Release of methane from large marine reservoirs has been linked to climate change, as a causal
mechanism and a consequence of temperature changes, during the Holocene to Late Quaternary.
These inferred linkages are based primary on variation in benthic foraminifer’s singnatures. This
study examines and illustrates deep sea benthic foraminifera from Holocene to Late Quaternary
sample from North Pacific Ocean IODP site 890B,Cascadia Margin. Deep sea benthic foraminifera
has been quantatively analyzed in samples>125 μm size fractions. Factor and Cluster analysis of the
29 highest ranked species made it possible to identify six biofacies, characterizing distinct deep sea
environmental setting. The environmental interpretation of each biofacies is based on the ecology of
recent deep sea benthic foraminifera. The benthic faunal record indicates fluctuating deep se
condition in environmental parameter including oxygenation, surface productivity and organic food
supply. The benthic assemblage show a major shift at 2 to3 kyrs BP and 6 to10.5 BP marked by
major turnover in the relative abundance of species coinciding with in increasing amplitude of interstadial
cycles. There are strong possibilities of methane flux in this site. Dissociation of gas hydrates
and release of methane to the atmosphere could be a cause of increase in the population abundance of
highly reducing environmental species, which we interpreted in our data.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/1202 |
| Date | 07 1900 |
| Creators | Kumar, Amit, Gupta, Anil Kumar |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Rights | Kumar, Amit |
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