Evolution and geodynamic significance of the tertiary orogenic volcanism in Northeastern Greece
Evolution and geodynamic significance of the tertiary orogenic volcanism in Northeastern Greece
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希腊东北部第三纪造山火山活动的演化及其地球动力学意义
DOI：
10.1007/bf01960538
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
L. Villari
中科院分区：
文献类型：
--
作者：
F. Innocenti;N. Kolios;P. Manetti;R. Mazzuoli;G. Peccerillo;F. Rita;L. Villari
东马其顿和西色雷斯（希腊）的第三纪火山活动与罗多彼地块南缘始新世至渐新世形成的沉积盆地有关。火山产物的成分从玄武安山岩到流纹岩不等，总体上显示出钙碱性造山的亲和力，而化学特征则区分了不同的岩石群，可能反映了母岩浆之间的细微差异。流纹质岩段的Sr同位素组成显示出与玄武安山岩相当的初始87 Sr/86 Sr比值，加强了结晶/液体下降线的假设。研究表明，造山带是在一个活动大陆边缘上发展起来的，其特点是地壳相对较厚，对基性岩浆起着密度过滤器的作用，有利于它们在地壳内的储存和分馏。地层学和K/Ar年代学资料表明，火山活动始于上始新世，在上渐新世达到最大发展。早中新世以来，火山活动在爱琴海中部和安纳托利亚西部部分地区向南迁移，到中新世中期结束，火山前缘向南迁移被解释为Benioff带倾角增加的结果，这是由于大陆碰撞主阶段后穿透强度降低所致。
The Tertiary volcanism of Eastern Macedonia and Western Thrace (Greece) developed in association with the sedimentary basin which formed, from Eocene to Oligocene, along the southern margin of the Rhodope Massif.The volcanic products, ranging in composition from basaltic andesites to rhyolites, show an overall calc-alkaline orogenic affinity, while chemical characteristics identify different groups of rocks, probably reflecting minor differences among parent magmas. The observed evolution within any group of rocks is compatible with fractional crystallization processes acting on relatively shallow magma bodies.The Sr isotopic composition of rhyolitic member shows an initial87Sr/86Sr ratio comparable with that of basaltic andesites, reinforcing the hypothesis of a crystal/liquid line of descent.Geochemical and petrographic evidence, on the whole, suggests that the investigated orogenic association developed on an active continental margin characterized by a relatively thick crust, acting as a density filter for the basic magmas and facilitating their storage and fractionation within the crust itself. Minor contamination by interaction with host materials may also have occurred.Stratigraphic and K/Ar geochronological data indicate that the volcanic activity started in Upper Eocene and reached its maximum development in Upper Oligocene. From Lower Miocene, the volcanism shifted southward in the Central Aegean area and in part of Western Anatolia, coming to an end by Middle Miocene.The southward migration of the volcanic front has been interpreted as a consequence of the increase in the dipping of the Benioff zone, due to the decrease of penetrative strength after the main phase of continental collision.