GCR block - Cambrian - Tremadoc (CAM-TRE)

Cambrian - Tremadoc

Block Description

UK map showing distribution of GCR sites of GCR block CAM-TRE
Distribution of GCR sites of GCR block Cambrian - Tremadoc

The GCR sites selected for this GCR Block represent the British geological record of Earth history around 495 million years ago (Ma), as represented by the rocks that range across the Cambrian–Tremadoc boundary (the Cambrian Period (545 to 495 Ma) was the first period of the Palaeozoic Era (545 to 251 Ma). Rocks that formed during the Cambrian Period constitute the Cambrian System; the Tremadoc Epoch was the first of the Ordovician Period, 495–440 Ma).

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). There are no globally agreed divisions of the Cambrian System, although ‘Lower’, ‘Middle’ and ‘Upper’ are widely used, but not universally defined.

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


Volume Introduction

Cambrian - Tremadoc


Site List

Your selection found 5 GCR sites. Sites are sorted alphabetically by country, local authority and then by site name -
CodeNameCountryLocal AuthorityGrid RefGCR Site Account
1009DurnessScotlandCaithness and Sutherland and Ross and CromartyNC358687Not available
1008OrdScotlandLochaber, Skye and Lochalsh and Argyll and the IslandsNG618124Not available
416Bryn-Llin-FawrWalesGWYNEDDSH773296Not available
1088Dol-cyn-afonWalesGWYNEDDSH793285Not available
415Rhiw-for-FawrWalesGWYNEDDSH515380Not available
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