Gir Gypsum Fm
Period:
Paleogene
Age Interval:
Ypresian, Lb1
Province:
Libya
Type Locality and Naming
Lithology and Thickness
Currently also known as the Al Jir Formation, there are many inconsistencies among geologists regarding this formation. Some areas of this formation have no gypsum present. Members: 1. The upper Bir Ziden limestone, which is now known as the Bi'r Zaydan Member quite often, is composed of white limestones and 2. the lower Bin Asa (also spelled Bin Isa) chalk, which is composed of hard chalk and chalky limestone that contains chert nodules and gypsum stringers.
Lithology Pattern:
Chalk
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Beshimah Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Al Gata Chalk Fm
Regional extent
GeoJSON
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Fossils
Age
Ypresian
Age Span:
Beginning stage:
Ypresian
Fraction up in beginning stage:
0.5
Beginning date (Ma):
52.04
Ending stage:
Ypresian
Fraction up in the ending stage:
1.0
Ending date (Ma):
48.07
Depositional setting
Depositional pattern:
Additional Information
Compiler:
Chart derived from: USGS Correlation Chart and Columnar Section for Rocks in Libya, 1963. Descriptions from: Hallet, Don: Petroleum Geology of Libya, 2002.