Stratigraphic Zone

Stratigraphic Zone

 

the stratigraphic unit next in rank below a stage and including beds corresponding to the period of the existence of a distinctive group of fossils not found in overlying and underlying deposits. The stratigraphic zone is named after one or two of the most characteristic fossil types of the given group. Many zones are local but some have been identified on several continents and are worldwide, for example, the zones established in the Ordovician and Silurian on evidence of graptolites; in the Mesozoic, of ammonites; and in the Cretaceous, Paleogene, and Neocene, of planktonic foraminifera and nannoplankton.

References in periodicals archive ?
Mineralization in both FC-36 and FC-41 are interpreted to be within the Milagros stratigraphic zone which remains open to the northeast.
The Fort Worth federal district court determined recently that the patent claims covering a "Method of Maintaining a Borehole in a Stratigraphic Zone during Drilling" should be construed in the manner urged by UPR.
In addition to the many folded and faulted traps, there is a variety of stratigraphic zones yet to be properly studied.
Structurally, it is a wide southeast convex belt comprising several thrust-bounding stratigraphic zones.
This formation will be the first of nine separate potential stratigraphic zones identified for EOR using CO2 injection.
Cummings (1987) has broken down the amygdaloids into four distinct and discernible stratigraphic zones based on the secondary mineralization expected in each.
It will test the oil production potential of four separate stratigraphic zones at depths between 4,900 to 13,100 feet.
The audit program, which is part of the Kamoto Joint Venture feasibility study in progress, consisted of diamond-drill core samples selected from each resource area and from stratigraphic zones that are representative of the areas to be mined.