  The tectonic interaction between the Rivera and North American plates north
of the Bahia de Banderas is poorly understood. The nature of the crust and
where the subduction ends in the western part of the Islas Marias Archipelago
are still controversial. Based on new geophysical data provided by the TsuJal
project, we present the shallow and deep crustal structure of the Rivera North
American plate contact zone along two seismic transects, TS09b and RTSIM01b,
and the bathymetry obtained across the northern region of Maria Madre Island.
Detailed bathymetric analysis allowed mapping of a series of lineaments along
the study region, with two main preferred tendencies (020 050 and 290 320)
associated with the evolution of the Pacific-Rivera rise and the transform
faults of the Gulf of California, respectively. The shallow structure is
characterized by five sedimentary basins without deformation, whose horizons
are subparallel, suggesting that the sediment deposition occurred after the
extension process ended. The deep structure corresponds to a transition between
oceanic crust (Rivera Plate), with an average thickness of 10 km to the Islas
Marias Escarpment, and a thinned continental crust, whose thickness increases
toward the continent until it reaches 28 km, with a dip angle of 7 10. The
absence of an accretionary prism suggests that the subduction process of the
Rivera Plate beneath the North American Plate to the north of Islas Marias has
ceased. In this study, we determined that the morphological expression of the
northern limit of the Rivera Plate corresponds to the Islas Marias Escarpment.
