Pakistan Stratigraphy · stratigraphy.pk
Ashtigar formation
https://stratigraphy.pk/formation/ashtigar-formation
Ashtigar formation
Jurassic
Karakoram-Hindukush Basin · Central Karakoram Batholith
Jurassic in the time scale →Stratigraphic position
Band colour = period; texture = dominant rock type. Lines between bands mark the contact type. True scale makes height ∝ recorded thickness; hatched = thickness not recorded. Ages approximate, for ordering.
This unit (highlighted) within its province column; faded ends continue above and below. Line style marks the contact type.
An Early Jurassic deep-water shale-and-turbidite unit above the Aghil Limestone in the Chapursan valley.
Ashtigar formation is named after the Ashtigar village by Gaetani et al. (1993) and comprised of shale and fine grain sandstone (turbidites) of Liassic age.
Significance. An Early Jurassic (Liassic) terrigenous turbidite unit that conformably overlies the Aghil Limestone; its erosional upper contact with the Yashkuk Formation is marked by a conglomerate rich in Aghil Limestone clasts. The turbidites point to deposition in a deepening, tectonically active basin.
- Lithology
- Thick, dark grey marly shale interbedded with fine-grained turbidites, calcarenite and volcanic debris.
- Type locality
- Ashtigar village, Chapursan valley, upper Hunza
- Basin
- Karakoram-Hindukush Basin
- Region
- Central Karakoram Batholith
- Environment
- marine, deep marine
- Introduced by
- Gaetani et al. (1993)
Fossils
Provinces
References
- Malkani, M.S. & Mahmood, Z. (2017). Stratigraphy of Pakistan. Geological Survey of Pakistan, Memoir Vol. 24.
- Kazmi, A.H. & Jan, M.Q. (1997). Geology and Tectonics of Pakistan. Graphic Publishers, Karachi.
Reviewer confidence: medium
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