Andrean-type Late Neoproterozoic subalkaline magmatism in southern Turkey: Evidence for an active continental margin in the Peri-Gondwanan Realm

2018-06-26
GÜRSU, SEMİH
KÖKSAL, SERHAT
MÖLLER, Andreas
GÖNCÜOĞLU, MEHMET CEMAL
The Gondwanan Late Neoproterozoic successions in Turkey mainly crop out in the Tauride-Anatolide Platform (TAP) and the South Anatolian Autoctone Belt (SAAB) of the northern Arabian Plate. The Neoproterozoic meta-granitic (~542 Ma-Gürsu ad Göncüoğlu, 2008) and meta-pelitic basement rocks are unconformably overlain by trace fossils bearing Early Cambrian (e.g. Erdoğan et al., 2004; Demircan et al., 2018) volcanoclastics and Middle Cambrian trilobite-rich meta-carbonates (Dean and Özgül, 1994) in Sandıklı (TAP), Menderes Massif (TAP) and Derik (SAAB) areas. The Late Neoproterozoic basement rocks in Sandıklı area comprise meta-siliciclastics associated with meta-felsic volcanic rocks (543±7 Ma - Gürsu and Göncüoğlu, 2006) and cut by meta-quartz-porphyry dykes (541.3±10.9 Ma - Gürsu and Göncüoğlu, 2006). The Late Neoproterozoic basement rocks in Menderes Massif start with meta-tonalities/meta-granodiorites (580 to 570 Ma - Koralay, 2015) and meta-granitic rocks (augen gneisses, biotite-rich granite mylonites and tourmaline-rich granite mylonites - ~542 Ma - Gürsu, 2015). Similar succession is also observed in Derik (Mardin) area and includes Late Neoproterozoic early-stage andesites (~582 Ma - Gürsu et al., 2016) and rhyolites (570 Ma - Gürsu et al., 2016) alternating with pyroclastics and rare siltstone/sandstone intercalations. They are cut by late-stage andesitic lavas (560 Ma - Gürsu et al., 2017) and mafic dykes. The uppermost part of the succession contains pyroclastic rocks (mostly tuffs) associated with agglomerates/volcanic breccias. The Andean type arc-related igneous activity at 580-560 Ma represent source of the subduction-enriched depleted mantle-derived magmas (Nd(T): +0.15 to +4.20) and was followed by post-collisional granitic magmatism (Nd(T): -4.63 to -0.54) at 530-560 Ma, which have been emplaced during late- to post-collisional back-arc extension behind the Cadomian arc concomitant with southward subduction of the Proto-Tethys Ocean along the northern margin of Gondwana. Lithospheric thinning and back-arc development in peri-Gondwanan continental crust has resulted in development of N-MORB type gabbroic stocks, mafic lavas and dykes in the TAP between 560 and 530 Ma just behind the Cadomian arc. Similar tectonic scenarios have been suggested for other peri-Gondwanan terranes in Europe to the Middle East to eastern Asia. Dean, T.W., Özgül, N. 1994: Cambrian rocks and faunas, Hüdai area, Taurus Mountains, south-western Turkey. Bulletin de l’Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre 64, 5-20. Demircan, H., Gürsu, S., Göncüoğlu, M.C., 2018. Early Cambrian trace fossils at the northern margin of the Arabian Plate; Telbesmi Formation, Turkey. Acta Geologica Polonica 68(2) (in press). Erdoğan, B., Uchmann, A., Güngör, T., Özgül, N. 2004: Lithostratigraphy of the Lower Cambrian metaclastics and their age based on trace fossils in the Sandıklı region, southwestern Turkey. Geobios 38, 346-360. Gürsu, S., 2015. New petrogenetic model for meta-granitic rocks in the central and southern Menderes Massif-W Turkey: Implications for Cadomian crustal evolution within the Pan-African mega-cycle. Precambrian Research 275, 450-470. Gürsu, S., Göncüoğlu, M.C., 2008: Petrogenesis and geodynamic evolution of the Late Neoproterozoic post-collisional felsic magmatism in NE Afyon area, western central Turkey. Geological Society, London, Special Publication, 297, 409-431. Gürsu, S., Möller, A, Göncüoğlu, M.C., Köksal, S., Demircan, H., Köksal, F.T., Kozlu, H., Sunal, G., 2016: Neoproterozoic continental arc volcanism at the northern edge of the Arabian Plate, SE Turkey. Precambrian Research 258, 208-233. Koralay, O.E., 2015: Late Neoproterozoic granulite facies metamorphism in the Menderes Massif, western Anatolia/Turkey: implication for the assembly of Gondwana. Geodinamica Acta 27(4), 244-266.
Citation Formats
S. GÜRSU, S. KÖKSAL, A. MÖLLER, and M. C. GÖNCÜOĞLU, “Andrean-type Late Neoproterozoic subalkaline magmatism in southern Turkey: Evidence for an active continental margin in the Peri-Gondwanan Realm,” presented at the 3rd European Mantle Workshop 26-28 June, 2018, Pavia, Italy, 2018, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/87721.