U-Pb zircon SHRIMP data from the Cana Brava layered complex: new constraints for the mafic-ultramafic intrusions of Northern Goiás, Brazil

SHRIMP zircon U–Pb age constraints on Neoproterozoic Quruqtagh diamictites in NW China

The Neoproterozoic Quruqtagh Group in the Tarim Block, NW China, contains multiple diamictites in the Bayisi, Altungol, Tereeken, and Hankalchough formations. These diamictites may represent three or possibly four discrete glaciations, although evidence for a glacial origin of the Bayisi and Altungol diamictite is ambiguous. To constrain their age and duration, we dated three volcanic beds (V1,...

The Sungun porphyry magma resource and the 120,000-year difference in age between the main stock and the first dike: New evidence from 87Sr/86Sr, 143Nd/144Nd and Pb, SHRIMP U–Pb zircon dating in NW Iran

The Sungun  copper  porphyry deposit is hosted by a Tertiary magmatic complex in  the  Azarbayjan province , northwestern Iran. The  Sungan mine  in its southern and eastern parts is limited  by early Miocene volcanic and by Late Cretaceous limestone rocks in northern and eastern parts respectively . The Sungun  deposit is associated with a suite of porphyritic granitoids and late dikes intrudi...

Mafic - Ultramafic Rock Studies

Pre-Variscan evolution of the Western Tatra Mountains: new insights from U-Pb zircon dating.

In situ LA-MC-ICP-MS U-Pb zircon geochronology combined with cathodoluminescence imaging were carried out to determine protolith and metamorphic ages of orthogneisses from the Western Tatra Mountains (Central Western Carpathians). The metamorphic complex is subdivided into two units (the Lower Unit and the Upper Unit). Orthogneisses of the Lower Unit are mostly banded, fine- to medium-grained r...

U-Pb zircon constraints on obduction initiation of the Unst Ophiolite: an oceanic core

7 The Unst Ophiolite is the best exposed of a chain of early Ordovician ophiolites in the 8 Scottish Caledonides and is widely regarded as having formed in a supra-subduction zone 9 setting within the Iapetus Ocean. Reinterpretation of sheeted dykes suggests that it formed 10 as an oceanic core complex, presumably during subduction roll-back immediately prior to 11 obduction onto the Laurentian...