دانلود ترجمه مقاله ویژگیهای ژئوشیمیایی و معدنشناسی Fe-Ni
ترجمه در قالب فایل Word و قابل ویرایش میباشد
سال انتشار:2000
تعداد صفحه ترجمه:15
تعداد صفحه فایل انگلیسی:18
موضوع انگلیسی :Geochemical and mineralogical characteristics of Fe–Ni- and
bauxitic-laterite deposits of Greece
موضوع فارسی:دانلود ترجمه مقاله ویژگیهای ژئوشیمیایی و معدنشناسی Fe-Ni
چکیده انگلیسی:Contiguous vertical sample profiles from Ni-laterite deposits with in situ features Kastoria, Profitis Ilias, and Tsouka.
and allochthonous Ni- and bauxitic-laterite deposits in contact with basement limestone Nissi. and bauxitic-laterites lying
on peridotite Parhari. were analyzed for major, trace including Th and U., rare earth and platinum-group elements REE
and PGE, respectively.. In addition, minerals with emphasis to chromite grains found as residual components in these
laterites, inherited from the ophiolitic parent rocks, were analyzed by microprobe.
Low Al2O3, TiO2, REE, Th and U contents are common features of the Kastoria, Bitincka and Tsouka deposits. In
contrast, elevated REE contents are present in the karst-type bauxitic- and Ni-laterite ores of Nissi and bauxitic-laterites of
Parhari. The bauxitic-laterite deposit of Nissi attains REE contents of thousands parts per million in samples from the contact
between the lowest part of the bauxitic-laterite and the footwall limestone. Highest contents of Th and U are found in the
bauxitic-laterites, with Th ranging from 4 to 28 ppm and U from 4 to 66 ppm. In general, increasing Al contents are
accompanied by elevated Ti, REE, Th and U contents at the Parhari and Nissi laterite deposits. Goethite, is the dominant
mineral in all Ni-laterite profiles studied, while boehmite co-existing with goethite is common in the bauxitic-laterites at
Nissi and Parhari. Goethite exhibits variable Al contents, while the AlrFe ratio increases towards the top of the profiles.
The PGE concentrations are generally low, ranging from less than 100 ppb to a few hundred parts per billion. The lowest
values — lower than in the bedrock — were recorded in the saprolite zone. A certain enrichment in Pt up to 48 ppb., Pd 7
ppb., and Au 16 ppb. is recorded in the reddish altered peridotite overlying the saprolite zone at Profitis Ilias. The Fe–Ni
ore overlying the reddish altered peridotite has the highest Os values 14 ppb., Ir 32 ppb., Ru 66 ppb., Rh 20 ppb., Pt 86
ppb., and Pd 186 ppb.. Gold contents are below 36 ppb. An increasing PtrPd ratio from 3.0 in Fe–Ni-laterites to 6.0 in
bauxitic-laterites is apparent.
Both whole rock compositions and mineral chemistry of laterites indicate that major controlling factors of the
composition of the bauxitic-laterites are the conditions during transportationrdeposition of the weathered material and
during diagenesisrmetadiagenesis stage rather than parent mafic ophiolitic rocks.
چکیده فارسی:مشخصات نمونه عمود و پیوسته رسوبات Ni- لاتریت همراه با ویژگیهای در محل (کاستوریا، کوه Profitis Iiris) و شکو و رسوبات بوکسیت- لاتریت و نیکل دگربوم (غیربومی) در تماس با سنگ آهک زیرزمینی (Nissi) و بوکسیت- لاتریت واقع بر روی پری دوتیت از نظر عناصر عمده، کمیاب (از جمله Th و U)، عناصر گروه پلاتینیوم و فلزات خاکهای کمیاب مورد تجزیه و تحلیل قرار گرفتند. بعلاوه، مواد معدنی با تأکید بر دانههای کرومیت به عنوان اجزاء باقیمانده در این لاتریتها یافت شدند که میراث سنگهای افیولیتی والد میباشند که از طریق میکروپروب تحلیل میشود.
