The Early Cretaceous Arperos basin: an oceanic domain dividing the Guerrero arc from nuclear Mexico evidenced by the geochemistry of the lavas and sediments

During the Early Cretaceous, the Arperos basin was located between the Guerrero arc terrane and nuclear Mexico. Remnants of this basin now form an oceanic suture zone between the coeval carbonate platforms to the east and the accreted Guerrero terrane to the west. The geochemistry on the Arperos mafic hypabyssal and volcanic rocks, based on the incompatible and trace element distribution and the ϵNd(T=110 Ma) values, shows that this basin was floored by basalts that likely were generated by the mixing of OIB and N-MORB sources. The submarine lavas are overlain by and/or interbedded with siliceous sediments that have the highest ϵNd(T=110 Ma) and lowest Th levels. In contrast, the turbidites interlayered with the pelagic carbonates located at the top of the Arperos stratigraphic column show the lowest ϵNd(T=110 Ma) values and the highest Th contents. This evolution with time in the chemistry of the Arperos sediments is interpreted as marking the approach of the Guerrero juvenile arc to nuclear Mexico.