T104 Impacts of Volcanism on Global Climate and Oceans—Drivers of Mass Extinctions through the Phanerozoic II

Monday, 11 October 2021
1:30 PM - 5:30 PM
Portland Ballroom 255 (Hybrid Room)

VOLCANIC LOADING OF METALS AND NUTRIENTS INTO THE CRETACEOUS BOREAL SEA – NOT ALL LIPS ARE KILLERS

Paper number: T104-3
Program: Technical Sessions
Time: 1:55 PM – 2:10 PM

Authors

Abstract

Cretaceous sediments of Arctic Canada were deposited at near present day latitudes and provide insight into the impacts that the High Arctic Large Igneous Province (HALIP) and arc volcanism along western North America had within the Cretaceous Boreal marine environment. Here we examine Upper Cretaceous sediments from the Smoking Hills, on the northern mainland coast of Arctic Canada, in the Northwest Territories. These sediments include the anomalous bituminous mudstone of the Smoking Hills Formation occurs, that is characterised by a prominent negative carbon isotope excursion. Likely deposited during OEA3, the Smoking Hills Formation is a pyritiferous mudstone enriched in organic matter (mean total organic carbon content of 5.2 wt. %) and trace metals (maximum values expressed as multiples of average shale composition are: Cd 650x, Zn 12x, As 14x, Cu 3.4x, Pb 2.2x, Ni 2.0x, Co 1.7x, Cr 1.3x). A strong correlation between total trace metal content and heulandite (a zeolite mineral formed as an alteration product of volcanic glass) suggest a relationship between metal loading and volcanism. While geochemical indicators indicate euxinic bottom waters formed at this time, abundant organic matter and marine fauna indicate a highly productive oxic surface waters in the Cretaceous Boreal realm. We suggest that volcanic emissions at this time provided nutrient loading to the boreal sea boosting primary productivity, which led to bottom-water anoxia and black shale deposition.

Geological Society of America Abstracts with Programs. Vol. 53, No. 6

doi: 10.1130/abs/2021AM-366375

© Copyright 2021 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.