Abstract Clusters of early central volcanoes in the mid-Cenozoic Southern Rocky Mountain volcanic field (SRMVF; southwestern Colorado, USA) record sites initial magmatic focusing that led to assembly sizable upper-crustal magma bodies capable generating large ignimbrites. Peak growth at precursor andesitic was followed by extended periods (0.5 >2 m.y.) reduced eruptive activity during in...

Abstract Rapakivi-type quartz monzonite and the underlying dark-grey granodiorite from Pietkowo IG1 borehole, in Polish part of southernmost Fennoscandia have been investigated using whole-rock geochemistry, Sm–Nd isotope geochemistry U–Pb zircon dating. The was emplaced at 1495–1491 Ma, although slightly older cores (antecrysts) 1513 Ma imply a two-stage crystallization. geochemical similariti...

The Karakoram Terrane (KT) represents the southern margin of Eurasian Plate, mainly consisting Late Jurassic-Early Cretaceous subduction-related granites and post-collisional Miocene leucogranites, which intrude Neo-Proterozoic basement. We report for first time existence Cryogenian KT basement as recorded from geochemistry geochronology tonalite gneiss (ca. 806 Ma) in southeastern terrane, NW ...

Volcanic activity at convergent plate margins is localized along lineaments of active volcanoes that focus rising magma generated within the mantle below. In many arcs worldwide, particularly continental arcs, the volcanic front migrates away from the interface of subduction (the trench) over millions of years, reflecting coevolving surface forcing, tectonics, crustal magma transport, and mantl...

[1] Abstract: Gas data were collected from geothermal production fields, fumaroles, and hot springs in Central America in order to investigate the relation between volatile output and spatial distribution of volcanic systems. The He/He ratios are 6.5 ± 0.7 Ra throughout the region, indicating that helium is predominantly of mantle origin and is largely independent of variations in the character...

[1] We collected 56 marine gravity cores from the Pacific seafloor offshore Central America which contain a total of 213 volcanic ash beds. Ash-layer correlations between cores and with their parental tephras on land use stratigraphic, lithologic, and compositional criteria. In particular, we make use of our newly built database of bulk-rock, mineral, and glass major and trace element compositi...

Abstract The Longshou Shan of western China is the northern backstop Cenozoic Himalayan-Tibetan orogen and occupies a key linkage between Tarim continent North craton which separate pre-Cenozoic Tethyan orogenic system Central Asian system. Therefore, Paleoproterozoic–Paleozoic evolution this region critical to understanding extent overprinting deformation, construction Eurasian continent, rela...

In the Mariana convergent margin, large arc volcanoes disappear south of Guam even though the Pacific plate continues to subduct and instead, small cones scatter on the seafloor. These small cones could form either due to decompression melting accompanying back-arc extension or flux melting, as expected for arc volcanoes, or as a result of both processes. Here, we report the major, trace, and v...