The Geological Evolution of the Aden‐Owen‐Carlsberg Triple Junction (NW Indian Ocean) Since the Late Miocene

Abstract

The Aden-Owen-Carlsberg triple junction is the place where Arabia, Somalia, and India meet in the Arabian Sea (NW Indian Ocean). Here we present a new seismic data set crossing a key structure of the triple junction, namely, the Beautemps-Beaupré pull-apart basin at the southern end of the Owen Fracture Zone. The seismic data set is tied to Ocean Drilling Program Leg 117 Sites at the top of the Owen Ridge, which provides a detailed tectono-stratigraphic framework since the Late Miocene. We show that the triple junction configuration has been disturbed by a major kinematic change at~8 Ma and since then experienced a series of transient structural adjustments. A major structural episode is recorded at 2.4 Ma, expressed by the opening of the Beautemps-Beaupré Basin and the uplift of its southern flank (the Beautemps-Beaupré Ridge). This episode is coeval with the formation of the present-day Owen Fracture Zone and must be considered as a part of a major structural reorganization of the entire India-Arabia plate boundary up to the Makran subduction zone. This 2.4-Myr-old geological episode is unrelated to any significant kinematic change, leaving questions over its driving mechanism.

Tectonic Evolution of a Sedimented Oceanic Transform Fault: The Owen Transform Fault, Indian Ocean

“…In red, the Owen Fracture Zone active trace from Rodriguez et al. (2011, 2018). Multibeam is complemented with SRTM30_PLUS in the background (Becker et al., 2009).…”

“…Some of the profiles acquired previously during the OWEN-2 cruise (Figure 2) were reprocessed to improve ties between the two surveys. In red, the Owen Fracture Zone active trace from Rodriguez et al (2011Rodriguez et al ( , 2018. Multibeam is complemented with SRTM30_PLUS in the background (Becker et al, 2009).…”

“…(a) Location map of drilling sites and seismic lines. In red, the Owen Fracture Zone active trace fromRodriguez et al (2011Rodriguez et al ( , 2018. Multibeam is complemented with SRTM30_PLUS in the background(Becker et al, 2009).…”

The Amirante Ridge and Trench System in the Indian Ocean: the southern termination of the NW Indian subduction

“…The present-day configuration of the Dalrymple Trough and the Murray Ridge results from a series of Late Miocene-Early Pleistocene tectonic events related to the structural evolution of the India-Arabia plate boundary (i.e. the Owen Fracture Zone, Rodriguez et al, 2014Rodriguez et al, , 2018. This series of vertical motions of the lithosphere opened a window to the lithospheric mantle.…”