A gravity survey of eastern Notre Dame Bay, Newfoundland

• Main Author: Miller, Hugh G.
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 1970
• Subjects: Notre Dame Bay; Change Islands; Luke's Arm; Newfoundland
• Online Access: https://research.library.mun.ca/7162/; https://research.library.mun.ca/7162/1/Miller_HughG.pdf; https://research.library.mun.ca/7162/3/Miller_HughG.pdf

A gravity survey was undertaken on the archipelago and adjacent coast of eastern Notre Dame Bay, Newfoundland. A total of 308 gravity stations were occupied with a mean station spacing of 2.5 km, and 9 gravity sub-bases were established. Elevations for the survey were determined by barometric and direct altimetry. The densities of rock samples collected from 223 sites were determined. -- A Bouguer anomaly map was obtained and a polynomial fitting technique was employed to determine the regional contribution to the total Bouguer anomaly field. Residual and regional maps based on a fifth-order polynomial were obtained. Several programs were written for the IBM 360/40 computer used in this and model work. -- Three-dimensional model studies were carried out and a satisfactory overall fit to the total Bouguer field was obtained. Several shallow features of the anomaly maps were found to correlate well with surface bodies, i.e. granite or diorite bodies. Sedimentary rocks had little effect on the gravity field. The trace of the Luke's Arm fault was delineated. -- The following new features were discovered: (1) A major structural discontinuity near Change Islands; (2) A layer of relatively high density (probably basic to ultrabasic rock) at 5 - 10 km depth.