Iranian Socity of Crystallography and Mineralogy
Iranian Journal of Crystallography and Mineralogy
1726-3689
10
1
2002
4
1
Application of geochemical data in recognizing origin of
Soltanieh dolomite and determining temperature of dolomite
formation, in North of Semnan
3
16
FA
Shahmirzad village is located on the
southern parts of the Eastern Alborz Mountain
Ranges. One of the sedimentary rock units that crops
out in this area is Soltanieh Formation (Upper
Precambrian Lower Cambrian). Thin section and
oxygen isotope studies have been used in order to
determine the petrological characteristics and the
temperature of Soltanieh dolomites formation
environment. Examination of the petrographic
properties of the dolomite samples, along with
geochemical data reveals that all of the dolomite
samples are diagenetic (secondary) and were formed
under reducing conditions in shallow to deep phreatic
environment. The heaviest and lightest IRO values
illustrate that temperature of early to late diagenetic
dolomites range from 72 t to 113.5 t respectively.
Iranian Socity of Crystallography and Mineralogy
Iranian Journal of Crystallography and Mineralogy
1726-3689
10
1
2002
4
1
Mineralo - Geochemical investigation on Kohe-zar Gold
mineralization area, Torbate-Heydarie
17
32
FA
Gold - Polymetal mineralization of Kohe-zar area is
located alout 35 kilometers southwest of Torbat - Heydarieh
in Khorasan province. Mineralization was oeeured in quartz -
speeularite ± pyrite ± chacopyrite veins and vein lets. The main
ore minerals are specularite, chalcopyrite, pyrite, avinite (Bi -
bearing tetraedrite), acanthite, native bismuth (occurred
intergrowth with barite), native gold, electrum, coveline -
digenite and weathered minerals such as geothite,
hydrogeothite, eu-fe oxides, malachite. Ore minetalization of
Kohe - zar is related to low - sulfide, quartz - hematite type of
hydrothemal ore deposists.
On the basis of therrnobarogeochemical investigation on
quartz, medium temperature fluid with low potential
mineralization is responsible for mineralization in this area.
Iranian Socity of Crystallography and Mineralogy
Iranian Journal of Crystallography and Mineralogy
1726-3689
10
1
2002
4
1
Mineralogical and Geochemical Evaluation of Clay Minerals
of Zonuz Mine, in Marand According to REE & SEM
Studies in Comparison with Esteghlal Mine, in Abadeh
33
50
FA
The Zonuz irregular lens shaped kaolin deposit located
in Marand, Azarbaygan, is exploited as an openpit. Andesite,
Trachyandesite and dacite igneous rocks are located in south, west
and east parts of the deposit, respectively. The Ore was analysed
by XRD, SEM and NAA. Assemblage of major minerals including
Quartz, Kaolinite, Illite and Calcite, and minor minerals of
Dolomite, Montmorillonite and Limonite are detected.
Geochemical analysis show that La, Ce, Nd are present in minor
amounts, and the high ratio of LREEIHREE indicates the
enrichment of LREE which is probably the result of surface
tension ofthese elements on clay particles.
Geological and Geochemical evidence indicate that hydrothermal
fluids played a major role in the formation of the Ore body,
particulary along fault zones.
A comparison is also made between autogentic Zonuz deposit with
allogentic Esteghlal deposit.
Iranian Socity of Crystallography and Mineralogy
Iranian Journal of Crystallography and Mineralogy
1726-3689
10
1
2002
4
1
Textures and REE geochemistry in Gian copper occurrence
51
65
FA
The Upper Devonian - Lower Carboniferous Sourian
complex, is composed of clastic - carbonates, volcanic, metamorphic
rocks and quartz lenses hosts copper mineralization in Gian area of
Fars province.
This complex is metamorphosed to green schist facies. This
metamorphism resulted In massIve to disseminated sulfide
mineralization in the direction of schistosity and within quartz lenses.
Low-grade green schist facies metamorphism is recognized with
cataclastic flow and fracturing of pyrite crystals, infilling of fractures
of pyrite with chalcopyrite, pressure shadow of chalcopyrite around
pyrite, recrystalization and presence of triple junctions in pyrite.
Distribution pattern of REE in schists of Gian copper shows a
decreasing trend from La to Lu. The ratio of 2:LREE/LHREE is more
than one and the ratio of LaN I YbN is less than 15. This indicates that
schists are formed by the metamorphism of shales and the ratio of
(LalLu),,> 1 indicates that the transfer of REE has been affected by
surface adsorption. It may be concluded that this copper occurrence is
the result of ore-bearing shale metamorphism.
Iranian Socity of Crystallography and Mineralogy
Iranian Journal of Crystallography and Mineralogy
1726-3689
10
1
2002
4
1
CLASSIFICATION OF AMPHIBOLES
FROM IRON ORE DEPOSITES, SANGAN AREA, KHAF
67
80
FA
oeeuring in the Sangan arca was
fonned within two different rock groups· graitoids and
skarns. Based on the new amphibole classification and
nomenclature, the general fonnula of amphibols IS
(AB2C,T,O"OH),. Amphibole of granitoids is a
ferroedenite in which Si = 6.87 - 7.75, CaR> 1.5,
(Na+K)A > 0.5 and Ti < 0.5. Skarn amphiboles are
mostly developed within amphibole skarns and
gamet-pyroxene skarns during retrograde stage of
skarn evolution. High-temperature amphiboles are
rich in Al while low-temperature amphiboles are poor
in AI. Skarn amphiboles are classified in two groups:
(a) hastingsite in which Si = 5.99 - 6.08, CaB> 1.5,
(Na+K)A > 0.5, Ca < 0.5 and Al < Fe+] (b)
ferroactinolite in which Si = 7.61 - 7.90, CaB>1.5,
(Na+K)A < 0.5 and CaA < 0.5. Amphibole in (a) is
AI-rich while amphibole in (b) is AI-poor.
Iranian Socity of Crystallography and Mineralogy
Iranian Journal of Crystallography and Mineralogy
1726-3689
10
1
2002
4
1
Growth of MnCI2.4H20 crystals and measurement the exact
percent of cobalt impurities in the crystal, using radioactive
isotopes of 54Mn, 60Co, 57CO and NMRON technique
81
86
FA
In this paper, MnCl,.4H,O crystals with monoclinic
structure, for the study of magnetic hyperfine field in magnetic
crystal at low temperature, have been grown. To study the effect
of impurities on T, (spin-lattice relaxation time), crystals with
different percent of "Co impurities, from saturated mixed
solution of MnCl,.4H,O and CoCl,.6H,O at temperature of
30Q'K, have been grown. The percent of cobalt impurities in the
solution and crystal was determined by using the radioactive
isotopes of "Mn, 6OCO and "Co as probes. The result indicated
that the ratio of "Co/"Mn was about 6.2% which has a good
correspondence with the results of the NMRON spectrum of
54Mn in low temperatures (T<lOOmK).
Iranian Socity of Crystallography and Mineralogy
Iranian Journal of Crystallography and Mineralogy
1726-3689
10
1
2002
4
1
Study of Transformation of Clay Minerals in the Interaction
Process with Additives by uS,e of Scanning Electron
Microscope and XRD and its Relation to Mechanical
Behaviour of Soil
87
97
FA
The use of lime as additive to soil is a very
common technique in engineering projects. The purposes of
this proceses are the increase in strength and a decrease in
plasticity behaviour of the soil. The results of this research
indicate that in the chemical interaction process of soil
minerals with lime, a part of minerals, specifically clay
minerals, transform to other minerals. In fact, this
transformation is the base for the different mechanical
response of soil. In the present study, attention is made to the
tri-calcium-silica-hydrate (CSH), tetra-calcium-alumnahydrate
(CAH), and ettringite, as the three major minerals
formed in this process. This transformation is monitored by
use of scanning electron microscope and x-ray diffraction
testing.