DEPOSITIONAL RESPONSE OF ORDOVICIAN FORELAND BASIN TURBIDITES TO BATHYMETRY IN THE FRONTAL THRUST OF THE TACONIC THRUST WEDGE

The geology of the Hudson and Mohawk Valleys of eastern upstate New York is defined by the events of the Ordovician Taconic Orogeny, which was dominated by the collision of the Taconic arc and the formation of a foreland basin that was largely filled largely by turbitides. The Taconic foreland basin is well exposed in the Hudson and Mohawk valleys. To the west (Schenectady and west) are undeformed autochthonous rocks that accumulated in this tectonically active foreland basin. To the east, para-autochthonous rocks are comprised of foreland basin strata that were deformed in the frontal boundary of the Taconic Thrust Belt. The geometry of the Taconic foreland basin can be examined using paleocurrent data from two mid Ordovician units: the undeformed Schenectady Formation and the deformed Austin Glen Formation. The objective of this project is to examine these rocks to obtain a clearer picture of foreland basin geometry and infilling along the Taconic deformation front, specifically examining how regional structure is reflected in sediment transport. Paleocurrent data from flutes and grooves from autochthonous turbidites indicate a relatively simple NE transport direction parallel to the thrust front. Paleocurrent data from the deformation front (para-autochthon) show primary transport directions to the NE as well as the NW and flow directions are highly variable, even in a single outcrop. Kinematic analysis of folds and thrusts in the frontal part of the Taconic thrust belt have a Northwest vergence and tectonic transport to 290-300 degrees. Together these data indicate that sediment transport along the deformation front may have been influenced by thrust topography in the deformation front, producing sediment transport perpendicular and parallel to the thrust complex.