Lithostratigraphy of the Ordovician rocks in the Southern Uplands: Crawford Group, Moffat Shale Group, Leadhills Supergroup

Floyd, J. D.

doi:10.1017/s0263593300002200

Cited by 38 publications

(4 citation statements)

References 45 publications

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“…4, column A). This occurrence is quite similar to the contact between the Kirkton Formation and the succeeding Moffat Shale Group described at the type locality of Gripps Cleuch by Floyd (1996). Fine-grained sandstone and buff-coloured mudstone occur further downstream.…”

Section: Description Of the Measured Sectionssupporting

confidence: 82%

“…The Kirkton Formation overlying the Raven Gill Formation consists of basic lava more than 50 m thick, and siliceous mudstone and chert that are 70 m thick at the type section (Floyd 1996). Pygodus anserius, indicating a late Llanvirn to early Cardoc age, has been recovered from red chert at the Glencaple Burn, Kilbucho and Crawford sites (Armstrong et al 1990, 1996, 2002; Clarkson et al 1993; Danelian & Clarkson 1998; Danelian & Floyd 2001).…”

Section: Geological Setting Of Studied Outcropsmentioning

confidence: 99%

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Trace fossils in Ordovician radiolarian chert successions in the Southern Uplands, Scotland

Kakuwa

Floyd²

2016

Earth and Environmental Science Transactions of the Royal Socie

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Radiolarian chert and associated siliceous claystone in the Southern Uplands of Scotland are examined, in order to study the Great Ordovician Biodiversification Event of benthic animals on the pelagic ocean bottom. Trace fossils which are uncommon, but convincing, are found in the grey chert and siliceous claystone of Gripps Cleuch. These observations constitute firm evidence that large benthic animals which could leave visible trace fossils had colonised the Iapetan Ocean by the late Middle Ordovician, confirming previous studies from Australia for Panthalassa, the other huge ocean. Red chert is, however, a poor recorder of trace fossils, probably because the highly oxidising environment breaks down organic matter, both inhibiting high-density activity of large benthic animals and removing clear traces of benthic animal life.

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Section: Description Of the Measured Sectionssupporting

confidence: 82%

Section: Geological Setting Of Studied Outcropsmentioning

confidence: 99%

Trace fossils in Ordovician radiolarian chert successions in the Southern Uplands, Scotland

Kakuwa

Floyd²

2016

Earth and Environmental Science Transactions of the Royal Socie

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“…2). The Leadhills Supergroup, Gala Group and Midland Valley Silurian inliers comprise predominately greywacke sandstone with siltstone, chert, mudstone and conglomerate (Floyd 1995). Devonian Old Red Sandstone strata are present in the centre of the Basin and N of the River Clyde estuary around Dumbarton.…”

Section: Clyde Basin Study Areamentioning

confidence: 99%

Soil metal/metalloid concentrations in the Clyde Basin, Scotland, UK: implications for land quality

Fordyce

Everett

Bearcock

et al. 2017

Earth and Environmental Science Transactions of the Royal Socie

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An assessment of topsoil (5–20cm) metal/metalloid (hereafter referred to as metal) concentrations across Glasgow and the Clyde Basin reveals that copper, molybdenum, nickel, lead, antimony and zinc show the greatest enrichment in urban versus rural topsoil (elevated 1.7–2.1 times; based on median values). This is a typical indicator suite of urban pollution also found in other cities. Similarly, arsenic, cadmium and lead are elevated 3.2–4.3 times the rural background concentrations in topsoil from the former Leadhills mining area. Moorlands show typical organic-soil geochemical signatures, with significantly lower (P<0.05) concentrations of geogenic elements such as chromium, copper, nickel, molybdenum and zinc, but higher levels of cadmium, lead and selenium than most other land uses due to atmospheric deposition/trapping of these substances in peat. In farmland, 14% of nickel and 7% of zinc in topsoil samples exceed agricultural maximum admissible concentrations, and may be sensitive to sewage-sludge application. Conversely, 5% of copper, 17% of selenium and 96% of pH in farmland topsoil samples are below recommended agricultural production thresholds. Significant proportions of topsoil samples exceed the most precautionary (residential/allotment) human-exposure soil guidelines for chromium (18% urban; 10% rural), lead (76% urban; 45% rural) and vanadium (87% urban; 56% rural). For chromium, this reflects volcanic bedrock and the history of chromite ore processing in the region. However, very few soil types are likely to exceed new chromiumVI-based guidelines. The number of topsoil samples exceeding the guidelines for lead and vanadium highlight the need for further investigations and evidence to improve human soil-exposure risk assessments to better inform land contamination policy and regeneration.

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“…In the Southern Uplands these are seen in the oldest, most northerly tract, the Corsewall and Marchburn Formations of the Tappins Group. 6 The abundance of Cr in stream sediment is then relatively low (in local terms) over the outcrop of the late Ordovician, quartzo-feldspathic Kirckolm Formation (profile cc', Fig. 4) but rises intermittently southwards across the andesitic Portpatrick Formation, the quartzofeldspathic Shinnel Formation and the northern part of the Gala Group.…”

Section: The Ultramafic Association: Cr-ni-mgmentioning

confidence: 99%

Regional geochemistry of cryptic geology: variations in trace element distribution across the Southern Uplands terrane, Scotland

Stone

Breward²,

Merriman³

et al. 2004

Applied Earth Science

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Stream-sediment geochemistry is commonly used to provide a regionally averaged, background composition against which may be judged the anomalies caused by unusual geology, mineralisation or pollution. Its interpretation may be based on assumptions of relative compositional uniformity within broad categories of bedrock lithology. This approach is undermined by the dramatic variations in stream-sediment chemistry that occur over some large areas of superficially homogeneous geology. In these cases, regional geochemistry may pickout subtle compositional variations in bedrock that are not otherwise apparent. Thick greywacke sequences present a particular problem of geological interpretation by virtue of their general uniformity, with a good example provided by the Southern Uplands terrane. There, some stratigraphical variations in greywacke composition, reflecting changes in sedimentary provenance, are known from petrographic and analytical work but are not visible macroscopically. However, contoured stream sediment geochemistry maps, supplemented by cross-strike element abundance profiles, reveal a remarkable level of detailed variation pertinent to stratigraphical sub-division and a much-improved provenance interpretation. Of particular value are the transition metals Cr-Ni-Mg-V and the feldspar-related elements Sr-Rb-K-Ba, the latter defining a major structural break within the terrane. An important corollary to the improved geological understanding arising from regional geochemical survey is the parallel improvement in understanding of the surface processes influencing element distribution in the stream-sediment environment.

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Lithostratigraphy of the Ordovician rocks in the Southern Uplands: Crawford Group, Moffat Shale Group, Leadhills Supergroup

Cited by 38 publications

References 45 publications

Trace fossils in Ordovician radiolarian chert successions in the Southern Uplands, Scotland

Trace fossils in Ordovician radiolarian chert successions in the Southern Uplands, Scotland

Soil metal/metalloid concentrations in the Clyde Basin, Scotland, UK: implications for land quality

Regional geochemistry of cryptic geology: variations in trace element distribution across the Southern Uplands terrane, Scotland

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