This presentation was originally prepared for the 2020 joint NE-SE GSA meeting, however, like many large events at that time, the conference was canceled. The content of this presentation is based on collaborative research with Jeffrey Chiarenzelli (St. Lawrence University, Canton, NY) and Joshua Valentino (Terracon, Ashburn, VA).
NNE striking oblique-slip faults divide the basement of the Adirondacks into several structural blocks. Mesozoic differential uplift of these blocks contributed to the rise of the Adirondack dome. These faults extend southward into the Mohawk Valley fault system that was active during the development of the early Paleozoic shelf, and reactivated during various Appalachian tectonic events. An E-W transect to systematically study faults and fracture systems in the Adirondacks was carried out across the massif from the interior to the western nonconformity with Ordovician carbonates. Similarly, fracture systems were documented in the basement along the northernmost and easternmost margins for comparison with macroscopic features that occur in the overlying Cambrian strata in those regions. This presentation will include three parts:
1. Examine faults in the basement from the interior to the western margin, kinematic analysis of those faults, and characterize fracture systems and mineralization that occur within the fault blocks;
2. Characterize macroscopic brittle deformation in the Ordovician strata that directly overlies the basement on the western margin, compare those results with brittle deformation in Cambrian strata that occurs along the northern and eastern margin of the basement;
3. Assess the link between brittle deformation in the basement and any link with similar features in the overlying strata.