Petrographic and geochemical features of the dolostones at the Golbogazi Formation (Upper Devonian), Southwest Konya, Turkey
Küçük Resim Yok
Tarih
2017
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
SPRINGER HEIDELBERG
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This paper describes the occurrence of dolostone and the mechanism of dolomitization of the Upper Devonian Golbogazi Formation in the allochthonous Taurus Mountains Aladag unit in Turkey. The Upper Devonian Golbogazi Formation carbonates, with dominant ostracod-bearing mudstone and wackestone, formed tidal and subtidal environments, and some of these rocks were dolomitized from shallow to deep burial. On the basis of the field, the petrographic and geochemical features, four different replaceable and cement dolostone phases have been recognized. The replacive dolostones contain (1) very fine to fine crystalline planar-s dolostone (df1), (2) medium to coarse crystalline planar-s to planar-e dolostone (df2), (3) coarse to very coarse crystalline non-planar-a dolostone (df3), and (4) coarse to very coarse crystalline planar dolostone cement (df4). The replacive dolostones are disordered to moderate the ordered and calcium-rich. They are non-stoichiometric and have 46-59 mol% CaCO3 and 41-54 mol% MgCO3 total contents. The df1 dolostones have MgCO3 contents of 41-54 mol%, the df2 dolostones have 41-53 mol%, the df3 dolostones have 49 mol%, and the df4 dolostones have 49-50 mol%, respectively. The Golbogazi dolostones have delta O-18 values of -9.44 to -2.20% Vienna Pee Dee Belemnite (VPDB) and d13C values of -1.58 to + 2.52 VPDB. Sr, Na, Mn, and Fe concentrations of replacive dolostones are 74-184, 148-593, below detection level (bdl)-619, and 1049-9233 ppm, respectively. The petrographic and geochemical data demonstrate that the replacive dolostones occurred prior to the chemical compaction at shallow to intermediate burial depths from Late Devonian seawater and/ or seawater lightly modified by water-rock interaction process and later recrystallized by basinal brines at increasing burial depths and temperature. The North American Shale Composite-normalized rare earth element values of both limestone and dolostone show very similar rare earth element patterns characterized by slightly or considerably negative cerium (Ce) anomalies and a clear depletion in all rare earth element species. The dedolomitization observed in the Golbogazi Formation is thought to occur by the oxidizing effect of the meteoric water in the shallow burial environment during the telodiagenesis.
Açıklama
Anahtar Kelimeler
Dolostone, Dedolostone, Golbogazi, Hadim Petrography, Geochemistry
Kaynak
ARABIAN JOURNAL OF GEOSCIENCES
WoS Q Değeri
Q4
Scopus Q Değeri
N/A
Cilt
10
Sayı
14
