Iranian Journal of Crystallography and Mineralogy
Year:2002 | Volume:9 | Issue:2|Papers Count:5

X-ray diffraction (XRD) technique is commonly used for qualitative analysis of minerals, and has also been successfully used for quantitative measurements. In this research, the matrix flushing and a new X-ray diffraction method have been used for the determination of crystallinity and amorphous content of Opal and Quartz mixture. The PCAPD is used to determine the quantitative analysis of these two minerals.

Bolboluyieh bauxite-laterite deposit of south-east Kerman is presented at the base of the Naiband Formation (upper Triassic) and was directly formed on a Karstic surface of dolomitic parts of the Shotori Formation. This deposit has a reserve of 15 million tonnes. Diaspore, boehmite, chlorite, hematite, goethite, kaolinite, anatase and rutile are the major minerals in this deposit. The common texture of this unit is oolitic to pisolitic. The presence of some volcanic rock fragments with pilotaxitic texture as well as bipyramid pseudomorphic shape of olivine and clinopyroxene grains reveal that the protolith of bauxites was probably a volvanic rock of basaltic type.Geochemical studies indicate that Bolboluyieh bauxite is composed of 40.37% Al2O3, 24.64% Fe2O3 and 13.92% SiO2. Based on the geochemical characteristics, Bolboluyieh bauxite is formed under condition of high silica leaching and concomitant enrichment of aluminium and iron which corresponds with pH between 4 to 8.5 and Eh of +0.4 to + 1.

The Deh-Sard area is located about 90 km south of Baft in the Kerman province, situated in southern part of Sanandaj-Sirjan zone. It consists of intermittent lava flows (basalt, basaltic andesite and trachyandesite), pyroclastic rocks (various types of tuffs and paloebereccias) and sedimentary rocks (lime stones and shales) of Jurassic age. The Deh-Sard lava flows are essentially composed of plagioclase (both as phenocryst and microlite), clinopyroxene (diopside-augite) and accessory minerals (opaque and apatite). Secondary minerals such as quartz, chlorite and calcite occur both as a materix and as a pore filling minerals. The main textures of the lava flows are microlitic porphyritic, intergranular and intersertal. The plagioclase crystals have disequilibrium characteristics such as sieve texture, resorption phenomena, reaction with magma, corrosion and oscillatory zoning. These are associated with, mineral grindings and formation of Fe-Ti oxides in the cleavage planes of the clinopyroxenes. All of these evidences confim the formation of disequilibrium conditions as a result of decompression, caused by fast magma uprising toward the earth surface. In the evolution of these crystals, minor processes such as rapid skeletal growth as a result of quench crystallization, effects of PH20 and magma mixing are also played an important rule.

Igneous bodies in Manshad-Taft fault zone are intruded into Shirkuh granitic batholitic basement. They also cause different skarn-marble mineralization in dolomitized limestones which are covered granitic basement. Skarns are composed of variety of minerals. Marbles consist of various minerals such as brucite, forsterite, diopsid, periclase, talc, calcite, dolomite, and hydromagnesite. Petrographic and geochemical data have revealed that there is several stages during the formation of marble minerals. At the first stage, anhydrous minerals formed, then followed byhydrous assemblage. Generation of brucite occurs at the second stage and is due to late hydrothermal system withlow XCO2 and high XH2O fluids. Hydromagnesite deposition is occured by oxidation of brucite.

Double Layered Hydroxides (DLHs) or anionic clays have been extensively used in various fields as heterogeneous catalysts, sorbents, anionic exchangers and so on. In this research Double Layered Hydroxides pillared with carbonate and p-toluensulfonate anions were generated by coprecipitation of concentrated aqueous solutions of Al(NO3)3. 9H2O and Mg(NO3)2.6H2O respectively with concentrated basic solutions of sodium carbonate and p-toluensulfonic acid at room temperature. DLH-oxides (DLO) of each compound was prepared with a special thermal programming. In another part of this research, thermal interaction was used to prepare the pillared DLH and DLO with p-toluensulfonic acid. Comparison of the size of interlayer intervals of DLH and pillared DLH (or DLO) shows that both coprecipitation and thermal methods were successful in intercalating of p-toluensulfonincacid.