Origin of Pillow Basalts in the Maden Complex (Çatak-Van): Petrographic and Geochemical Approach

Year 2024, Volume: 45 Issue: 3, 227 - 246, 31.12.2024

Tijen Üner

https://doi.org/10.17824/yerbilimleri.1440128

Abstract

The Southeastern Anatolia orogenic belt is formed by the tectonic amalgamation of units with different ages and lithologies. The Middle Eocene pillow-structured basaltic rocks and sedimentary units within this belt are generally referred to as the Maden Complex. The characterization, dating, origin, and structural position of the volcanic rocks within the Maden Complex are highly debated. This study aims to petrographically analyze samples taken from the volcanic units of the Maden Complex in the Çatak-Van region and to elucidate the formation mechanism of the basalts.
As a result of petrographic examinations of the basaltic rocks, it was found that plagioclase, pyroxene, and olivine phenocrysts are present as phenocrysts in the basaltic rocks, while the groundmass is characterized by plagioclase, pyroxene, olivine ± opaque minerals. The basalts generally exhibit a hypocrystalline texture. The presence of chlorite and epidote minerals observed in the basaltic rocks indicates that these rocks have undergone low-grade metamorphism. Geochemical analyses also support the effects of low-grade metamorphism and hydrothermal alteration in the basalts. The pillow-structured basaltic rocks observed in the region exhibit subalkaline-tholeiitic and transitional characteristics. It has been determined that the pillow basalts of the Maden Complex originated from a spinel lherzolite-type mantle source representing shallow depth. Geochemically, a slight enrichment in Th, Ta, and Nb, along with a moderate enrichment in light rare earth elements (LREE) [(La/Yb)N=2.1-3.6], indicates that these rocks have received contributions from a more chemically enriched, unexhausted source. The studies conducted show that the major and trace element data of the pillow basalts observed in the region exhibit similar characteristics, suggesting that the magma forming the basalts might have been influenced by an enriched source and similar processes.

Keywords

Alteration, E-MORB, Southeastern Anatolian, Pillow basalt, Enrichment

Maden Karmaşığı’ndaki (Çatak-Van) Yastık Yapılı Bazaltların Kökeni: Petrografik ve Jeokimyasal Yaklaşım

Abstract

Çalışma alanı (Çatak-Van), farklı yaş ve litolojilere sahip birimlerin tektonik olarak bir arada bulunduğu, Güneydoğu Anadolu Orojenik Kuşağı içerisinde yer almaktadır. Bitlis Masifi ile tektonik olarak birlikte yer alan Maden Karmaşığı, bölgede Orta Eosen yaşlı volkanik ve sedimanter birimlerle temsil edilmektedir. Bu çalışmada, Çatak-Van bölgesinde Maden Karmaşığı volkanik birimlerinden alınan örnekler, karmaşıktaki bazaltların oluşum mekanizmasının ortaya konulması amacıyla incelenmiştir.
Alınan örnekler üzerinden yapılan petrografik incelemeler sonucunda, bazaltlarda düşük dereceli metamorfizma ve hidrotermal alterasyonun etkileri jeokimyasal çalışmalarla da desteklenmiştir. Jeokimyasal çalışmalara göre, bölgede gözlenen yastık yapılı bazaltik kayaçlar, subalkalin-toleyitik özellik sunmaktadır. Maden Karmaşığı’na ait bu yastık bazaltlar, %10’luk granat fasiyesi ve %90’lık spinel fasiyesinden gelen eriyik fraksiyonlarının karışmasından oluşmuştur. Jeokimyasal olarak, Th, Ta, Nb bakımından hafif bir zenginleşme ve hafif nadir toprak elementleri (LREE) [(La/Yb)N=2.1-3.6] bakımından da kısmen zengin birleşimde olmaları bu kayaların tüketilmiş bir kaynağa ek olarak, daha zengin bir kimyaya sahip tüketilmemiş bir kaynaktan katkı aldığını göstermektedir. Yapılan çalışmalar sonucunda, bölgede gözlenen yastık bazaltlarının ana ve iz element verileri birbirine benzer özellik sunmaktadır. yastık bazaltlarında gözlenen benzer özellikler, bölgede gözlenen bazaltları oluşturan magmanın aynı kaynaktan ve benzer süreçlerden etkilenmiş olabileceği söylenebilir.

Keywords

Alterasyon, E-MORB, Güneydoğu Anadolu, Yastık bazaltlar, Zenginleşme

References

• Aktaş, G., Robertson, A.H.F., 1984. The Maden Complex, SE Turkey: evolution of a neo-tethyan active margin, in The Geological Evolution of the Eastern Mediterranean, (Editor: J. E., Dixon and A.H.F. Robertson). Blackwell Scientific Publications, 0305-8719, Oxford. 375-402.
• Aktas, G., Robertson, A.H.F., 1990. Tectonic Evolution of the Tethys Suture Zone in S.E. Turkey: Evolution Evidence from the Petrology and Geochemistry of Late Cretaceous and Middle Eocene Extrusives. In: Malpas J, Moores E, Panayiotou A, Xenophontos C (eds.) Ophiolites-Oceanic Crustal Analogues. Proc Troodos Ophiolite Symp,Geological Survey, Cyprus 1987, 311-329.
• Allégre, C.J., Hamelin, B., Dupre, B., 1984.Statistical analysis of isotopic ratios in MORB: the mantle blob cluster model and the convective regime of the mantle. Earth and Planet Sci., Lett., 71(1) 71-84.
• Best, M.G., 2003. Igneous and metamorphic petrology, Newyork, W.H. Freeman, Betton, 2nd edition, 552p.
• Beyarslan, M., Bingöl, A. F., 2000. Petrology of a supra-subduction zone ophiolite (Kömürhan-Elazığ-Turkey). Canadian Journal of Earth Sciences, 37(10), 1411-1424.
• Bingöl, A.F., 1988. Petrographical and petrological features of intrusive rocks of Yüksekova Complex in the Elazığ region (Eastern Taurus, Turkey). The Journal of Fırat University Science and Technology, 3/2, 1-17.
• Dimroth, E., Cousineau, P., Leduc, M., Sanschagrin, Y., 1978. Structure and organization of Archean subaqueous basalt flows, Rouyn-Noranda area, Quebec, Canada. Canadian Journal Earth Sci. 15:902-918.
• Erler, A., 1982. Madenköy-Siirt masif sülfid yatağı çevresindeki hidrotermal alterasyon. ODTU, Doçentlik Tezi, 131 s.
• Frey, F.A., Clague, D.A., 1983. Geochemistry of diverse basalt types from Loihi Seamount, Hawaii: petrogenetic implications. Earth Planet. Sci. Lett., 66, 337-355
• Göncüoğlu, M.C., 2010. Türkiye Jeolojisi’ne Giriş: Alpin ve Alpin öncesi tektonik birliklerin jeodinamik evrimi. Monografi Serisi No: 5, MTA Genel Müd. Ankara.
• Günay, Y. Şenel, M., 2002. 1/500000 ölçekli Türkiye jeoloji haritaları Cizre paftası, Maden Tetkik ve Arama Genel Müdürlüğü, Ankara.
• Hempton, M., 1985. Structure and deformation history of the Bitlis suture near Lake Hazar, SE Turkey. Geol. Soc. Am. Bull., 96, 223–243.
• Hempton, M., 1987, Constraints on Arabian plate motion and extensional history of the Red Sea: Tectonics, 6, 687–705.
• İleri, S., Salancı, B., Bitem, M., Doğan, R., 1976. Ergani (Maden) bakır yatağı ve plaka tektoniği, Türkiye Jeoloji Kurumu Bülteni, 19, 133-142.
• Kaya, A., 2004. Gezin (Maden-Elazığ) çevresinin jeolojisi. Pamukkale Üniversitesi Mühendislik Bilimleri Dergisi, 10 (1), 41-50.
• Kinzler, R.J., 1997. Melting of mantle peridotite at pressures approaching the spinel to garnet transition: Application to mid-ocean ridge basalt petrogenesis. Journal Of Geophysıcal Research, 102(B1), 853-874.
• Le Maitre, R.W. 1976. The chemical variability of some common igneous rocks. Journal of Petrology, 17, 589-637.
• Macdonalt, G.A., Katsura, T., 1964. Chemical composition of Hawaiian Lavas. Journal of Petrology, 5(1), 82-133
• McDonough, W.F., 1990. Constraints on the composition of the continental lithospheric mantle, Earth Planet. Sci. Lett. 101, 1-18.
• McKenzıe,D., Bıckle, M.J.,1988. The Volume and Composition of Melt Generated by Extension of the Lithosphere. Journal of Petrology, 29(3), 625–679.
• Meschede, M., 1986. A method of discriminating between different types of mid-ocean ridge basalts and continental tholeiites with the Nb-Zr-Y diagram. Chemical Geology, 56, 207-218.
• Miyashiro, A., 1973. The Troodos complex was probably formed in island arc. Earth and Planet Sci. Lett., 19, 218-224.
• Okay, A.I., Tüysüz, O., 1999. Tethyan Sutures of northern Turkey. In The Mediterranean Basins: Tertiary Extension within the Alpine Orogen (eds B.Durand, L. Jolivet, F.Hovarth and M. Seranne), Geological Society of London, Special Publication,156, 475-515.
• Parlak, O., Rızaoğlu, T., Bağcı, U., Karaoğlan, F., Höck, V., 2009. Tectonic significance he geochemistry and petrology of ophiolites in southeast Anatolia, Turkey. Tectonophysics, 473, 173-187.
• Pearce, J.A., 1983. Role of sub-continental lithosphere in magma genesisi at active margins, in Hawkesworth, C.J., and Norry, M.J., eds., Continental basalts and mantle xenoliths. Nantwich, UK, Shiva Publishers, 230-249.
• Pearce, J.A., 2008. Geochemical fingerprinting of oceanic basalts with applications to ophiolite classification and the search for Archean oceanic crust. Lithos 100, 14-48.
• Pearce, J.A., Cann, J.R., 1973. Tectonic setting of basic volcanic rocks determined using trace element analysis. Earth and Planetary Science Letters, 19, 290-300.
• Perinçek, D., 1979. The geology of Hazro-Korudağ-Çüngüş-Maden-Ergani-Hazar-Elazığ- Malatya Area. The Geological Society of Turkey, 34.
• Perinçek, D., 1980. Bitlis metamorfitlerinde volkanitli Triyas. Türkiye Jeoloji Kurultayı Bülteni, 23, 201-211.
• Perinçek D. Özkaya, 1981. Arabistan Levhası kuzey Kenarı tektonik evrimi. H.U. Yerbilimleri, 8, 91-102.
• Rigo De Righi, M., Cortesini, A., 1964. Gravity tectonics foot hills structure belt of Southeast Turkey. Amer. Assoc. Pet. Geol. Bull., 48 (12),1915-1937.
• Robertson, A.H.F., 1998. Mesozoic-Tertiary Tectonic Evolution Of The Easternmost Mediterranean Area; Integration Of Marine And Land Evidence. Proc Ocean Drill Prog Sci Res., 160, 723-782.
• Robertson, A.H.F., 2002. Overview of the genesis and emplacement of Mesozoic ophiolites in the Eastern Mediterranean Tethyan region. Lithos, 65, 1–67.
• Robertson, A. H. F., 2000. Mesozoic–Cenozoic tectonic-sedimentary evolution of a south Tethyan oceanic basin and its margins in southern Turkey, in Tectonics and Magmatism in Turkey and the Surrounding Area. In: Bozkurt, E., Winchester, J.A. ve Piper, J.D.A., (eds.) Geological Society, Special Publications, 173, 97–138.
• Robertson, A.H.F., Ustaömer, T., Pickett, E.A., Collins, A.S., Andrew, T., Dixon, J.E., 2004. Testing models of Late Palaeozoic Early Mesozoic orogeny in Western Turkey: support for an evolving open-Tethys model. Journal of the Geological Society, 161, 501–511.
• Robinson, J.A.C., Wood, B.J., 1998. The depth of thespinel to garnet transition at the peridotite solidus.Earth. Planet. Sci. Lett., 164(1-2), 277-284
• Saccani, E., 2015. A new method of discriminating different types of post-Archean ophiolitic basalts and their tectonic significance using Th–Nb and Ce–Dy–Yb systematics. Geoscience Frontiers, 6, 481–501.
• Saccani, E., Allahyari, K., Beccaluva, L., Bianchini, G., 2013a. Geochemistry and petrology of the Kermanshah ophiolite (Iran): implication for the interaction between passive rifting, oceanic accretion, and OIB-type components in the Southern Neo-Tethys Ocean. Gondwana Research, 24, 392–411.
• Saccani, E., Azimzadeh, Z., Dilek, Y., Jahangiri, A., 2013b. Geochronology and petrology of the early carboniferous Misho Mafic Complex (NW Iran), and implications for the melt evolution of Paleo-Tethyan rifting in Western Cimmeria. Lithos, 162–163, 264–278.
• Saccani, E., Photıades, A., Padoa, E., 2003. Geochemistry, petrogenesis and tectono-magmatic significance of volcanic and subvolcanic rocks from the Koziakas Mélange (Western Thessaly, Greece). Ofioliti, 28 (1), 43-57
• Schilling, J.G., Zajac, M., Evans, R., Johnston, T., White, W., Devine, J.D., Kingsley, R.,1983. Petrologic and geochemical variations along the Mid-Atlantic Ridge. Am. J. Sci. 283, 510–586.
• Shaw, D.M., 1970.Trace element fractionation during anatexis. Geochimica et Cosmochimica Acta, 34, 237-243.
• Stern, C.R., Kilian, R., Olker, B., Hauri, E.H., Kurtis Kyser,T., 1999. Evidence from mantle xenoliths for relatively thin (<100 km) continental lithosphere below the Phanerozoic crust of southernmost South America. Developments in Geotectonics, 24, 217–235.
• Sun, S.S., McDonough, W. F., 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes, in Magmatism in the Ocean Basins. In: Saunders, A. D. ve Norry, M.J., (eds.) Geological Society of London, Special Publications, 42, 313-347.
• Swanson, S.E., Schiffman, P., 1979. Textural evolution and metamorphism of pillow basalts from the Franciscan Complex, western Marin County, California. Contributions to Mineralogy and Petrology, 69(3), 291–299.
• Şengör, C., Yılmaz, Y., 1981. Türkiye’de Tetis’in evrimi: Levha tektoniği açısından bir yaklaşım. Yerbilimleri Dergisi, 1, 3-75.
• Ustaömer, T., Robertson, A.H.F., 1997. Tectonic-Sedimentary Evolution of the North Tethyan Margin in the Central Pontides of Northern Turkey. In: Robinson, A.G. (Ed.), Regional and Petroleum Geology of the Black Sea and Surrounding Region. Memoir-American Association of Petroleum Geologists, 68, 255–290.
• Walker, G.P.L., 1992. Morphometric study of pillow-size spectrum among pillow lavas: Bulletin of Volcanology, 54, 459-474.
• Wilson, M., 1989. Igneous Petrogenesis: London, Unwin-Hyman, 465p.
• Winchester, J., Floyd, P.A., 1977. Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chemical Geology, 20, 325-43.
• Yazgan, E., 1984. Geodynamic evolution of the Eastern Taurus region. In The International Symposium on Geology of the Taurus Belt; Tekeli, O., Göncüoglu, M.C., Eds., MTA, Ankara, Turkey, 199–208.
• Yazgan, E., Chessex, R., 1991. Geology and tectonic evolution of the Southeastern Taurides in the region of Malatya. Turkiye Petrol Jeologları Deneği Bülteni, 3, 11-42.
• Yılmaz, Y., 1989. Comparison of young volcanic associations of Western and Eastern Anatolia formed under a compreosionl regime: A review. Journal of Volcanology and geotermal Research, 44, 69-87.
• Yılmaz, Y., 1993. New evidence and model evolution of the southeast anatolian orogen. Geological Society of America Bulletin, 105, 251-271.
• Yılmaz, Y., Yıldırım, M., 1996. Güneydoğu Anadolu Orojenik Kuşağında Nap Alanının (Metamorfik Masiflerin) Jeolojisi ve Evrimi, Turkish Journal of Earth Sciences, 5, 21-38.
• Yılmaz, Y., Yigitbaş, E., Genç, S.C., 1993. Ophiolitic and metamorphic assemblages of southeast Anatolia and their significance in the geological evolution of the orogenic belt. Tectonics, 12, 1280-1297.
• Yiğitbaş, E., Yılmaz, Y., 1996. New evidence and solution to the Maden complex controversy of the southeast Anatolian orogenic belt (Turkey), Geologische Rundschau, 85, 250-263.
• Zindler, A., Hart, S., 1986. Chemical Geodynamics. Annual Review of Earth and Planetary Sciences, 14, 493–571.