Studies of several samples of the large Caddo County IAB iron meteorite reveal andesitic material, enriched in Si, Na, Al and Ca, which is essentially unique among meteorites. This material is believed to have formed from a chondritic source by partial melting and to have further segregated by grain coarsening. Such an origin implies extended metamorphism of the IAB parent body. New 39Ar40Ar ag...

Juxtaposition of different-grade metamorphic slices is a typical feature Phanerozoic orogens but relatively scarce in Precambrian orogens. Here, we focus on the Chengde Complex at northern segment late Paleoproterozoic Trans-North China Orogen, North Craton as case, to explore how orogeny-related metamorphism was juxtaposed The Orogen collisional orogen and records abundant information about or...

In the Western Gneiss Region in Norway, mafic eclogites form lenses within granitoid orthogneiss and contain best record of pressure temperature evolution this ultrahigh-pressure (UHP) terrane. Their exhumation from UHP conditions has been extensively studied, but their prograde rarely quantified although it represents a key constraint for tectonic history area. This study focused on well-prese...

The Sør Rondane Mountains, East Antarctica have been thought to be situated in the collision zone between and West Gondwana during final stage of amalgamation supercontinent. They are therefore recognized as a key region for understanding geological phenomena collisions testing proposed tectonic models. We identified metamorphic rocks with different pressure–temperature–time paths that bounded ...

Snow is a porous disordered medium consisting of air and three water phases: ice, vapor, and liquid. The ice phase consists of an assemblage of grains, ice matrix, initially arranged over a random load bearing skeleton. The quantitative relationship between density and morphological characteristics of different snow microstructures is still an open issue. In this work, a three-dimensional fract...

We present an improved analytic calculation for the tidal radius of satellites and test our results against N-body simulations. The tidal radius in general depends upon four factors: the potential of the host galaxy, the potential of the satellite, the orbit of the satellite and, which is new to this paper, the orbit of the star within the satellite. We demonstrate that this last point is criti...

A Monte Carlo algorithm to simulate the isothermal recrystallization process of snow is presented. The snow metamorphism is approximated by two mass redistribution processes: surface diffusion and sublimation-deposition. The algorithm is justified and its parametrization is determined. The simulation results are compared to experimental data, in particular, the temporal evolution of the specifi...

The axial component of the oceanic tidal angular momentum (OTAM) has been demonstrated tobe responsible for most of the diurnal and semidiurnal variations in Earth's rotational rate. In this paper we study the equatorial components of OTAM and their corresponding effects on the orientation of Earth's rotational axis, or polar motion. Three ocean tide models derived from TOPEX/Poseidon satellite...

Introduction: In this work, we report on the results of a combined scanning electron microscopy and micro-Raman spectroscopy investigation of stishovite and coesite in shocked Hospital Hill quartzite from the Vredefort impact structure of South Africa. Sanples have investigated using optical microscopy and under the scanning electron microscope, using energy dispersive x-ray spectrometry (EDS),...