Tectonic Reconstructions of the Southernmost Andes and the Scotia Sea During the Opening of the Drake Passage [chapter]

Graeme Eagles
2016 Springer Earth System Sciences  
Study of the tectonic development of the Scotia Sea region started with basic lithological and structural studies of outcrop geology in Tierra del Fuego and the Antarctic Peninsula. To 19 th and early 20 th century geologists, the results of these studies suggested the presence of a submerged orocline running around the margins of the Scotia Sea. Subsequent increases in detailed knowledge about the fragmentary outcrop geology from islands distributed around the margins of the Scotia Sea, and
more » ... er their interpretation in light of the plate tectonic paradigm, led to large modifications in the hypothesis such that by the present day the concept of oroclinal bending in the region persists only in vestigial form. Of the early comparative lithostratigraphic work in the region, only the likenesses between Jurassic-Cretaceous basin floor and fill sequences in South Georgia and Tierra del Fuego are regarded as strong enough to be useful in plate kinematic reconstruction by permitting the interpretation of those regions' contiguity in mid-Mesozoic times. Marine and satellite geophysical data sets reveal features of the remaining, submerged, 98% of the Scotia 124 Sea region between the outcrops. These data enable a more detailed and quantitative approach to the region's plate kinematics. In contrast to longused interpretations of the outcrop geology, these data do not prescribe the proximity of South Georgia to Tierra del Fuego in any past period. It is, however, possible to reinterpret the geology of those two regions in terms of the plate kinematic history that the seafloor has preserved.
doi:10.1007/978-3-319-39727-6_4 fatcat:sp6nq32vmnakpbbkrbbqpv4csu