TY - JOUR
T1 - Asia
T2 - A frontier for a future supercontinent Amasia
AU - Safonova, Inna
AU - Maruyama, Shigenori
N1 - Funding Information:
The study was supported by Grant-in-Aid for Scientific Research no. 23224012 (SM), Global COE programme ‘From the Earth to “Earths”’, Scientific Project of the Institute of Geology and Mineralogy SB RAS, Ministry of Education and Science (Russia), JSPS Invitation Program Grant No. 14526 (IS), and RFBR Project #14-05-00143. It is a contribution to IGCP#592 Project ‘Continental construction in Central Asia’ under the patronage of UNESCO-IUGS. The authors appreciate the constructive comments and criticism from Professor Yukio Isozaki and an anonymous reviewer and from Editor-in-Chief Robert Stern, all of which helped us improve the manuscript. Our cordial thanks are extended to Ms Shio Watanabe for her help with figure drawing.
PY - 2014/7/4
Y1 - 2014/7/4
N2 - Asia is the worlds largest but youngest continent, in which Pacific-type (P-type) and collision-type (C-type) orogenic belts coexist with numerous amalgamated continental blocks. P-type orogens represent major sites of continental growth through tonalite-trondhjemite-granodiorite type (TTG-type) juvenile granitoid magmatism and accretion of oceanic crust and intra-oceanic arcs. The Asian continent includes several P-type orogenic belts, of which the largest are the Central Asian and Western Pacific. The Central Asian Orogenic Belt is dominated by P-type fossil orogens arranged with a regular northward subduction polarity. The Western Pacific is characterized by ongoing P-type orogeny related to the westward subduction of the Pacific plate. Asia has a multi-cratonic structure and its post-Palaeozoic history has witnessed amalgamation of the Laurasia composite continent and Pangaea supercontinent. Nowadays, Asia is surrounded by double-sided subduction zones, which generate new TTG-type crust and supply oceanic crust and microcontinents to its active margins. The TTG-crust can be tectonically eroded and subducted down to the mantle transition zone to form a second continent, which may generate mantle upwelling, plumes, and extensive intra-plate volcanism. Moreover, recent plate movements around Asia are dominated by northward directions, which resulted in the India-Eurasia and Arabia-Eurasia collisions beginning at 50-45 and 23-20 Ma, respectively, and will result in Africa-Eurasia collision in the near future. Therefore, Asia is the best candidate to serve as the nucleus for a future supercontinent Amasia, likely to form 200-250 Ma in the future. In this paper we unravel a puzzle of continental growth in Asia through P-type orogeny by discussing its tectonic history and geological structure, subduction polarity in P-type orogens, tectonic erosion of TTG-type crust and arc subduction at convergent margins, generation of mantle plumes, and prospects of Asia growth and overgrowth.
AB - Asia is the worlds largest but youngest continent, in which Pacific-type (P-type) and collision-type (C-type) orogenic belts coexist with numerous amalgamated continental blocks. P-type orogens represent major sites of continental growth through tonalite-trondhjemite-granodiorite type (TTG-type) juvenile granitoid magmatism and accretion of oceanic crust and intra-oceanic arcs. The Asian continent includes several P-type orogenic belts, of which the largest are the Central Asian and Western Pacific. The Central Asian Orogenic Belt is dominated by P-type fossil orogens arranged with a regular northward subduction polarity. The Western Pacific is characterized by ongoing P-type orogeny related to the westward subduction of the Pacific plate. Asia has a multi-cratonic structure and its post-Palaeozoic history has witnessed amalgamation of the Laurasia composite continent and Pangaea supercontinent. Nowadays, Asia is surrounded by double-sided subduction zones, which generate new TTG-type crust and supply oceanic crust and microcontinents to its active margins. The TTG-crust can be tectonically eroded and subducted down to the mantle transition zone to form a second continent, which may generate mantle upwelling, plumes, and extensive intra-plate volcanism. Moreover, recent plate movements around Asia are dominated by northward directions, which resulted in the India-Eurasia and Arabia-Eurasia collisions beginning at 50-45 and 23-20 Ma, respectively, and will result in Africa-Eurasia collision in the near future. Therefore, Asia is the best candidate to serve as the nucleus for a future supercontinent Amasia, likely to form 200-250 Ma in the future. In this paper we unravel a puzzle of continental growth in Asia through P-type orogeny by discussing its tectonic history and geological structure, subduction polarity in P-type orogens, tectonic erosion of TTG-type crust and arc subduction at convergent margins, generation of mantle plumes, and prospects of Asia growth and overgrowth.
KW - 'second' continent
KW - Pacific-type orogeny
KW - collision-type orogeny
KW - double-sided subduction
KW - mantle plume
KW - mantle transition zone
KW - tectonic erosion
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U2 - 10.1080/00206814.2014.915586
DO - 10.1080/00206814.2014.915586
M3 - Review article
AN - SCOPUS:84903550821
SN - 0020-6814
VL - 56
SP - 1051
EP - 1071
JO - International Geology Review
JF - International Geology Review
IS - 9
ER -