Production of a residual gravity anomaly map for Gaspésie (northern Appalachian Mountains), Quebec, by a graphical method

The authors present a residual gravity map for Gaspesie based on a separation of the regional and residual fields by a graphical method. This map results from the smoothing of 24 gravity profiles with lengths that far exceed the dimension of the zone of interest. The base value of the regional field has been estimated by taking into account surface data and by calculating the maximum gravity lows associated with relatively low-density Silurian-Devonian rocks. The residual gravity map includes all the gravity features that are clearly associated with shallow sources and shows a minimum distortion of the shape of the anomalies. Current Research 2006-D1 1 N. Pinet et al. Resume : Nous presentons une carte de l’anomalie de Bouguer residuelle de la peninsule de la Gaspesie basee sur une methode graphique de separation des composantes regionale et residuelle du champ de gravite. Cette carte resulte du lissage de 24 profils de gravite dont la longueur excede grandement les dimensions de la zone d’interet. La valeur de base de la composante regionale a ete estimee en prenant en compte les donnees de surface et en calculant les bas gravimetriques maximums associes aux roches siluriennes et devoniennes de densite relativement faible. La carte de l’anomalie de Bouguer residuelle comprend l’ensemble des anomalies clairement associees a des sources peu profondes et montre une distorsion minimale de la forme des anomalies gravimetriques.

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