Submarine morpho-structure and active processes along the North American-Caribbean plate boundary (Dominican Republic sector)

Abstract

The northern margin of Hispaniola records the oblique collision/underthrusting of the Bahamas Carbonate Province with the island-arc. Due to the collision, northern Hispaniola has suffered several natural disasters caused by major earthquakes and tsunamis, such as the historic earthquake of 1842, the tsunami caused by earthquake-driven slumping in 1918 in the Mona Passage, the seismic crisis of 1943-1953 with five events of M>7.0 or the seismic crisis of 2003 with a main shock of M6.3 and a large aftershock of M5.3. Using new swath multibeam bathymetry data and vintage single-and multi-channel seismic profiles, we have performed a regional scale analysis and interpretation of the shallow surface and active processes along the northern margin of the Dominican Republic. We have identified three morphostructural provinces: a) the Bahamas Banks, b) the Hispaniola Trench and c) the Insular Margin, which are divided into two tectonic domains, the Collision Domain and Underthrusting Domain. The southern slope of the Bahamas Carbonate Province shows a very irregular morphology produced by active erosive processes and normal dip-slip faulting, evidence of an extensional tectonic regime and margin collapse. This collapse is of major extent in the Oblique Collision Domain where there are erosive and fault escarpments with higher dip-slip fault throws. The Hispaniola Trench, is formed by the Caicos and Hispaniola basins in the underthrusting domain, and by the Santisima Trinidad and Navidad basins in the Oblique Collision Domain. They have a flat seafloor with a sedimentary filling of variable thickness consisting of horizontal or sub-horizontal turbiditic levels. The turbiditic fill mostly proceeds from the island arc through wide channels and canyons, which transports sediment from the shelf and upper slope. The Insular Margin comprises the Insular Shelf and the Insular Slope. The active processes are generated on the Insular Slope where the Northern Hispaniola Deformed Belt is developed. This Deformed Belt shows a very irregular morphology, with a WNW-ESE trending N verging imbricate thrust-and fold system. This system is the result of the adjustment of the oblique collision/underthrusting between the North American plate and the Caribbean plate. In the Oblique Underthrusting

The Tectonics and Active Faulting of Haiti from Seismicity and Tomography

“…While these events are far outside our network and have large location uncertainties, it seems clear that the two most seismically active faults in this region are the SOFZ and the North Hispaniola fault, which lies offshore to the north. Rodriguez et al () also observed similarly high levels of seismicity associated with these faults; however, while the North Hispaniola fault has been mapped offshore (Rodríguez‐Zurrunero et al, ), there is still much work needed to fully characterize the structure of the SOFZ which bisects much of the northern Dominican Republic onshore. The present day seismicity highlights the seismic hazard potential of the northern edge of the Caribbean‐North American plate boundary, which can also be seen by the >M w 7.0 historical earthquakes associated these faults (Prentice et al, ; ten Brink et al, ).…”

“…Haiti is bisected by two major left‐lateral strike‐slip faults, the Septentrional‐Oriente fault zone (SOFZ) in the north, which has been mapped offshore (Calais & Mercier de Lépinay, ; Leroy et al, ; Rodríguez‐Zurrunero et al, ), and the EPGF in the south (Figure ; Mann et al, ). Between these faults, the fold and thrust belt, known as the Trans‐Haiti belt and active in the Miocene and Pliocene, controls much of the relief on Haiti (Pubellier et al, ).…”

Paleogene V‐Shaped Basins and Neogene Subsidence of the Northern Lesser Antilles Forearc

“…This fault accommodated the left‐lateral component of the plate convergence, revealing active strain partitioning along the oblique plate boundary to the northwest of Barbuda (Laurencin et al., 2019; ten Brink & Lin, 2004). Farther west, at the Puerto Rico and the Virgin Islands (PRVI) Margin, the Bunce and Bowin left‐lateral strike‐slip faults connect to the northern Hispaniola lithospheric transpressive faults, which bound the Bahamas Bank–Hispaniola collisional system (Mann et al., 2005; Rodríguez‐Zurrunero et al., 2019; ten Brink & Lin, 2004).…”

Along-strike segmentation in the northern Caribbean plate boundary zone (Hispaniola sector): Tectonic implications

“…3). That indicates that the thicker crust of the BCP cannot truly subducts beneath the CARIB plate (Dolan et al, 1998;Rodríguez-Zurrunero et al, 2019).…”