The age of the Nazca plate where it enters the Peru and northern Chile trenches varies from 30 Ma in the north to 45 Ma in the south as its dip beneath the South American continent steepens from 13' to 300. If the elastic thickness Te of oceanic lithosphere depends only on its age, and therefore thermal state, we would expect that Te determined from fitting the flexure of the lithosphere over t...

Introduction: On Earth magmatism occurs on continents in the absence of subduction, often producing volatile-rich magmas such as those in the Leucite Hills, the Sierra Nevada, and Peru’s Altiplano [1]]. The primary hypothesis to explain this volcanism is foundering of the lower lithosphere into the mantle. The surface of Venus displays volcanic features indicating eruption of lavas with a wide ...

In this paper we compare two models to compute the isostatic response of the Earths lithosphere to an external load. The lithosphere is modeled as a linear elastic solid. The two models differ in the mathematical formulation of the problem, their applicability in the incompressible limit, the choice of the finite elements used for discretization, and the solution strategy for the arising algebr...

Platinum Group Element (PGE) concentrations in garnet pyroxenite xenoliths from Oahu, Hawaii, are significantly lower than those in mantle peridotites and show fractionated patterns (e.g. PdN/OsN = 2–10, PdN/IrN = 4–24; N = chondrite normalized) and very high ReN/OsN ratios ( 9–248). Mass balance calculations show that the bulk rock pyroxenite PGE inventory is controlled by the presence of sulf...

the iranian plateau is characterized by diverse tectonic domains, including the continental collisions (e.g. the zagros and alborz mountains) and oceanic plate subduction (e.g. makransubduction zone). to derive a detailed image of the crust–mantle (moho) and lithosphere–asthenosphere (lab) boundaries in some tectonically units of the iranian plateau, we used a large number of s receiver functio...

[1] Integration of stress indicator data, gravity data, crustal kinematics data, and analysis of topography and recent vertical motions demonstrates the occurrence of consistently oriented spatial patterns of large-scale Alpine to recent intraplate deformation in Iberia. The inferred upper crustal and lithospheric deformation patterns and the timing of the associated expressions at or near the ...

Lithospheric extension can generate passive margins that bound oceans worldwide. Detailed geological and geophysical studies in present and fossil passive margins have highlighted the complexity of their architecture and their multi-stage deformation history. Previous modeling studies have shown the significant impact of coarse mechanical layering of the lithosphere (2 to 4 layer crust and mant...

[1] Laboratory and numerical experiments show that when a chemically different layer overlies a hotter but otherwise denser layer, analogous to continental mantle lithosphere over asthenosphere, convective stability depends strongly on both the critical Rayleigh number and the buoyancy number, B, of the lithosphere-like layer. Sufficient cooling at low buoyancy number results in an oscillatory ...

The lithosphere-asthenosphere boundary divides the rigid lid from the weaker mantle and is fundamental in plate tectonics. However, its depth and defining mechanism are not well known. We analyzed 15 years of global seismic data using P-to-S (Ps) converted phases and imaged an interface that correlates with tectonic environment, varying from 95 +/- 4 kilometers beneath Precambrian shields and p...