Ratawi Fm
Period:
Cretaceous
Age Interval:
Valanginian – Hauterivian, Iq2
Province:
Iraq
Type Locality and Naming
Column: Central Iraq; Ratawi Shale Mbr, Ratawi Limestone Mbr
Synonym:
Lithology and Thickness
Ratawi Shale Mbr: Claystone. Comprises dark, slightly pyritic, shales; beds of buff, pyritic, pseudo-oolitic, detrital fossiliferous limestones are present in the lower part of the formation. Ratawi Limestone Mbr: Clayey limestone. Comprises dark, slightly pyritic, shales; beds of buff, pyritic, pseudo-oolitic, detrital fossiliferous limestones are present in the lower part of the formation. Thickness ranges from 23 to 629m in S Iraq
Lithology Pattern:
Claystone
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Yamama Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Zubair Fm
Regional extent
GeoJSON
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Fossils
Age
Valanginian – Hauterivian
Age Span:
Beginning stage:
Valanginian
Fraction up in beginning stage:
0.1
Beginning date (Ma):
137.19
Ending stage:
Hauterivian
Fraction up in the ending stage:
0.2
Ending date (Ma):
131.38
Depositional setting
Depositional pattern:
Additional Information
Compiler:
From S. Z. Jassim and J. C. Goff, Geology of Iraq, 2006. pg 124, Fig. 11-1: "Stratigraphic correlation of formation of Megasequence AP8."