首页|Geochemistry of volcanic glass from Mahanadi offshore region,eastern continental margin of India:Constraints on the contribu-tion of latest Toba super-eruption

Geochemistry of volcanic glass from Mahanadi offshore region,eastern continental margin of India:Constraints on the contribu-tion of latest Toba super-eruption

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The tephra layers in multiple sediment cores from the offshore region of the Mahanadi basin in the northern Bay of Bengal were investigated for possible volcanic sources.The glass shards from those tephra layers were studied for size distribution,texture,and elemental geochemistry to establish chronostratigraphic markers for regional and global Quaternary correlation.The textural features of fine-grained(silty)volcanic glasses suggest the distal source of these tephra deposits.Major element composition with elevated SiO2 contents ranging between 75%-76%and dominance of K2O(>4.5%)over CaO(<0.9%)suggest ashes have originated from siliceous rhyolitic melts,similar to the petrographic composition of tephra from the Toba volcano.The bulk trace element compositions of the same glass shards were comparable with those reported in the youngest Toba tephra reported elsewhere.Likewise,the LREE-dominated chondrite normalized REE profiles of tephra from the Mahanadi basin closely resemble the characteristic REE patterns in Toba ash from other parts of the Indian Ocean and thus confirmed the contribution of the youngest Toba super-eruption for this ash layers.

Mahanadi basinBay of Bengalvolcanic glassglass morphologyglass-chemistry

Muralidhar Kocherla、Durbar Ray、Manavalan Satyanarayanan、Hilda Joao、Virsen Gaikwad、P.B Ramamurty

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CSIR-National Institute of Oceanography,Dona Paula 403004,Goa,India

CSIR-National Geophysical Research Institute,Uppal Road,Hyderabad 500007,India

National Gas Hydrate Program(NGHP)Indiaincharge of IPEV operations is thanked for providing onboard technical support and facilities

2024

海洋学报(英文版)
中国海洋学会

海洋学报(英文版)

CSTPCD
影响因子:0.323
ISSN:0253-505X
年,卷(期):2024.43(2)
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