Mineralogy and geochemistry of the hydrate sulfate minerals in relation to the black shales, Qroqchy, Mymeh, Isfahan

Abstract

Qroqchy area is located northwest of Isfahan, in the central Iranian structural zone. The Nayband black shale is a significant geological unit which is widespread occurrences in the study are. Weathering process lead to black sale alteration and formation of acidic pool. The pool is located on the black shale basement. Around of the pool sulfate minerals occur with various colors. The aim of the research is identify rare sulfate minerals around acidic pool and investigation of formation mechanism of these minerals. On the base of XRD results, the most important minerals are :(ferricopiapite (hydrous iron sulfate,) tamarugite (hydrous sodium sulfate, (kieserite (hydrated magnesium sulfate, ) blodite (sodium, magnesium hydrous sulphate, and gypsum. Weathering process and decomposition of black shale minerals lead to release sulfate mineral components. Presence of pyrite in black shale is an effective factor increasing weathering and resulting acidic conditions. Acid drainage leads to decomposition of black shale and released cations of crystalline framework. Deposition of secondary minerals resulted acidic equilibrium. Geochemically, the Qoroqchi black shale characterized by LREE enrichment
(ΣLREE = 140/463) and HREE depletion (ΣHREE = 5/037ppm), in comparison NASC has similar pattern.

Keywords


[1] Chou, I-Ming, Robert R. Seal, and Alian Wang. "The stability of sulfate and hydrated sulfate minerals near ambient conditions and their significance in environmental and planetary sciences." Journal of Asian Earth Sciences 62 (2013): 734-758.

[2] Hammarstrom, J. M., et al. "Secondary sulfate minerals associated with acid drainage in the eastern US: recycling of metals and acidity in surficial environments." Chemical Geology 215.1 (2005): 407-431.

[3] Jambor, J. L., Nordstrom, D. K., and Alpers, C. N. "Metal-sulfate salts from sulfide mineral oxidation".Reviews in Mineralogy and Geochemistry, 40(1) (2000).: 303-350.

[4] Majzlan, Juraj, et al. "Thermodynamic properties and crystal structure refinement of ferricopiapite, coquimbite, rhomboclase, and Fe2 (SO4) 3 (H2O) 5." European Journal of Mineralogy 18.2 (2006): 175-186.

[5] Joeckel, Robert Matthew, et al. "Sulfate mineral paragenesis in Pennsylvanian rocks and the occurrence of slavikite in Nebraska." (2007).

[6] Burton, Edward D., et al. "Reductive transformation of iron and sulfur in schwertmannite-rich accumulations associated with acidified coastal lowlands." Geochimica et Cosmochimica Acta 71.18 (2007): 4456-4473.

[7] Joeckel, R. M., BJ Ang Clement, and LR VanFleet Bates. "Sulfate-mineral crusts from pyrite weathering and acid rock drainage in the Dakota Formation and Graneros Shale, Jefferson County, Nebraska." Chemical Geology 215.1 (2005): 433-452.

[8] Ptacek, Carol, and David Blowes. "Predicting sulfate-mineral solubility in concentrated waters." Reviews in Mineralogy and Geochemistry 40.1 (2000): 513-540.

[9] King, R. J. "Tamarugite on the Isle of Wight, UK." Mineralogical Magazine 62.3 (1998): 371-372.

[10] Bobocioiu, Ema, and Caracas R. "What Lurks in the Martian Rocks and Soil? Investigations of Sulfates, Phosphates, and Perchlorates." American Mineralogist 99.7 (2014): 1216-1220.

[11] Keller, W. D "The occurrence of Mendozite and Tamarugite in Missoury". Journal mineralogical society of America, (1934): 537-539.

[12] Fang, J. H., and P. D. Robinson. "Crystal-structures and mineral chemisrry of double-salt hydrates. 2. crystal-structure of mendozite, naal (SO4) 2.11 H2O." American mieralogist 57.7-8 (1972): 1081.

[13] Mees, Florias, et al. "Bloedite sedimentation in a seasonally dry saline lake (Salada Mediana, Spain)." Sedimentary Geology 238.1 (2011): 106-115.

[14] Peterson, R.C., Nelson, W., Madu, B., and Shurvell, H.F. Meridianiite: a new mineral species observed on Earth and predicted to exist on Mars. American Mineralogist, 92 (2007) , 1756–1759.

[15] McAdam, Amy C., et al. "Sulfur- bearing phases detected by evolved gas analysis of the Rocknest aeolian deposit, Gale Crater, Mars." Journal of Geophysical Research: Planets 119.2 (2014): 373-393.

[16] Bobocioiu, Ema, and Razvan Caracas. "Stability and spectroscopy of Mg sulfate minerals: Role of hydration on sulfur isotope partitioning." American Mineralogist 99.7 (2014): 1216-1220.

[17] Xu, Wenqian. Evolution of Ferric Sulfates with Relative Humidity and Temperature and Their Potential Usage as Environmental Indicators in Martian Research. diss. State university of new York at stony brook, (2011).

[18] Joeckel, R. M., et al. "Secondary minerals from extrapedogenic per latus acidic weathering environments at geomorphic edges, Eastern Nebraska, USA." Catena 85.3 (2011): 253-266.