Paleomagnetic studies have been performed on five rapakivi related complexes in Sweden and Finland. Poles of varying quality defined the majority ?1640–1497 Ma poles are clustering low latitudinal positions. By combining data from ?1500 intrusions a new high-quality pole (Plat: 13°N; Plon: 190°E; A95: 11°, K: 14) for Baltica has defined. Tectonic reconstructions, basis previously published data...

Both single and multigrain U-Pb zircon thermal ionization mass spectrometry (TIMS) as well as sensitive high resolution ion microprobe (SHRIMP ll) dating of two suites of Adirondack granites have yielded ages constraining the principal tectonomagmatic events of the Ottawan Orogeny to the interval ca 1090–1035 Ma. The earliest of these consists of mildly A-type hornblende granites of the Hawkeye...

Emeralds require the unusual association of typically compatible elements (Cr, V), with incompatible Be to form, and occur in complex tectonic settings associated sediments (type IIB; Colombia) or, more commonly, magmatism regional metamorphism (IA). Precise rare earth element (REE) trace abundances are reported for a global suite emeralds, enabling identification environments which they formed...

A program of geologic mapping and lithogeochemical and geochronological sampling has been carried out over a 745-km area of the Atacama Desert surrounding the porphyry Cu deposits at Escondida, Zaldívar, and Chimborazo (Cordillera de Domeyko, northern Chile). The purpose of this study was to examine the regional tectonic and magmatic setting of this preeminent porphyry Cu district for evidence ...

The subarctic North Atlantic Ocean has experienced a complex and gradual magmatic evolution, including continental breakup, mature seafloor spreading, episodic ridge jumps. Here, we present new in situ major-element, trace-element, Sr isotopic compositions for minerals (olivine, clinopyroxene, plagioclase) from the Jan Mayen microcontinent (Integrated Drilling Program [IODP] Sites 907 985), Rey...

Post-rift magmatism associated with seafloor spreading (∼32 Ma to ∼15 Ma) and post-spreading tectonics (from the present day) is widely recorded in South China Sea (SCS). However, phenomena originating this are still under debate, hindering a full understanding of SCS’ evolution. In study, extensive voluminous magmatic bodies northern SCS investigated based on integration 3D/2D seismic borehole...

in the centeral iranian volcanic belt (civb), north-west of shahre-babak, in area of javazm, dehaj and khabr, about 20 plutonic porphyritic tonalitic to granodioritic masses (1-50 km2) are intruded into a varity of rock sequences from eocene to early miocene in age. tonalitic and granodioritic rocks are some part of dehaj-sardoieh belt and having early miocene age. the civb contains intrusive a...