Highlights—The Secret’s in the Crust

Regional stresses can lead to re-activations in basement structures, which in turn have a profound influence on stratigraphic patterns.  In this contribution, Dix et al. describe the Middle-to-early Upper Ordovician Chazyan epicontinental platform succession developed landward of an arc-collision plate boundary peripheral to the ancient Quebec Embayment (northern Appalachians).  A comprehensive sedimentologic and stratigraphic data set from core, outcrop, and wireline sections from the platform interior reveal patterns that contrast with contemporaneous outer platform systems.  The interpretations illustrate how this regional platform aggraded, but was shaped by the developing foreland basin. These results are interpreted to be significant in that they illustrate how regional and platform-interior structurally controlled depositional surfaces can be an important influence on epicontinental aggradation, and these surfaces correspond to episodes of prominent tectonics along the convergent plate boundary, and that stratigraphic patterns well removed from the convergent margin may still record regional tectonic signatures.

Tectonostratigraphy of the Chazyan (late Middle–early Late Ordovician) mixed siliciclastic–carbonate platform, Quebec Embayment  by George R. Dix, Odette Nehza, and Itor Okon