| Petrology and Geochemistry of Post-Collisional Early Miocene Volcanism in the Karacada? Area (Central Anatolia, Turkey) |
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| 引用本文： | Kür?ad ASAN,Hüseyin KURT.Petrology and Geochemistry of Post-Collisional Early Miocene Volcanism in the Karacada? Area (Central Anatolia, Turkey)[J].Acta Geologica Sinica,2011,85(5):1100-1117. |
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| 作者姓名： | Kür?ad ASAN Hüseyin KURT |
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| 作者单位： | Department of Geological Engineering, Sel?uk University, 42079, Konya, Turkey |
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| 基金项目： | This study was financially supported by the Sel?uk University Scientific Research Projects Coordination (Project No: 05401043 and 2003/186). The authors gratefully thank the Sel?uk University for its support. |
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| 摘 要： | Early Miocene (ca.?21–18 Ma) volcanism in the Karacada? area comprises three groups of volcanic rocks: (1) calcalkaline suite (andesitic to rhyolitic lavas and their pyroclastics), (2) mildly-alkaline suite (alkali basalt, hawaiite, mugearite, benmoreite and trachydacite), and (3) a single trachyandesitic flow unit. Field observations, 40Ar/39Ar ages and geochemical data show that there was a progressive temporal transition from group 1 to 3 in a post-collisional tectonic setting. The calcalkaline suite rocks with medium-K in composition resemble those of subduction-related lavas, whereas the mildly-alkaline suite rocks having a sodic tendency (Na2O/K2O=1.5–3.2) resemble those of within-plate lavas. Incompatible element and Sr-Nd isotopic characteristics of the suites suggest that the lithospheric mantle beneath the Karacada? area was heterogeneously enriched by two processes before collision: (1) enrichment by subduction-related processes, which is important in the genesis of the calcalkaline volcanism, (2) enrichment by small degree melts from the astenosphere, which dominates the mildly alkaline volcanism. Perturbation of the enriched lithosphere by either delamination following collision and uplift or removal of the subducted slab following subduction and collision (i.e., slab breakoff) is the likely mechanism for the initiation of the post-collision volcanism.
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| 关 键 词： | post-collision calcalkaline Sr-Nd isotopes Karacada? Central Anatolia |
| 收稿时间： | 2010/7/17 0:00:00 |
| 修稿时间： | 2010/11/15 0:00:00 |
Petrology and Geochemistry of Post‐Collisional Early Miocene Volcanism in the Karacadaǧ Area (Central Anatolia,Turkey) |
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| Authors: | Kür?ad ASAN Hüseyin KURT |
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| Institution: | Department of Geological Engineering, Sel?uk University, 42079, Konya, Turkey |
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| Abstract: | Early Miocene (ca. 21–18 Ma) volcanism in the Karacada? area comprises three groups of volcanic rocks: (1) calcalkaline suite (andesitic to rhyolitic lavas and their pyroclastics), (2) mildly‐alkaline suite (alkali basalt, hawaiite, mugearite, benmoreite and trachydacite), and (3) a single trachyandesitic flow unit. Field observations, 40Ar/39Ar ages and geochemical data show that there was a progressive temporal transition from group 1 to 3 in a post‐collisional tectonic setting. The calcalkaline suite rocks with medium‐K in composition resemble those of subduction‐related lavas, whereas the mildly‐alkaline suite rocks having a sodic tendency (Na2O/K2O=1.5–3.2) resemble those of within‐plate lavas. Incompatible element and Sr‐Nd isotopic characteristics of the suites suggest that the lithospheric mantle beneath the Karacada? area was heterogeneously enriched by two processes before collision: (1) enrichment by subduction‐related processes, which is important in the genesis of the calcalkaline volcanism, (2) enrichment by small degree melts from the astenosphere, which dominates the mildly alkaline volcanism. Perturbation of the enriched lithosphere by either delamination following collision and uplift or removal of the subducted slab following subduction and collision (i.e., slab breakoff) is the likely mechanism for the initiation of the post‐collision volcanism. |
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| Keywords: | post‐collision calcalkaline Sr‐Nd isotopes Karacada? Central Anatolia |
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