Ian Knight’s research while affiliated with Memorial University of Newfoundland and other places

During the Carboniferous, the assembly of the supercontinent Pangea periodically reactivated strike-slip faults and shear zones that transect the northern Appalachian Orogen. These strike-slip deformation zones represent crustal-scale zones of structural weakness that have long-lived and complex kinematic histories. Their periodic reactivation controlled the evolution of the transtensional sedimentary basins of the region. The continuous interplay between the lithospheric plates, their subcontinental lithospheric mantle, and surficial processes (i.e. oceanic/riverine, biological, atmospheric, gravitational, erosional) controlled the development of the Deer Lake Basin in western Newfoundland. The Saltwater Cove Formation of the Deer Lake Basin is a late Tournaisian deltaic succession interrupted by minor eruption of basalt flows and pyroclastic deposits. The basalts have E-MORB (enriched-mid ocean ridge basalt) to OIB (ocean island basalt) chemical affinities with LREE enriched profiles, lack negative Nb and Ti anomalies and εNd(t=350 Ma) values between +2.8 to +6.4. Pyroclastic deposits include mafic lapilli tuff and intermediate tuff, and have compositions similar to CAB (continental arc basalt), having steep LREE relative to HREE patterns, negative Nb and Ti anomalies, and εNd(t=350 Ma) ranging from -6.1 to -1.0. Geochemical variation within the mafic rocks is explained by an E-MORB source variably influenced by crustal contamination processes. Lithofacies analysis coupled with geochemical and isotopic data support their eruption in a transtensional, intra-orogenic basin setting that formed during the assembly of Pangea. Their moderately primitive chemistry supports the interpretation that faulting, associated with transtensional basin development, facilitated asthenosphere upwelling via edge-driven convection.

During the Carboniferous, the assembly of the supercontinent Pangea periodically reactivated strike-slip faults and shear zones that transect the northern Appalachian Orogen. These strike-slip deformation zones represent crustal-scale tectonic boundaries that likely originated in association with Paleoproterozoic rifting of the paleo-Laurentian margin and have long-lived and complex kinematic histories. Their periodic reactivation controlled the evolution of the transtensional sedimentary basins of the region. The continuous interplay between the lithospheric plates, their subcontinental lithospheric mantle, and surficial processes (i.e. oceanic/riverine, biological, atmospheric, gravitational, erosional) controlled the development of the Deer Lake Basin (DLB) in western Newfoundland. The Saltwater Cove Formation of the DLB is a late Tournaisian deltaic succession where sedimentation was interrupted by minor intervals of basalt flows and pyroclastic deposits. The basalt samples have E-MORB (enriched-mid ocean ridge basalt) to OIB (ocean island basalt) chemical affinities, i.e. enriched LREE to HREE, and have εNd(t=345 Ma) values between +2.8 to +6.4. Pyroclastic deposits include mafic lapilli tuff and intermediate tuff, and have compositions similar to CAB (continental arc basalt), with steep LREE relative to HREE patterns, negative Nb and Ti anomalies, and have εNd(t=345 Ma) ranging from -6.1 to -1.0. Geochemical variation within the mafic rocks is explained by an E-MORB source variably influenced by crustal contamination processes. Coupled with field evidence, the geochemical and isotopic data support their emplacement in a transtensional, intra-orogenic basin setting that formed during the assembly of Pangea. Their moderately primitive chemistry supports the interpretation that faulting associated with transtensional basin development facilitated asthenosphere upwelling via edge-driven convection.

https://www.gov.nl.ca/iet/mines-geoscience-reports-maps-docs-open-file-012H-03-2333/ - Digital Files This Open File release consists of wholerock geochemical data for 12 rock samples collected in the Deer Lake Basin map area (NTS 12H/03), Newfoundland (Figure 1). Details of the analytical methods used are provided by Finch et al. (2018). NOTES ON THE DATABASE This data release contains wholerock geochemical analyses of lithological units collected in 2015. This open file places data in the public domain; no interpretation of the data is included in this report. The compilation includes for each sample the location in UTM coordinates (NAD 27, Zone 21), a brief lithological description, and major and trace element data (Appendix A). Analyses of standards are included in a separate file (Appendix B). The data are available in comma separated value format (*.csv files) from the Geofiles website link (see Appendices).

The Cambro-Ordovician Green Point shale (part of the Green Point Formation, Cow Head Group of the Taconic Humber Arm Allochthon), is the principal source rock for hydrocarbons in western Newfoundland; thick sections of these rocks are known and have potential as an unconventional shale resource. Previous geochemical studies have shown that the shales are rich in Type BI organic matter of mostly algal origin and Type I/II Kerogen and that the chemistry of its oils are similar to those of the oil seeps and is consistent with a pre-Devonian clastic source rock. Regional geochemistry studies indicate that the shale ranges from thermally immature to mature (possibly ranging up to overmature) and that thermal maturity increases (at the surface) from west to east and from south to north (late mature); Green Point shale, occurring north of Parson’s Pond, may reside in the gas window. The Green Point shale was complexly deformed during multiple tectonic events and its distribution, stratigraphy and structure is generally poorly understood. There is no robust model of the subsurface because of limited onshore mapping, the scarcity of well data, and the fine-grained nature of the rocks that make seismic resolution and interpretation difficult. Further study of the stratigraphy, sedimentology, geochemistry, maturity, and mineralogy, together with structural and mapping studies of the Green Point Formation and associated rocks, would lead to a better understanding of the shale’s hydrocarbon potential.