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The Chalk Group is now divided into a White Chalk Subgroup and a Grey Chalk Subgroup, both of which are further subdivided into formations.These modern divisions replace numerous earlier divisions, references to which occur widely on geological maps and in other geological literature.
The Chalk Group which includes all of the different units which make up the succession in England, is subdivided into an earlier/lower Grey Chalk Subgroup and a later/higher White Chalk Subgroup. The Chalk has previously been subdivided in other ways and references to Upper, Middle and Lower abound in the literature and on geological maps.
Overlying the Selborne Group is the Chalk Group, a suite of limestones of Upper Cretaceous age which is formally divided into a lower/older Grey Chalk Subgroup (of Cenomanian age) and an upper/later White Chalk Subgroup (of Cenomanian to Campanian age). The Grey Chalk corresponds to the traditional Lower Chalk division and comprises 15-25m of ...
The Ulster White Limestone Group is a late Cretaceous lithostratigraphic group (a sequence of rock strata) in Northern Ireland. The name is derived from the characteristic chalk rock which occurs particularly along the Antrim coast.
Two subsections of England's famous chalk formation, the Grey Chalk Subgroup and the lower sections of the White Chalk Subgroup, yield three-dimensionally preserved fossils of marine fishes. This exquisite level of preservation is unlike fish fossils from other deposits from around the same time, which are only preserved as two-dimensional ...
The White Chalk Formation is a Mesozoic geologic formation in southern England. Pterosaur fossils have been recovered from the formation. See also
Chalk is a soft, white, porous, sedimentary carbonate rock.It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor.
The white cliffs of Dover as seen from Cap Gris-Nez. The Straits of Dover were carved out of the anticline surface layer, presumably chalk, by glacial lake outburst floods. The Strait of Dover is geologically speaking a very young feature, which cuts through the much older Weald–Artois Anticline. The anticline continues uninterrupted in the ...