STRATIGRAPHY OF THE PAN – AFRICAN BASEMENT OF THE MENDERES MASSIF AND THE RELATIONSHIP WITH LATE NEOPROTEROZOIC/CAMBRIAN EVOLUTION OF THE GONDWANA

Osman CANDAN; O. Özcan DORA; Roland OBERHÄNSLI; Ersin KORALAY; Mete ÇETİNKAPLAN; Cüneyt AKAL; Muharrem SATIR; Fukun CHEN; Orhan KAYA

Makale detayları

STRATIGRAPHY OF THE PAN – AFRICAN BASEMENT OF THE MENDERES MASSIF AND THE RELATIONSHIP WITH LATE NEOPROTEROZOIC/CAMBRIAN EVOLUTION OF THE GONDWANA

Yazarlar:

Osman CANDAN | O. Özcan DORA | Roland OBERHÄNSLI | Ersin KORALAY | Mete ÇETİNKAPLAN | Cüneyt AKAL | Muharrem SATIR | Fukun CHEN | Orhan KAYA

Yayıncı:

Maden Tetkik Arama Genel Müdürlüğü

Ana Başlıklar:

Uygulamalı fizik

Dergi:

Bulletin of the Mineral Research and Exploration 2011 Vol.142 Issue 142, pp.25-68

Belge Tipi:

Makale

Yayın Tarihi:

10/2011

Belge Dili:

İngilizce

Document ID (Org No.):

2000520608

Sıklık:

Üç Yıllık

pISSN:

0026-4563

Özet:

 


The Menderes Massif, exposed in the Western Anatolia, is tectonically overlain to the north by the
Afyon Zone and to the south by the Lycian Nappes. In the northwest, two high-pressure units, the Cycladic
Complex and overlying the Lycian Nappes, as well as the nappes of Ýzmir - Ankara Zone tectonically overlay the
Menderes Massif. The metamorphic rock succession of the Massif can be divided into two main units: 1-PanAfrican
basement (core series) and 2-Palaeozoic - Early Tertiary metasedimentary rocks (cover series). The PanAfrican
basement shows a stratigraphy consisting of a partly migmatized metaclastic sequence and polymetamorphic
basic and acidic igneous rocks that intruded into these metaclastics. This metaclastic sequence, which is
composed of paragneiss and conformably overlying schist units reaches a minimum thickness of eight kilometers
and forms the oldest rocks of the Pan-African basement of the Menderes Massif. Field studies and geochronological
data suggest that the protoliths of the paragneisses are predominantly clastic sediments of litharenitic
composition. Frequently, the paragneisses alternate and interfinger in all directions with micaschists and
biotite-albite schists, originating from mudstone and subarkosic sandstone, respectively. The paragneisses are
conformably overlain by a schist unit. The originally gradual sedimentary contact is represented by a paragneiss
and schist intercalation. The schists are dominated by micaschists with biotite-albite schist layers, derived from
mudstone and subarkose, respectively. In the Menderes Massif, the paragneisses are generally extensively
migmatized. Widespread anatectic granites occur as irregular-shaped bodies with migmatized margins. The
detrital zircons of the paragneisses yielded ages scattered between 610 - 2558 Ma. Detrital zircons of the schist
unit of the Pan-African basement were dated at 592 - 3239 Ma. The intrusion ages of the orthogneiss showing
clear intrusive contact relationship with metaclastic sequence range from 570 to 520 Ma. The granulite facies
metamorphism of the paragneiss unit was dated at 583±5.7 Ma. These geochronological evidence and the
contact relationships clearly reveal that the deposition age of the protoliths of the metaclastic sequence of the
Pan-African basement can be constrained to Late Neoproterozoic between ca 590 - 580 Ma. The metaclastic
sequence is intruded by large granitoid bodies and gabbroic stocks. The intrusion ages of the granitic precursors
now represented by orthogneisses with changed mineralogical compositions and primary textures range from 520
to 570 Ma with a major event at about 550 Ma. These granites, which can be divided into three main groups
(biotite orthogneiss, amphibole orthogneiss and tourmaline leucocratic orthogneiss) are the products of a
poly-phase Pan-African acidic magmatic activity that intruded the metaclastic sequence. They are syn- to
post-metamorphic intrusions with respect to the Pan-African orogeny. The basic meta-igneous rocks occurring in
the Pan-African basement have gabbroic to noritic composition. They display massive cores and foliated margins
that consist mainly of garnet amphibolites with relics of eclogites revealing the polymetamorphic history of the
Pan-African basement. Field evidence and radiometric age data indicate that the primary contact relationship between the Pan-African basement and the Palaeozoic cover series in the Menderes Massif was an unconformity
(Supra-Pan-African unconformity) and the cover series were sourced from the Pan-African basement. The
protoliths of the paragneiss and schist of the Pan-African basement were deposited on the passive continental
margin of a basin occurring between East and West Gondwana during the Late Neoproterozoic time
(Mozambique ocean). All the magmatic and metamorphic ages obtained from Pan-African basement coincide with
the closure of this ocean and the final assemblage of the Gondwana supercontinent during Late NeoproterozoicCambrian
time.

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Makale detayları

STRATIGRAPHY OF THE PAN – AFRICAN BASEMENT OF THE MENDERES MASSIF AND THE RELATIONSHIP WITH LATE NEOPROTEROZOIC/CAMBRIAN EVOLUTION OF THE GONDWANA

Yazarlar: Osman CANDAN | O. Özcan DORA | Roland OBERHÄNSLI | Ersin KORALAY | Mete ÇETİNKAPLAN | Cüneyt AKAL | Muharrem SATIR | Fukun CHEN | Orhan KAYA

Yayıncı: Maden Tetkik Arama Genel Müdürlüğü

Ana Başlıklar: Uygulamalı fizik

Dergi: Bulletin of the Mineral Research and Exploration 2011 Vol.142 Issue 142, pp.25-68

Belge Tipi: Makale

Yayın Tarihi: 10/2011

Belge Dili: İngilizce

Document ID (Org No.): 2000520608

Sıklık: Üç Yıllık

pISSN: 0026-4563

Sayı

Yazarlar:

Osman CANDAN | O. Özcan DORA | Roland OBERHÄNSLI | Ersin KORALAY | Mete ÇETİNKAPLAN | Cüneyt AKAL | Muharrem SATIR | Fukun CHEN | Orhan KAYA

Yayıncı:

Maden Tetkik Arama Genel Müdürlüğü

Ana Başlıklar:

Uygulamalı fizik

Dergi:

Bulletin of the Mineral Research and Exploration 2011 Vol.142 Issue 142, pp.25-68

Belge Tipi:

Makale

Yayın Tarihi:

10/2011

Belge Dili:

İngilizce

Document ID (Org No.):

2000520608

Sıklık:

Üç Yıllık

pISSN:

0026-4563