COMBINED CRUSTAL-GEOLOGICAL CROSS-SECTION OF ELLESMERE ISLAND

Ellesmere Island, in Canada’s Arctic, consists of a series of ~SW-NE trending tectonic provinces, the crustal structure and geological expression of which represent a combination of interplate, accretionary orogenesis in the Palaeozoic and, most recently, intraplate deformation in the Cenozoic (Eurekan “Orogeny”). An almost complete absence of information about the crustal or lithosphere structure of Ellesmere Island has been addressed by the acquisition of teleseismic data between 2010 and 2012 on a passive seismological array called ELLITE (“Ellesmere Island Teleseismic Experiment”). The ELLITE array consisted of seven broadband stations, deployed for two years on a 520 km long, N-S orientated profile and was logistically supported by the GSC (Canada) and SEIS-UK. Extracted Receiver Functions (RFs) and a resulting composite two-dimensional crustal scale cross-section of Ellesmere Island are reported in detail in another presentation at this symposium (Schiffer et al.). Moho depth, a number of intracrustal horizons and sedimentary thicknesses can be inferred. Meanwhile, geological mapping on Ellesmere Island in the framework of BGR’s (Germany) CASE (“Circum-Arctic Structural Events”) programme resulted in a regional geological cross-section spanning Ellesmere Island from Hansen Point (NW) to the Bache Peninsula (SE). This cross-section, based on the excellent surface exposure afforded in this region, provides a model of the structure of the upper crust to a depth of about 10 km. Although the crustal structure and geological cross-sections are not co-incident, they both cross the same major crustal terranes comprising the geology of Ellesmere Island, through the accretionary and Eurekan overprinted terranes to the passive continental margin of Laurentia in the south. Here, the cross-sections have been integrated to produce a single, combined crustal-geological 2-D model of Ellesmere Island with the aim of illuminating the relationships between crustal architecture and geology as expressed at the surface of and in the topography of Ellesmere Island.