Morphotectonic architecture of an India–Madagascar breakup related anomalous submarine terrace complex on the southwest continental margin of India

An integrated approach on satellite geodesy data to delineate morphotectonic and neotectonic activities in the West Coast off Kerala, Southern India

“…This change in direction of isobaths may be of fault. Similar observation was made by Yatheesh et al [2013] and Nathaniel [2013] and inferred as landward extension of the VFZ, whose expression continues southward into the Central Indian Basin. Recent studies by Unnikrishnan et al [2017] has observed that VFZ is a crustal scale feature and plays a significant role on the sedimentation pattern on either side (east and west) of the fracture zone.…”

“…The southern part of QP has a gentle slope with step-like features/terraces. These terraces are part of Allepy Trivandrum Terrace Complexes (ATTC), [Biswas, 1987;Yatheesh et al, 2006Yatheesh et al, , 2013. It is inferred that these terraces are rifted and sheared segment of pre-drift plate boundary related to IndiaMadagascar separation during 86.5 Ma.…”

Structure and tectonics of the continental margins of India and the adjacent deep ocean basins: current status of knowledge and some unresolved problems

“…The seismic reflection data in and around this region reveals that the Alleppey Terrace is associated with a basement high in the west of its present-day geometry (Unnikrishnan et al, 2018). The Trivandrum Terrace is characterized by the presence of a NNW-SSE trending wide basement high in its central part that is flanked by thick sediment-filled grabens in its easterly and westerly sides (Figure 3b, 3c), referred to as the TT-Eastern Basin and the TT-Western Basin, respectively (Yatheesh et al, 2013b). Both these basins are characterized by the presence of NNW-SSE trending block-faulted basement features, extending across the entire Trivandrum Terrace.…”

“…The Kerala Basin is the southernmost basin in the western continental margin of India, extending from the Tellicherry Arch in the north to Cape Comorin in the south (Figure 2). The entire western continental margin in the northern part shows a regular shelf-slope topography, but the mid-continental slope region south off Cochin shows an anomalous topography due to the presence of two contiguous terraces, the Alleppey Terrace and the Trivandrum Terrace (Figure 3), together known as the Alleppey-Trivandrum Terrace Complex (Yatheesh et al, 2006;Yatheesh et al, 2013b). The seafloor depth of the Alleppey Terrace varies between 300 m and 400 m, while that of the Trivandrum Terrace varies between 1500 m and 1900 m (Yatheesh et al, 2013b).…”

“…Considering the presence of seaward dipping reflectors (SDRs) west of the Laccadive Plateau and the derived crustal configuration from the forward modelling of the gravity data, Ajay et al (2010) inferred that the continent-ocean boundary in this region lies west of the Laccadive Plateau implying that the Laccadive Basin is continental in nature. Yatheesh et al (2013b) demonstrated that the Laccadive Basin region could be explained either in terms of a much thinned continental crust or as anomalously thick oceanic crust, based on forward modelling of the gravity profiles.…”