Distribution patterns, petrography, whole-rock and mineral chemistry, and shape and fabric data are described for the most representative basement lithologies occurring as clasts (granule to boulder grain-size class) from the 625 m deep CRP-2/2A drillcore. A major change in the distribution pattern of the clast types occurs at c. 310 mbsf, with granitoid-dominated clasts above and mainly doleri...

The final closure time of the Paleo-Asian Ocean and Permo-Carboniferous tectonic settings in northern Alxa are very important but controversial issues. geochronology petrogenesis mafic igneous rocks superior clarifying regional settings. Here, we report on zircon U-Pb-Hf isotopes, biotite 40Ar/39Ar whole-rock geochemical data hornblende gabbro from Baogeqi pluton Alxa. LA-ICP MS U-Pb analysis g...

Previous studies have shown that the 2.04 Ga Kangâmiut dyke swarm of SW Greenland was injected into an active tectonic environment associated with the formation of the Nagssugtoqidian orogenic belt. Major and trace element modelling of the swarm shows that its chemical evolution was controlled by simple clinopyroxene–plagioclase fractionation. However, such trends — although typical of continen...

The Sonju Lake intrusion (SLI) is a 1200-m thick, sheet-like, tholeiitic layered intrusion located within the 1096 Ma Beaver Bay Complex of NE Minnesota. Its cumulus stratigraphy of Ol Pl+Ol Pl+Cpx+Ol Pl+Cpx+Ox±Ol Pl+Cpx+Ox+Ol+Ap indicates formation by closed-system fractional crystallization of a tholeiitic magma. In 1999, outcrop sampling revealed a stratiform PGE-enriched interval within oxi...

RATIONALE We report new (87) Rb-(87) Sr isochron data for the Duluth Gabbro, obtained with a laser ablation resonance ionization mass spectrometer that is a prototype spaceflight instrument. The gabbro has a Rb abundance and a range of Rb/Sr ratios that are similar to those of KREEP-rich basalts found on the nearside of the Moon. Dating of previously un-sampled young lunar basalts, which genera...

Abu Hamamid (AH) Neoproterozoic (Sm/Nd model age of 770 ± 20 Ma) mafic–ultramafic intrusion lies along a NE–SW fracture zone in the Shadli Metavolcanic Belt, south Eastern Desert, Egypt. AH intrusion is concentrically zoned with cumulate clinopyroxenebearing dunite core mantled by olivine clinopyroxenite, hornblende clinopyroxenite and hornblende gabbroic rim. The observed crystallization seque...

Abstract Exhumation of basement rocks on the seafloor is a worldwide feature along passive continental margins and (ultra-) slow-spreading environments, documented by dredging, drilling or direct observations diving expeditions. Complementary from exhumed ophiolites in Alps allow for better understanding underlying processes. The Aiguilles Rouges ophiolitic units (Val d’Hérens, Switzerland) are...

Lithological, structural, metamorphic and geochronological data for the North China Craton enable its division into the Western and Eastern Blocks of Archean to Paleoproterozoic age separated by a north–south trending Paleoproterozoic orogenic belt: the Central Zone. The Central Zone is divisible into a series of lowto medium-grade granite–greenstone belts and high-grade metamorphic terrains co...