The Nazca, Caribbean, and South America plates meet in northwestern South America where the northern end of the Andean volcanic arc and Wadati-Benioff zone seismicity indicate ongoing subduction. However, the termination of Quaternary volcanism at ~5.5°N and eastward offset in seismicity underneath Colombia suggest the presence of complex slab geometry. To help link geometry to dynamics, we ana...

west directed subduction zones show common characteristics, such as low structural elevation, deep trench, steep slab and a conjugate back-arc basin that are opposite to those of the east directed subduction zones. the tectonomagmatic and metallogenic setting of the lut block is still a matter of debate and several hypotheses have been put forward. despite some authors denying the influence of ...

Subduction of oceanic lithosphere can cause crustal growth and destruction, but whether this balancing act is common in a single fossil convergent system has been unclear. Here we report geochronologic-geochemical-isotopic data on Mesozoic igneous rocks the central-eastern Gangdese arc. Our results reveal: (a) A coupling magmatic arc migration toward continent interior with marked incompatible ...

Volumetric Modulated Arc Therapy (VMAT), a form of Intensity Modulated Arc Therapy (IMAT), has become a topic of research and clinical activity in recent years. As a form of arc therapy, portal images acquired during the treatment fraction form a (partial) Radon transform of the patient. We show that these portal images, when used in a modified global cone-beam Filtered Back-Projection (FBP) al...

Keyhole plasma arc welding is a unique arc welding process for deep penetration. To ensure the quality of the welds, the presence of the keyhole is critical. Understanding of the keyhole will certainly benefit the improvement of the process and weld quality. Currently, the size of the keyhole is assumed to be correlative with the robustness of the keyhole process in maintaining the keyhole. To ...

Abstract The “Rinkian belt” of West Greenland is a metamorphic terrain Paleoproterozoic age comprising: (1) the north Rinkian fold-thrust belt (FTB)—a pro- or fore-arc domain, highly deformed and metamorphosed with widespread anatexis; (2) Prøven Igneous Complex—a magmatic arc characterized by hypersthene granitic rocks (“charnockites”); (3) south FTB—an inverted back-arc basin; 4) continental ...

There has been only one limited report dating from 1941 using dissection which has described the tibiofemoral joint between 120 degrees and 160 degrees of flexion despite the relevance of this arc to total knee replacement. We now provide a full description having examined one living and eight cadaver knees using MRI, dissection and previously published cryosections in one knee. In the range of...

Three tectono-magmatic systems create volcanism in Central America; the volcanic front, a weak secondary front and the back-arc. Most magma output occurs at the volcanic front along narrow lines of historically active composite volcanoes in strikeslip/extensional settings. Lavas have strong slab signature, are water-rich and plagioclase and pyroxene phyric. A sporadic secondary front occurs abo...