Evaluating micas in petrologic and metallogenic aspect: Part II—Applications using the computer program Mica+

Yavuz, Fuat

doi:10.1016/s0098-3004(03)00143-2

Cited by 33 publications

(14 citation statements)

References 37 publications

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“…Pyrox (Yavuz 2001), Newamphcal (Yavuz 1999), and WinAmphcal (Yavuz 2007) programs are used for pyroxene and amphibole calculation, classification (Leake et al 2004), and Al-in hornblende thermobarometry estimation. Recalculation of micas, mole fractions, stoichiometric ferric iron estimates, fluorine and chlorine intercept values, biotite geothermometer, and fugacity ratios were carried out using the Bioterm and Mica + programs (Yavuz and Öztaş 1997;Yavuz 2003aYavuz , 2003b.…”

Section: Analytical Techniquesmentioning

confidence: 99%

“…Representative microprobe analyses of mica from different domes and their calculated chemical formulae by Mica+ software (Yavuz 2003a(Yavuz , 2003b) based on 22 cation charges are given in Table 5. According to the revision of the IMA mica classification scheme (Rieder et al 1998), all the micas are trioctahedral true micas with a total of octahedrally coordinated M cations between 2.90 and 2.99 apfu.…”

Section: Biotite Chemistrymentioning

confidence: 99%

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Mineral chemistry of Plio-Quaternary subvolcanic rocks, southwest Yazd Province, Iran

Sherafat

Yavuz

Noorbehesht

et al. 2011

International Geology Review

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The NW-SE-trendingLate Cretaceous-Cenozoic Urumieh-Dokhtar Magmatic Arc (UDMA) in southwest Iran hosts numerous Plio-Quaternary subvolcanic porphyritic andesitic to rhyodacitic domes intruded into a variety of rock sequences. Bulk-rock geochemical data show that the calc-alkaline dacitic to rhyodacitic subvolcanic rocks share compositional affinities with high-silica adakites, including high ratios of Na 2 O/K 2 O >1, Sr/Y (most >70), and La/Yb (>35), high Al 2 O 3 (>15 wt.%), low Yb (<1.8 ppm) and Y (<18 ppm) contents, no significant Eu anomalies, and flat to gently upwardsloping chondrite-normalized heavy rare-earth element (HREE) patterns. All analysed rocks are characterized by enrichment in large-ion lithophile elements (LILEs) and depletion in high field strength elements (HFSEs). They also display typical features of subduction-related calc-alkaline magmas. In chondrite-normalized rare-earth element patterns, the light rare-earth elements (LREEs) are enriched ((La/Sm) N = 3.49-7.89) in comparison to those of the HREE ((Gd/Yb) N = 1.52-2.38). Except for the G-Aliabad Dome, plagioclase crystals in the Shamsabad, Ostaj, Abdollah, and Bouragh Domes are mostly oligoclase to andesine (An 19-49 ). Amphibole and biotite are abundant ferromagnesian minerals in the subvolcanic rocks. Calcic amphiboles are dominantly magnesiohornblende, magnesiohastingsite, and tschermakite with Mg/(Mg + Fe tot ) ratios ranging from 0.58 to 0.78. In all the studied domes, amphiboles are typically ferric iron-rich, but that those the Shamsabad Dome have the highest Fe 3+ /(Fe 3+ + Fe 2+ ) ratios, between 0.69 and 0.98. Amphiboles from the Ostaj and Shamsabad Domes are relatively rich in F (0.39-1.01 wt.%) in comparison to the other studied domes. This phase commonly shows pargasitic and hastingsitic substitutions with a combination of tschermakitic and edenitic types.Temperature-corrected Al-in-hornblende data show that amphibole phenocrysts from the Ostaj, Abdollah, and G-Aliabad Domes crystallized at pressures ranging from 2.14 to 3.42 kbar, 3.49 to 3.96 kbar, and 2.02 to 3.47 kbar, respectively. Temperatures of crystallization calculated with the amphibole-plagioclase thermometer for the Ostaj, Abdollah, and G-Aliabad subvolcanic domes range from 735 • C to 826 • C (mean = 786 ± 29), 778 • C to 808 • C (mean = 791 ± 13), and 866 • C to 908 • C (mean = 885 ± 12), respectively. In the annite-siderophyllite-phlogopite-eastonite quadrilateral, biotite from the G-Aliabad, Bouragh, and Ostaj Domes are characterized by relatively low total Al contents with variable Fe tot /(Fe tot + Mg) values from 0.26 to 0.43. All biotite analyses define a nearly straight line in the X Mg versus Fe tot plot, with r = -0.96 correlation coefficient. In comparison to other domes, the F content of biotite from the G-Aliabad Dome shows high concentrations in the range of 1.80-2.57 wt.% (mean = 2.20). Inferred pre-eruptive conditions based on the calcic amphibole thermobarometric calculations for the Shamsabad, Abdollah, and Ostaj Domes show that the calc-alk...

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Section: Analytical Techniquesmentioning

confidence: 99%

Section: Biotite Chemistrymentioning

confidence: 99%

Mineral chemistry of Plio-Quaternary subvolcanic rocks, southwest Yazd Province, Iran

Sherafat

Yavuz

Noorbehesht

et al. 2011

International Geology Review

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“…[41][42][43] Although the halogen fugacity and intercept values of the Lar biotites fall into the field of the Sarcheshmeh porphyry copper deposit, the IV (Cl) of later tends to be more Cl-rich than the Larsample [ Figure 8]. Moreover, the Sarcheshmeh porphyry copper deposit was formed by the hydrothermal activity related to a sub-volcanic Miocene granodioritic stock, which introduces the Eocene andesitic volcanic and granitoids sequence; [44] however, the Lar Cu-Mo prospect is related to the shoshonitic intrusions that intruded to the volcanic rocks of the Oligocene LIC.…”

Section: Resultsmentioning

confidence: 99%

Untitled

Moradi¹

2017

IJGP

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Background and Objective: The Lar Cu-Mo prospect is located in Sistan suture zone, southeast of Iran. In this study, the chemical composition of biotite is determined using electron probe micro-analyzer in shoshonitic igneous rocks. Shoshonitic rocks are syenitic to monzonitic in composition that can be divided into the granular and porphyroid groups. Methods: Studying biotites generally occurs as primary and secondary types. The primary biotites are large poikilitic phenocrysts associated with Fe-Ti oxides, giving the rocks a spotted texture. In addition, secondary biotites show varying size, color, and shape. All of the Lar analyzed biotites are Mg-and Ti-rich and F-and Cl-poor. Analyses of the Lar biotites suggested that crystallization took place at an average temperature of 731°C and 640°C for primary and secondary samples, respectively. Results: Estimation of the oxygen fugacity, based on chemical composition and Fe3+ content of biotite, shows that the oxygen fugacity was limited in fayalitemagnetite quartz to middle of HM buffers in quality and was about 10 −12 to 10 −14 bar in quantity for primary and secondary type, respectively. Halogen fugacity ratios in biotite show that the Lar porphyroid rocks (ore-bearing) are affected mainly by meteoric water than granular type (barren). Calculated halogen fugacity values for biotite in the Lar Cu-Mo prospect are consistent with many other porphyry copper-forming systems. Conclusion: The Lar Cu-Mo prospect was formed by the hydrothermal activity related to the syenitic to monzonitic porphyroid igneous rocks with shoshonitic nature which introduces the Lar igneous complex volcanic sequence. The hydrothermal alterations are limited and occurred as silicic, potassic, phyllic, propylitic, and argillic. Hypogene sulfide minerals mainly occur as disseminated and sulfidic and silicic veins and veinlets consisting of chalcopyrite, bornite, molybdenite, and minor pyrite. Biotite as main ferromagnesian mineral of host rocks occurs as primary in less altered rocks and secondary in the alteration areas.

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“…The reported operating conditions were 15 kV of accelerating voltage with a beam current of 15 nA. Biotite chemical compositions obtained by EPMA (Table 2) were processed using the MICA+ program of Yavuz (2003) which provides standard classification and discrimination plots and calculates temperature, fugacities of oxygen and halogen species using existing formulations.…”

Section: Methodsmentioning

confidence: 99%

Reconstructing physico-chemical parameters of hydrothermal mineralization of copper at the Malanjkhand deposit, India, from mineral chemistry of biotite, chlorite and epidote

et al. 2008

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Mineral chemistry of biotite, chlorite and epidote associated with the granitoid ore body of the Malanjkhand coppermolybdenum deposit have been studied to constrain temperature, oxidation and sulfidation states as well as fugacity ratios of HF, HCl and H 2 O of the hydrothermal mineralizing fluid. Calculated mineralizing temperatures from biotite, chlorite and epidote are mutually consistent and agree well with earlier estimates derived from fluid inclusion studies. Major element chemistry of biotite indicates low oxidation state (FMQ-NNO) and re-equilibrated nature (~300°C). However, exchange of Cl-F-OH between biotite and the fluid continued to lower temperatures. Subtle differences between the Malanjkhand deposit and known porphyry copper deposits have been evidenced by the fugacity ratios of halogens and water. Chlorite registers equilibrium with fluid down to 200°C and, together with biotite composition, indicates that copper was transported as chloride complex in the fluid. Sulfide deposition occurred during a prompt rise in fugacity of H 2 S at 300°C, possibly resulting from a coupled oxidation of Fe 2+ and reduction of SO 4 2-. Interaction of ore fluid with epidote in the wall-rock favored the deposition of chalcopyrite, enhanced the Ca 2+ activity in the fluid and inhibited a fall in pH and a subsequent acid alteration of K-feldspar in the wall-rock. These physicochemical characteristics of the mineralized fluid suggest that the Malanjkhand deposit represents an ancient granitoid-associated geothermal system rather than a classic porphyry copper ore deposit.

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Evaluating micas in petrologic and metallogenic aspect: Part II—Applications using the computer program Mica+

Cited by 33 publications

References 37 publications

Mineral chemistry of Plio-Quaternary subvolcanic rocks, southwest Yazd Province, Iran

Mineral chemistry of Plio-Quaternary subvolcanic rocks, southwest Yazd Province, Iran

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Reconstructing physico-chemical parameters of hydrothermal mineralization of copper at the Malanjkhand deposit, India, from mineral chemistry of biotite, chlorite and epidote

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