St Andrews Research Repository

St Andrews University Home
View Item 
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  • Register / Login
JavaScript is disabled for your browser. Some features of this site may not work without it.

A marine origin for the late Mesoproterozoic Copper Harbor and Nonesuch Formations of the Midcontinent Rift of Laurentia

Thumbnail
View/Open
Jones_2019_PR_Nonesuch_AAM.pdf (6.779Mb)
Date
01/2020
Author
Jones, S.M.
Prave, A.R.
Raub, T.D.
Cloutier, J.
Stüeken, E. E.
Rose, C.V.
Linnekogel, S.
Nazarov, K.
Keywords
Midcontinent Rift
Keweenawan Supergroup
Copper Harbor Formation
Nonesuch Formation
Lacustrine
Mesoproterozoic
GE Environmental Sciences
DAS
SDG 14 - Life Below Water
Metadata
Show full item record
Abstract
The c. 1.1 Ga Copper Harbor and Nonesuch Formations of the Keweenawan Supergroup exposed along the Canadian-United States shorelines of Lake Superior are part of the surface exposures of the Laurentian Midcontinent Rift. These units have long been considered non-marine in origin and have figured prominently in ideas regarding the evolution of microbial life and the redox conditions of Earth’s ocean-atmosphere system at the close of Mesoproterozoic time. However, these rocks also host hydrothermal metal deposits, the emplacement of which may have compromised primary geochemical signals that are used to underpin those ideas. Here we highlight new sedimentological observations to provide an independent framework for assessing the depositional setting and geochemistry of those strata. We show that the totality of sedimentological features leads to the conclusion that parts of the upper Copper Harbor Formation and the entirety of the Nonesuch Formation were deposited along tide- and wave-influenced shorelines and in shallow-marine settings under evaporitic conditions. Evidence for this interpretation includes the abundance of flaser, wavy, linsen and pinstripe bedding, ubiquity of reactivation surfaces and mud drapes associated with all ripple forms, superposed sets of ripple cross-lamination showing bimodal (herring-bone) sediment transport directions, desiccation cracks and metre-scale hummocky cross-stratification. Further, evaporite fabrics and pseudomorphs after gypsum in the upper 200 m of the Copper Harbor Formation and in numerous stratigraphic positions within the Nonesuch Formation indicate that the water body was saline, not fresh. The emerging palaeogeographic image is one of a large, shallow-marine embayment with fringing sabkha-like shorelines. Ideas about late Mesoproterozoic biospheric evolution and Earth’s surface redox and oxygenation that rely on the Nonesuch Formation and Copper Harbor stromatolites having been deposited within a lacustrine setting require reassessment.
Citation
Jones , S M , Prave , A R , Raub , T D , Cloutier , J , Stüeken , E E , Rose , C V , Linnekogel , S & Nazarov , K 2020 , ' A marine origin for the late Mesoproterozoic Copper Harbor and Nonesuch Formations of the Midcontinent Rift of Laurentia ' , Precambrian Research , vol. 336 , 105510 . https://doi.org/10.1016/j.precamres.2019.105510
Publication
Precambrian Research
Status
Peer reviewed
DOI
https://doi.org/10.1016/j.precamres.2019.105510
ISSN
0301-9268
Type
Journal article
Rights
Copyright © 2019 Elsevier B.V. All rights reserved. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1016/j.precamres.2019.105510
Description
This work was supported by First Quantum Minerals Ltd., Vancouver, Canada.
Collections
  • University of St Andrews Research
URI
http://hdl.handle.net/10023/20926

Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

Advanced Search

Browse

All of RepositoryCommunities & CollectionsBy Issue DateNamesTitlesSubjectsClassificationTypeFunderThis CollectionBy Issue DateNamesTitlesSubjectsClassificationTypeFunder

My Account

Login

Open Access

To find out how you can benefit from open access to research, see our library web pages and Open Access blog. For open access help contact: openaccess@st-andrews.ac.uk.

Accessibility

Read our Accessibility statement.

How to submit research papers

The full text of research papers can be submitted to the repository via Pure, the University's research information system. For help see our guide: How to deposit in Pure.

Electronic thesis deposit

Help with deposit.

Repository help

For repository help contact: Digital-Repository@st-andrews.ac.uk.

Give Feedback

Cookie policy

This site may use cookies. Please see Terms and Conditions.

Usage statistics

COUNTER-compliant statistics on downloads from the repository are available from the IRUS-UK Service. Contact us for information.

© University of St Andrews Library

University of St Andrews is a charity registered in Scotland, No SC013532.

  • Facebook
  • Twitter