عنوان

Origin of magnesite in Turkey :

شماره

TLets796951

عنوان اصلي

Origin of magnesite in Turkey :

نام عام مواد

[Thesis]

نام نخستين پديدآور

Zedef, Veysel

عنوان اصلي به قلم نويسنده ديگر

a stable isotope study

نام ناشر، پخش کننده و غيره

University of Glasgow

تاریخ نشرو بخش و غیره

1994

جزئيات پايان نامه و نوع درجه آن

Ph.D.

کسي که مدرک را اعطا کرده

University of Glasgow

امتياز متن

1994

متن يادداشت

This thesis is concerned with the problem of the genesis of the various types of cryptocrystalline magnesite deposits found in western Turkey. Veins and stockworks of cryptocrystalline magnesite deposits are found within the discontinuous ultramafic belts of western Turkey. Sedimentary-hydrothermal lacustrine magnesites and presently forming hydromagnesite deposits lie above these ultramafic rocks. A hot-spring calcite deposit at the northern edge of a Menderes graben is also considered. From the stable carbon and oxygen isotopic signatures of the magnesite, hydromagnesite and calcite formations of western Turkey, three end-members can be distinguished End-member-1: represents the cryptocrystalline, vein-type of magnesite deposits. Decarboxylation of organic-rich sediments may have provided about two thirds of the carbonate in the vein-type of Koyakci Tepe magnesite deposits, Konya, which have ~-13 and ~+27 % of delta13C and delta18O respectively. Stockwork deposits at Helvacibaba, Yunak and Kozagac, all in Konya, have slightly heavier delta13C and delta18O values indicating more involvement of atmospheric carbon dioxide (as bicarbonate in the circulating meteoric water) compared to those of Koyakci Tepe. End-member-2 : represents carbon dioxide of atmospheric origin. Presently forming hydromagnesite deposits at Saida lake, Yesilova, Burdur reflect such a carbon dioxide origin with of delta13C of ~+4‰PDB and delta18O of ~+36‰SMOW. End-member-3 : represents the carbon dioxide of metamorphic origin. Present-day, hot-spring travertine (calcite) deposits at Pamukkale, Denizli, have the heaviest delta13C (~+6 %o,PDB) and extremely light delta13C (~+20‰SMOW) values and these values are probably the result of decarbonation and/or dissolution of limestone formations beneath travertines. Sedimentary magnesite deposits at Hirsizdere, Denizli and stockwork magnesite deposit at Arapomer Deresi have unexpectedly heavy delta13C (~+2 and 0‰PDB respectively), and these deposits probably gained their carbonates from decarbonation and/or dissolution of limestones. The extremely low REE contents of magnesite, hydro magnesite and ultramafic host- rocks indicate that the magnesium is derived from the ultramafic rocks. The Saida lake hydromagnesite deposits are being formed by a microbial community in the lake itself. In terms of isotopic signatures, physical features and geological environment, Saida's hydromagnesite deposits are comparable with the Miocene, lacustrine, sedimentary magnesite deposits elsewhere, perhaps especially to Bela-Stena in Serbia. Therefore Saida's hydromagnesites may be a precursor of magnesite.

مستند نام اشخاص تاييد نشده

Zedef, Veysel

مستند نام تنالگان تاييد نشده

University of Glasgow

نام الکترونيکي

فرمت انتشار

p

نوع ماده

[Thesis]

کد کاربرگه

276903

سطح دسترسي

a

تكميل شده

Y