Kanger Fm
Period:
Ectasian
Age Interval:
middle and late Ectasian
Province:
Proterozoic S.India Indravati Basin
Lithology and Thickness
Limestone; with volcanics -- Tokapal and Bhejripadar kimberlite pyroclastics.
Lithology Pattern:
Limestone
Relationships and Distribution
Lower contact
Underlain by Cherakur Fm
Upper contact
Overlain by Jagadalpur Fm; but potentially with a large stratigraphic gap (see "Age" below)
Regional extent
GeoJSON
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Fossils
Age
On the basis of the stratigraphic position of the Tokapal and Bhejripadar kimberlite pyroclastics (Laser ablation inductively coupled mass spectrometry, LA-ICPMS U-Pb age 620 +/-30 Ma) within Kanger Formation, Mainkar et al. (2004) proposed an event-break between the Kanger and the overlying Jagdalpur Fm. However, this is difficult to reconcile with later LA-ICPMS of zircons from the Birsaguda tuff (Fig. 9B), within the Jagdalpur Fm that point to closure of the basin at 1001 +/-7 Ma (Mukherjee et al., 2012). [This may reflect problems with the LA-ICPMS technique that doesn't adequately pre-process zircons?]
Age Span:
Beginning stage:
Ectasian
Fraction up in beginning stage:
0.25
Beginning date (Ma):
1,350.00
Ending stage:
Ectasian
Fraction up in the ending stage:
0.8
Ending date (Ma):
1,240.00
Depositional setting
Carbonate platform
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.