GEOLOGICAL OVERVIEW AND HYDROCARBON POTENTIAL OF CAMBRIAN–ORDOVICIAN STRATA OF THE OUTER HUMBER ZONE, WESTERN NEWFOUNDLAND

• Main Author: Hinchey, Alana
• Format: Text
• Language: unknown
• Published: figshare 2021
• Subjects: Geology; FOS Earth and related environmental sciences; Cow Head; Green Point; Newfoundland
• Online Access: https://dx.doi.org/10.6084/m9.figshare.14495346.v1; https://figshare.com/articles/journal_contribution/GEOLOGICAL_OVERVIEW_AND_HYDROCARBON_POTENTIAL_OF_CAMBRIAN_ORDOVICIAN_STRATA_OF_THE_OUTER_HUMBER_ZONE_WESTERN_NEWFOUNDLAND/14495346/1

Naturally occurring hydrocarbon seeps and shows have been documented along the coast of western Newfoundlandthrough the 1800s. Historically, hydrocarbon exploration and drilling have targeted conventional oil and gas resources withinCambrian–Ordovician sedimentary rocks of the western (outer) part of the Humber (tectonostratigraphic) Zone. However,to date, the hydrocarbon potential of western Newfoundland has not been fully evaluated, even though much of the Cambro-Ordovician rocks of the outer Humber Zone reside within the oil-window. Earlier studies described and illustrated a successfulpetroleum play within the western part of the zone and proposed two petroleum fairways; one extensional, the otherinversional, with reservoirs anticipated to be principally in the lower autochthonous Paleozoic shelf rocks.The Cambro-Ordovician Green Point shale (part of the Green Point Formation, Cow Head Group of the Taconic HumberArm Allochthon) is the principal source rock for hydrocarbons in western Newfoundland; thick sections of these rocks areknown, and have potential as an unconventional shale resource. Previous geochemical studies have shown that the shales arerich in Type BI organic matter of mostly algal origin and Type I/II Kerogen and that the chemistry of its oils are similar tothose of the oil seeps and is consistent with a pre-Devonian clastic source rock. Regional geochemistry studies indicate thatthe shale ranges from thermally immature to mature (possibly ranging up to overmature) and that thermal maturity increases(at 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 andstructure are 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. Furtherstudy of the stratigraphy, sedimentology, geochemistry, maturity, and mineralogy, together with structural and mappingstudies of the Green Point Formation and associated rocks, would lead to a better understanding of the shale’s hydrocarbonpotential.