Tectonic environment of mesozoic volcanic rocks in the coastal areas of SE China

1986 ◽  
Vol 5 (3) ◽  
pp. 195-205
Author(s):  
Huo Yuhua
Keyword(s):  
Volcanic Rocks ◽  
Coastal Areas ◽  
Tectonic Environment ◽  
Se China

Geochemistry and tectonic environment of the Şarkışla area volcanic rocks in central Anatolia, Turkey

1987 ◽  
Vol 51 (362) ◽  
pp. 553-559 ◽  
Author(s):  
E. Gökten ◽  
P. A. Floyd
Keyword(s):  
Upper Cretaceous ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Central Anatolia ◽  
Magmatic Arc ◽  
Early Tertiary ◽  
Tectonic Environment ◽  
Geochemical Study ◽  
Lithological Composition ◽  
Back Arc

AbstractThe volcanic rocks of the Şarkışla area in northeastern central Anatolia are associated with volcaniclastics, turbiditic limestones and pelagic-hemipelagic shales of Upper Cretaceous-Palaeocene age. A preliminary geochemical study was undertaken to constrain local tectonic models, and due to the variable altered nature of the volcanics, determine the lithological composition and magma type. Chemically the volcanics are an andesite-dominated suite of calc-alkali lavas, probably developed adjacent to an active continental margin in a local (ensialic back-arc?) basinal area. The volcanic activity was probably related to a postulated magmatic arc just south of the area during the early Tertiary.

Detrital modes of the Riding Island Graywacke, north-central Newfoundland: evidence for deposition in a collisional successor basin in the Dunnage Zone

1994 ◽  
Vol 31 (1) ◽  
pp. 176-181 ◽  
Author(s):  
Gary G. Lash
Keyword(s):  
Volcanic Rocks ◽  
Island Arc ◽  
North Central ◽  
Arc Volcanism ◽  
Tectonic Environment ◽  
Complex Source ◽  
Island Arc Volcanism ◽  
Sandstone Provenance ◽  
Silicic Volcanic ◽  
Terrane Accretion

The Riding Island Graywacke (late Caradoc – Ashgill) crops out in Notre Dame Bay, north-central Newfoundland. Previous tectonic interpretations suggest that this succession of turbidites and hemipelagic mudstone accumulated in a basin adjacent to an active volcanic arc. The varied framework mineralogy of 29 Riding Island samples studied, however, records derivation from a complex source terrane composed of mafic and silicic volcanic rocks, sedimentary and metamorphic successions, and plutonic rocks. Assessment of the tectonic environment of deposition of the Riding Island Graywacke by use of popular sandstone provenance ternary diagrams yields ambiguous results. The mineralogy of the Riding Island samples reveals a change in tectonic scenario from one dominated by island-arc volcanism in pre-Caradoc time to a setting marked by tectonic shortening, transcurrent faulting, and terrane accretion near the end of the Ordovician. The complex composition of these sandstones and the fact that they accumulated after island-arc volcanism had ended argue for deposition in a collisional successor basin that formed during the early stages of mountain building along the proto-North American continental margin. This inferred Late Ordovician collisional successor basin may have also been the locus of deposition for other minera-logically complex late Caradoc – Ashgill units exposed in Notre Dame Bay, such as the Sansom Formation.

The Solund–Stavfjord Ophiolite Complex and associated rocks, west Norwegian Caledonides: geology, geochemistry and tectonic environment

1990 ◽  
Vol 127 (3) ◽  
pp. 209-224 ◽  
Author(s):  
H. Furnes ◽  
K. P. Skjerlie ◽  
R. B. Pedersen ◽  
T. B. Andersen ◽  
C J. Stillman ◽  
...  
Keyword(s):  
Volcanic Rocks ◽  
Realistic Model ◽  
Island Arc ◽  
Andaman Sea ◽  
Upper Ordovician ◽  
Ophiolite Complex ◽  
Magmatic Rocks ◽  
Tectonic Environment ◽  
Subduction System ◽  
Norwegian Caledonides

AbstractMetabasalts of the Upper Ordovician Solund-Stavfjord Ophiolite Complex of the westernmost Norwegian Caledonides, show N-to E-MORB affinity, with high Th/Ta (or Nb) ratios giving evidence of subduction influence. The Solund–Stavfjord Ophiolite Complex is overlain by a heterogeneous assemblage of sedimentary and volcanic rocks, the Stavenes Group, of which the Heggøy Formation of metasandstones and phyllites conformably overlies the metabasalts of the Solund–Stavfjord Ophiolite Complex. The Heggøy Formation contains, in places, abundant metabasalt pillow lavas and minor intrusions, geochemically similar to those of the Solund–Stavfjord Ophiolite Complex, and basic metavolcaniclastites of island arc tholeiite (IAT) composition. This indicates that the Solund–Stavfjord Ophiolite Complex and Heggøy Formation developed in a marginal basin between a continental margin and an active subduction system, for which the present-day Andaman Sea may provide a realistic model. The other magmatic rocks of the Stavenes Group, showing both calc-alkaline and alkaline affinities, are less well time-constrained, but they are thought to represent an advanced stage of the island arc development, and ocean island build-up, respectively.

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