M. P. Searle's recent paper in the Journal of Structural Geology (Searle 1986) included a major departure from published structural interpretations of the Ladakh Himalaya. The geologic history of Ladakh is a vital key to understanding the timing and sequence of events during the Himalayan orogeny. Ophiolitic rocks and island arc volcanics along the Indus Suture zone (Frank et al. 1977, and many...

In the Katha Range of central Myanmar, lithologic tracers and pressure-temperature-deformation-time data identify Cambro-Ordovician, Indian-affinity Tethyan Himalaya Series, located ∼700 km from their easternmost outcrop in S-Tibet, ∼450 Himalayan rocks Eastern Syntaxis. Metamorphism began at ∼65 Ma, peaked ∼45 Ma (∼510°C, 0.93 GPa), exhumation/cooling (∼25°C/Myr) occurred until ∼30 a subductio...

Age delimitation integrated with aeromagnetometric and aerogammaspectrometric survey advances the understanding of ophiolite evolution in Brasiliano Orogen. We focused on Bossoroca ophiolite, because oceanic crustal mantle rocks contain zircon metasomatic chloritite. A metadiorite a metavolcanoclastic rock were also studied to delimit relationship between island-arc infrastructure superstructur...

Pine Island Glacier (PIG) terminates in a rapidly melting ice shelf, and ocean circulation and temperature are implicated in the retreat and growing contribution to sea level rise of PIG and nearby glaciers. However, the variability of the ocean forcing of PIG has been poorly constrained due to a lack of multi-year observations. Here we show, using a unique record close to the Pine Island Ice S...

Subducted oceanic metabasalts are believed to be a primary source of volatiles for arc magmatism and fluid-induced seismicity. From phase equilibria computed for an average oceanic metabasalt we present a model for subduction zone devolatilization for pressures up to 6 GPa (V180 km). Along high temperature geotherms complete dehydration occurs under forearcs, whereas dehydration does not occur ...

[1] Subduction zones are where sediments, oceanic crust, and mantle lithosphere return to and reequilibrate with Earth’s mantle. Subduction zones are interior expressions of Earth’s 55,000 km of convergent plate margins and are the geodynamic system that builds island arcs. Excess density of the mantle lithosphere in subduction zones provides most of the power needed to move the plates while in...

Lake Urmia in northwestern Iran is one of the hypersaline lakes of world. In the Urmia region a Cenozoic island arc was formed by northeastward subduction of Neo-Tethyan oceanic plate beneath central Iran; the lake is therefore located in the fore-arc basin tectonic setting. Satellite imagery of the Urmia region illustrates that the trend of faults are in two main NE-SW and NW-SE directions. Th...

Intraplate volcanism initiated shortly after the cessation of Cenozoic seafloor spreading in the South China Sea (SCS) region, but the full extent of its influence on the Indochina block has not been well constrained. Here we present major and trace element data and Sr-Nd-Pb-Hf isotope ratios of late Cenozoic basaltic lavas from the Khorat plateau and some volcanic centers in the Paleozoic Sukh...

Oceanic islands have reduced resources and natural enemies and potentially affect life history traits of arriving organisms. Among the most spectacular invasions in the Western hemisphere is that of the Africanized honeybee. We hypothesized that in the oceanic island Puerto Rico, Africanized bees will exhibit differences from the mainland population such as for defensiveness and other linked tr...