On the interaction of the North Andes plate with the Caribbean and South American plates in northwestern South America from GPS geodesy and seismic data

Fault Creep and Strain Partitioning in Trinidad‐Tobago: Geodetic Measurements, Models, and Origin of Creep

“…The southern CA‐SA plate boundary is dominated by dextral shear in its central and eastern segments. Geodetic studies have determined that the ~20 mm/yr of dextral shear is accommodated on the San Sebastian, La Victoria, and El Pilar Faults in the west, and on the Central Range and Sub‐Tobago Terrane Faults in the east, with additional strain inferred south of Trinidad (Pérez et al, ; Reinoza et al ; Weber, Dixon, et al, , Weber et al, , ). Here, we determined that CA‐SA relative plate motion, at the longitude of Trinidad‐Tobago, is accommodated across three fault zones: (1) the South Coast Fault accommodates motion between South America and southern Trinidad; (2) the CRF accommodates motion between south and north Trinidad crustal slivers or microplates by fault creep; and (3) the Sub‐Tobago‐Terrane Fault likely accommodates motion between Trinidad and Tobago (Figures and ).…”

“…Geodetic studies have determined that the~20 mm/yr of dextral shear is accommodated on the San Sebastian, La Victoria, and El Pilar Faults in the west, and on the Central Range and Sub-Tobago Terrane Faults in the east, with additional strain inferred south of Trinidad (Pérez et al, 2018;Reinoza et al 2015;Weber, Dixon, et al, 2001, Weber et al, 2015. Here, we determined that CA-SA relative plate motion, at the longitude of Trinidad-Tobago, is accommodated across three fault zones: (1) the South Coast Fault accommodates motion between South America and southern Trinidad;…”

“…Plate motion studies indicate relative CA-SA dextral shear of~20 mm/yr, oriented~N80-90°E (Kreemer et al, 2014;Pérez et al, 1997Pérez et al, , 2001Weber, Dixon, et al, 2001). Plate motion is accommodated in a right-stepping, segmented fault system, including the Central Range Fault in Trinidad and on the El Pilar, San Sebastian, and La Victoria Faults to the west in Venezuela (e.g., Audemard, 2006;Beltran-Pousse et al, 2016;Mendoza, 2000;Pérez et al, 2001;Pérez et al, 2018;Reinoza et al, 2015;Weber et al, 2011;Weber, Dixon, et al, 2001) (Figures 1 and 2). Geodetic observations across the eastern Moonan and Weber (2017), and NGC -National Gas Company of Trinidad and Tobago (2015).…”

Lithospheric Structure of Northwestern Venezuela From Wide‐Angle Seismic Data: Implications for the Understanding of Continental Margin Evolution

“…During the last 60 years, several models regarding the shallow and deep structure of northern South America have been proposed, as the existence of Caribbean allochthonous related to the peri-Caribbean suture (Stéphan, 1985), continental subduction of Maracaibo block beneath South America (e.g., Colletta et al, 1997;Kellogg & Bonini, 1982), or orogenic float with incipient subduction of South America beneath Maracaibo block (Audemard & Audemard, 2002). Northwestern Venezuela is characterized by the presence of the Maracaibo triangle block and the strike-slip fault systems at the southwestern, southeastern, and northern boundaries of this block (Santa Marta-Bucaramanga, Boconó, and Oca-Ancón faults, respectively) belonging to the North Andes plate (Pérez et al, 1997(Pérez et al, , 2018 Figure 1). This plate together with the Maracaibo block is currently being extruded to NNW with respect to South America (Bird, 2003;Trenkamp et al, 1996) with an indentation process as the main expulsion mechanism (Audemard, 2014a).…”

“…The main objective of the 560-km-long Northern Andes wide-angle onshore refraction profile, analyzed in this work, is to improve the understanding of the structure and evolution of this plate boundary by (after Feo-Codecido et al, 1984;Audemard et al, 2000;Audemard & Audemard, 2002;Monod et al, 2010;Escalona & Mann, 2011), showing the location of the Northern Andes seismic profile (thick yellow line) and other GIAME seismic profiles (purple lines), and some of the major tectonic provinces and faults systems (black lines). GPS vectors (gray arrows) are expressed within the South America plate reference frame (Pérez et al, 2001(Pérez et al, , 2018Reinoza et al, 2015;Trenkamp et al, 2002). Topographic map is derived from the Shuttle Radar Topography Mission database (SRTM30), and bathymetry from the TOPEX global database (Smith & Sandwell, 1997) plotted with the Generic Mapping Tools (Wessel et al, 2013).…”