sangan magnetite skarn mine is located 300 km southeast of mashhad, along the eastern part of khaf-drouneh volcanic-plutonic belt. granitoids from three areas within the sangan mine a, c-north and dardvay were studied. within the study area, three intrusive rocks including biotite-hornblende monzonite porphyry, biotite syenite and syenogranite were recognized. based on field cross cutting, abse...

the lalezar granitoids crop out within volcanic successions of the urumieh-dokhtar magmatic assemblage (udma). these granitoids have a range from gabbro-diorites to granites in composition. the mineral compositions of the most felsic rocks are characterized by the abundances of na-plagioclase, quartz, alkali feldspar, biotite and hornblende. in the gabbro-diorite rocks, plagioclase (ca-rich), h...

the aligoodarz granitoid occurs in sanandaj-sirjan zone (ssz), western iran. tonalite, granodiorite and granite are the main rock types cropping out in the area. comparison of aligoodarz granitoid with dehno and boroujerd granitoids reveals several similarities in their chemical characteristics. thus, the above mentioned granitoids can be assigned as a co-genetic magmatic suite, in which pluton...

the lut block (eastern iran) extends over 900 km in a north-south direction and is only 200 km wide in an east-west direction. it is confined by the nayband fault and shotori range on the west. the eastern edge is bordered by the sistan suture zone and nehbandan fault. the northern termination of lut block is the depression of kavir-e-namak and the great kavir fault. the makran arc, including t...

Field activities in the Britannia Range (Transantarctic Mountains, Antarctica) highlighted new geological features around the so-called Byrd Glacier discontinuity. Recent field surveys revealed the occurrence of significant amounts of mediumto high-grade metamorphic rocks, intruded by abundant coarse-grained porphyritic granitoids. Most of the granitoids are deformed, with foliation parallel to...

The Witwatersrand Basin formed over a period of 360 Ma between 3074 and 2714 Ma. Pulses of sedimentation within the sequence and its precursors were episodic, occurring between 3086-3074 Ma (Dominion Group), 2970-2914 Ma (West Rand Group) and 2894-2714 Ma (Central Rand Group). Detritus was derived from a mixed granite-greenstone source of two distinct ages; the first comprises Barberton-type gr...

Melt produced by friction during earthquakes may act either as a coseismic fault lubricant or as a viscous brake. Here we estimate the dynamic shear resistance (tau(f)) in the presence of friction-induced melts from both exhumed faults and high-velocity (1.28 meters per second) frictional experiments. Exhumed faults within granitoids (tonalites) indicate low tau(f) at 10 kilometers in depth. Fr...

The ~1.08 Ga anorogenic, A-type Pikes Peak batholith (Front Range, central Colorado) is dominated by coarsegrained, biotite±amphibole syenogranites and minor monzogranites, collectively referred to as Pikes Peak granite (PPG). The batholith is also host to numerous small, late-stage plutons that have been subdivided into two groups (e.g. Wobus, 1976. Studies in Colorado Field Geology, Colorado ...

A-type granites are typically formed in stable intra-plate, back-arc or postcollisional settings and characterized by highly ferroan potassic major element compositions, strong enrichment incompatible trace elements. Unlike I-, S- M-type granites, where the letters denote dominant source material (igneous, sedimentary mantle derived), there is no consensus on processes giving rise to magmas. In...