Consag Basin: northern Gulf of California, evidence of generation of new crust, based on seismic reflection data

Abstract

The Gulf of California is an excellent example of how new ocean basins form. Tectonically, the northern Gulf of California is an incipient ocean basin and studies on it have defined acoustic basement and reveal the presence of new oceanic crust and intrusive bodies. Some recent studies report fundamental differences between the basins of the northern and southern Gulf of California: that the latter have well-developed oceanic crust beneath a thin cover of sediments, whereas the northern basins show proto-ocean basins, which may reflect thermal insulation of the thick sedimentary cover, the presence of lowangle faults, and more diffuse and distributed deformation. During the 1970s, Petróleos Mexicanos (PEMEX) undertook a 2D seismic reflection survey in the northern Gulf of California, over many active rift basins, including the Consag Basin. Through the processing and interpretation of these data, we describe the structural characteristics of the Consag Basin beyond 2 km depths. Using seismic reflection data, we identified an intrusion in the central part of this basin that may represent new oceanic crust buried by more than 4 km of sediments.

Analogue Modeling of Plate Rotation Effects in Transform Margins and Rift‐Transform Intersections

“…In the northern GoC, the nature and timing of continental rupture are still uncertain, with the presence of oceanic crust suggested in some basins (González‐Escobar et al, ; Martín‐Barajas et al, ) and delayed rupture suggested for others (Lizarralde et al, ; Martín‐Barajas et al, ). Deformation in the north is distributed across a pull‐apart structure between the Cerro Prieto Fault and the Ballenas Transfrom Fault Zone (Figure a; Persaud et al, ).…”

Mantle Degassing Through Continental Crust Triggered by Active Faults: The Case of the Baja California Peninsula, Mexico

“…In the southernmost portion of the rift, the Alarcon basin has experienced seafloor spreading and the formation of oceanic crust with magnetic lineation since 3.5 Ma (Lonsdale, 1989). Further north, the Guaymas basin contains nearly 280 km of new oceanic crust under thick sedimentary deposits according to seismic refraction experiments, while the Delfín, Consag, and Wagner basins apparently have narrow troughs with oceanic crust under >6-km-thick sedimentary deposits from the Colorado River (González-Escobar et al, 2014;González-Fernández et al, 2005;Martín-Barajas et al, 2013;Persaud et al, 2003, Figure 1). These basins do not show obvious magnetic lineation (González-Fernández et al, 2005).…”

Nature of the crust in the northern Gulf of California and Salton Trough

“…As with the Salton Trough transects, adjustments are made to layer thicknesses in places that are not constrained by available data, or within uncertainties. Basement depths in the Wagner Basin transect are constrained using González-Escobar et al (2009) and González-Escobar et al (2014). Bathymetry is constrained by Bischoff and Niemitz (1980).…”

“…Bathymetry is constrained by Bischoff and Niemitz (1980). The locations of the Wagner and Consag faults are obtained from González-Escobar et al (2009). Twoway travel times from seismic line 5023 from González-Escobar et al (2009) are used to estimate basement depth.…”

“…Potential-field data may discriminate between oceanic and continental crust based on differences in composition and thus density and magnetic susceptibility. Potential-field models are, however, nonunique and are therefore constrained in this study by seismic reflection and refraction profiles, receiver functions, and tomographic images (Fuis and Kohler, 1984;Parsons and McCarthy, 1996;Lewis et al, 2001;González-Escobar et al, 2009, 2014Barak et al, 2015;Persaud et al, 2016;Han et al, 2016). Burial history (geohistory) and thermal models were developed for the Salton Trough to obtain the geotherm, the depth to the Curie isotherm, and the antigorite breakdown depth.…”