Geologic and plate tectonic setting of the Villa de Cura belt

The Villa de Cura blueschist belt is one of the east-west trending allochtonous belts that make up the Caribbean - South American plate margin in Venezuela. Previous studies in the VdC metamorphic belt have led to the formation of the two main hypotheses to explain the presence of this belt of high pressure (HP) metamorphic rocks:

1. during the Cretaceous multiple parts of an intra-oceanic volcanic arc were subducted and exhumed (with two distinct pressure-temperature-time (P-T-t) paths) to form the current rocks making up the VdC blueschist belt somewhere around the present location of the northwestern tip of South America, and
2. that the entire suite of rocks was tectonically transported from that position to its present day position by a combination of strike-slip and thrust faulting related to the highly oblique subduction of the Caribbean plate below the South - American plate.

1. satisfactory answers regarding the details of how the rocks of the Villa de Cura blueschist belt got to their present position, and
2. if there are any differences in the deformation and metamorphic ages along the strike of this east-west trending belt.

1. involving exhumation using a single mega-thrust, or
2. obduction and exhumation as an imbricate thrust sheet within the fold and thrust belt making up the Caribbean-South American plate boundary zone.

Planned Studies

The main theme of this PhD project is to provide a more complete understanding on how the VdC blueschist rocks were emplaced by specifically focusing on when deformation events took place, what type(s) of deformation were involved and what the deep structure (crustal scale) and geometry of the VdC belt looks like. These three main objectives will be:

1. Field (structural) geologic mapping of multiple transects across the Villa de Cura belts from westernmost to easternmost areas and taking samples for age dating (40Ar/39Ar), Universal Stage (U-Stage) fabric analysis, and additional P-T-t analysis;
2. Fluid inclusion analysis of quartz veins in samples taken during previous and planned field studies to better confine the uplift history of this area;
3. Collection and processing of deep seismic data (both land and marine based) to unravel the geometry and deeper structures of the VdC belt.