GCR block - Arenig - Llanvirn (ARE-LLV)

Arenig - Llanvirn

Block Description

UK map showing distribution of GCR sites of GCR block ARE-LLV
Distribution of GCR sites of GCR block Arenig - Llanvirn

The GCR sites selected for this GCR Block represent the British geological record of Earth history from about 483 to 460 million years ago (Ma), as represented by the rocks deposited during the second and third 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–Tremadoc boundary sites have their own GCR Blocks. See TRE and ARE-TRE. The former Llandeilo Series (now the Llandeilian Stage of the Llanvirn Series) is also afforded its own GCR Block. See LDO.

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 - Llanvirn


Site List

Your selection found 35 GCR sites. Sites are sorted alphabetically by country, local authority and then by site name -
CodeNameCountryLocal AuthorityGrid RefGCR Site Account
132Bergam QuarryEnglandShropshire CCSO356997Not available
133Betton DingleEnglandShropshire CCSJ317019Not available
134Granham's Moor, Eastridge Wood and Linley Big WoodEnglandShropshire CCSJ389036Not available
135Hope ValleyEnglandShropshire CCSJ342012Not available
136Mytton Dingle and SnailbeachEnglandShropshire CCSJ363004Not available
137Shelve ChurchEnglandShropshire CCSO336990Not available
303BalnakeilScotlandCaithness and Sutherland and Ross and CromartyNC372688Not available
2199Lime Craig QuarryScotlandPerth and Kinross and StirlingNN533018Not available
2198Balcreuchan Port - Bennane HeadScotlandSouth AyrshireNX097875Not available
2829Raven GillScotlandSouth LanarkshireNS923199Not available
111Afon SeiontWalesGWYNEDDSH483617Not available
112Amnodd-Wen and FfilltergerigWalesGWYNEDDSH818372Not available
113Bryn Glas QuarryWalesGWYNEDDSH732421Not available
115Llynniau CregennenWalesGWYNEDDSH655145Not available
2200Nant-y-GadwenWalesGWYNEDDSH211267Not available
119Trwyn Llech y DdolWalesGWYNEDDSH301237Not available
120Wig BachWalesGWYNEDDSH186257Not available
114Fferam-uchafWalesISLE OF ANGLESEYSH361865Not available
116Nantannog RavineWalesISLE OF ANGLESEYSH375838Not available
117Ogof Gynfor - Hell's Mouth)WalesISLE OF ANGLESEYSH378948Not available
118Treiorwerth–Ty-HenWalesISLE OF ANGLESEYSH354796Not available
84Bach-y-graig Stream SectionWalesPOWYSSO071610Not available
85Howey BrookWalesPOWYSSO087591Not available
2726NewmeadWalesPOWYSSO057543Not available
121AbergwaunWalesSOUTH WEST WALESSM956377Not available
122Allt PenycoedWalesSOUTH WEST WALESSN443181Not available
123Cwm yr AbbeyWalesSOUTH WEST WALESSN500195Not available
124Dan-lan-y-castellWalesSOUTH WEST WALESSN363163Not available
125Ffairfach Railway Cutting and River SectionWalesSOUTH WEST WALESSN628211Not available
126Glan PibwrWalesSOUTH WEST WALESSN417179Not available
127LlanfalltegWalesSOUTH WEST WALESSN157201Not available
128Llanvirn - AbereiddiWalesSOUTH WEST WALESSM797305Not available
129Ogof HenWalesSOUTH WEST WALESSM705250Not available
130Pont y FenniWalesSOUTH WEST WALESSN238169Not available
131Whitesands BayWalesSOUTH WEST WALESSM730276Not available
Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access. Search Again