Gérard M. Stampfli

Bio: Gérard M. Stampfli is an academic researcher from University of Lausanne. The author has contributed to research in topics: Plate tectonics & Terrane. The author has an hindex of 40, co-authored 69 publications receiving 9356 citations.

The TRANSMED Transects in Space and Time: Constraints on the Paleotectonic Evolution of the Mediterranean Domain

Abstract: The Phanerozoic evolution of the western Tethyan region was dominated by terrane collisions and accretions, during the Variscan, Cimmerian and Alpine cycles. Most terranes were derived from Gondwana and present a similar early Palaeozoic evolution. Subsequently, they were detached from Gondwana and affected by different deformation and metamorphic events, which permit to decipher their geodynamic history. Lithospheric scale peri-Mediterranean transects show the present-day juxtaposition of these terranes, but do not allow to unravel their exotic nature or their duplication. To create a reliable palinspastic model around these transects, plate tectonics constraints must be taken into consideration in order to assess the magnitude of lateral displacements. For most of the transects and their different segments, thousand km scale differential transport can be demonstrated.

Age, spreading rates, and spreading asymmetry of the world's ocean crust

Abstract: We present four companion digital models of the age, age uncertainty, spreading rates, and spreading asymmetries of the world's ocean basins as geographic and Mercator grids with 2 arc min resolution. The grids include data from all the major ocean basins as well as detailed reconstructions of back-arc basins. The age, spreading rate, and asymmetry at each grid node are determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading. Ages for ocean floor between the oldest identified magnetic anomalies and continental crust are interpolated by geological estimates of the ages of passive continental margin segments. The age uncertainties for grid cells coinciding with marine magnetic anomaly identifications, observed or rotated to their conjugate ridge flanks, are based on the difference between gridded age and observed age. The uncertainties are also a function of the distance of a given grid cell to the nearest age observation and the proximity to fracture zones or other age discontinuities. Asymmetries in crustal accretion appear to be frequently related to asthenospheric flow from mantle plumes to spreading ridges, resulting in ridge jumps toward hot spots. We also use the new age grid to compute global residual basement depth grids from the difference between observed oceanic basement depth and predicted depth using three alternative age-depth relationships. The new set of grids helps to investigate prominent negative depth anomalies, which may be alternatively related to subducted slab material descending in the mantle or to asthenospheric flow. A combination of our digital grids and the associated relative and absolute plate motion model with seismic tomography and mantle convection model outputs represents a valuable set of tools to investigate geodynamic problems.