Geochemical characterization of a Quaternary monogenetic volcano in Erciyes Volcanic Complex: Cora Maar (Central Anatolian Volcanic Province, Turkey)
Geochemical characterization of a Quaternary monogenetic volcano in Erciyes Volcanic Complex: Cora Maar (Central Anatolian Volcanic Province, Turkey)
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埃尔吉耶斯火山群第四纪单生火山的地球化学特征：科拉玛尔（土耳其安纳托利亚中部火山省）
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发表时间：
2011
期刊：
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通讯作者：
Gonca Gençalioǧlu
中科院分区：
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作者：
Gonca Gençalioǧlu
中安纳托利亚火山省(CAVP)是阿尔卑斯-地中海地区新近纪-第四纪后碰撞火山作用的典范。阿尔卑斯-地中海地区的火山活动包括拉斑玄武岩、过渡性火山、钙碱性火山岩和具有“造山”特征的玄武岩。在造山火山作用后，该地区普遍报道了很少或没有造山特征的次生板内碱性玄武岩(Sl)。CAVP以广泛的钙碱性安山岩-英安岩火山作用为特征，具有造山作用的微量元素特征，反映了与俯冲有关的流体对其源区的富集性。Cora Maar(CM)位于Erciyes拉分盆地内，是CAVP许多第四纪单生火山的一个例子，通常被认为是碱性的。文中给出了该火山的常量元素、微量元素、地球化学和年代学数据，并与其他CAVP单生火山进行了比较。Cm Score为玄武岩安山岩，属过渡性钙碱性岩石，具有Nb-Ta、Ba、P、Ti负异常的地幔归一化特征。与地中海地区的碱性玄武岩不同，CAVP单生火山的其他晚期玄武岩被归类为拉斑玄武岩、过渡性玄武岩和中碱性玄武岩。它们表现出与CM样品相同的负异常和不相容元素比率。在这方面，CM与其他CAVP单生玄武岩(SL)相当，但不同于中地底板内碱性玄武岩。几条证据表明，CM和其他CAVP单生玄武岩来自岩石圈地幔内的浅层，即来自不含石榴石的来源。在更广泛的区域背景下，CAVP玄武岩(Sl)可与阿普塞尼(罗马尼亚)和Big Pine(美国大盆地西部)火山岩相媲美，但前者具有贫化的Ba含量。这是CAVP火山岩的共同特征，可能与地壳混染或源区特征有关。事实上，HFS和其他不相容元素比率表明，地壳污染在CAVP单生玄武岩的成因中起到了作用。
Central Anatolian Volcanic Province (CAVP) is a fine example of Neogene-Quaternary post-collisional volcanism in the Alpine-Mediterranean region. Volcanism in the Alpine-Mediterranean region comprises tholeiitic, transitional, calc-alkaline, and shoshonitic types with an “orogenic” fingerprint. Following the orogenic volcanism, subordinate, within-plate alkali basalts (sl) showing little or no orogenic signature are generally reported in the region. CAVP is mainly characterized by widespread calc-alkaline andesitic-dacitic volcanism with orogenic trace element signature, reflecting enrichment of their source regions by subduction-related fluids. Cora Maar (CM) located within the Erciyes pull-apart basin, is an example to numerous Quaternary monogenetic volcanoes of the CAVP, generally considered to be alkaline. Major and trace element geochemical and geochronological data for the CM are presented in comparison with other CAVP monogenetic volcanoes. CM scoria is basaltic andesitic, transitional-calc-alkaline in nature, and characterized by negative Nb–Ta, Ba, P and Ti anomalies in mantle-normalized patterns. Unlike the “alkaline” basalts of the Mediterranean region, other late-stage basalts from the CAVP monogenetic volcanoes are classified as tholeiitic, transitional and mildly alkaline. They display the same negative anomalies and incompatible element ratios as CM samples. In this respect, CM is comparable to other CAVP monogenetic basalts (sl), but different from the Meditterranean intraplate alkali basalts. Several lines of evidence suggest derivation of CM and other CAVP monogenetic basalts from shallow depths within the lithospheric mantle, that is from a garnet-free source. In a wider regional context, CAVP basalts (sl) are comparable to Apuseni (Romania) and Big Pine (Western Great Basin, USA) volcanics, except the former have depleted Ba contents. This is a common feature for the CAVP volcanics and might be related to crustal contamination or source characteristics. Indeed, HFS and other incompatible element ratios suggest the role of crustal contamination in the genesis of the CAVP monogenetic basalts.