Mineralogy and sedimentology of the Miocene Gocenoluk borate deposit, Kirka district, western Anatolia, Turkey
SEDIMENTARY GEOLOGY, cilt.290, ss.85-96, 2013 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 290
- Basım Tarihi: 2013
- Doi Numarası: 10.1016/j.sedgeo.2013.03.006
- Dergi Adı: SEDIMENTARY GEOLOGY
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.85-96
- Anahtar Kelimeler: Borates, Evaporites, Borax, Ulexite, Colemanite, Miocene
- Dokuz Eylül Üniversitesi Adresli: Evet
Özet
The Miocene boratiferous district of Kirka, in western Anatolia (Turkey), is the most important Na-borate (borax) resource in the world. Two separate deposits in the Kirka district are located near the villages of Sarikaya and Gocenoluk (Eskisehir Province). Borax is intensively exploited in open-pit mines in the Sankaya deposit while only small quarries of colemanite are known in the Gocenoluk deposit. Recent exploratory drilling in the Gocenoluk area intersected a thick succession of dolostones, tuffs and three borate-bearing units (Lower, Intermediate and Upper Borate Units). In them, the most abundant borate mineral is ulexite (Ca-Na-borate) passing at depth to probertite. Borax (Na-borate) is only present in the Intermediate Borate Unit. Minor amounts of colemanite (Ca-borate) and hydroboracite (Ca-Mg-borate) occur at the base, and/or top, of each mineralized unit. Pyroclastic layers within the borate units show intense alteration by alkaline, boron-bearing waters and formation of diagenetic clay minerals (smectites), zeolites (analcime) and borosilicates (searlesite). The Gocenoluk succession is interpreted as a shallow, ephemeral, alkaline lake deposit in which carbonates formed as stromatolites and travertines. Borate precipitation in the Gocenoluk area took place interstitially within muddy and carbonate sediments in a lateral progression from marginal Ca-borates towards Na-Ca-borates and rarely to Na-borates in the center of the lake. Authigenic silicate mineral distribution shows parallel changes toward the center of the lake that reflect increasing pH gradient. (c) 2013 Elsevier B.V. All rights reserved.