GCR block - Arenig - Tremadoc (ARE-TRE)

Arenig - Tremadoc

Block Description

UK map showing distribution of GCR sites of GCR block ARE-TRE
Distribution of GCR sites of GCR block Arenig - Tremadoc

The GCR sites selected for this GCR Block represent the British geological record of Earth history around 483 million years ago (Ma), as represented by the rocks that range across the Tremadoc–Arenig boundary, the first two epochs of the Ordovician Period (495–440 Ma), which is the second period of the Palaeozoic Era (545 to 251 Ma). Rocks that formed during the Ordovician Period constitute the Ordovician System. Tremadoc and Arenig–Llanvirn sites have their own GCR Blocks. See TRE and ARE-LLV.

The Cambrian and Ordovician rocks of Britain are essentially of marine origin; freshwater and subaerial deposits have been identified only in settings where volcanic edifices were raised above sea level. Within the marine setting there are rocks of the widest variety, from sandstones and limestones of the shoreline and shallow shelves to beds that accumulated in deep basins or on the continental slopes. Transects from shelf to basin are seen in both Cambrian and Ordovician rocks, and examples of shallow- and deep-water deposits are recognized in both Anglo-Welsh and Scottish areas.

The traditional series of the Ordovician System are Tremadoc (oldest), Arenig, Llanvirn, Caradoc and Ashgill (youngest).

For details of Ordovician stratigraphy, palaeogeography, palaeontology and GCR site selection, see CAM.


Volume Introduction

Arenig - Tremadoc


Site List

Your selection found 4 GCR sites. Sites are sorted alphabetically by country, local authority and then by site name -
CodeNameCountryLocal AuthorityGrid RefGCR Site Account
3160BarfEnglandWest CumbriaNY217265Not available
3159Blaze Bridge and Scawgill QuarryEnglandWest CumbriaNY17922499Not available
2201Great CockupEnglandWest CumbriaNY277336Not available
2189River Calder, Latter BarrowEnglandWest CumbriaNY068117Not available
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