About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
CSPG Bulletin
Abstract
Ichnofabrics and Biologically Mediated Changes in Clay Mineral Assemblages from a Deep-water, Fine-grained, Calcareous Sedimentary Succession: an Example from the Upper Cretaceous Wyandot Formation, Offshore Nova Scotia
Abstract
The Upper Cretaceous Wyandot Formation is a 400 m thick succession of fine-grained calcareous mudstone deposited in an outer shelf to upper bathyal setting. The formation is divided into two lithofacies, a pure chalk and an interbedded kaolinite-bearing, argillaceous and calcareous claystone. Components of both lithofacies are derived from primary production in the photic zone, being rich in foraminifers and coccoliths. The Wyandot Formation is bioturbated, showing classic tiering and continual overprinting of trace fossils related to low pelagic sediment accumulation rates. Ichnological analysis reveals trends of environmental deterioration and amelioration. Changes in trace fossil assemblages are linked to fluctuations of organic matter input leading to rising of the redox front and low porewater/sediment oxygenation which excluded many endobenthic organisms. Mineralogical differences between burrow fill and host sediment demonstrate that bioturbation affects sediment texture by altering authigenic clay mineral assemblages. The clay mineral assemblage within burrows was found to be more diverse than in the surrounding sediment. This is probably the result of low temperature authigenesis in the digestive system of deposit feeding endobenthos, ingesting sedimentary particles and egesting material of a different mineralogical composition.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |