Hinterland-directed transtensional faulting at an orogen structural front: The example of the Cap-Chat melange, Quebec Appalachians

The St Lawrence Platform and Appalachian deformation front in the St Lawrence Estuary and adjacent areas (Quebec, Canada): structural complexity revealed by magnetic and seismic imaging

“…Owing to its structural complexity, the geometry of the tectonic wedge above the décollement at the base of the Appalachians remains poorly constrained by seismic data in the study area and along most of the Quebec Appalachians. Recent studies indicate that the present-day geometry of the Appalachian frontal units is more complicated than usually thought, including both foreland and hinterland-directed thrusts as well as normal and strike-slip faults (see the review in Pinet, 2011 a ). Moreover, field and geochronological evidence indicates that these complex structures result from the superimposition of several deformation events (Pinet, 2011 a ).…”

“…Ph.D. thesis, Laval Univ., 1984; Tremblay & Pinet, 1994, Pinet & Tremblay, 1995). The imprint of younger tectonic events, recorded by both extensional and compressional structures, is, however, increasingly documented (see Pinet, 2011 a for a review), and deformation of the Humber Zone is now attributed to a long-lived tectonic history including the Taconian (Ordovician), Salinian (Silurian) and Acadian (Devonian) tectonic events (Pincivy et al . 2003; Malo et al .…”

Revisiting the Appalachian structural front and offshore Anticosti Basin (northern Gulf of St. Lawrence, Canada) by integrating old and new geophysical datasets

“…Offshore of Gaspé Peninsula and Newfoundland, the southern boundary of the basin corresponds to a series of thin-to thick-skinned Appalachian structural slices (Waldron et al, 1993;Stockmal et al, 1998Stockmal et al, , 2004Pinet et al, 2010;Pinet, 2011). Deformation of the frontal Appalachian thrust sheets has been attributed to a long-lived tectonic history including the Taconian (Ordovician), Salinian (Silurian) and Acadian (Devonian) tectonic events (van Staal et al, 2009).…”

“…Major structural features in the area bounding the St. Lawrence River were interpreted to belong to a typical north-directed foreland fold-and-thrust belt (St-Julien and Hubert, 1975). However, a more complex interpretation was recently documented in a regional-scale dismembered unit (Cap-Chat mélange) that recorded foreland-directed thrusting, post-Taconian transtensional hinterland-directed motion and subsequent Acadian shortening (Pinet, 2011).…”

“…J, Jupiter Formation. The summary of the stratigraphic and tectonic relationships of the various tectonic elements is adapted fromPinet (2011).…”