Interpretation of the Magma Chamber Processes with the help of Textural Stratigraphy of the Plagioclases (Konya-Central Anatolia)

Year 2021, Issue: 25, 222 - 237, 31.08.2021

Gülin Gençoğlu Korkmaz , Huseyin Kurt

https://doi.org/10.31590/ejosat.898587

Cited By: 1

Abstract

The variations in the chemical composition and micro-texture of a mineral from the core to the rim allow the sequencing of the formation of the magma chamber processes and the interpretation of which texture might have been formed by which process. In this study, the textural and chemical zoning of the plagioclases, which are a significant recorder of magma chamber processes, from some enclave-containing andesite (calc-alkaline) and basalts (calc-alkaline) from the Karapınar Karacadağ Volcanic Complex, were examined and their textural stratigraphies were created to enlight the magma chamber processes. Plagioclases in enclave bearing andesites and their enclaves have the same composition and are andesine-bitovnite (An34-An75) in composition. It is noteworthy that the plagioclases in the host-rock are mostly rounded, and reverse and oscillatory zoned with Fe, Mg, An, Sr, and Ba. However in the enclaves they display generally fine sieve texture and dusty sieve texture. Plagioclase micro-phenocrysts in calc-alkaline basalts are andesine-labrador (An32-An66) in composition from core-to-rim, suggesting that they may be xenocrysts rather than phenocrysts. Remarkably, plagioclases in basalts show reverse and oscillatory zoning with Fe, Mg, An, Sr, and Ba, and as well as exhibit coarse-grained sieve texture with glass and microlithic inclusions, and spongy cellular textures. Considering the textural and chemical properties of the plagioclases, in the formation of reverse and oscillatory zoning in the basaltic rocks, the decompression processes in addition to the magma mixing processes (magma mixing/self-mixing) also affect the genesis of the basalts. However, in the formation of andesitic rocks, the magma replenishment processes have a key role rather than decompression or temperature-pressure change.

Keywords

decompression, magma mixing, oscillatory zoning, plagioclase, sieve texture

Supporting Institution

Selçuk Üniversitesi ÖYP Koordinatörlüğü

Project Number

2016-ÖYP-041

Thanks

This study is part of the Ph.D. thesis of the first author and funded by Selçuk University ÖYP project number 2016-ÖYP-041. We thank Prof. Dr. Yusuf Kağan Kadığlu and Associate Professor Kıymet Deniz for realizing the EPMA analyses.

Plajiyoklazların Dokusal Stratigrafisi ile Magma Odası Süreçlerinin Yorumlanması (Konya-Orta Anadolu)

Abstract

Çekirdekten kenara bir mineralin kimyasal bileşimindeki ve mikro dokusundaki varyasyonlar, magma odası süreçlerinin oluşumunun sıralanmasına ve hangi dokunun hangi süreçle oluşmuş olabileceğinin yorumlanmasına olanak tanır. Bu çalışmada, Karapınar Karacadağ Volkanik Kompleksi'nden bazı anklav içeren andezit (kalk-alkalen) ve bazaltlardan (kalk-alkalen) alınan, magma odası süreçlerinin önemli bir kaydedicisi olan plajiyoklazların dokusal ve kimyasal zonlanması incelenmiştir ve dokusal stratigrafileri magma odası süreçlerini aydınlatmak için oluşturulmuştur. Anklav içeren andezitler ve bunların anklavları içindeki plajiyoklazlar aynı bileşime sahiptirler ve bileşimleri andezin-bitovnit (An34-An75)tir. Ana kayadaki plajiyoklazların çoğunlukla yuvarlaklaşmış ve Fe, Mg, An, Sr ve Ba ile ters ve salınımlı zonlu olması dikkat çekicidir. Ancak anklavlarda yer alan plajiyoklazlar genellikle ince elek dokusu ve kirli yüzeyli elek dokusu sergilerler. Kalk-alkalen bazaltlardaki plajiyoklaz mikro-fenokristalleri, çekirdekten kenara bileşimde andezin-labrador (An32-An66) olup, bu durum onların fenokristallerden ziyade ksenokristal olabileceklerini düşündürmektedir. Dikkat çekici bir şekilde, bazaltlardaki plajiyoklazlar, Fe, Mg, An, Sr ve Ba ile ters ve salınımlı zonlanma gösterirler ve ayrıca cam ve mikrolitik kapanımlarla iri taneli elek dokusu ve süngerimsi hücresel dokular sergilerler. Plajiyoklazların dokusal ve kimyasal özellikleri göz önüne alındığında, bazaltik kayaçlarda ters ve salınımlı zonlanma oluşumunda, magma karışımı işlemlerinin (magma karışımı/kendi kendine karışma) yanı sıra dekompresyon süreçleri de bazaltların oluşumunu etkilemektedir. Bununla birlikte, andezitik kayaçların oluşumunda, magmanın yeniden beslenmesi süreçleri, dekompresyon veya sıcaklık-basınç değişiminden ziyade anahtar bir role sahiptir.

Keywords

dekompresyon, plajiyoklaz, elek dokusu, magma karışmı, salınımlı zonlanma

Project Number

2016-ÖYP-041

References

• Brophy, J., Dorais, M., Donnelly-Nolan, J., & Singer, B. (1996). Plagioclase zonation styles in hornblende gabbro inclusions from Little Glass Mountain, Medicine Lake Volcano, California: Implications for fractionation mechanisms and the formation of composition gaps. Contributions to Mineralogy and Petrology, 126, 121-136. doi:10.1007/s004100050239
• Castro, A. (2001). Plagioclase morphologies in assimilation experiments. Implications for disequilibrium melting in the generation of granodiorite rocks. Mineralogy and Petrology, 71(1-2), 31-49.
• Couch, S., Sparks, R., & Carroll, M. (2001). Mineral disequilibrium in lavas explained by convective self-mixing in open magma chambers. Nature, 411(6841), 1037.
• Deer, W. A., Howie, R. A., & Zussman, J. (1963). Rock-forming Minerals: Vol. 4: Framework Silicates: Longman.
• Deniz, K., & Kadıoğlu, Y. K. (2019). Investigation of feldspar raw material potential of alkali feldspar granites and alkali feldspar syenites within Central Anatolia. Maden Tetkik Ve Arama Dergisi, 158(158), 265-289.
• Duda, A., & Schmincke, H.-U. (1985). Polybaric differentiation of alkali basaltic magmas: evidence from green-core clinopyroxenes (Eifel, FRG). Contributions to Mineralogy and Petrology, 91(4), 340-353.
• Gill, J. B. (1981). Orogenic Andesites and Plate Tectonics (Vol. 16). Berlin, Heidelberg, New York: Springer-Verlag.
• Ginibre, C., Kronz, A., & Wörner, G. (2007). Crystal Zoning as an Archive for Magma Evolution. Elements, 3(4), 261-266. doi:10.2113/gselements.3.4.261
• Ginibre, C., & Wörner, G. (2007). Variable parent magmas and recharge regimes of the Parinacota magma system (N. Chile) revealed by Fe, Mg and Sr zoning in plagioclase. Lithos, 98(1), 118-140. doi:https://doi.org/10.1016/j.lithos.2007.03.004
• Ginibre, C., Wörner, G., & Kronz, A. (2002). Minor- and trace-element zoning in plagioclase: implications for magma chamber processes at Parinacota volcano, northern Chile. Contributions to Mineralogy and Petrology, 143(3), 300-315. doi:10.1007/s00410-002-0351-z
• Humphreys, M. C. S., Blundy, J. D., & Sparks, R. S. J. (2006). Magma Evolution and Open-System Processes at Shiveluch Volcano: Insights from Phenocryst Zoning. Journal of Petrology, 47(12), 2303-2334. doi:10.1093/petrology/egl045
• Huppert, H. E., Sparks, R. S. J., Whitehead, J. A., & Hallworth, M. A. (1986). Replenishment of magma chambers by light inputs. Journal of Geophysical Research: Solid Earth, 91(B6), 6113-6122.
• Logfren, G. (1974). An experimental study of plagioclase crystal morphology: isothermal crystallization (Vol. 274).
• Lunney, M. (2002). Andesıte magma evolutıon based on textural and composıtıonal analysıs of plagıoclase phenocrysts of arenal volcano, Costa Rıca. (Master). Portland State University,
• Nakamura, M., & Shimakita, S. (1998). Dissolution origin and syn-entrapment compositional change of melt inclusion in plagioclase. Earth and Planetary Science Letters, 161, 119-133. doi:10.1016/S0012-821X(98)00144-7
• Nelson, T. S., & Montana, A. (1992). Sieve-textured plagioclase in volcanic rocks produced by rapid decompression. American Mineralogist, 77.
• Nixon, G. T., & Pearce, T. (1987). Laser-interferometry study of oscillatory zoning in plagioclase; the record of magma mixing and phenocryst recycling in calc-alkaline magma chambers, Iztaccihuatl Volcano, Mexico. American Mineralogist, 72(11-12), 1144-1162.
• Okay, A. I., & Tüysüz, O. (1999). Tethyan sutures of northern Turkey. Geological Society, London, Special Publications, 156(1), 475-515.
• Pearce, T. H. (1994). Recent Work on Oscillatory Zoning in Plagioclase. In I. Parsons (Ed.), Feldspars and their Reactions (pp. 313-349). Dordrecht: Springer Netherlands.
• Perugini, D., Ventura, G., Petrelli, M., & Poli, G. (2004). Kinematic significance of morphological structures generated by mixing of magmas: a case study from Salina Island (southern Italy). Earth and Planetary Science Letters, 222(3), 1051-1066. doi:https://doi.org/10.1016/j.epsl.2004.03.038
• Renjith, M. L. (2014). Micro-textures in plagioclase from 1994–1995 eruption, Barren Island Volcano: Evidence of dynamic magma plumbing system in the Andaman subduction zone. Geoscience Frontiers, 5(1), 113-126. doi:https://doi.org/10.1016/j.gsf.2013.03.006
• Singer, B., Dungan, M., & Layne, G. (1995). Textures and Sr, Ba, Mg, Fe, K, and Ti compositional profiles in volcanic plagioclase: clues to the dynamics of calc-alkaline magma chambers. American Mineralogist, 80, 776-798. doi:10.2138/am-1995-7-815
• Stewart, L. M., & Pearce, H. T. (2004). Sieve-textured plagioclase in dacitic magma: Interference imaging results. American Mineralogist, 89, 348-351. doi:10.2138/am-2004-2-313
• Streck, M. J. (2008). Mineral Textures and Zoning as Evidence for Open System Processes. Reviews in Mineralogy and Geochemistry, 69(1), 595-622. doi:10.2138/rmg.2008.69.15
• Streck, M. J., Broderick, C. A., Thronber, C. R., Clynne, M. A., & Pallister, J. S. (2008). Plagioclase populations and zoning in dacite of the 2004-2005 Mount St. Helens eruption: constraints for magma origin and dynamics: Chapter 34 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006 (1750-34). Retrieved from Reston, VA: http://pubs.er.usgs.gov/publication/pp175034
• Streck, M. J., Leeman, W. P., & Chesley, J. T. (2007). High-magnesian andesite from Mount Shasta: A product of magma mixing and contamination, not a primitive melt: comment and reply: reply. Geology, 35(1), e150-e150. doi:10.1130/g24356y.1
• Tomiya, A., & Takahashi, E. (2005). Evolution of the Magma Chamber beneath Usu Volcano since 1663: a Natural Laboratory for Observing Changing Phenocryst Compositions and Textures. Journal of Petrology, 33.
• Tsuchiyama, A. (1985). Dissolution kinetics of plagioclase in the melt of the system diopside-albite-anorthite, and origin of dusty plagioclase in andesites. Contributions to Mineralogy and Petrology, 89(1), 1-16. doi:10.1007/bf01177585
• Vance, A. J. (1965). Zoning in Igneous Plagioclase: Patchy Zoning (Vol. 73): Journal of Geology.
• Vance, J. A. (1969). On synneusis. Contributions to Mineralogy and Petrology, 24(1), 7-29. doi:10.1007/bf00398750