scholarly journals First vertical derivative of the Bouguer gravity anomaly, airborne gravity survey of the Patterson Lake area, Athabasca Basin, Alberta and Saskatchewan, parts of NTS 74-E, F, K and L

2019 ◽  
Author(s):  
O Boulanger ◽  
F Kiss ◽  
V Tschirhart
Keyword(s):  
Gravity Anomaly ◽  
Gravity Survey ◽  
Airborne Gravity ◽  
Lake Area ◽  
Bouguer Gravity ◽  
Athabasca Basin ◽  
Vertical Derivative ◽  
Bouguer Gravity Anomaly ◽  
Airborne Gravity Survey ◽  
First Vertical Derivative

THE CORRELATION BETWEEN PRE‐CAMBRIAN ROCK DENSITIES AND BOUGUER GRAVITY ANOMALIES NEAR PARRY SOUND, ONTARIO

Geophysics ◽  
1954 ◽  
Vol 19 (1) ◽  
pp. 76-88
Author(s):  
C. H. G. Oldham
Keyword(s):  
Gravity Anomaly ◽  
Gravity Anomalies ◽  
Canadian Shield ◽  
Gravity Survey ◽  
Uniform Density ◽  
Bouguer Gravity ◽  
Geological Evidence ◽  
Bouguer Gravity Anomaly ◽  
Bouguer Gravity Anomalies

A gravity survey and a survey of rock densities have been carried out over an area of two thousand square miles near Parry Sound. A closed positive Bouguer gravity anomaly of thirty milligals was delineated, and a considerable variation was found to exist in the densities of pre‐Cambrian gneisses. In most previous interpretations of gravity over the Canadian Shield the gneisses have been assumed to possess a uniform density and anomalies have been attributed to changes in the thickness of horizontal crustal layers. In this paper it is shown that the Parry Sound anomaly can be explained in terms of structures within the crust taking the form of projections downward of the density variations found at the surface. The postulated structure is a nearly circular basin of dense gneisses. The shape is reasonable and agrees with such geological evidence as is available.

Gravity and magnetic signatures of the Ackley Granite Suite, southeastern Newfoundland: implications for magma emplacement

1989 ◽  
Vol 26 (12) ◽  
pp. 2697-2709 ◽  
Author(s):  
H. G. Miller ◽  
J. Tuach
Keyword(s):  
Gravity Anomaly ◽  
Magma Chamber ◽  
Volcanic Rocks ◽  
Gravity Survey ◽  
Bouguer Gravity ◽  
Density Data ◽  
Bouguer Gravity Anomaly ◽  
Gravity And Magnetic ◽  
Magnetic Signatures ◽  
Granite Suite

A detailed gravity survey (255 stations over an area of 3000 km2) over the posttectonic, Devonian, Ackley Granite Suite in southeastern Newfoundland suggests that a set of northwest-trending geophysical lineations, interpreted as faults, controlled the bottom morphology of the magma chamber during emplacement.The main negative Bouguer gravity anomaly over the Ackley Granite Suite trends in a north–south direction across the trace of the Dover – Hermitage Bay Fault, the boundary between the Gander and Avalon terranes. Inversion of the gravity and density data indicates that the thickness of the granite suite varies between 2 and 8 km.Magnetic interpretation and modelling suggest that the southeast portion of the suite is underlain by mafic volcanic rocks typical of the Avalon Terrane. The magnetically determined depth to the top of these is consistent with that calculated from the gravity data.The combined geophysical models are indicative of a process of megablock stoping in which large crustal blocks were displaced downwards in midcrustal regions to permit the emplacement of what is now the Ackley Granite Suite and associated plutons.

Sign in / Sign up

Export Citation Format

Share Document