TY - JOUR
T1 - Geological setting of basaltic rocks in an accretionary complex, Khangai-Khentei Belt, Mongolia
AU - Tsukada, Kazuhiro
AU - Nakane, Yuki
AU - Yamamoto, Koshi
AU - Kurihara, Toshiyuki
AU - Otoh, Shigeru
AU - Kashiwagi, Kenji
AU - Chuluun, Minjin
AU - Gonchigdorj, Sersmaa
AU - Nuramkhaan, Manchuk
AU - Niwa, Masakazu
AU - Tokiwa, Tetsuya
PY - 2013/6
Y1 - 2013/6
N2 - We describe the mode of occurrence and geochemical characteristics of basalts, in the Khangai-Khentei belt in Mongolia, overlain by Middle Paleozoic radiolarian chert in an extensive accretionary complex. These basalts are greatly enriched in K, Ti, Fe, P, Rb, Ba, Th, and Nb in comparison to the composition of the mid-ocean ridge basalts, indicative of within-plate alkaline type. Ti/YvsNb/Y and MnO/TiO2/P2O5 ratios of the basalts also suggest within-plate affinities. Considering the geochemical characteristics as well as the conformable relationship with the overlying radiolarian chert, the alkaline basalts were clearly not continental but formed a pelagic oceanic island. The mode of occurrence and geochemistry of the basalts show that the alkaline basaltic volcanic activity had taken place to form an oceanic island in the Paleozoic pelagic region sufficiently far from continents to allow radiolarian ooze accumulation.
AB - We describe the mode of occurrence and geochemical characteristics of basalts, in the Khangai-Khentei belt in Mongolia, overlain by Middle Paleozoic radiolarian chert in an extensive accretionary complex. These basalts are greatly enriched in K, Ti, Fe, P, Rb, Ba, Th, and Nb in comparison to the composition of the mid-ocean ridge basalts, indicative of within-plate alkaline type. Ti/YvsNb/Y and MnO/TiO2/P2O5 ratios of the basalts also suggest within-plate affinities. Considering the geochemical characteristics as well as the conformable relationship with the overlying radiolarian chert, the alkaline basalts were clearly not continental but formed a pelagic oceanic island. The mode of occurrence and geochemistry of the basalts show that the alkaline basaltic volcanic activity had taken place to form an oceanic island in the Paleozoic pelagic region sufficiently far from continents to allow radiolarian ooze accumulation.
KW - Accretionary complex
KW - Central Asian Orogenic Belt
KW - Khangai-Khentei Belt
KW - Mongolia
KW - OIB
UR - http://www.scopus.com/inward/record.url?scp=84878196254&partnerID=8YFLogxK
U2 - 10.1111/iar.12028
DO - 10.1111/iar.12028
M3 - 学術論文
AN - SCOPUS:84878196254
SN - 1038-4871
VL - 22
SP - 227
EP - 241
JO - Island Arc
JF - Island Arc
IS - 2
ER -