Source rock studies of natural seep oils near Parsons Pond on the west coast of Newfoundland

• Main Author: Weaver, Faye J. (Faye Janet)
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 1988
• Subjects: Cow Head; Green Point; Broom Point; Newfoundland
• Online Access: https://research.library.mun.ca/4288/; https://research.library.mun.ca/4288/1/Weaver_FayeJ.pdf; https://research.library.mun.ca/4288/3/Weaver_FayeJ.pdf

The seep oils occurring on the west coast of Newfoundland in the Parsons Pond region have presented numerous questions to the scientific community since the oils were first discovered in 1812. The area has been studied in detail for geological and depositional features. The purpose of this thesis was to ascertain the source, maturation and potential for recoverable hydrocarbons using geochemistry. -- The Parsons Pond Region represents the destroyed margin of the eastern coast of ancient North America in Cambro-Ordovician time, now superimposed in northeast-southwest trending thrust sheets. Sediments include carbonate breccias/conglomerates, limestones and clastics with interbedded black shales. Organic content in these shales is moderate (TOC from 0.2 to 4.3%). The presence of trisnorhopane, gammacerane, abundant hopanes and rearranged steranes suggest admixed Type I/II kerogen, derived from prokaryotic organisms preserved under stratified marine anoxic conditions. Abundant C₂₉ hopanes, odd dominance from nC₁₇ to nC₂₁ n-alkanes and the occurrence of C₂₈ steranes suggest Ordovician type organic matter. The occurrence of pristane and phytane indicate the Cow Head Group shales are different in character from global G. Prisca facies common in Ordovician deposits. -- The potential for hydrocarbon generation is good (70 l/t), although many of the samples in outcrop are immature and reservoirs may be limited. Samples are above to within the upper limits of the oil generation window and increase in maturity across the Humber Arm Allochthon from the coast toward the Long Range Mountains. The source of the oils is within the Broom Point Member of the Green Point Formation.