Some Geological Problems in the Development of Japan and the Neighboring Island Arcs

2013 ◽  
pp. 481-485 ◽  
Author(s):  
Masao Gorai
Keyword(s):  
Island Arcs

Why and where great thrust earthquakes occur along island arcs

1974 ◽  
Vol 79 (32) ◽  
pp. 4889-4899 ◽  
Author(s):  
John Kelleher ◽  
John Savino ◽  
Hugh Rowlett ◽  
William McCann
Keyword(s):  
Island Arcs

Lead isotopes in island arcs

1971 ◽  
Vol 35 (1) ◽  
pp. 27-63 ◽  
Author(s):  
R. L. Armstrong ◽  
J. A. Cooper
Keyword(s):  
Lead Isotopes ◽  
Island Arcs

The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America

1988 ◽  
Vol 79 (2-3) ◽  
pp. 105-121 ◽  
Author(s):  
L. T. Silver ◽  
B. W. Chappell
Keyword(s):  
Baja California ◽  
Volcanic Rocks ◽  
Oceanic Lithosphere ◽  
Radiometric Dating ◽  
Island Arcs ◽  
Magmatic Arc ◽  
Metasedimentary Rocks ◽  
Basaltic Composition ◽  
Peninsular Ranges ◽  
General Aspects

ABSTRACTThe Peninsular Ranges Batholith of southern and Baja California is the largest segment of a Cretaceous magmatic arc that was once continuous from northern California to southern Baja California. In this batholith, the emplacement of igneous rocks took place during a single sequence of magmatic activity, unlike many of the other components of the Cordilleran batholiths which formed during successive separate magmatic episodes. Detailed radiometric dating has shown that it is a composite of two batholiths. A western batholith, which was more heterogeneous in composition, formed as a static magmatic arc between 140 and 105 Ma and was intrusive in part into related volcanic rocks. The eastern batholith formed as a laterally transgressing arc which moved away from those older rocks between 105 and 80 Ma, intruding metasedimentary rocks. Rocks of the batholith range from undersaturated gabbros through to felsic granites, but tonalite is the most abundant rock throughout. Perhaps better than elsewhere in the Cordillera, the batholith shows beautifully developed asymmetries in chemical and isotopic properties. The main gradients in chemical composition from W to E are found among the trace elements, with Ba, Sr, Nb and the light rare earth elements increasing by more than a factor of two, and P, Rb, Pb, Th, Zn and Ga showing smaller increases. Mg and the transition metals decrease strongly towards the E, with Sc, V and Cu falling to less than half of their value in the most westerly rocks. Oxygen becomes very systematically more enriched in18O from W to E and the Sr, Nd and Pb isotopic systems change progressively from mantle values in the W to a more evolved character on the eastern side of the batholith. In detail the petrogenesis of the Peninsular Ranges Batholith is not completely understood, but many general aspects of the origin are clear. The exposed rocks, particularly in the western batholith, closely resemble those of present day island arcs, although the most typical and average tonalitic composition is distinctly more felsic than the mean quartz diorite or mafic andesite composition of arcs. Chemical and isotopic properties of the western part of the batholith indicate that it formed as the root of a primitive island arc on oceanic lithosphere at a convergent plate margin. Further E, the plutonic rocks appear to have been derived by partial melting from deeper sources of broadly basaltic composition at subcrustal levels. The compositional systematics of the batholith do not reflect a simple mixing of various end-members but are a reflection of the differing character of the source regions laterally and vertically away from the pre-Cretaceous continental margin.

Island arcs: Japan and its environs (developments in geotectonics 3)

Geoforum ◽  
1975 ◽  
Vol 6 (3-4) ◽  
pp. 271-272
Author(s):  
Tadashi Sato
Keyword(s):  
Island Arcs

scholarly journals Tectonic reconstruction of Uda-Murgal arc and the Late Jurassic and Early Cretaceous convergent margin of Northeast Asia–Northwest Pacific

2009 ◽  
Vol 4 ◽  
pp. 273-288 ◽  
Author(s):  
S. D. Sokolov ◽  
G. Ye. Bondarenko ◽  
A. K. Khudoley ◽  
O. L. Morozov ◽  
M. V. Luchitskaya ◽  
...  
Keyword(s):  
Northeast Asia ◽  
Upper Jurassic ◽  
Island Arc ◽  
Passive Margin ◽  
Northwest Pacific ◽  
Island Arcs ◽  
The South ◽  
Convergent Margin ◽  
Tectonic Zone ◽  
The North

Abstract. A long tectonic zone composed of Upper Jurassic to Lower Cretaceous volcanic and sedimentary rocks is recognized along the Asian continent margin from the Mongol-Okhotsk fold and thrust belt on the south to the Chukotka Peninsula on the north. This belt represents the Uda-Murgal arc, which was developed along the convergent margin between Northeast Asia and Northwest Meso-Pacific. Several segments are identified in this arc based upon the volcanic and sedimentary rock assemblages, their respective compositions and basement structures. The southern and central parts of the Uda-Murgal arc were a continental margin belt with heterogeneous basement represented by metamorphic rocks of the Siberian craton, the Verkhoyansk terrigenous complex of Siberian passive margin and the Koni-Taigonos Late Paleozoic to Early Mesozoic island arc with accreted oceanic terranes. At the present day latitude of the Pekulney and Chukotka segments there was an ensimatic island arc with relicts of the South Anyui oceanic basin in a backarc basin. Accretionary prisms of the Uda-Murgal arc and accreted terranes contain fragments of Permian, Triassic to Jurassic and Jurassic to Cretaceous (Tithonian–Valanginian) oceanic crust and Jurassic ensimatic island arcs. Paleomagnetic and faunal data show significant displacement of these oceanic complexes and the terranes of the Taigonos Peninsula were originally parts of the Izanagi oceanic plate.

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