Double seismic zones are two-layered distributions of intermediate-depth earthquakes that provide insight into the thermomechanical state of subducting slabs. We present new precise hypocenters of intermediate-depth earthquakes in the Tonga subduction zone obtained using data from local island-based, ocean-bottom, and global seismographs. The results show a downdip compressional upper plane and...

Findings of coesite and microdiamond in metamorphic rocks of supracrustal protolith led to the recognition of continental subduction to mantle depths. The crust-mantle interaction is expected to take place during subduction of the continental crust beneath the subcontinental lithospheric mantle wedge. This is recorded by postcollisional mafic igneous rocks in the Dabie-Sulu orogenic belt and it...

Deformation processes related to early stages of collisional belts, especially the inversion rifted systems remain poorly constrained, partly because evidence these is usually obliterated during subsequent collision. The Pyrenean belt resulting from a Cretaceous hyperextended margin associated with high-temperature and low-pressure metamorphism in Internal Metamorphic Zone (IMZ), good example f...

In order to better constrain the utility of multispectral datasets in the characterization of surface materials, Landsat Thematic Mapper (TM) data were evaluated in the discrimination of geological classes in the Cape Smith Belt of Quebec, a greenstone belt that hosts Early Proterozoic units including those of the Purtuniq ophiolite. Ground-based measurements collected for the study area highli...

In order to obtain a high-resolution Pleistocene stratigraphy, eleven continuously cored boreholes, 100 to 220m deep were drilled in the northern part of the Po Plain by Regione Lombardia in the last five years. Quantitative provenance analysis (QPA, Weltje and von Eynatten, 2004) of Pleistocene sands was carried out by using multivariate statistical analysis (principal component analysis, PCA,...

The Amber El Amino area is located 75 kilometres southeast of Prince Rupert. Access to the area is by helicopter from Prince Rupert or Terrace (Figure 1). The El Amino showing (BC MINFILE 103H 071) is located on Sulphide Creek (Figure 2) which drains eastward into Hanna (El Amino) Creek. The Amber showing (BC MINFILE 103H 171) is located 700 metres north of the El Amino showing. Hanna Creek dra...

In this research, petrographic and geochemical (major and trace elements) characteristics of siliciclastic rocks of the Mozduran Formation in the eastern Kopet-Dagh Basin have been carried out in order to reveal their provenance such as source area paleoweathering, parent rock composition and tectonic setting. Mozduran Formation is mainly composed of limestone and dolomite, with minor amounts o...