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The Bolton Igneous Group rocks in the Southern Quebec Appalachians appear to be tectonic slices in an accretionary prism, with the rocks generated in the Iapetus Ocean's ocean ridge environment. The rocks are pre-Taconian basaltic pillow lavas with compositions which are similar to transitional mid-ocean ridge basalts. The Dunnage zone's mafic volcanic rocks can be separated into three groups by the TiO2 content, consisting of the high-TiO2, medium TiO2 and low TiO2 groups.

Epizonal plutons exposed on the Cordillera de Talamanca mountain range in Costa Rica provide access to information about the Chorotega block's tectonic evolution. The plutons are exposed due to rapid uplift and both tropical and glacial erosion and weathering conditions. Significant lithologic and compositional diversity is represented in the Talamanca Intrusive Suite, from hornblende gabbro to granite. The evident volcanism must be late Miocene or younger. The data is based on major and trace element and isotopic modeling.

Elkahatchee Quartz Diorite (EQD) parental magmas are obtained by the melting of altered MORB source material. The melting process is subjected to hornblende eclogite metamorphic environment. The production of EQD is associated with orogenesis of the continental margin and reduction of the arc basin oceanic crust. The oceanic crust divides Laurentia and Carolina arc terrane. The EQD magmas appear to have formed through the Laurential continental crust.

A report on Hf isotopic data by ICPMS technology combined with laser ablation systems for detrital zircons from the khondalites in the Jining Complex and their whole rock Sr-Nd isotope compositions is examined. It provides insights into the Paleoproterozoic crustal accretionary history of the Western Block of the North China Carton (NCC).

Technique based on inverse methods for directly inverting mapped patterns of whole-rock chemical alteration finding magnitude and three-dimensional (3D) geometry of the associated reactive fluid flow is discussed.

Observations on the formation of magnetite-and ilmenite-series granitic rocks in the Japan arc are made. These formations are not due to the properties of the lower crust but rather to more than 15% melted subducted material contaminating granitic magmas.

The origin of the synplutonic magmatism in New Hampshire is discussed. Various models to explain the origin of granitic magmatism in orogenic belts are also presented.

The Para genetic relations and compositional variations of garnet were studied from an exposure in the Eastern Ghats Belt in India. This region has been investigated for over forty years because of the occurrence of remnants of a layered magmatic complex and associated chromite ores.

The Late NeoProterozoic metavolcanic Tibbit Hill Formation (THF) covers a large crustal segment exposed along a belt about 250 km long in the Appalachian fold belt. Geochemical modeling revealed that the THF basaltic magma was produced by a very small degree of batch partial melting of a garnet-bearing primitive mantle source. A final basaltic melt segregation depth was estimated at 80 to 100 km. Melting may have occurred within the thermal anomaly of a rising mantle plume under the Sutton Mountains triple junction.