ГЕОЛОГИЯ РУДНЫХ МЕСТОРОЖДЕНИЙ, 2008, том 50, № 2, с. 164-173
FLUID INCLUSION AND STABLE-ISOTOPE CHARACTERISTICS OF THE KARALAR (GAZIPA§A-ANTALYA) BARITE-GALENA DEPOSITS,
SOUTHERN TURKEY
© 2008 A. Gok ç e and G. Bozkaya
Department of Geological Engineering, Cumhuriyet University, 58140 Sivas, Turkey
Received: April 4, 2005
Abstract. Karalar galena-barite deposits are the typical examples of the carbonate hosted barite-galena deposits widely occurred in the Central Tauride Belt. These deposits are located in the Permian limestones as ore veins along the fault zones which discordant to the bedding planes, and as thin veinlets within the hardly brecciated bottom zones of the Permian limestones. The ore deposits mainly contain barite and galena and small amounts of sphalerite, pyrite, fahlerz, limonite, quartz and calcite. Barites are occurred during the earlier episode of mineralization and mylonitized before than the galena formation. Galena and other minerals are epigenetically occurred with barite, along the porous zones between the brecciated barite crystals and enriched especially in the hardly mylonitized zones.
Fluid inclusion studies indicate that the ore deposits of the area were developed by hydrothermal fluids with following characteristics; they contain NaCl, CaCl2 and MgCl2, the salinity of the fluids were relatively high and their temperature were low during the crystallization of barites in the earlier episode of mineralization, and the salinity of the fluids decreased while their temperatures increased during the crystallization of sulfide minerals through the later episode of mineralization.
The S18O and the S D results indicate that the water in the mineralizing fluid was meteoric origin. The deposits were formed by deep circulated meteoric water, through the marine sediments. The shallow circulated and slightly warmed fluids dissolved the Ba and sulfate from the marinal sediments of the basement and transported to the mineralization environment during the early episode, while the deeply circulated and more heated fluids dissolved the Pb, Zn and other elements from the basement and reached to the environment during the later episode of mineralization.
INTRODUCTION
Carbonate hosted barite deposits are widespread in the Gazipa §a region. Some contain galena and small amounts of other sulfide minerals. The most important deposits and prospects are located in the Karalar, Ay-dap, Yulari, Burhan Mahallesi, Kicik, Endi§eguney and Seyfe areas along the Mediterranean Sea coast (Fig. 1). The depositional styles, ore/host-rock relations, and mineralogical compositions of the deposits have been investigated by numerous geologists, and two different hypothesis were appeared about the genesis of the deposits.
The first type of hypothesis may be summarised as the deposits were occurred syn-sedimentary processes as stratiform mineralization and modified by remobili-zation, recrystallization and deformation processes during the post-depositional geological events such as diagenesis, regional metamorphism and tectonic movements (Striebel, 1965; §enel, 1977; Sadiklar, 1978; Sadiklar and Amstutz, 1981; Ayhan, 1979, 1981, 1982; Gulseren, 1987; Çopuroglu, 1994).
The second type of hypothesis accept that the deposits were formed by epigenetic hydrothermal processes and show mainly vein type depositional style (Baru-
Address for correspondence: A. Gökge. E-mail: gokce@cumhu-riyet.edu.tr
togglu, 1942; Petrascheck, 1966; Turner and Türk, 1974; Bilgisu, 1976; Cöteli and Turk, 1977; Remzi, 1978; Gümü§ et al., 1996).
Karalar deposit was the only deposit which was being mined during the field investigations of this study, and so our investigations were focused on the Karalar deposits. The observation on the ore geology, mineralogy, trace- and rare earth-element geochemistry report the following conclusions (Gök ge and Bozkaya, 2003; Bozkaya and Gök ge, 2004). The mineralization occurs as epigenetic ore veins along fault zones and ore filled brecciate zones along the strongly deformed bottom lying walls of limestone blocks in the Permian limestones called Bi gkici formation. Trace-element geochemical studies show that Ba and Pb may have been derived from different sources: Ba is enriched in the mudstones of the Ordovician Cakmak formation, and Pb is enriched in the limestones of the Permian Bi gkici formation. The trends of the REEs-Y profiles and the plots of the values of barites and galenas on the CeN/SmN versus CeN/YbN diagram indicate that a sea water dominated hydrothermal fluid deposited the barite and supplied the barium and sulfate ions, while a fluid mixture of sea water and Tibetan type (terrestrial) hydrothermal fluid is responsible in galena deposition. There is also a genetic relation of galena with Permian limestone and do-lomitization processes.
32°
38°
44°
_I__
32°30' E 36°00' N
Fig. 1. (a) Geographic distribution of Taurides (Ozgul, 1984), (b) Simplified geologic map of the Alanya-Gazipaj a part of the Central Tauride Belt (Ozgul, 1984; 1: Antalya Unit, 2: Alanya Unit, 3: Aladag Unit, 4: Neogene sediments), (c) Location map of the Karalar and neighbouring barite deposits.
This study deals with the results of the microther-mometric and stable-isotope (oxygen and hydrogen) investigations of the fluid trapped in barite crystals and aims to identify the origin of the mineralizing fluids.
GEOLOGICAL SETTING
The Karalar barite-galena deposits occur in the Or-dovician to Upper Cretaceous detrital and calcareous sediments of the Antalya Unit, which is tectonically overlain by the Alanya Unit - the metamorphosed equivalent of the Antalya unit (Fig. 1). The Antalya unit only crops out in places where the Alanya Unit is deeply eroded; this area is geologically known as the Alanya tectonic window (Ozgul, 1976, 1984).
In the study area, the Antalya unit consists of Or-dovician detrital sediments, Permian limestones and Triassic detrital sediments of the Çakmakkaya, Biçkici, Yoreme and Çamlica formations (Ulu, 1983; Gulseren,
1987). Older rock units are thrust over the clastic sediments of the Triassic Çamlica formation (Fig. 2); conversely, we claim that the older units may have glided into the Triassic sedimentary environment during the deposition of the Çamlica formation.
Ore deposits of the study area crop out in two different mining areas (Gok çe, Bozkaya, 2003): the Buyuk mine and the Boyalik mine. In the Buyuk mine, there are three different ore veins, all discordant to local bedding planes: (1) vein V-1 (N85°W/35°SW), (2) vein V-2 (N70°W/85°NE) and (3) vein V-3 (N85°E/85°NW). The veins characteristically occur along fault zones that deform limestones of the Permian Bi çkici formation (Fig. 3). The thickness of the veins varies between 0.2 to 2.5 m. In the Boyalik mine, the mineralization developed as thin ore veinlets within slightly brecciated limestones that are the lowermost lithologies of the Biçkici formation along a tectonic contact (overthrust zone) between the Permian Bi çkici formation and the
N
l i T i f T i i f i i f l YVi
' 1' I' I' 1' I' I' 1' I' I' 1' ljf V}^ ' I' I'!' I'
■!■).!.! \ i ¡.i j.i' 111 j 11 i.) г ^^^A ф±тгт
^T1! ' I ' \y
m
0 250 500
ШЯшШШ
Quaternary
Triassic
Permian
Ordovician-L.Devonian
ЛЛЛЛЛ/
вод
/wwv
Alluvium
CC amlica Formation Bickici Formation CC akmak Formation
70
y;
x
Thrust fault Strike and dip Working mine Abondoned mine
Fig. 2. Geology map of the Karalar area (modified after Ulu, 1983).
structurally underlying Triassic Camlica formations barite (80-85%) and galena (10-15%), and small (Fig. 4).
amounts of sphalerite, pyrite, marcasite, fahlore, limo-nite, quartz and calcite.
The macroscopic and microscopic characteristics of the deposits suggest that barite developed during an Microscopic and XRD investigation of the ore sam- early episode of mineralization and was later my-ples documents that the ore deposits contain mainly lonitized prior to galena crystallisation (Fig. 5a, b). Ga-
ORE PETROGRAPHY
S5EE5EÄ ' T ' 1 1 'r 1 1 .
I ' 11 i11 ' 11111111111111111111111111111111 'rj-Fri j !1 1 1 1 1 1 1 1 1 1 '1 '1 !1 !1 '1 ! '!1 !1 !1 1 !1 !1 !'
V-1 vein (N85W/35SE)
m N 380
360 340320300
280-A
V-2 vein
m 10
S
r 380
V-1 vein
M /Ж
' i '
Bic kici Formation CC akmak Formation
Ore vein
4
40
Dolomitisation
Gallery
Strike and dip of bedding
-360
-340
-320
-300
280 B
Unconformity Stabilized road
bA
Line of cross section
Fig. 3. Geology map and cross section of the Big Mine area.
lena and other minerals are epigenetically related to barite. Galena formed along porous zones between brecciated barite crystals, and is particularly enriched
in weakly mylonitized zones (Fig. 5c). Quartz also crystallised along the fissures in barite, forming comb texture (Fig. 5d).
N
rzt
Biç kici Formation (Permian) Overthrust
Ç amlica Formation (Triassic)
ш
Barite-galena veinlets
Brecciated zone
Fig. 4. Sketch cross-section of the Boyalik mine showing overthrust zone between Biçkici and Ç amlica formations.
Fig. 5. Various petrographic views from the investigated deposits and samples: (a) Macroscopic view from the V-1 ore vein, (b) Mylonitized barites and porphyroblastic texture (Sample No: GK-38, thin-section, crossed nicol), (c) Galena occurences along the porouse zones and fissures among the barite crystals (Sample No: GK-47, polished block, single nicol), (d) Quartz veinlets cutting across the barite (polished thin-section, single nicol).
Fig. 6. Photomicrographs from the various types of fluis inclusions: (a) Monophase liquid fluid inclusion within the barite crystals (polished thin-section, single nicol). (b) Secondary inclusion series developed along the fissures within the barite crystals (polished thin-section, single nicol).
FLUID-INCLUSION STUDIES
Samples and methods
Fluid-inclusion studies were carried out on barite and quartz crystals in the samples collected from the various parts of the V-1 and V-
Для дальнейшего прочтения статьи необходимо приобрести полный текст. Статьи высылаются в формате PDF на указанную при оплате почту. Время доставки составляет менее 10 минут. Стоимость одной статьи — 150 рублей.