Lineament mapping and geological history of the Kangerlussuaq region, southern West Greenland

摘要

How could future ice ages affect deep nuclear waste repositoriesin crystalline basement rocks? Deep repositories may beaffected by a number of glacially induced processes including,but not limited to, (1) fault activation or re-activationand associated seismicity, (2) changing hydraulic and chemicalgroundwater dynamics and (3) enhanced erosion. Suchprocesses are likely to affect not only man-made barriers inspent fuel repositories such as copper canisters and bentoniteclay buffers, but also the rock masses that contain and isolatethe repositories. In order to increase our understandingof this problem, an international study (the GreenlandAnalogue Project) was set up in 2008. The aim of the studywas to use crystalline bedrock at the margin of the InlandIce near Kangerlussuaq airport in West Greenland as an analogue for future nuclear fuel waste repositories affectedby glaciation in Fennoscandia and Canada. Accordingly, awide range of field surveys were conducted for the analogueproject (Fig.? 1). This paper describes a detailed structuralinvestigation of lineament zones and the establishment ofan event succession for fault and fracture zone evolution incentral parts of the study area (Figs 1B, 2), as well as an interpretationof the distribution of fracture and fault zones withpotentially increased permeability. Three deep holes weredrilled in the study area, and instruments were installed intwo of them for subsequent down-hole sampling and monitoringof groundwater to a depth of c. 600 m. The cores wereused to compare the subsurface fracture patterns with thoseestablished on the basis of surface mapping.