Nagthat Fm
Period:
Neoproterozoic
Age Interval:
late Tonian
Province:
N.India Lesser Himalaya
Type Locality and Naming
Himachal Pradesh-Uttarakhand, Deoban Basin, named after Nagthat Village. [Original Publication: Auden, J.B. (1934). The Geology of the Krol Belt. Rec. Geol. Surv. India, 67, 357-454.]
Lithology and Thickness
Sandstone. Quartz arenite, quartz wacke, arkose, grit, conglomerate, clay-slates, phyllites; ~1550 m
Lithology Pattern:
Sandstone
Relationships and Distribution
Lower contact
Conformable with Chandpur Fm
Upper contact
Unconformable with the Sundernagar Gr (locally) or Unconformable with Blaini Fm glacial till regionally.
Regional extent
In Sirmaur (HP) and Dehradun districts (Uttarakhand). Correlated with the Sanjauli Fm.
GeoJSON
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Fossils
None
Age
Late Tonian (assuming that disconformable contact to overlying Blaini Fm glacial till (Cryogenian) is a Tonian/Cryogenian unconformity. Age span estimates taken from A.J. Martin, 2017. A review of Himalayan stratigraphy, magmatism, and structure. Gondwana Research 49 (2017) 42–80.
Age Span:
Beginning stage:
Tonian
Fraction up in beginning stage:
0.85
Beginning date (Ma):
762.00
Ending stage:
Tonian
Fraction up in the ending stage:
1.0
Ending date (Ma):
720.00
Depositional setting
Shallow marine in a receding basin with continuous uplift in the provenance area.
Depositional pattern:
Additional Information
Compiler:
O.N. Bhargava & Birendra Singh. Age estimates based on A.J. Martin, 2017. A review of Himalayan stratigraphy, magmatism, and structure. Gondwana Research 49 (2017) 42–80.