Nambi Breccia Fm
Period:
Tonian
Age Interval:
late Tonian
Province:
Proterozoic S.India Pranhita-Godavari east basin
Type Locality and Naming
Lower formation (2 of 3) of User Gr.
Lithology and Thickness
Conglomerate. 200-m-thick bouldery, breccia-conglomerate with gritty sandstone
Lithology Pattern:
Conglomerate
Relationships and Distribution
Lower contact
Unconformable onto Chalamala Sandstone Fm at top of Alabaka Gr. Development of breccia-conglomerate with gritty sandstone in the lower part of the Usur Gr represent a new cycle of deposition over the Albaka Gr.
Upper contact
Overlain by Doli Sandstone Fm
Regional extent
Approximately coeval with Encharani Fm (alluvial fan at base) of lowest Sullavai Gr in Pranhita-Godavari west basin
GeoJSON
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Fossils
Age
Age Span:
Beginning stage:
Tonian
Fraction up in beginning stage:
0.7
Beginning date (Ma):
804.00
Ending stage:
Tonian
Fraction up in the ending stage:
0.77
Ending date (Ma):
784.40
Depositional setting
Alluvial fan. The thick breccia conglomerate represents graben-fill deposit (alluvial fan), which rapidly evolved into fluvial to shallow coastal depositional system in the upper part
Depositional pattern:
Additional Information
Compiler:
From: Saha D. (Dilip), Patranabis-Deb, S., and Colllins, A.S. (2016) Proterozoic stratigraphy of southern Indian cratons and global context. In: Stratigraphy & Timescales, 1: 1-59.