Petrogenesis of the meta-igneous rocks of the Sierra El Arco and coeval magmatic rocks in Baja California: Middle Jurassic-Early Cretaceous (166-140 Ma) island arc magmatism of NW México

The petrogenesis of Early–Middle Jurassic magmatism in southern and central Mexico and its role during the break-up of Western Pangaea

“…Specifically, the production of new oceanic crust in the GM may have produced enough tectonic force to initiate subduction in Mexico, converting the proposed Late Triassic-Middle Jurassic conservative margin into a subduction zone by the end of Middle Jurassic or the beginning of Late Jurassic times. The early manifestation of arc magmatism in Baja California (~165-160 Ma; Kimbrough & Moore, 2003;Contreras-López et al 2021) also supports the onset of subduction by the end of Middle Jurassic time along the central and southern sectors of the Mexican margin, consistent with the proposed time lapse between the subduction initiation and the onset of arc magmatism (~7 Ma; Arculus et al 2019). In this view, we suggest that the onset of subduction in southern and central Mexico during late Middle Jurassic time was triggered by changes in plate motions related to the opening of the GM, as a result of the Atlantic-related extensional tectonic regime associated with Pangaea break-up.…”