Seismic sequence stratigraphy during the Cretaceous through the early Paleogene in the northern Scotian basin (Laurentian Subbasin) offshore Nova Scotia and Newfoundland, Canada

• Main Author: Sulistyaningrum, Ika
• Format: Text
• Language: unknown
• Published: No Publisher Supplied 2010
• Subjects: Canada; Newfoundland
• Online Access: https://dx.doi.org/10.7282/t35x292b; https://rucore.libraries.rutgers.edu/rutgers-lib/26651/

This thesis uses seismic-sequence-stratigraphic analysis to show the stratigraphic development of the northern Nova Scotia passive margin (the Laurentian Subbasin) during the Cretaceous through Paleogene. It documents the interplay of several variables on margin evolution including changes in relative sea-level, sediment supply, and tectonic activity including thermoflexural subsidence and salt movement. Salt structures, basement-involved deformation, and sparse well control impede the interpretation of stratigraphic patterns in the study area. Despite these difficulties, I have identified eight candidate sequence boundaries using seismic-reflection terminations: (1) top-lap andtruncation below a discontinuity, and (2) on-lap and down-lap above a discontinuity.Study of the sequence stratigraphy in the Laurentian Subbasin reveals two significant unconformities, the Jurassic-Cretaceous (Avalon) unconformity and theCretaceous-Paleogene (KP) unconformity, and seven sequences: three Cretaceous sequences (Sequences 1, 2, and 3) and four Paleogene sequences (Sequences 4, 5, 6 and 7). Change in relative sea level and sediment-supply directions during the Cretaceous are not well documented. Salt tectonics and thermoflexural subsidence created the accommodation space for the Early Cretaceous sequences. System tracts controlled by relative sea-level change show that sediment supply was from the northwest anddepocenters migrated from northeast to southeast during the Paleogene.Comparison of the Baltimore Canyon Trough with the Laurentian Subbasin shows that these basins in the passive margin of eastern North America have similarities and differences. The similarity includes the presence of clinoform geometries above the KPboundary indicating aggradational-progradational stratigraphic patterns. The differences include the major Jurassic-Cretaceous (JK) unconformity, the presence of salt structures, and the presence of Paleogene sequences. In the Scotian Basin, the JK unconformity is a major angular unconformity (Avalon unconformity) separating gently dipping Cretaceousrocks above from folded Jurassic rocks below. However, the JK unconformity in the Baltimore Canyon Trough generally is a paraconformity separating subparallel beds above and below the unconformity.