistry of a naturally occurring massive marine gas hydrate. Organic Geochemistry, 6, 703-713, https://doi.org/10.1016/0146-6380(84)90091-3 84-570 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg84 North Pacific/SLOPE Dataset 1984 ftpangaea https://doi.org/10.1594/PANGAEA.763350 https://doi.org/10.1016/0146-6380(84)90091-3 2023-01-20T07:32:15Z During Deep Sea Drilling Project (DSDP) Leg 84 a core 1 m long and 6 cm in diameter of massive gas hydrate was unexpectedly recovered at Site 570 in upper slope sediment of the Middle America Trench offshore of Guatemala. This core contained only 5-7% sediment, the remainder being the solid hydrate composed of gas and water. Samples of the gas hydrate were decomposed under controlled conditions in a closed container maintained at 4°C. Gas pressure increased and asymptotically approached the equilibrium decomposition pressure for an ideal methane hydrate, CH4.5-3/4H2O, of 3930 kPa and approached to this pressure after each time gas was released, until the gas hydrate was completely decomposed. The gas evolved during hydrate decomposition was 99.4% methane, ~0.2% ethane, and ~0.4% CO2. Hydrocarbons from propane to heptane were also present, but in concentrations of less than 100 p.p.m. The carbon-isotopic composition of methane was -41 to -44 per mil, relative to PDB standard. The observed volumetric methane/water ratio was 64 or 67, which indicates that before it was stored and analyzed, the gas hydrate probably had lost methane. The sample material used in the experiments was likely a mixture of methane hydrate and water ice. Formation of this massive gas hydrate probably involved the following processes: (i) upward migration of gas and its accumulation in a zone where conditions favored the growth of gas hydrates, (ii) continued, unusually rapid biological generation of methane, and (iii) release of gas from water solution as pressure decreased due to sea level lowering and tectonic uplift. Dataset Methane hydrate PANGAEA - Data Publisher for Earth & Environmental Science Pacific ENVELOPE(-91.392800,-91.392800,13.285300,13.285300) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
84-570 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg84 North Pacific/SLOPE |
spellingShingle |
84-570 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg84 North Pacific/SLOPE Kvenvolden, Keith A Claypool, George E Threlkeld, Charles N Sloan, E Dendy Geochemistry of gas hydrates of DSDP Hole 84-570 |
topic_facet |
84-570 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg84 North Pacific/SLOPE |
description |
During Deep Sea Drilling Project (DSDP) Leg 84 a core 1 m long and 6 cm in diameter of massive gas hydrate was unexpectedly recovered at Site 570 in upper slope sediment of the Middle America Trench offshore of Guatemala. This core contained only 5-7% sediment, the remainder being the solid hydrate composed of gas and water. Samples of the gas hydrate were decomposed under controlled conditions in a closed container maintained at 4°C. Gas pressure increased and asymptotically approached the equilibrium decomposition pressure for an ideal methane hydrate, CH4.5-3/4H2O, of 3930 kPa and approached to this pressure after each time gas was released, until the gas hydrate was completely decomposed. The gas evolved during hydrate decomposition was 99.4% methane, ~0.2% ethane, and ~0.4% CO2. Hydrocarbons from propane to heptane were also present, but in concentrations of less than 100 p.p.m. The carbon-isotopic composition of methane was -41 to -44 per mil, relative to PDB standard. The observed volumetric methane/water ratio was 64 or 67, which indicates that before it was stored and analyzed, the gas hydrate probably had lost methane. The sample material used in the experiments was likely a mixture of methane hydrate and water ice. Formation of this massive gas hydrate probably involved the following processes: (i) upward migration of gas and its accumulation in a zone where conditions favored the growth of gas hydrates, (ii) continued, unusually rapid biological generation of methane, and (iii) release of gas from water solution as pressure decreased due to sea level lowering and tectonic uplift. |
format |
Dataset |
author |
Kvenvolden, Keith A Claypool, George E Threlkeld, Charles N Sloan, E Dendy |
author_facet |
Kvenvolden, Keith A Claypool, George E Threlkeld, Charles N Sloan, E Dendy |
author_sort |
Kvenvolden, Keith A |
title |
Geochemistry of gas hydrates of DSDP Hole 84-570 |
title_short |
Geochemistry of gas hydrates of DSDP Hole 84-570 |
title_full |
Geochemistry of gas hydrates of DSDP Hole 84-570 |
title_fullStr |
Geochemistry of gas hydrates of DSDP Hole 84-570 |
title_full_unstemmed |
Geochemistry of gas hydrates of DSDP Hole 84-570 |
title_sort |
geochemistry of gas hydrates of dsdp hole 84-570 |
publisher |
PANGAEA |
publishDate |
1984 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.763350 https://doi.org/10.1594/PANGAEA.763350 |
op_coverage |
LATITUDE: 13.285300 * LONGITUDE: -91.392800 * DATE/TIME START: 1982-02-17T00:00:00 * DATE/TIME END: 1982-11-30T00:00:00 |
long_lat |
ENVELOPE(-91.392800,-91.392800,13.285300,13.285300) |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
Supplement to: Kvenvolden, Keith A; Claypool, George E; Threlkeld, Charles N; Sloan, E Dendy (1984): Geochemistry of a naturally occurring massive marine gas hydrate. Organic Geochemistry, 6, 703-713, https://doi.org/10.1016/0146-6380(84)90091-3 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.763350 https://doi.org/10.1594/PANGAEA.763350 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.763350 https://doi.org/10.1016/0146-6380(84)90091-3 |
_version_ |
1766068665995755520 |