مجله بلور شناسی و کانی شناسی ایران
سال پنجم شماره 2 (پیاپی 11، پاییز 1376)

The north - cast Arsanjan ophiolite complex is part of the Neyriz ophiolite complex located 24 km north - east of Arsanjan in the south - eastern part of the Zagros range . In I :250,000 geologic map of Shiraz, this complex has been conside red as an ultramalic t:umplcx, however, it is principally represented by serpentinized harzburgite and dunile, basalt, metadolerite, spilite, limestone, radiolarian chert, dolos tone, sedimentary breccia, and listvenites which arc reported fo r the first time from the outer Zagros ophiolite belt in this article. Economic mineral indications In this region can be divided into two groups : 1) primary magmatic deposits which include chromite and platinum group elements, and 2) secondary depo.c;its which are produced due to alteration, and include listvenites and talc

In this work the effect of nonmagnetic oxide additives on microstructure and magnetic propperties or barium ferrite is studied. Two groups of samples were prepared, one with limonite and the other with hematite, both huving similar barium carbonate. The conventional wet ceramic tcdlnitjuc was used for the preparalion of the samples and the percentage o f different impurities in the raw materils was determined by XRF and atomic absorption Ler..:hniques. The magnetic results ob tained for the first group arc suppcrior und their grian sizes arc smaller us compared to the second group. By adjusting only two or the additives (Al z0 3 and Si0 2) in the second group the magnetic parameters were improved and the grain sizes were reduced. The inhibiting effect of Si02 on grain growth mcr..:hanism during sintering is also discussed.

Anjirch Pb-Zn deposits are located 55 km wesl of Esrahan. These deposits belong 10 a part of a large sedimenta ry basin containing lead ttnd zinc metal epieiences, in Sanand aj - Si rjan zone. This basin contains Lower CretO:tceous (Albian - Abtian) sedimentary sequences. The Anjireh deposits are typical of Mississippi-valley type stratttbound lead-zinc deposits. The principal metal minerals in these deposits are Cd-rich sphalerite and Ag-poor galena. These ores arc rich in Cd, Hg and poor in Au and Ag.

Geochemical variations of the Pro terozoic dolomite samples close to the ore deposits in the Renison mine area, Tasmania, Austra lia. arc the result of alteration. The oxygen tsotope va lues of the most altered dolomites surrounding the orc deposit indicates that these arc affected oy hot (up to abou t 350°C) hydro thermal nuids. There is a trend of decreasing lighter oxygen and carbon isotope values LOwards the are deposit. Carbon isotope val ucs in dolomites are significantly lighter than those least· altered dolomites away from mineralised area, due to alteration ranging from 47 to 95% . Oxygen isotope values arc also significantly li ghter close 10 the a re deposil, than less allered sa mples away from mineral ised area. Alteration in oxygen rang ing from 20 10 97% . Geochemical analys is also indicates th aI Fe a nd Mn are very high but Ca, Mg, Sr and Na arc very low in dolomile sa mples close 10 Ihe ore deposils. Thus, the result of thi s study shows Ih at the gradual decreases in oxygen and carbon isotope values, which corresponds to the increasing a lt e ralion perce nt , lowards Ihe o rebody, a long with e lemenlal composi tio ns, are us eful for recognition of ore deposiLs.

Formation o f any kinll:-; ur crys ta l defects is followed hy creatIOn of mechanil.:ul s t resscs wi thim the t:ry:-;tal strut:tun.!. which in turn l.:chr('39')IUses l<.lllicc paramc ters to change. these changes resu lt a rclevant disp lacement of the X-ray dilfractogram pcaks. In this wo rk r e la tive tli :-;piaccmcllt ur it certa in peak ( III) of de fect ed and annealed :-;amp!c:.:s of AI and Cu [hive bCl:n studied u:-; ing an X-f<.ly diffrat:Lomctl:r, co ntro lled and assis ted by a high t:apahle computer progr<.lm. These fac ilit ies p rovide a high rc:-;olution for determinatio n o f peakchr('39')s positio n on the dirrral.:logram so that the relative displacement of a certain pcak, relevanlto the defected and an nealed samples was obtained with precision better than -{).Ol A. This study shows the reliability of our XRD high resol ution method for va ri o us <.I pp li Cl.ll io ns in the material resea rch fi e ld s. As an example of its appl it:at ions, using the resu lts o f t his wo rk, thl,; amount of residual stresses in these samples have been ue tcrmiocd.