Regional geochemical patterns in SE Scotland: source lithology, inheritance and glacial overprinting

Stone, P.; McMillan, A.A.. 2013 Regional geochemical patterns in SE Scotland: source lithology, inheritance and glacial overprinting. Scottish Journal of Geology, 49 (1). 33-40. https://doi.org/10.1144/sjg2013-002

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Official URL: http://dx.doi.org/10.1144/sjg2013-002

Abstract/Summary

The Lower Palaeozoic Southern Uplands terrane shows a NE–SW, strike-parallel coincidence of regional geochemical lineaments defined from stream-sediment data, and major lithostratigraphically significant structures. West of Moffat, Silurian strata of the Gala and Hawick groups are divided by geochemical lineaments coincident with the Laurieston Fault. East of Moffat, the geochemical lineaments diverge towards the NE with Gala-type regional geochemistry (high Sr and Ba, low CaO) to the north of the Moffat Valley Fault, whilst Hawick-type regional geochemistry (low Sr and Ba, high CaO) continues to the south of the Laurieston Fault; between the faults lies the recently-defined Ettrick Group. Beyond the eastern end of the Lower Palaeozoic outcrop, its geochemical lineaments extend across the unconformable cover of Devonian ‘Old Red Sandstone’. This is partly a drainage catchment effect, but two other possible explanations are considered: a localized derivation of the Devonian clastic rocks, such that they inherit the compositional patterns of the underlying Lower Palaeozoic sandstones; or a geochemical signature imposed by glacial deposits derived from the Lower Palaeozoic outcrop. The local effect of glacial dispersion is confirmed by the distribution of TiO2; anomalously high levels associated with Carboniferous mafic lavas have been transported NE across the low-TiO2 Carboniferous sedimentary rocks of the Tweed Basin.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1144/sjg2013-002
ISSN:	0036-9276
Date made live:	24 Dec 2013 16:20 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/504373

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1144/sjg2013-002

ISSN:

0036-9276

Date made live:

24 Dec 2013 16:20 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/504373