Basement control of structures in the Mesozoic rocks in the Strait of Dover region, and its reflexion in certain features of the present land and submarine topography

Abstract

The purpose of this paper is to review current information and opinions on the structures of the concealed Palaeozoic rocks of southeastern England and adjacent parts of northwestern Europe. The authors attempt a regional synthesis, which suggests that certain structural trends in these older rocks have been reactivated several times in the subsequent history of the area, and in some cases control the alinement of present-day surface features. We have drawn on the accumulated data of field surveys, deep boreholes and geophysical investigations carried out by the Institute of Geological Sciences, and also information obtained during the commercial search for coal and oil. The results of marine gravity measurements recently made by I.G.S. and the Admiralty in the eastern English Channel and southern North Sea are presented for the first time. Similarly, we are glad to include data from M r P. L. Rumsby’s recent analyses of fault trends in the Kent collieries, for the National Coal Board. Reference is also made to some of the results of the Channel Tunnel site investigation 1964 5 (Destombes & Shephard-Thorn 1971). Published literature and maps form the basis of our remarks on northern Europe, though we are grateful to Destombes for unpublished information on the Boulonnais.

Geometry and kinematics of the Boulonnais fold-andthrust belt (N France): implications for the dynamics of the Northern Variscan thrust front

“…3a). This recent uplift is related to tertiary contractional movements along localized fault zones of the basin that have been shown to parallel the basement structural framework [33,34]. The process of basin inversion allowed the exhumation of the Paleozoic substratum in the northern part of the structure (i.e.…”

“…Illite cristallinity and Tmax data from Upper Devonian shales situated in the outer part of the Boulonnais thrust belt suggest a minimum burial of ca 2,100 m [38] which in turn may imply a Westphalian molassic sequence about 1,000 m thick. The Boulonnais coal basin has been proposed to prolongate westward in a complex way through the Channel to connect the Kent basin on-shore Great-Britain [23,33,39]. The style of folding and thrusting within the remaining deposits of these basins suggests that they are situated few kilometres north of the major Variscan deformation front i.e.…”

Variscan structures in the Kent Coalfield, southeast England, and their regional significance

“…A detailed account of the non-thrust structures in the coalfield is beyond the scope of this paper; some detail is given by Shephard-Thorn, Lake & Atitullah (1972) and Shephard-Thorn (1988). These papers regarded most of the high dip faults as normal, although some reversals of throw direction were recorded.…”

Joint and Lineament Patterns across the Midcontinent Indicate Repeated Reactivation of Basement-Involved Faults

“…[2] used geomorphological domains in addition to subsurface datasets to infer the geodynamic evolution of the Southern Apennines. Similarly, [3] described the influence of the reactivation of basement faults on the structures of SE England.…”