The origin of granophyric rock dikes (the Vredefort Granophyre) at the 2 Ga Vredefort structure in South Africa has been controversial. They have been interpreted as either impact melt or igneous intrusions. Most Vredefort Granophyre samples have considerably higher Os contents than the country rocks and Re/Os and Os/Os ratios that scatter about a 2 Ga isochron. Their initial Os/Os ratios (at 2...

Introduction: Shock-metamorphic effects including shatter cones, planar deformation features (PDFs) in quartz grains, and both E-and S-type pseu-dotachylites were discovered in deeply eroded Ar-chean granites near the Yarrabubba homestead in Western Australia (119°50'E, 27°10'S). Preliminary estimates indicate that the Yarrabubba impact structure is of a Paleoproterozoic age and at least 30 km ...

Small bodies of granophyre occur as a volumetrically insignificant but ubiquitous component of the Banded series of the Stillwater Complex. White to pink granophyre typically occurs as veins, 1-12 cm thick and as much as 100 m long. A geochemically similar body of coalescing alaskite dikes, associated with an occurrence of Pt-group elements in the Banded series of the complex, crops out approxi...

Abstract Variable single and/or swarms of post-granitic dikes are widespread at Gabal Serbal, Southwestern Sinai, Egypt. The present article aims to identify and discriminate these multiphase through detailed geological, petrographical, geochemical examinations. These classified into two subphases: (1) acidic (porphyritic dacite, microgranite, granophyre, alkaline granophyre dikes); (2) basic (...

Abstract Murujuga in Western Australia has the largest concentration of ancient rock engravings (petroglyphs) world. However, art is potentially threatened by local industrial air pollution, particular acid rain, but unambiguous scientific evidence still missing. Here, we report on results an accelerated weathering experiment, simulating weather and climate conditions that was designed performe...