Origin of the Myklegardfjellet Bed, a basal Cretaceous marker on Spitsbergen

The Ryazanian Myklegardfjellet Bed, composed of yellow to greenish plastic clays, is a regional marker horizon in central and eastern Spitsbergen, where it occurs just above the boundary between the Agardhfjellet and Rurikfjellet formations. Through a combined mineralogical, sedimentological and mic...

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Bibliographic Details
Published in:Polar Research
Main Authors: Dypvik, Henning, Nagy, Jenø, Krinsley, Dave H.
Format: Article in Journal/Newspaper
Language:English
Published: Norwegian Polar Institute 1992
Subjects:
Online Access:https://polarresearch.net/index.php/polar/article/view/2285
https://doi.org/10.3402/polar.v11i1.6714
Description
Summary:The Ryazanian Myklegardfjellet Bed, composed of yellow to greenish plastic clays, is a regional marker horizon in central and eastern Spitsbergen, where it occurs just above the boundary between the Agardhfjellet and Rurikfjellet formations. Through a combined mineralogical, sedimentological and micropaleontological approach, it is demonstrated that the bed was deposited by marine shelf processes and subsequently altered by decomposition of the unstable glauconite bearing components. These sediments were deposited at the culmination of a shallowing episode in the depositional area. This event marks a shift in depositional mode, from predominantly shelf sedimentation controlled by global eustatic sea level changes (Late Bathonian-Ryazanian), to a locally regulated, deep sea to shallow shelf-prodeltaic to deltaic pattern of deposition (Ryazanian-Hauterivian).