Search results for "Mid-ocean ridge"
showing 2 items of 12 documents
Os isotopes and highly siderophile elements (HSE) in the Ligurian Ophiolites, Italy.
2000
The Os isotopic and highly siderophile element (HSE) concentration systematics of the upper mantle have been the focus of much recent interest. However, little systematic study has addressed the combined HSE and Os isotopes in mantle rocks from MOR ophiolites. The Ligurian ophiolites in northern Italy represent an important class of ophiolites representing, like Zabargad or the Galicia margin, crust with clear ocean ridge affinity floored by older mantle with arguably more continental affinities [Rampone et al., J. Petrol. 36, 18–105, 1995; Rampone et al., Contrib. Mineral. Petrol. 123, 61–67, 1996]. We have studied a suite of 15 geochemically and geologically well characterized mantle peri…
Inversion of gravity anomalies over spreading oceanic ridges
2005
Abstract Models of spreading ocean ridges are derived by Bayesian gravity inversion with geophysical and geodynamic a priori information. The aim is to investigate the influence of spreading rate, plate dynamics and tectonic framework on crust and upper mantle structure by comparing the Mid Atlantic Ridge (MAR), the Indian Ocean Ridge (IND) and the East Pacific Rise (PAC). They differ in mean spreading rate, dynamic settings, as attached slabs, and plume interaction. Topography or bathymetry, gravity, isostasy, seismology and geology, etc. are averaged along the ridges and guide the construction of initial 2D models, including features as mean plumes, i.e. averaged along the ridge. This is …