Key fault systems such as the Dent, Craven and Stockdale separate the Project Area into major geological regions, blocks and basins, which over time have influenced the nature of the deposits. The Askrigg Block and Craven and Stainmore Basins are the most significant and the key deposits associated with them are illustrated on the cross-section. The following account outlines the major sequence of events on the Askrigg Block.
Above figure: Cross-section from the Craven Basin in the south, through the Askrigg Block and northwards to the Stainmore Basin, © BGS (NERC) (after Aitkenhead et al. 2002 with additional information on new terminology from Colin Waters).
PERIOD | AGE | ASKRIGG BLOCK GROUPS | CRAVEN BASIN GROUPS | EVENT | |||
QUATERNARY | Holocene | Glacial and post glacial deposits | Glacial and post glacial deposits | Regional uplift and eastward tilting | |||
Pleistocene | |||||||
NEOGENE | Pliocene | Unconformity | Unconformity | ||||
Miocene | Basin inversion | Alpine Orogeny | |||||
PALAEOGENE | Oligocene | Regional uplift | |||||
Eocene | |||||||
Palaeocene | |||||||
CRETACEOUS | Upper | Regional shelf subsidence | |||||
Lower | |||||||
JURASSIC | Upper | Episodes of regional crustal extension | |||||
Middle | |||||||
Lower | |||||||
TRIASSIC | Upper | Dominantly extensional faulting in west | |||||
Middle | |||||||
Lower | |||||||
PERMIAN | Upper | Zechstein Group | Dominantly regional subsidence in east | ||||
Lower | Unconformity | ||||||
Appleby Group ? | |||||||
CARBONIFEROUS | Stephanian | Unconformity | |||||
Warwickshire Group? | Basin inversion, regional uplift and erosion | Variscan Orogeny | |||||
Westphalian | Unconformity | ||||||
Pennine Coal Measures Group | Pennine Coal Measures Group | Regional subsidence with minor extensional faulting | |||||
Namurian | Millstone Grit Group | Millstone Grit Group | |||||
Yoredale Group | Craven Group | ||||||
Visean | |||||||
Great Scar Limestone Group | Bowland High Group | Major periods of extensional faulting and basin formation | |||||
Tournaisian | Ravenstonedale Group | ||||||
DEVONIAN | Upper | Upper Old Red Sandstone Group | Unconformity | Regional erosion | |||
Middle | Unconformity | Acadian orogenic phase | Caledonian Orogeny | ||||
Lower | |||||||
SILURIAN | Pridoli | Windermere Supergroup | Kendal Group | Windermere Supergroup | Kendal Group | ||
Ludlow | Foreland Basin Development | ||||||
Coniston Group | Coniston Group | ||||||
Wenlock | Tranearth Group | Tranearth Group | |||||
Llandovery | Stockdale Group | Stockdale Group | |||||
ORDOVICIAN | Ashgill | Dent Group | Dent Group | Shelvian orogenic phase | |||
Caradoc | Unconformity | Unconformity | Subduction related arc magmatism | ||||
Llanvirn | Basin development on Avalonia margin | ||||||
Arenig | |||||||
Tremadoc | |||||||
CAMBRIAN | Late | ||||||
Middle | |||||||
Early | |||||||
PRECAMBRIAN | Ingleton Group? | Ingleton Group? |