TERTIARY FAULTING AND PSEUDOTACHYLYTES IN THE EAST GREENLAND VOLCANICRIFTED MARGIN - SEISMOGENIC FAULTING DURING MAGMATIC CONSTRUCTION

Volcanic rifted margins have voluminous magmatic constructions at cont inent ocean transitions including thick sequences of flood basalts, di ke swarms, and mafic plutons developed in crustal-scale flexures. In t he Tertiary East Greenland volcanic rifted margin, upper crustal dilat ion and flexure were accommodated by extensive faulting, locally perva sive cataclastic deformation, and pseudotachylyte generation, The wide spread distribution and large volumes of pseudotachylyte suggest that regional seismogenic faulting was vigorous during rapid crustal subsid ence, dike intrusion, and the start of sea-floor spreading.