Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Applying laterally varying density corrections to ground gravity and airborne gravity gradiometry data; a case study from the Bathurst mining camp

Peter Tschirhart, William A. Morris, John Mims and Hernan Ugalde
Applying laterally varying density corrections to ground gravity and airborne gravity gradiometry data; a case study from the Bathurst mining camp (in Geophysics applied to mineral exploration, Nicolas Pinet (editor), Erwan Gloaguen (editor) and Bernard Giroux (editor))
Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre (May 2019) 56 (5): 493-503

Abstract

The influence of topography on gravity and gravity gradiometry measurements is profound and should be minimized prior to geological interpretation. The standard way of minimizing these effects is through the computation of a terrain correction. Terrain corrections require two inputs: topography and density. Often, geology and topography are inextricably intertwined: topography is caused by a change in geology. In geologic environments where there is a structural and (or) stratigraphic control on the near-surface mass distribution, using a single density value in the corrections leads to removal of the topographic effect of rocks having the chosen density. Any remaining gravity signal that correlates with topography is providing geological information. If the objective is to produce a gravity map with minimal topographic signal, then a regionally variable density correction is a means of compensating for this effect. In this paper, we demonstrate how to apply a spatially variable density correction using ground gravity and airborne gravity gradiometry data for the geologically complex Bathurst Mining Camp, northern New Brunswick, Canada. Ground gravity and airborne full tensor gravity gradiometry measurements are subdivided into a series of domains on the basis of the underlying tectonostratigraphic group. Terrain and Bouguer corrections are calculated for each domain using representative density values obtained from drill core and surface sampling throughout the Bathurst Mining Camp. The output from the spatially variable density correction is then compared with previous maps. Overall, the differences are subtle, but the spatially variably density allows for isolated anomalies to be better resolved.


ISSN: 0008-4077
EISSN: 1480-3313
Coden: CJESAP
Serial Title: Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre
Serial Volume: 56
Serial Issue: 5
Title: Applying laterally varying density corrections to ground gravity and airborne gravity gradiometry data; a case study from the Bathurst mining camp
Title: Geophysics applied to mineral exploration
Author(s): Tschirhart, PeterMorris, William A.Mims, JohnUgalde, Hernan
Author(s): Pinet, Nicolaseditor
Author(s): Gloaguen, Erwaneditor
Author(s): Giroux, Bernardeditor
Affiliation: Paterson, Grant and Watson, Toronto, ON, Canada
Affiliation: Geological Survey of Canada, Quebec City, QC, Canada
Pages: 493-503
Published: 201905
Text Language: English
Summary Language: French
Publisher: National Research Council of Canada, Ottawa, ON, Canada
References: 31
Accession Number: 2019-067095
Categories: Applied geophysics
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables, geol. sketch maps
N47°19'60" - N48°00'00", W66°15'00" - W64°30'00"
Secondary Affiliation: McMaster University, CAN, CanadaJ and J Mims Enterprises, USA, United StatesBrock University, CAN, Canada
Country of Publication: Canada
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute. Reference includes data from Canadian Science Publishing, NRC Research Press, Ottawa, ON, Canada. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201935
Close Modal

or Create an Account

Close Modal
Close Modal