**2.2 Break up stage**

The first break up between Africa and India took place in Late Jurassic and rifting was completed in Early Cretaceous with the separation of Africa and Madagascar-India. As a result, the related intra-cratonic rifting mostly happened in the western pericratonic region of the Indian plate [3]. This was followed by the early Late

*Intra-Plate Dynamics and Active Tectonic Zones of the Indian Plate DOI: http://dx.doi.org/10.5772/intechopen.105647*

#### **Figure 1.**

*Present position of the Indian plate with major active tectonic zones (***TZ***). Black arrows indicate the direction of movement of plates and prevailing stress. The white arrow indicates the direction of plate rotation. Red lines mark major fault/thrust zones. (key:***A-A SD zone***- Afgan-Arabian Ocean subduction zone,* **CTF***- Chaman transcurrent fault,* **MF***-Makran fault,* **ONT***- Ornach Nai Transcurrent fault,* **OFZ-** *Owen fracture zone,* **LR-***Laxmi ridge,* **CLR***- Chagos-Laccadive ridge,* **DF***- Dauki fault,* **ASA***- Andaman-Sumatran arc,* **SCR-EQ zone***stable continental region earthquake zone,* **TZ***- tectonic zone,* **Th***- thrust).*

Cretaceous break up of India and Australia-Antarctica in the eastern part. Rifting of eastern pericratonic basins and a few Upper Gondwana intracratonic basins took place during this time.

### **2.3 Rift-drift transition**

Rift drift transition occurred in the latest Cretaceous-Early Paleocene time, marked by a widespread unconformity in depositional sequences of both eastern and western pericratonic rift basins. This was a period of stress release and trailing edge uplift of the Indian plate due to the slab-pull from the Tethyan trench. This uplift is responsible for the aborting of the rifts and large-scale upthrusts along primordial faults boosting horst-graben structures along the evolved passive margins where the continents split.

#### **Figure 2.**

*Map showing major Gondwana and Mesozoic-tertiary rift basins of India and mid-continental NSG. Arrows indicate intra-plate dynamics at different periods.*

#### **2.4 Drift stage**

As the Indian plate drifted northward with anticlockwise rotation along a curved path (**Figure 3**), the reactivated rift-faults were subjected to horizontal stress, inducing transtensional movements within the pericratonic rift basins. This is evident by the breaking of upthrust-related drape folds along the tilted-up edges of the uplifts (horsts) into small sub-order folds. The best example is seen in the structure of Kutch uplifts (**Figure 4**).

**Figure 3.** *Path of post-cretaceous drifting of the Indian plate.*

#### **Figure 4.**

*Tectonic map of Kutch rift basin, the zone of intensive seismic activity in SCR. The map shows major fault-bound tilted uplifts and intervening grabens/half-grabens. Evidence of strike-slip movement is indicated by the breakup of marginal drape fold over the tilted-up edges of the horst (indicated by fold symbols) and left step over of the KMF as SWF towards the east with en echelon shift of Kutch mainland and Wagad uplifts.*

#### **2.5 Collision stage**

India collided head on with the Eurasian plate in late Middle Eocene initiating uplift of the Himalayan orogenic belt in the north (**Figure 3**). In Late Oligocene Burmese plate collided obliquely with the Indian plate at its northeastern corner giving rise to Assam-Arakan orogenic belt (**Figures 1** and **5**). This stage is continuing as the northern and northeastern edges of the plate are continuing to subduct under the two converging plates. In the NE, due to oblique collision, the plates are still under the process of convergence with progressive southwestward closing of the intervening NE Indian remnant ocean basin, Bengal basin and Bay of Bengal [4] (**Figure 5**). Widespread compressive stress developed in the plate due to southerly backthrust from the collision front and northerly ridge-push from Carlsberg Ridge as the Arabian Sea continues to spread. This compressive regimen is continuing in the present neotectonic cycle. It is responsible for the initiation of inversion tectonic cycle in Eocene-Oligocene and its continuation in the current neotectonic cycle. This is quite evident from the inversion structures seen in all the intra-cratonic basins as well as in the offshore pericratonic basins. Morphotectonic features of India with predominance of the first-order topography also indicate active neo-tectonic cycle dominated by compressive stress.

*Intra-Plate Dynamics and Active Tectonic Zones of the Indian Plate DOI: http://dx.doi.org/10.5772/intechopen.105647*

#### **Figure 5.**

*Plate collision dynamics of NE India – AATZ: The straight collision of Eurasian plate and oblique collision of Burmese plate at the NE corner of India, sutured part is Naga Schuppen belt, and open, the converging region, is the remnant basin of Bengal & bay of Bengal.*
