Arbuthnott-Garvock Group

The Arbuthnott-Garvock Group (or Arbuthnot-Garvock Group) is a Devonian lithostratigraphic group (a sequence of rock strata) in central Scotland. The name is derived from the village of Arbuthnott in Aberdeenshire and the Hill of Garvock near Laurencekirk.[1] The group comprises the previously separate overlying Garvock Group and the underlying Arbuthnott Group.

Arbuthnott-Garvock Group
Stratigraphic range: ?Lochkovian-Pragian, (Devonian)
TypeGroup
Unit ofOld Red Sandstone Supergroup
Sub-unitsCatterline Conglomerate, Scone Sandstone, Craighall Conglomerate, Ruchil Flagstone and Craig of Monievreckie Conglomerate formations
UnderliesCromlix Mudstone Formation of Strathmore Group
OverliesCrawton Volcanic Formation and other units
Thickness2400 - 3150m
Lithology
Primarysandstone
Othermudstone, siltstone, conglomerate
Location
RegionArgyll, Fife, Angus, Aberdeenshire
CountryScotland
Extentalong northern margin of Central Lowlands, south of Highland Boundary Fault from Kintyre to Aberdeenshire
Type section
Named forArbuthnott and Hill of Garvock near Laurencekirk, both in Aberdeenshire

Outcrops

These rocks are exposed in the west in southern Kintyre between Campbeltown and Southend and in an arcuate belt between Machrie and Sannox on the Isle of Arran. They occur in a southwest–northeast trending belt parallel to and just south of the Highland Boundary Fault between Helensburgh and Blairgowrie via Aberfoyle and Callander and as far as the southern edge of Stonehaven on the Scottish east coast. An extensive area in the east between Stonehaven and Dundee is underlain by these rocks including the Brechin, Forfar and Arbroath areas. A further belt of country between Forfar and Dunblane through Perth and extending into northern Fife is underlain by these rocks.[2]

Lithology and stratigraphy

The Group comprises numerous formations including the Catterline Conglomerate, Scone Sandstone, Craighall Conglomerate, Ruchil Flagstone and Craig of Monievreckie Conglomerate formations laid down during the Lochkovian to Pragian stages of the Devonian Period.[3]

References
  1. http://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=ATGK (BGS on-line lexicon of rock units)
  2. http://mapapps.bgs.ac.uk/geologyofbritain/home.html? Geology of Britain viewer
  3. British Geological Survey 1:50,000 scale geological map (Scotland) sheets
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