The composition of Mars' crust records the planet's integrated geologic history and provides clues to its differentiation. Spacecraft and meteorite data now provide a global view of the chemistry of the igneous crust that can be used to assess this history. Surface rocks on Mars are dominantly tholeiitic basalts formed by extensive partial melting and are not highly weathered. Siliceous or calc...

the area of study is located 120 km north-east of shahrood city. in terms of structure and geological classification, this area is located in the northern part of central iran zone. granitoids of troud ranging from monzonite to granite. the main minerals of granitoids are quartz, plagioclase, and orthose. the accessory minerals are biotite, hornblende, sphene, and opaque minerals. various textu...

Thin oceanic crust is formed by decompression melting of the upper mantle at mid-ocean ridges, but the origin of the thick and buoyant continental crust is enigmatic. Juvenile continental crust may form from magmas erupted above intraoceanic subduction zones, where oceanic lithosphere subducts beneath other oceanic lithosphere. However, it is unclear why the subduction of dominantly basaltic oc...

The Toba Caldera has been the site of several large explosive eruptions in the recent geological past, including the world's largest Pleistocene eruption 74,000 years ago. The major cause of this particular behaviour may be the subduction of the fluid-rich Investigator Fracture Zone directly beneath the continental crust of Sumatra and possible tear of the slab. Here we show a new seismic tomog...

The straightforward but unexpected relationship presented here relates crustal thickness to magma type in the Izu-Ogasawara (Bonin) and Aleutian oceanic arcs. Volcanoes along the southern segment of the Izu-Ogasawara arc and the western Aleutian arc (west of Adak) are underlain by thin crust (10-20 km). In contrast those along the northern segment of the Izu-Ogasawara arc and eastern Aleutian a...

the dehno granite massive is located in the east dehno village and southern khomein city and within themetamorphic sanandaj–sirjan zone. the composition of these rocks include: granodiorite, quartzdiorite(tonalite), monzogranite and leucogranite. quartz, alkali feldspar, plagioclase, biotite, andalusite, hornblendemuscovite, tourmaline, zircon and apatite are examples of the existing major and ...

[1] We present a new quantitative framework to understand the process of mantle melting based on the velocity structure of igneous crust. Our approach focuses on the lower crustal section, which is expected to be least affected by porosity and seawater alteration, especially for thick igneous crust. Our methodology is thus best for constraining the origin of large igneous provinces. First, a qu...

Crustal growth in the Coast Mountains, along the leading edge of the Canadian Cordillera, was the result of processes associated with horizontal flow of material during transpression and subsequent transtension, and the vertical accretion of mantle derived melts. From 85 to 58 Ma, as exotic terranes were translated northward during transpression, the crust was thickened to about 55 km, and melt...

The total magmatic output in modern arcs, where continental crust is now being formed, is believed to derive from melting of the mantle wedge and is largely basaltic. Globally averaged continental crust, however, has an andesitic bulk composition and is hence too silicic to have been derived directly from the mantle. It is well known that one way this imbalance can be reconciled is if the paren...

A recent significant achievement in trace element modeling is the development of the congruent (eutectic) dynamic melting (CDM) model where only melt is generated. However, melting reactions in the mantle and crust often produce not only melt but also minerals. By introducing melting reactions into the dynamic melting model, we present a series of equations for incongruent dynamic melting (IDM)...