Geology of the Noel Paul's Brook area, central Newfoundland

• Main Author: Mullins, John
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 1961
• Subjects: Newfoundland
• Online Access: https://research.library.mun.ca/6838/; https://research.library.mun.ca/6838/1/JohnMullins.pdf; https://research.library.mun.ca/6838/3/JohnMullins.pdf

This thesis is concerned with a study of the general geologic features of the Noel Paul’s Brook area in Central Newfoundland, with emphasis on the systematic description and classification of rock types. -- In the gently rolling terrain the remnants of two Cenozoic erosion surfaces may still be recognized. As a result of Pleistocene glaciation the countryside has been left with a think mantle of boulder clay, but because of two conflicting lines of evidence no definite conclusion as to the direction of glacial ice motion could be reached. -- The bedrock geology is characterized by narrow - often persistent - bands of clastic sedimentary rocks and volcanic formations striking approximately northeast. Their total thickness, if the possibility of repetition through isoclinal folding is disregarded, is over 30,000 feet. With the exception of one conglomerate member the sedimentary rocks are fine grained. The volcanic rocks consist of metamorphosed acid and intermediate flows and tuffs. The intermediate rocks are associated with thin bands of slightly metamorphosed limestone, limy shale and greenstones of sedimentary origin. -- A large granite batholith lies along the southern boundary of the map area, and smaller intrusive stocks, sills and dikes, ranging in composition from diorite to micropegmatite also occur. -- No fossils were found in the sedimentary rocks, but by lithological correlation with rocks beyond the thesis area the formations mapped are believed to range in age from middle Ordovician to post-Ordovician. -- It is believed that the rocks were deformed by two major orogenies: one in the late Ordovician, the other late in the Devonian period. The conglomerate member mentioned above may have formed in connection with the late Devonian upheaval. -- The sedimentary rocks have steep dips, generally in a southeasterly direction, but the beds are often overturned. These high dips are indicative of tight, isoclinal folding, and observation of minor folds tends to support this assumption. Faults are not ...