Foça-Karaburun ve Ayval?k-Midilli grabenleri, Bat? Anadolunun k?y? kesiminde kalan, KB-GD yönlü iki önemli genle?me alanlar?d?r. Bu grabenler, Ege Denizinin yay arkas? havzas?n?n aç?l?m? ile de ili?kili olan Erken Miyosen-Holosen genle?mesinin etkisinde kalm?? geni? alanlar?n petrojenik ve jeodinamik geli?imlerine örnek te?kil eden çok önemli lokasyonlard?r. Bu ba?lamda, Foça-Karaburun ve Ayval?k-Midilli grabenleri, D-B transtansiyonel faylar ile parçalara ayr?lm??, KD-GB yönlü aç?lma sunan bölgedeki büyük graben sistemleridir. Bat? Anadolu'da, kalkalkali ve ?o?onitik volkanikler ile UK, UK-?o?onitik veya lamproitik kayalar orojenik ortamlar? yans?t?rlarken, daha genç olan K ve Na alkali bazaltik kayalar k?tasal ko?ullar alt?ndaki k?ta içi magmatizmas? ürünleri olan okyanus adas? bazaltlar? (OIB) ile temsil edilirler. Çal??ma alan?n?n tektonik hatlar?, Bat? Anadolu ve Ege Denizi'nin tektonik evrimini yeniden yap?land?rabilirken, çal???lan iki grabendeki ve çevresindeki Neojen volkanizmas?n?n farkl? seviyelerindeki kayalar?, bu kayalar? üreten magma kaynaklar?n?n jeokimyasal geli?iminin kesin bir kayd?n? tutmaktad?rlar.
The Foça-Karaburun and Ayvalık-Lesvos grabens (western coast of Anatolia, Turkey) are two important NW-SE-trending extensional areas generated in response to the Early Miocene-Holocene extension of the Western Anatolian region, related to the opening of the "unconventional" back-arc basin of the Aegean Sea. The abundance of geo-structural evidence and the occurrence of volcanic rocks representing all the stages of the Aegean-Western Anatolia volcanism render the Foça-Karaburun and Ayvalık-Lesvos Grabens key localities to exemplify the petrogenetic and geodynamic evolution of the area. In this context, the Foça-Karaburun and Ayvalık-Lesvos grabens, possibly formerly a single graben, formed along an original NE-SW-trending extension, later dissected by E-W-trending transtensional faults, are investigated to constrain the petrogenetic and geodynamic evolution of the whole Aegean region. Calc-alkaline and shoshonitic volcanic rocks with scattered ultrapotassic-shoshonitic or lamproitic lavas and dykes represent the orogenic phase of the magmatic activity, while the younger K- and Na-rich alkaline basaltic rocks are the result of later magmatism characterized by an intraplate geochemical signature reflecting progressively decreasing subduction rates. While the tectonic lineaments and the structures of the study area allow the reconstruction of the tectonic evolution of Western Anatolia and Aegean Sea, the volcanic rocks from the different stages of Neogene volcanism within the two studied grabens and surrounding areas permit a precise record of the geochemical evolution of the magma sources.
Volcanic rocks from Foça-Karaburun and Ayvalık-Lesvos grabens (Western Anatolia) and their petrogenic-geodynamic significance.
Agostini S;
2010
Abstract
The Foça-Karaburun and Ayvalık-Lesvos grabens (western coast of Anatolia, Turkey) are two important NW-SE-trending extensional areas generated in response to the Early Miocene-Holocene extension of the Western Anatolian region, related to the opening of the "unconventional" back-arc basin of the Aegean Sea. The abundance of geo-structural evidence and the occurrence of volcanic rocks representing all the stages of the Aegean-Western Anatolia volcanism render the Foça-Karaburun and Ayvalık-Lesvos Grabens key localities to exemplify the petrogenetic and geodynamic evolution of the area. In this context, the Foça-Karaburun and Ayvalık-Lesvos grabens, possibly formerly a single graben, formed along an original NE-SW-trending extension, later dissected by E-W-trending transtensional faults, are investigated to constrain the petrogenetic and geodynamic evolution of the whole Aegean region. Calc-alkaline and shoshonitic volcanic rocks with scattered ultrapotassic-shoshonitic or lamproitic lavas and dykes represent the orogenic phase of the magmatic activity, while the younger K- and Na-rich alkaline basaltic rocks are the result of later magmatism characterized by an intraplate geochemical signature reflecting progressively decreasing subduction rates. While the tectonic lineaments and the structures of the study area allow the reconstruction of the tectonic evolution of Western Anatolia and Aegean Sea, the volcanic rocks from the different stages of Neogene volcanism within the two studied grabens and surrounding areas permit a precise record of the geochemical evolution of the magma sources.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
