Advertisement

C2/c pyroxene phenocrysts from three potassic series in the Neogene alkaline volcanics, NE Turkey: their crystal chemistry with petrogenetic significance as an indicator of PT conditions

  • Faruk Aydin
  • Richard M. Thompson
  • Orhan Karsli
  • Hinako Uchida
  • Jason B. Burt
  • Robert T. Downs
Original Paper

Abstract

Chemical and structural data are reported for C2/c pyroxene phenocrysts collected from three potassic series (Group A: basanite-tephrite, Group B: tephrite-phonolitic tephrite, Group C: alkaline basalt-trachybasalt) of the Neogene alkaline volcanics (NAVs) in northeastern Turkey, in order to investigate the evolution of the magmatic plumbing system and the location of magma chamber(s) with crystallization conditions. The rock series hosting the clinopyroxene phenocrysts show generally porphyritic texture and have a variable phenocryst-rich nature (20–58%), with phenocryst assemblages characterized by cpx ± ol ± plag ± foid ± amp ± bio. The clinopyroxene phenocrysts can be chemically classified as Ti- and Fe3+-rich Al-diopsides for Groups A and B (AB-cpxs) and Ti- and Fe3+-poor Al-diopsides for Group C (C-cpxs). They have poorly variable composition, clustering in the diopside field. Structurally, the diopside groups have nearly similar a (ranging from 9.73 to 9.75 Å), V cell (437.2–440.9 Å3), and 〈beta〉 angle values (106.01°–106.23°), but some differences in polyhedral parameters and geometries of the AB-cpxs and C-cpxs have been observed. For example, the AB-cpxs are characterized by larger c (5.27–5.30 vs. 5.25–5.28 Å), V T (2.27–2.30 vs. 2.23–2.28 Å3), and V M2 (25.53–25.72 vs. 25.41–25.59 Å3) values and smaller b (8.87–8.88 vs. 8.88–8.91 Å) and V M1 (11.49–11.63 vs. 11.64–11.83 Å3) values with respect to the C-cpxs. In addition, the AB-cpxs show higher values of V M2/V M1 (2.20–2.23) due to large V M2 and small V M1 compared to the V M2/V M1 ratios of the C-cpxs (<2.19). Such differences in the crystal structure of the AB-cpxs and C-cpxs from the NAVs are partly related to different crystallization pressures, but mostly related to variation in melt composition and, possibly, the influence of other crystallizing mineral phases. In particular, R(M2-O1) and R(M1-O2) (i.e. bond lengths) differences in the clinopyroxenes of different groups support the presence of evolved host rocks with different alkaline character (i.e. silica-undersaturated Groups A–B and silica-saturated Group C). Based on the cpx-geothermobarometry, the crystallization pressures for the C-cpxs are lower than 4.5 kbars, but the AB-cpxs have relatively high-pressure values (5.6–10.6 kbars), suggesting that the AB-cpxs crystallized in higher pressure environments. The relatively higher crystallization temperatures of the AB-cpxs also indicate higher cooling rates. The PT estimates suggest that the source regions of the clinopyroxene phenocrysts from the NAVs were crustal magma chambers in a closed plumbing system at a moderate- to low-pressure regime.

Keywords

Clinopyroxene Crystal-chemistry Low pressure Alkaline Volcanics NE Turkey 

Notes

Acknowledgments

The authors are glad to thank the DAAD for the partial financial support. Many thanks are given to M. Burhan Sadiklar (Karadeniz Teknik University, Trabzon, Turkey) for logistic support. Moreover, they would like to give special thanks to Rainer Altherr and Hans-Peter Meyer (Mineralogisches Institut, Universität Heidelberg, Germany) for the electron microprobe analyses of some clinopyroxene phenocrysts. Thoughtful reviews made by Keith Putirka and anonymous peer-reviewers greatly improved the original manuscript. Editorial managing by Gordon Moore is really appreciated. We would like to thank the National Science Foundation for funding RMT, HU, and JAB through grants No. EAR-0622371 and No. EAR-0609906.

References

  1. Avanzinelli R, Bindi L, Menchetti S, Conticelli S (2004) Crystallisation and genesis of peralkaline magmas from Pantelleria Volcano, Italy: an integrated petrological and crystal-chemical study. Lithos 73:41–69. doi: 10.1016/j.lithos.2003.10.007 CrossRefGoogle Scholar
  2. Aydin F (2003) Mineral chemistry, petrology and petrogenesis of the Degirmendere Valley volcanics (Trabzon–Esiroglu, NE-Turkey). PhD thesis. Karadeniz Technical University, Trabzon, Turkey (in Turkish with English abstract, unpublished)Google Scholar
  3. Aydin F, Karsli O, Sadiklar MB (2003) Mineralogy and chemistry of biotites from eastern Pontide granitoid roks, NE Turkey: some petrological implications for granitoid magmas. Chem Erde-Geochem 63:163–182. doi: 10.1078/0009-2819-00027 CrossRefGoogle Scholar
  4. Aydin F, Karsli O, Chen B (2008a) Petrogenesis of the Neogene alkaline volcanics with implications for post-collisional lithospheric thinning of the Eastern Pontides, NE Turkey. Lithos 104:249–266. doi: 10.1016/j.lithos.2007.12.010 CrossRefGoogle Scholar
  5. Aydin F, Karsli O, Sadiklar MB (2008b) Compositional variations and zoning types of low-pressure clinopyroxenes in the Neogene alkaline volcanic rocks with petrogenetic implications, northeastern Turkey. Turk J Earth Sci (in press)Google Scholar
  6. Barbieri M, Conforto L, Garbarino C, Masi U, Nicoletti M, Akinci Ö (2000) Geo-chemistry of hydrothermally-altered volcanic rocks of the upper volcanic cycle from the Eastern Pontides (Northeastern Turkey). Chem Erde-Geochem 60:81–95Google Scholar
  7. Bindi L, Cellai D, Melluso L, Conticelli S, Morra V, Menchetti S (1999) Crystal chemistry of clinopyroxene from alkaline undersaturated rocks of the Monte Vulture Volcano, Italy. Lithos 46:259–274. doi: 10.1016/S0024-4937(98)00069-3 CrossRefGoogle Scholar
  8. Bindi L, Taselli F, Olmi F, Peccerillo A, Menchetti S (2002) Crystal chemistry of clinopyroxenes from Linosa Volcano, Sicily Channel, Italy: implications for modelling the magmatic plumbing system. Mineral Mag 66:953–968. doi: 10.1180/0026461026660070 CrossRefGoogle Scholar
  9. Bozkurt E (2001) Neotectonics of Turkey—a synthesis. Geodin Acta 14:3–30. doi: 10.1016/S0985-3111(01)01066-X CrossRefGoogle Scholar
  10. Bozkurt E, Mittwede SK (2001) Introduction to the geology of Turkey—a synthesis. Int Geol Rev 43:578–594CrossRefGoogle Scholar
  11. Boztug D, Jonckheere R, Wagner GA, Yegengil Z (2004) Slow Senonian and fast Palaeocene-Early Eocene uplift of the granitoids in the Central Eastern Pontides, Turkey: apatite fission-track results. Tectonophysics 382:213–228. doi: 10.1016/j.tecto.2004.01.001 CrossRefGoogle Scholar
  12. Boztug D, Ercin AI, Kurucelik MK, Göc D, Kömür I, Iskenderoglu A (2006) Main geochemical characteristics of the composite Kaçkar batholith derived from the subduction through collision to extentional stages of Neo-Tethyan convergence system in the Eastern Pontides, Turkey. J Asian Earth Sci 27:286–302. doi: 10.1016/j.jseaes.2005.03.008 CrossRefGoogle Scholar
  13. Boztug D, Jonckheere R, Wagner GA, Ercin AI, Yegingil Z (2007) Titanite and zircon fission-track dating resolves successive igneous episodes in the formation of the composite Kaçkar batholith in the Turkish eastern Pontides. Int J Earth Sci 96:875–886. doi: 10.1007/s00531-006-0140-4 CrossRefGoogle Scholar
  14. Bruker (2005) SAINT, Version 6.0. Bruker AXS Inc., MadisonGoogle Scholar
  15. Cakir Ö, Erduran M (2004) Constraining crustal and uppermost mantle structure beneath station TBZ (Trabzon, Turkey) by receiver function and dispersion analyses. Geophys J Int 158:955–971. doi: 10.1111/j.1365-246X.2004.02345.x CrossRefGoogle Scholar
  16. Cakir Ö, Erduran M, Cinar H, Yilmaztürk A (2000) Forward modelling receiver functions for crustal structure beneath station TBZ (Trabzon, Turkey). Geophys J Int 140:341–356. doi: 10.1046/j.1365-246x.2000.00023.x CrossRefGoogle Scholar
  17. Cellai D, Conticelli S, Menchetti S (1994) Crystal-chemistry of clinopyroxene from potassic and ultrapotassic rocks in central Italy: implications on their genesis. Contrib Mineral Petrol 116:301–315. doi: 10.1007/BF00306499 CrossRefGoogle Scholar
  18. Cundari A, Salviulo G (1987) Clinopyroxenes from Somma-Vesuvius: implications of crystal chemistry and site configuration parameters for studying magma genesis. J Petrol 28:727–736Google Scholar
  19. Dal Negro A, Carbonin S, Molin GM, Cundari A, Piccirillo EM (1982) Intracrystalline cation distribution in natural clinopyroxenes of tholeiitic, transitional, alkaline basaltic rocks. In: Saxena SK (ed) Advances in physical geochemistry. Springer, New York, pp 117–150Google Scholar
  20. Dal Negro A, Carbonin S, Domeneghetti C, Molin GM, Cundari A, Piccirillo EM (1984) Crystal chemistry and evolution of the clinopyroxene in a suite of high pressure ultramafic nodules from the Newer Volcanics of Victoria, Australia. Contrib Mineral Petrol 86:221–229. doi: 10.1007/BF00373667 CrossRefGoogle Scholar
  21. Dal Negro A, Manoli S, Secco L, Piccirillo EM (1989) Megacrystic clinopyroxenes from Victoria (Australia): crystal chemical comparisons of pyroxenes from high and low pressure regimes. Eur J Mineral 1:105–121Google Scholar
  22. Dinter DA (1998) Late Cenozoic extension of the Alpine collisional Orogen, northeastern Greece: origin of the north Aegean basin. Geol Soc Am Bull 110:1208–1230CrossRefGoogle Scholar
  23. Droop GTR (1987) A general equation for estimating Fe3+ concentrations in ferromagnesian silicates and oxides from microprobe analyses, using stoichiometric criteria. Mineral Mag 51:431–435. doi: 10.1180/minmag.1987.051.361.10 CrossRefGoogle Scholar
  24. Faraone D, Molin GM, Zanazzi PF (1988) Clinopyroxenes from Vulcano (Aeolian Islands, Italy): crystal chemistry and cooling history. Lithos 22:13–126. doi: 10.1016/0024-4937(88)90020-5 CrossRefGoogle Scholar
  25. Griffin WL, Carswell DA, Nixon PH (1979) Lower crustal granulites and eclogites from Lesotho southern Africa. In: Boyd FR, Meyer HOA (eds) The mantle sample: inclusions in Kimberlites and other Volcanics. Am Geophys Union Washington, pp 59–86Google Scholar
  26. Güven IH (1993) 1/250.000 scaled geological and metallogenical map of the Eastern Black Sea Region. MTA, Trabzon (unpublished)Google Scholar
  27. Hoskin PWO, Wysoczanski RJ (1998) Insitu accurate and precise lead ısotopic analysis of ultra-small analyte volumes (10–16 m3) of solid ınorganic samples by high mass resolution secondary ıon mass spectrometry. J Anal At Spectrom 13:597–601. doi: 10.1039/a801286e CrossRefGoogle Scholar
  28. Jones AP, Smith JV, Dawson B, Hansen EC (1983) Metamorphism, partial melting, and K-metasomatism of garnet-scapolite-kyanite granulite xenoliths from Lashaine, Tanzania. J Geol 91:143–165CrossRefGoogle Scholar
  29. Karsli O, Aydin F, Sadiklar MB (2002) Geothermobarometric investigation of the Zigana Granitoid, eastern Pontides, Turkey. Int Geol Rev 44:277–286. doi: 10.2747/0020-6814.44.3.277 CrossRefGoogle Scholar
  30. Karsli O, Aydin F, Sadiklar MB (2004a) Magma interaction recorded in plagioclase zoning in granitoid systems, Zigana Granitoid, Eastern Pontides, Turkey. Turk J Earth Sci 13:287–305Google Scholar
  31. Karsli O, Aydin F, Sadiklar MB (2004b) The morphology and chemistry of K-feldspar megacrysts from İkizdere Pluton: evidence for acid and basic magma interactions in granitoid rocks, NE Turkey. Chem Erde-Geochem 64:155–170. doi: 10.1016/j.chemer.2003.02.001 CrossRefGoogle Scholar
  32. Karsli O, Chen B, Aydin F, Sen C (2007) Geochemical and Sr–Nd–Pb isotopic compositions of the Eocene Dölek and Sariçiçek Plutons, Eastern Turkey: implications for magma interaction in the genesis of high-K calc-alkaline granitoids in a post-collision extensional setting. Lithos 98:67–96. doi: 10.1016/j.lithos.2007.03.005 CrossRefGoogle Scholar
  33. Keskin M (2003) Magma generation by slab steepening and breakoff beneath a subduction-accretion complex: An alternative model for collision-related volcanism in Eastern Anatolia, Turkey. Geophys Res Lett 30(24):8046. doi: 10.1029/2003GL018019 CrossRefGoogle Scholar
  34. Keskin M, Genc SC, Tuysuz O (2008) Petrology and geochemistry of post-collisional Middle Eocene volcanic units in North-Central Turkey: evidence for magma generation by slab breakoff following the closure of the Northern Neotethys Ocean. Lithos 104:267–305. doi: 10.1016/j.lithos.2007.12.011 CrossRefGoogle Scholar
  35. Malgarotto C, Molin G, Zanazzi F (1993) Crystal chemistry of clinopyroxenes from Filicudi and Salina (Aeolian Islands, Italy). Geothermometry and barometry. Eur J Mineral 5:915–923Google Scholar
  36. Molin G, Zanazzi PF (1991) Intracrystalline Fe2+–Mg ordering in augite: experimental study and geothermometric application. Eur J Mineral 3:863–875Google Scholar
  37. Morimoto N (1989) Nomenclature of pyroxenes. Can Mineral 27:143–156Google Scholar
  38. Nazzareni S, Molin G, Peccerillo A, Zanazzi PF (1998) Structural and chemical variations in clinopyroxenes from the island of Alicudi (Aeolian Arc) and their implications for the conditions of crystallization. Eur J Mineral 10:291–300Google Scholar
  39. Nazzareni S, Molin G, Peccerillo A, Zanazzi PF (2001) Volcanological implications of crystal-chemical variations in clinopyroxenes from the Aeolian Arc, Southern Tyrrhenian Sea (Italy). Bull Volcanol 63:73–82. doi: 10.1007/s004450100125 CrossRefGoogle Scholar
  40. Nimis P (1995) A clinopyroxene geobarometer for basaltic systems based on crystal structure modeling. Contrib Mineral Petrol 121:115–125. doi: 10.1007/s004100050093 CrossRefGoogle Scholar
  41. Nimis P (1998) Clinopyroxene geobarometry of pyroxenitic xenoliths from Hyblean Plateau (SE Sicily, Italy). Eur J Mineral 10:521–533Google Scholar
  42. Nimis P (1999) Clinopyroxene geobarometry of magmatic rocks. Part 2. Structural geobarometers for basic to acid, tholeiitic and midly alkaline magmatic systems. Contrib Mineral Petrol 135:62–74. doi: 10.1007/s004100050498 CrossRefGoogle Scholar
  43. Nimis P (2000) CpxBar-Excel version program. http://dmp.unipd.it/Nimis/researche.html
  44. Nimis P, Ulmer P (1998) Clinopyroxene geobarometer of magmatic rocks. Part 1: An expanded structural geobarometer for anhydrous and hydrous, basic and ultrabasic systems. Contrib Mineral Petrol 133:122–135. doi: 10.1007/s004100050442 CrossRefGoogle Scholar
  45. Nimis P, Bertolo S, Dal Negro A, Mellini M (1996) Crystal chemistry and geobarometry of clinopyroxenes in ancient and historical basic volcanic rocks Mt. Etna (Sicily, Italy). Acta Vulcanol 8:63–71Google Scholar
  46. Okay AI (1989) Tectonic units and sutures in the Pontides, Northern Turkey. In: Sengör AMC (ed) Tectonic evolution of the Tethyan region. NATO ASI Ser C 259:109–116Google Scholar
  47. Okay AI, Sahintürk Ö (1997) Geology of the Eastern Pontides. In: Robinson AG (ed) Regional and Petroleum Geology of the Black Sea and Surrounding Region. AAPG Memoir 68:291–311Google Scholar
  48. Pasqual D, Molin GM, Zanazzi PF (1995) Crystal chemistry of Stromboli clinopyroxene: a comparison with analogues from other Aeolian Islands (Italy). Eur J Mineral 7:369–378Google Scholar
  49. Princivalle F, Tirone M, Comin-Chiaramonti P (2000) Clinopyroxenes from spinel-peridotite mantle xenoliths from Nemby (Paraguay): crystal chemistry and petrological implications. Mineral Petrol 70:25–35. doi: 10.1007/s007100070011 CrossRefGoogle Scholar
  50. Putirka K, Johnson M, Kinzler R, Longhi J, Walker D (1996) Thermobarometry of mafic igneous rocks based on clinopyroxene-liquid equilibria, 0–30 kbar. Contrib Mineral Petrol 123:92–108. doi: 10.1007/s004100050145 CrossRefGoogle Scholar
  51. Putirka KD, Mikaelian H, Ryerson F, Shaw H (2003) New clinopyroxene-liquid thermobarometers for mafic, evolved, and volatile-bearing lava compositions, with applications to lavas from Tibet and the Snake River Plain, Idaho. Am Mineral 88:1542–1554Google Scholar
  52. Robertson AHF (2000) Mesozoic-Tertiary tectonic-sedimentary evolution of a south Tethyan oceanic basin and its margin in southern Turkey. In: Bozkurt E, Winchester JA, Piper JDA (eds) Tectonics and magmatism in Turkey and surrounding areas. J Geol Soc Lond, Spec Publ 173:97–136Google Scholar
  53. Robinson AG, Banks CJ, Rutherford MM, Hirst JPP (1995) Stratigraphic and structural development of the Eastern Pontides, Turkey. J Geol Soc Lond 152:861–872. doi: 10.1144/gsjgs.152.5.0861 CrossRefGoogle Scholar
  54. Sen C, Arslan M, Van A (1998) Geochemical and petrological characteristics of the Eastern Pontide Eocene (?) alkaline volcanic province, NE Turkey. Turk J Earth Sci 7:231–239Google Scholar
  55. Sengör AMC, Kidd WSF (1979) Post-collisional tectonics of the Turkish-Iranian plateau and a comparison with Tibet. Tectonophysics 55:361–376CrossRefGoogle Scholar
  56. Sengör AMC, Yilmaz Y (1981) Tethyan evolution of Turkey: a plate tectonic approach. Tectonophysics 75:181–241. doi: 10.1016/0040-1951(81)90275-4 CrossRefGoogle Scholar
  57. Sengör AMC, Görür N, Saroglu F (1985) Strike slip faulting and related basin formation in zones of tectonic escape: Turkey as a case study. In: Biddle TR, Christie-Blick N (eds) Strike-slip deformation, basin formation and sedimentation. Int J Soc Econ Paleontol Mineral, Special Publuciation 37:227–264Google Scholar
  58. Sengör AMC, Özeren S, Genc T, Zor E (2003) East Anatolian high plateau as a mantle-supported, North-south shortened domal structure. Geophys Res Lett 30(24):8045. doi: 10.1029/2003GL017858 Google Scholar
  59. Sheldrick GM (1997) SHELXL-97, a program for crystal structure refinement. University of Göttingen, GermanyGoogle Scholar
  60. Takahashi E, Kushiro I (1983) Melting of a dry peridotite at high pressures and basalt magma genesis. Am Mineral 68:859–879Google Scholar
  61. Thompson RM, Downs RT (2008) The crystal structure of diopside to 10 GPa. Am Mineral 93:177–186. doi: 10.2138/am.2008.2684 CrossRefGoogle Scholar
  62. Topuz G, Altherr R, Schwarz WH, Siebel W, Satir M, Dokuz A (2005) Post-collisional plutonism with adakite-like signatures: the Eocene Saraycik granodiorite (Eastern Pontides, Turkey). Contrib Mineral Petrol 150:441–455. doi: 10.1007/s00410-005-0022-y CrossRefGoogle Scholar
  63. Yegingil Z, Boztug D, Er M, Oddone M, Bigazzi G (2002) Timing of neotectonic fracturing by fission-track dating of obsidian in-filling faults in the Ikizdere-Rize area, NE Black Sea region, Turkey. Terra Nova 14:169–174. doi: 10.1046/j.1365-3121.2002.00407.x CrossRefGoogle Scholar
  64. Yilmaz Y, Tüysüz O, Yigitbas E, Genc SC, Sengör AMC (1997) Geology and tectonic evolution of the Pontides. In: Robinson AG (ed) Regional and Petroleum Geology of the Black Sea and Surrounding Region. AAPG Memoir 68:183–226Google Scholar
  65. Yilmaz A, Adamia S, Chabukiani A, Chkhotua T, Erdogan K, Tuzcu S, Karabiyikoglu M (2000) Structural correlation of the southern Transcaucasus (Georgia)-eastern Pontides (Turkey). In: Bozkurt E, Winchester JA, Piper JDA (eds) Tectonics and magmatism in Turkey and surrounding area. Geol Soc Lond Spec Pub 173:171–182Google Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Faruk Aydin
    • 1
  • Richard M. Thompson
    • 2
  • Orhan Karsli
    • 3
  • Hinako Uchida
    • 2
  • Jason B. Burt
    • 2
  • Robert T. Downs
    • 2
  1. 1.Department of Geological EngineeringNigde UniversityNigdeTurkey
  2. 2.Department of GeosciencesUniversity of ArizonaTucsonUSA
  3. 3.Department of Geological EngineeringGumushane UniversityGumushaneTurkey

Personalised recommendations