A GRAVIMETER SURVEY IN THE CRAVEN DISTRICT OF NORTH-WEST YORKSHIRE

Publisher Website
Google Scholar
Abstract
Summary: A brief description is given of the way in which the survey was carried out and the results of density measurements are discussed. The most important density contrast, so far as the deeper structure is concerned, is demonstrated to be that between the Palaeozoic and the Pre-Cambrian rocks. The manner in which the observed data were reduced is presented, and it is shown that the maximum value for the standard error of any single Bouguer anomaly is probably no greater than 0–19 mgal. A summary of the geology of the area follows, and the gravity data are interpreted in the light of this knowledge. Over the Askrigg tectonic block the isogams are considered to indicate a low density Pre-Cambrian core, and along the southern boundary of the block are roughly parallel to the North Craven Fault. The nature of the foundation, or “core”, of the Northern Pennines is discussed, and it is considered unlikely that the metalliferous deposits found therein owe their origin to a granitic magma.