Abstract
The present work recognizes a subdivision of the Cuddapah basin into 3 separate main units of deposition. Some of the earlier correlations proved to be untenable. For practical reasons King's widely used stratigraphy is retained where possible in a revised form.
We recognise: the Cuddapah Group, ∼ 2000-1490/1450 Ma; Nallamalai Group, ∼1490/1450-1090/870 Ma; and the Kurnool Group, ∼1090/870-500? Ma.
On the basis of surface geology mapping and photo-interpretation, we discern 5 tectonic zones. The boundaries of these zones coincide with deep crustal faults encountered in a Deep Seismic Sounding Survey.
Three phases of tectonic activity are:
1. crustal movements resulting in broad folds affecting the Cuddaph rocks exposed in the western area, followed by;
2. folding of the Nallamalai rocks east of the Rudravaram line; and
3. later folding and metamorphism in the eastern tectonic zones.
Structural sections allow an interpretation of an eastward continuation of the Cuddapah basin rocks into the highly metamorphosed series underlying the eastern Ghats complex.
A colour geological map and sections are included.
We recognise: the Cuddapah Group, ∼ 2000-1490/1450 Ma; Nallamalai Group, ∼1490/1450-1090/870 Ma; and the Kurnool Group, ∼1090/870-500? Ma.
On the basis of surface geology mapping and photo-interpretation, we discern 5 tectonic zones. The boundaries of these zones coincide with deep crustal faults encountered in a Deep Seismic Sounding Survey.
Three phases of tectonic activity are:
1. crustal movements resulting in broad folds affecting the Cuddaph rocks exposed in the western area, followed by;
2. folding of the Nallamalai rocks east of the Rudravaram line; and
3. later folding and metamorphism in the eastern tectonic zones.
Structural sections allow an interpretation of an eastward continuation of the Cuddapah basin rocks into the highly metamorphosed series underlying the eastern Ghats complex.
A colour geological map and sections are included.
| Original language | English |
|---|---|
| Pages (from-to) | 57-104 |
| Journal | Precambrian research |
| Volume | 26 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1984 |
Keywords
- ADLIB-ART-1762