Kustin Fm
Period:
Jurassic
Age Interval:
Middle Jurassic
Province:
Zaisan (Zaysan) Basin - Central
Type Locality and Naming
Synonym: Kustinskaya, J2k
Lithology and Thickness
Ca. 85 m of two benches. Upper are flood-plain deposits of aleurite (silt) and aleurite clay. Lower is varicolored sand and clay – weakly cemented gritstone, sandstone, aleurite, claystone. Saturated to various degrees with carbonized vegetal material. Sandstone prevails.
Lithology Pattern:
Clayey sandstone
Relationships and Distribution
Lower contact
Unconformable onto the Lower Jurassic clayey sands of the Tologoy Fm
Upper contact
Unconformably (Late Jurassic through Cretaceous is absent, partly due to regional erosion) below the North Zaisan Fm
Regional extent
GeoJSON
{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[82.65,48.87],[82.85,48.54],[82.61,48.18],[82.25,48.02],[83.07,47.29],[83.97,47.33],[84.52,48.24],[84.6,48.4],[84.1,48.36],[83.67,48.66],[83.49,48.97],[82.65,48.87]]]]}}
Fossils
Age
Middle Jurassic (Aalenian-Bathonian?)
Age Span:
Beginning stage:
Aalenian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
174.70
Ending stage:
Bathonian
Fraction up in the ending stage:
1.0
Ending date (Ma):
165.29
Depositional setting
Upper part are flood-plain deposits.
Depositional pattern:
Additional Information
Compiler:
Information provided by Nariman Jamikeshev from Kazakh-language sources and from other publications.