1 1726-3689 Iranian Socity of Crystallography and Mineralogy 841 Special Quantitative X-ray methods of amorphous content and crystallinity determination of Si02 in Quartz and Opal mixture 1 10 2001 9 2 79 92 04 07 2017 04 07 2017 X-ray diffraction (XRD) technique is commonly used for qualilative ana lysis of minerals, and has also been successfully used for quantitative measurements. In this research, the matrix fl ushing 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 detemline the quanti tative analysis of these two minerals.
842 Special Mineralogical and geochemical characteristics and genesis of Bolboluvieh bauxite deposit, KernHln. 1 10 2001 9 2 93 104 04 07 2017 04 07 2017 Boboluyieh bauxi te-laterite deposit of south-cast Kemlan 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 dcposit has a reserve of 15 mill ion lonnes. Diaspore, boehmite, chlorite, hematite, goethite, kaolinite, anatase and rutile arc the major minerals in this deposit. The common texture of tbis unit is oolitic to pisolitic. The presence of some volcanic rock fragments with pi lotaxitic texture as well as bipyramid pseudol11orphic shape of olivine and clinopy roxene gra ins reveal thai the protolith of bauxites was probably a volvan;c rock of basaltic type. Geochemical studies indicate that Bolboluy ieh bauxite is composed of40.37% AI20 3, 24.64% Fe20) and 13.92% Si02• Based on the geochemical characteristics, Bolboluyieh bauxi te is formed under condition of high silica leaching and concomitant enrichment of aluminium and iron which corrcsponds with pH between 4 to 8.5 and Eh of +0.4 to + I. 843 Special The mechanism of the formation of disequilibrium textures in the Deh-Sard lava nows, south of Baft 1 10 2001 9 2 105 116 04 07 2017 04 07 2017 The Deh-Sard area IS located about 90 km south of 8aft in the Kerman province, situated in southern part of Sanandaj-Sirjan zone. It consists of interm ittent lava flows (basalt, basaltic andes ite and trachyandesite), pyroclastic rocks (various types of tu ffs 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 fill ing minerals. The main textures of the Java 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 zon ing. These are associated with, mineral grindings and formation of Fe-Ti oxides In the cleavage planes of the clinopyroxenes. All of these evidences confirm the formation of disequilibrium conditions as a result of decompression, caused b~ fast magma uprising toward the earth surface. In the evolution of these crystals, minor processes such as rapid ske letal growth as a result of quench crystall ization, effects of PHZO and magma mixing are also played ao important rule. 844 Special Mineralogy of brucite bearing marbles, eastern margin of Shirkuh batholith (west of Vazd province) 1 10 2001 9 2 117 125 04 07 2017 04 07 2017 Igneous bodies in Manshad-Taft fau lt zone arc intruded into Shirkuh granitic batllolilic basement. They also cause different skam-marble mineralization in dolomitized limestones which are covered granitic basement. Skarns are composed of variety of minerals. Marbles consist of variolls minera ls such as brucite, forste rite, diopsid, pcriclase,taJc, calcite, dolomite, and hydromagnesite. Petrographic and geochemical data have revealed tbat there is several stages duri ng the formation of marble minerals. At the first stage, anhydrous minera ls fonned, then fo llowed byhydrous assemblage. Generation of brucite occurs at the second stage and is due to latc hydrothermal system withlow XCOl and high nuids. Hydromagnesite deposition is occurcd by oxidation of bruc ite. 845 Special Synthcsis and study of some physicochcmical properties of a new double layered hydroxide sorben! 1 10 2001 9 2 127 142 04 07 2017 04 07 2017 Double Layered lIydroxides (DUll) or anionic clays have been extensively used in various fie lds as heterogeneous catalysts, sorbcnts, anionic exchangers and so on, In this research Double Layered Hydroxides pillared with carbonate and p-toluensulfonate anions were generated by coprccipitation of concentrated aqueous solutions of AI(NO)J' 91-120 and Mg(NO,),.6H20 respectively with concentrated basic solUlions of sodium carbonate and p-toluensulfonic acid at room temperature, DLl I-oxides (DLO) of each compound was prepared with a special thermal programming, In .mother part of this research. thermal interaction was used to prepare the pi liared DLHand OLO with p-toluensulfonic acid, Comparison of the size of interlayer intcrvals of DLH and pillared DLI-I (or OLO) shows that both coprccipilation and thermal methods were successful in interca lating of p-tolucnsul fon incacid.