Abstract Ordovician and Silurian siliciclastic, volcanic, plutonic rocks in the southern Appalachian eastern Blue Ridge western Inner Piedmont, formerly interpreted as components of an obducted Taconic arc terrane, are recognized parts paired arc/back-arc system that formed on seaward edge Laurentian plate. New crystallization ages from metamorphosed plutonic-volcanic intruding intercalated wit...

Abstract Felsic tuff as a direct fallout deposit is known from one small area in the Kyrenia Range, north Cyprus, within deep-sea terrigenous turbidites. Nearby tuffaceous siltstones contain compositionally similar felsic volcanic rocks ( c. 5–10%), mixed with material. Sedimentary evidence indicates that was variable reworked locally, whereas are interpreted turbidites material derived Anatoli...

Arc magmas and the continental crust share many chemical features, but a major question remains as to whether these features are created by subduction or are recycled from subducting sediment. This question is explored here using Th/La, which is low in oceanic basalts (<0 2), elevated in the continents (>0 25) and varies in arc basalts and marine sediments (0 09–0 34). Volcanic arcs form linear...

Abstract The Yukon-Tanana terrane in the Finlayson Lake district, Yukon, represents one of first arc–back-arc systems that formed adjacent to Laurentian continental margin mid-Paleozoic. Back-arc rocks contain many large and high-grade volcanogenic massive sulfide (VMS) deposits. This study integrates U-Pb zircon geochronology, lithogeochemistry, Hf-Nd isotopes establish precise controls on tec...

• Record of adakitic high-Mg# magmatism along Hunter Ridge and Kadavu Island. records limited contribution from subducted sediments. Sr-Nd-Pb arc rocks record the melting subducting South Fiji MORB crust. This slab-melt component is also recorded in common (non-adakitic) rocks. Dehydration serpentinites leads to flux-melting unaltered MORB. The mostly submarine Ridge, located SW Pacific a ∼12 M...

keybarkuh area is located 70 km southwest of khaf, khorasan razavi province. the study area is situated in northeastern lut block. the rock units in the area are paleozoic metamorphic rocks and cretaceous to tertiary subvolcanic intrusions intruded as dike, stock and batholith; their composition varies from granite to diorite. based on magnetic susceptibility, the intrusive rocks are divided in...

The Core Zone of the Southeastern Churchill Province, northeastern Laurentia, is a composite of Paleoproterozoic lithotectonic domains assembled in the vise between obliquely colliding Archean Superior and North Atlantic cratons between ca. 1860 and 1810 Ma. Detailed geological and U–Pb geochronological studies of domains in the southern Core Zone highlight significant differences in Archean an...

The Bulkley Suite of intrusions are spatially associated with numerous important mineral occurrences in westcentral British Columbia. Previous K-Ar dating studies indicated that the Bulkley Suite ranges in age from 70 to 84 Ma (Carter, 1981). The purpose of this study is to better constrain the timing of Bulkley Suite magmatism and associated mineralization in the northern Tahtsa Lake District....