Rocks of Jurassic age crop out exclusively south of the River Tees, with both Lower and Middle Jurassic successions well represented. The rocks indicate an episode of marine sedimentation, represented by the Lias Group, followed by alternating cycles of deltaic and marine sedimentation represented by the overlying Ravenscar Group.
Marker on the Cleveland Way east of Saltburn. Huntcliff can be seen in the background.
Stretching along the coast between Redcar and Filey can be found a sequence of rocks that have been highly acclaimed by generations of geologists:
“In no part of England is the relation of the surface topography to the nature of the underlying rocks more instructively displayed than in this district; nor can the succession of a considerable part of the Jurassic series of formation be anywhere more advantageously examined than along the coast-sections…”
[Archibald Geikie, Director of the Geological Survey. (1888)]
Jurassic deposits locally total around 560 metres of strata which were deposited between c.199 million and 161 million years ago in environments which varied between deep sea, populated by a variety of distinctive marine creatures, to well-vegetated river delta upon which reptiles once roamed.
An example of the locally abundant ammonite Dactylioceras commune which has been split and polished to show crystals of calcite filling the internal chambers.
Geologists long-ago realised that similar rocks in diverse areas could be correlated by examining their fossil content. One of the earliest to realise this was Lewis Hunton (1814-1838), son of a Loftus alum-worker who studied remains of long extinct sea creatures in Jurassic rocks at Hummersea and Boulby. As far as correlation of different rock units is concerned, the most useful fossils turned out to be the coiled shells of many species of ammonite. Ammonites are now-extinct creatures related to modern day squid and octopuses (Cephalopods). Modern geologists can identify over sixty ammonite zones in the Lower Jurassic alone, which finely subdivide the various strata and make relationships between them much easier to understand.
Table showing the various sub-divisions of the Jurassic along with ammonite zones able to be seen within the Tees Valley and North Yorkshire.
Adapted from The Yorkshire Coast by P.F. Rawson & J.K. Wright (1992).
Lower Jurassic »
Please note: This page is still under construction. We apologise for any inconvenience.
©2011 Tees Valley RIGS Group.
Jurassic
Rocks of Jurassic age crop out exclusively south of the River Tees, with both Lower and Middle Jurassic successions well represented. The rocks indicate an episode of marine sedimentation, represented by the Lias Group, followed by alternating cycles of deltaic and marine sedimentation represented by the overlying Ravenscar Group.
Marker on the Cleveland Way east of Saltburn. Huntcliff can be seen in the background.
Stretching along the coast between Redcar and Filey can be found a sequence of rocks that have been highly acclaimed by generations of geologists:
Jurassic deposits locally total around 560 metres of strata which were deposited between c.199 million and 161 million years ago in environments which varied between deep sea, populated by a variety of distinctive marine creatures, to well-vegetated river delta upon which reptiles once roamed.
An example of the locally abundant ammonite Dactylioceras commune which has been split and polished to show crystals of calcite filling the internal chambers.
Geologists long-ago realised that similar rocks in diverse areas could be correlated by examining their fossil content. One of the earliest to realise this was Lewis Hunton (1814-1838), son of a Loftus alum-worker who studied remains of long extinct sea creatures in Jurassic rocks at Hummersea and Boulby. As far as correlation of different rock units is concerned, the most useful fossils turned out to be the coiled shells of many species of ammonite. Ammonites are now-extinct creatures related to modern day squid and octopuses (Cephalopods). Modern geologists can identify over sixty ammonite zones in the Lower Jurassic alone, which finely subdivide the various strata and make relationships between them much easier to understand.
Table showing the various sub-divisions of the Jurassic along with ammonite zones able to be seen within the Tees Valley and North Yorkshire.
Adapted from The Yorkshire Coast by P.F. Rawson & J.K. Wright (1992).
Lower Jurassic »
Please note: This page is still under construction. We apologise for any inconvenience.
©2011 Tees Valley RIGS Group.