Abstract The margins of the North Atlantic rift are covered by an extensive succession of volcanic rocks, with up to 5 km of continental flood basalts, hyaloclastites and interbedded sedimentary rocks. The volcanic succession deteriorates seismic imaging and has hampered petroleum exploration in these areas. Focused research and pioneering exploration activity, however, has improved the understanding and development of new play models in volcanic-influenced basins. In 2004, the Rosebank discovery finally proved that intra-volcanic siliciclastic sandstones of the Flett Formation may form attractive hydrocarbon reservoirs in the Faroe–Shetland Basin. The Kangerlussuaq Basin in southern East Greenland offers a unique opportunity to study the interaction of siliciclastic sediments with lavas and various volcaniclastic units. It is demonstrated that: (1) laterally extensive siliciclastic sedimentary units are present in the lower part of the volcanic succession; (2) the morphology of the lavas controlled variations in sandstone geometry and thickness; and (3) deposition of the interbedded sediments and lavas occurred in a low-relief environment close to sea level. The mineralogical composition of the intra-volcanic sediments is highly variable, ranging from siliciclastic to purely volcaniclastic. Diagenetic studies suggest that the nature of the volcanic component in volcaniclastic sandstones is more important to reservoir properties than the relative concentration.

Abstract This field guide describes a three-day trip from Vancouver, British Columbia, to the Wells Gray–Clearwater volcanic field (WGCVF) in east-central British Columbia. The WGCVF is the site of transitional to alkali olivine basaltic volcanism erupted over the last three million years. The small volume magmas (<1 km 3 ) erupted along preexisting normal faults related to the late stages of Cordilleran terrane amalgamation, along the boundary between the miogeoclinal and pericratonic rocks of the Kootenay terrane and the allochthonous Slide Mountain and Quesnellia terranes west of ancestral North America. The magmas are highly enriched in incompatible elements, especially large-ion lithophile elements, and are interpreted as the result of low degrees of partial melting of a heterogeneous, metasomatized mantle. Upon ascent through the crust, they carried up both crustal and mantle xenoliths. During the eruptive period of the WGCVF, at least four glacial periods have occurred. The interplay between volcanism and glaciation is captured in the wide range of volcanic features found in the region. Field trip participants will view numerous diverse volcanic landforms and deposits: from tuyas to ice-marginal valley-edge deposits, volcanoclastic-lacustrine deposits, and associated pillow lavas and hyaloclastites.