Sedimentology of the early Neoproterozoic Morar Group in northern Scotland : implications for basin models and tectonic setting

Bonsor, H.C.; Strachan, R.A.; Prave, A.R.; Krabbendam, M.. 2012 Sedimentology of the early Neoproterozoic Morar Group in northern Scotland : implications for basin models and tectonic setting. Journal of the Geological Society, 169 (1). 53-65. 10.1144/0016-76492011-039

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Official URL: http://jgs.geoscienceworld.org/content/169/1.toc

Abstract/Summary

The metasedimentary rocks of the Morar Group in northern Scotland form part of the early Neoproterozoic Moine Supergroup. The upper part of the Group is c. 2-3 km thick and contains two large km-scale facies successions: a coarsening-upwards marine-to-fluvial regression overlain by a fining-upwards fluvial-to-marine transgression. Fluvial facies make up less than a third of the total thickness; shallow-marine lithofacies comprise the remainder. Combining these new findings with previously published data indicates that the Morar Group represents, overall, a transgressive stratigraphic succession c. 6-9km thick, in which there is both an upward and eastward predominance of shallow-marine deposits, and a concomitant loss of fluvial facies. Smaller-scale (100s of m thick) transgressive-regressive cycles are superimposed on this transgressive trend. Collectively, the characteristics of the succession are consistent with deposition in a foreland basin located adjacent to the Grenville orogen, and possibly linked to the peri-Rodinian ocean. Subsidence and progressive deepening of the Morar basin may have, at least in part, been driven by loading of Grenville-orogeny-emplaced thrust sheets, and aided by sediment loading. However, the relative contributions of thrust loading versus plate boundary effects and/or eustatic sea-level rise on basin evolution remain speculative.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1144/0016-76492011-039
Programmes:	BGS Programmes 2010 > Geology and Landscape (Scotland)
ISSN:	0016-7649
NORA Subject Terms:	Earth Sciences
Date made live:	06 Jan 2012 11:41 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/14846

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1144/0016-76492011-039

Programmes:

BGS Programmes 2010 > Geology and Landscape (Scotland)

ISSN:

0016-7649

NORA Subject Terms:

Earth Sciences

Date made live:

06 Jan 2012 11:41 +0 (UTC)