Morphology and Structure of the Southern Labrador Sea
Geophysical surveys since 1971 and sounding data reveal the morphology and structures of the southern Labrador Sea. Ran Ridge and older mid-Labrador Sea crustal basement are well-defined. The West Thulean Rise (pre-60 Ma BP), counterpart to the Thulean Rise of the Northeast Atlantic, extends between the Charlie Fracture Zone and Ran Ridge {anomaly 24). Topographic and basement structural relief along a fault (herein called the Leifur Eiriksson Fracture Zone), offsetting the Ran Ridge crest (60–45 Ma BP) at 57 °N, 45 °W, is correlated with magnetic anomaly trends. The pre-Thulean and Thulean time structures of the mid-ocean ridge and magnetic data isochrons define the initial spreading orientations of the Ran/Reykjanes Triple Junction. Seismic data extend the known area of the transparent, kilometre-thick sedimentary body in the southern central Labrador Sea, and a circular trend of elongate crests surrounding a vortex region lend definition to the proposed name, Gloria Drift. Dunal morphology is character...