24 documents found, page 1 of 3

The bimodal Fii-A2-type and calc-alkaline volcanic sequence of the Aljustrel br...

ABSTRACT: The Iberian Pyrite Belt (IPB) is a late Devonian- Early Carboniferous world-class polymetallic VMS province that includes significant Cu-(Sn)-Pb-Zn-(Ag) deposits of massive sulphides and feeder zones. The Aljustrel brownfield region contains one of the highest concentrations of ore in the IPB in 6 known deposits (Gaviao, Sao Joao, Moinho, Algares, Estacao and Feitais). To delve into the petrogenesis o...

Early Cambrian S-type granites in the Sakarya Zone, NE Turkey: a record for tra...

Cadomian realms have recently received much attention in the Alpine–Mediterranean orogenic belts, with discontinuous outcrops extending from the Alps to the İstanbul Zone, Menderes Massif, Taurides in Turkey and Iran as well. However, they have not been identified in the Sakarya Zone, northern Turkey to date. Here, we present, for the first time, zircon Usingle bondPb geochronology, zircon Hf-isotopes and trace...

A tectonic carpet of Variscan flysch at the base of a rootless accretionary pri...

The allochthonous complexes of Galicia–Trás-os-Montes Zone (NW Iberia) are part of a rootless tectonic stack which preserves part of a Variscan accretionary prism. They are formed by individual tectonic slices marked by specific tectonometamorphic evolutions, which were piled up in a piggy-back mode onto its relative autochthon, the Central Iberian Zone (CIZ). Allochthony decreases from the structurally upper t...

Evidence formulti-cycle sedimentation and provenance constraints from

Laser ablation ICP-MS U–Pb analyses were conducted on detrital zircons of Triassic sandstone and conglomerate from the Lusitanian basin in order to: i) document the age spectra of detrital zircon; ii) compare U–Pb detrital zircon ages with previous published data obtained from Upper Carboniferous, Ordovician, Cambrian and Ediacaran sedimentary rocks of the pre-Mesozoic basement of western Iberia; iii) discuss p...

Tracing the geodymamic evolution of the North Gondwana

Pliocene–Pleistocene sand of the Alvalade basin was sampled from the sea-cliffs of SW Iberia close to Cape Sines for a provenance study using LA-ICPMS U-Pb dating of detrital zircons. The results are used to compare age distributions and to trace potential source areas based on existing knowledge of zircon-forming events in the pre-Cenozoic basement of SW Iberia. The 492 U-Pb ages obtained span a wide interval ...

Sedimentary record of the amalgamation and break-up of Pangaea: U-Pb detrital z...

In SW Iberia there is a basal unconformity where Triassic sandstones overlie previously deformed Carboniferous turbidites. This important stratigraphic boundary records the transition from the final stages of Pangaea’s amalgamation to the initial stages of break-up. U-Pb dating of detrital zircon from Carboniferous greywackes of the South Portuguese Zone and Triassic sandstones of the Algarve and Alentejo basin...

Provenance study of Pliocene–Pleistocene sands based on ancient detrital zircon...

Pliocene–Pleistocene sand of the Alvalade basinwas taken fromthe sea-cliffs of SWIberia coast for a provenance study using radiometric dating. The U–Pb ages obtained revealed a wide interval ranging from Cretaceous to Archean, with predominance of Paleozoic, Neoproterozoic and Cretaceous zircon ages. Cretaceous ages interpreted to indicate a Sines Massif provenance are dominant in sands close to Cape Sines but ...

Provenance of Cambrian-Ordovician siliciclastic rocks of the Southwestern Iberi...

Sedimentary provenance of Neogene strata from the SW Portuguese coast (Sines Ca...

In this preliminary study of provenance analysis Neogene sandstones and conglomerates of the Alvalade Basin were sampled, from the sea cliffs nearby the Sines Cape (SW Portuguese Coast). Detrital zircons were extracted by conventional methods of particle size separation, magnetic and heavy liquids separation. Detrital zircons were dated by U-Pb method with LA-ICPMS. The U-Pb geochronology results indicate as po...

Provenance of Cambrian-Ordovician siliciclastic rocks of the Southwestern Iberi...