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Use of clay fabric to distinguish turbiditic and hemipelagic siltstones and silts
Author(s) -
O'BRIEN NEAL R.,
NAKAZAWA* KEIJI,
TOKUHASHI* SHUICHI
Publication year - 1980
Publication title -
sedimentology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.494
H-Index - 108
eISSN - 1365-3091
pISSN - 0037-0746
DOI - 10.1111/j.1365-3091.1980.tb01157.x
Subject(s) - geology , turbidite , outcrop , sedimentary rock , sedimentation , clay minerals , sedimentary structures , geochemistry , sediment , geomorphology , weathering , slumping , total organic carbon , sedimentary depositional environment , mineralogy , structural basin , ecology , biology
Pliocene and Holocene siltstones and silts in outcrops from the Boso Peninsula, Japan and in cores from the East China were studied to determine distinctive characteristics of the turbiditic (Bouma E‐Division) and hemipelagic siltstones and silts. Weathering characteristics, colour, grain size, and organic carbon‐organic nitrogen ratio, plus clay fabric proved valuable in characterizing each unit. Clay and non‐clay mineral content was uniform throughout. Clay fabric differences are pronounced. Random clay flake orientation prevails in the turbiditic interval while the hemipelagic unit has more preferred orientation. The fabric reflects different conditions of sedimentation. The turbiditic clay was deposited more rapidly in the flocculated state while the interturbidite hemipelagic clay may have formed from more slowly sedimented dominantly dispersed clay. Results suggest that clay fabric may be useful in combination with other sedimentary features in the study of mud‐turbidite sedimentation.