Barite Deposits of Türkiye: A Review

Abstract

Türkiye hosts a wide variety of barite deposits that can be broadly classified into two major groups based on their tectonic settings: magmatism-associated and passive margin-hosted deposits. The magmatism-associated deposits include Kızılcaören (F + Ba + REE + Th, Beylikova–Eskişehir), Kirazören (Bulancak–Giresun), and Karacaören (Mesudiye–Ordu). The Kızılcaören deposit formed in relation to the emplacement of a late Oligocene carbonatitic sill, while the Kirazören and Karacaören deposits are associated with the Cretaceous Pontide magmatic arc. Passive margin-hosted deposits occur within various Paleozoic sedimentary lithologies—such as metasandstone, shale, schist, and limestone—and are found in the Taurides and the Arabian Platform. These deposits occur as either concordant or discordant veins. This barite belt extends from Şarkikaraağaç (Isparta), through Hüyük (Konya) and Alanya (Antalya), to Silifke (Mersin), Tordere (Adana), Önsen, Şekeroba (Kahramanmaraş), and Hasköy (Muş). The Paleozoic deposits represent the major barite resources of Türkiye, with an annual production of approximately 300,000 metric tons. Smaller deposits around Gazipaşa (Antalya) contain minor Pb-Zn sulfides. Mesozoic barite deposits are hosted in Triassic dolomites and are associated with Pb-Zn mineralization in the Hakkari region of the Arabian Platform. Pb and Sr isotope data indicate that the barium in these deposits was derived from ancient continental crust. The isotopic compositions of both concordant (stratabound) and discordant (vein-type) barites are generally homogeneous. In northwestern Türkiye, the Sr isotope compositions of the barite deposits align well with those of the Oligocene carbonatite host complex. The ⁸⁷Sr/⁸⁶Sr isotope ratio of the Kızılcaören deposit (0.706‰) is the least radiogenic among Turkish barite deposits, suggesting a mantle contribution. The Kirazören deposit in the Pontide magmatic arc follows with a slightly higher ratio (0.707‰). Triassic barites from the Hakkari region yield ⁸⁷Sr/⁸⁶Sr values around 0.709‰, slightly more radiogenic than coeval seawater. Paleozoic barite deposits show the most radiogenic ⁸⁷Sr/⁸⁶Sr values, including Aydıncık (0.718‰), Şarkikaraağaç (0.714‰), Hasköy (0.713‰), Kahramanmaraş (0.712‰), Tordere, and Hüyük (both 0.711‰), consistent with their respective host rocks. The elevated radiogenic Pb and Sr isotope values in the passive margin-hosted deposits suggest that the barium originated from deeper, barium-enriched rocks, whereas stable sulfur isotope data point to a marine sulfur source. Moreover, Sr and S isotopic signatures indicate that the Paleozoic sediment-hosted deposits formed in association with cold seeps on the seafloor, resembling modern analogs. In contrast, the Mesozoic Karakaya deposit (Hakkari) represents a typical vent-proximal, sediment-hosted deposit with no magmatic signature.

1. Introduction

Barite has been used as a filler, extender, or weighting agent in products such as plastics and rubber [1], as well as in paint primers, ceramic glazes, and optical glass [2], due to its high density (4.48 g/cm³), relative abundance, and ease of being ground into a fine powder. Recent supply chain disruptions have significantly shifted the perception of barite, leading to its classification as a critical mineral [1,2,3].

Barite can precipitate in various oceanic environments: in the water column, on the seafloor, and within marine sediments [4]. It forms over a wide range of pressures (1 to 2000 bar) and temperatures (0–400 °C) across many geological settings but is primarily produced through precipitation from aqueous solutions [5]. Most barium in the Earth’s crust is associated with K-feldspars and K-micas due to the similarity in their ionic radii (Ba²⁺ = 1.36 Å, K⁺ = 1.33 Å; [5]). Hydrothermal vents are recognized as a major source of barium to the ocean, contributing an estimated one-third of its total marine input [6,7]. In hydrothermal systems, barium is typically transported as chloride complexes, with barium- and sulfur-rich fluids moving separately. For barite to precipitate, these barium- and sulfur-bearing solutions must mix [8].

Early classifications of barite deposits, based primarily on deposit morphology, have been proposed by several authors [9,10,11,12]. These classifications identified three main types: stratiform, vein, and residual deposits. Among them, stratiform deposits are particularly significant due to their large reserves, whereas vein-type deposits are notable for their comparatively high ore grades. In a tectonic framework, Ref. [13] categorized barite deposits into two major types: continental margin and cratonic rift-related deposits. Later, Ref. [14] proposed a more detailed classification scheme that included three primary deposit types—magmatic, structure-related, and sedimentary—with clearly defined subclasses. Other researchers have classified barite deposits based on the source of barium. For example, Refs. [4,15] categorized barites as either diagenetic or hydrothermal, offering a simple yet practical classification. More recently, Ref. [16] provided an expanded classification system, distinguishing deposits as bedded-sedimentary, bedded-volcanic, vein, cavity-fill, metasomatic, and residual types. Furthermore, recent studies have significantly advanced the understanding of Ba ion mobility and barite precipitation in modern marine sediments. Insights from [4,15] have contributed valuable information for economic geologists. These authors classified barite deposits using stable isotopic data (Sr and S), as well as crystal size and morphology.

The aim of this study is to present and classify the barite deposits of Türkiye, which formed during different geological periods and within various tectonic environments, host rocks, and mineral parageneses. This classification is based on both geological context and isotopic geochemistry. Turkish barite deposits are categorized into two main groups: magmatism-associated and passive margin-hosted deposits, reflecting their distinct tectonic settings and geochemical characteristics. In addition to providing a comprehensive review, this study presents new data on the magmatism-associated Kızılcaören and Kirazören deposits. For the first time, it also includes barite mineral chemistry data from representative deposits of each type. A deeper understanding of Turkish barite deposits will enhance regional correlations and broader interpretations of barite mineralization across the Alpine–Himalayan Mountain Belt and the Atlas Mountains.

2. Geological Setting

Throughout its geological history, Türkiye has been situated between two major continents: Gondwana to the south and Eurasia to the north. Various continental fragments, originally part of one of these mega-continents, were later separated and reassembled through tectonic processes. As a result, the Anatolian region is composed of multiple oceanic and continental terranes, each with distinct geological characteristics. The most recent major orogenic event—the Alpine orogeny—was associated with the closure of several Neotethyan oceanic branches and has played a key role in shaping the present distribution of these terranes [17,18]. Türkiye is composed of three primary tectonic units: the Pontides, the Anatolides–Taurides, and the Arabian Platform. The Pontides display Laurussian affinities, whereas the Anatolides–Taurides exhibit Gondwanan affinities. These two domains are separated by the İzmir–Ankara–Erzincan Suture Zone (also named as North Anatolian Suture Zone (NASZ) (Figure 1) [19,20,21].

The Taurides–Anatolides collectively record the evolution of the northern margin of Gondwana until the Triassic period, when one or more continental fragments separated, leading to the formation of several adjacent Mesozoic oceanic basins. Oceanic crust and ophiolites developed within these Mesozoic basins during the Triassic–Cretaceous period. Subsequent northward subduction facilitated the gradual reassembly of these continental fragments, ultimately giving rise to the present-day Tauride–Anatolide belt during the Late Cretaceous to Early Cenozoic [22]. The pre-Triassic basement rocks of the Arabian Platform and the Taurides–Anatolides share similar geological features [18,20,23,24]. Both regions host Türkiye’s most economically significant barite deposits, including those at Şarkikaraağaç, Hüyük, Karalar, Aydıncık, Önsen, Şekeroba, Tordere, and Hasköy [25,26,27,28,29,30,31].

The oldest unit of the Arabian Plate is the Derik Formation, which comprises brownish-red andesitic lava, sandstone, shale, and conglomerate, interpreted as Neoproterozoic continental arc-type volcanics [32]. The Derik Formation is unconformably overlain by a passive margin sedimentary succession spanning the Cambrian to Cretaceous periods. This succession is tectonically overlain by ultrabasic rocks and an ophiolitic mélange [32]. The stratigraphic positions of these Paleozoic-hosted, passive margin barite deposits—occurring as stratiform, stratabound, and vein types—are illustrated in a columnar section by [30]. The Karakaya barite deposit, located in the Hakkari Pb-Zn province, occurs in Late Triassic–Early Jurassic limestones as feeder veins, stratabound, and stratiform bodies within the uppermost levels of the succession [33]. These deposits formed within the passive margin sequence of the Neotethyan Ocean.

The Late Cretaceous marked the subduction and eventual disappearance of the Neotethys Ocean beneath the Pontides [34]. This tectonic event led to the development of a continental arc, which hosted the formation of numerous volcanogenic massive sulfide (VMS) and barite deposits [35,36,37,38]. These settings are widely interpreted as rifted back-arc basins and are associated with a variety of deposit types, including Kuroko-type massive sulfides, Carlin-type gold, and vein-type manganese oxide deposits [39,40,41,42]. Within the Upper Cretaceous section of this extensive volcano-sedimentary sequence, large limestone blocks—several hundred meters in size—are present. These blocks host massive barite mineralization, occurring both within and along the outer rims as replacement bodies. The Dereli deposit, abandoned approximately 15 years ago, and the Kirazören barite deposit are representative examples of limestone-replacement barite deposits formed through hydrothermal processes. A geologically unique example is the carbonatite-hosted Kızılcaören F–Ba–REE–Th deposit in western Anatolia, which formed during Late Oligocene magmatic activity [43]. This mineralization is attributed to an extensional tectonic phase, during which magmatic melts were emplaced into shallow crustal levels through deep-seated faults. The mantle signature observed in the metallogeny of Anatolia from the Paleocene to the Miocene provides strong evidence for a post-collisional extensional regime [36,44].

Figure 1. Main mineral deposits and types of Türkiye (modified from [36]) and the location of barite deposits.

Figure 1. Main mineral deposits and types of Türkiye (modified from [36]) and the location of barite deposits.

3. Barite Deposits

Barite deposits in Türkiye can be classified into two major types—magmatism-associated and passive margin-hosted—based on their geological and tectonic settings (

Table 1. Essential information about the barite deposits of Türkiye.

	Deposit (City)	Mineralogy	Shape of Deposit	Host Rock	Tectonic Unit
Magmatism-associated deposits	Kirazören (Giresun)	Barite ± pyrite	Vein	Cretaceous limestone and arc volcanoclastics (this study)	Pontides
	Karacaören (Ordu)	Barite ± galena ± sphalerite ± hematite	Vein	Eocene andesites (this study)	Pontides
	Kızılcaören (Eskişehir)	Fluorite + barite + bastnaesite	Banded and disseminated ore	Late Paleozoic–Triassic accretionary complex (sandstone, shale, conglomerate, spilite, lithic tuff) [43,44]	Tavşanlı Zone, Anatolides
Passive margin-hosted deposits	Şarkikaraağaç (Isparta)	Barite ± galena ± sphalerite ± chalcopyrite ± pyrite ± bornite	Stratiform-stratabound and vein	Cambrian–Devonian schist and limestone [25]	Central Taurides
	Hüyük (Konya)	Barite ± pyrite	Vein	Cambrian–Devonian schist and limestone [26]	Central Taurides
	Tordere (Adana)	Barite ± chalcopyrite ± pyrite ± galena ± malachite ± fluorite	Vein	Cambrian limestone [30]	Eastern Taurides
	Karalar (Antalya)	Barite + galena + sphalerite + chalcopyrite + pyrite + bornite	Vein	Permian–Triassic limestones and schist [27,28]	Central Taurides
	Koçaşlı, Aydıncık, Gökbelen, Çilbayır (Mersin)	Barite ± galena	Vein	Cambrian–Devonian limestone [29]	Central Taurides
	Önsen (Kahramanmaraş)	Barite ± pyrite	Vein	Cambrian limestone [30]	Arabian Plate
	Şekeroba, Kahramanmaraş	Barite ± chalcopyrite ± galena	Vein	Ordovician–Devonian meta-sandstone and shale [30]	Arabian Plate
	Kızılağaç-Hasköy (Muş)	Barite ± chalcopyrite ± pyrite ± sphalerite galena± malachite	Stratiform and vein	Devonian dolomitic limestone [31]	Eastern Taurides
	Karakaya (Hakkari)	Barite	Stratiform	Jurassic limestone [33]	Arabian Plate

). Each type exhibits distinct geochemical characteristics (Figure 1). The term magmatism-associated refers to deposits formed in volcanic arc or post-collisional magmatic environments, while passive margin-hosted refers to deposits that developed in Atlantic-type continental margin settings, where magmatic activity is absent.

In this study, the largest and most representative deposit of each type (in terms of reserves) is examined in detail with respect to its geology, ore types, and geochemistry. Additional deposits of the same type are also briefly described to provide broader context and comparison.

3.1. Magmatism-Associated Barite Deposits

3.1.1. The Kirazören (Bulancak/Giresun) Deposit

The Kirazören barite deposit is located in the Bulancak district of Giresun Province, within the Pontide magmatic arc of the Upper Cretaceous. The deposit lies at higher elevations in the Giresun Mountains, where the ore occurs within crystallized limestone blocks of the volcano-sedimentary series. The mineralization forms a large replacement body, reaching up to 40 m in thickness and 100 m in length. The grayish-white barite contains up to 1 ppm gold and is characterized by a dense concentration of fine-grained, green-tinted pyrite. This region also hosts several local barite bodies, each with estimated ore reserves of up to 400,000 tons. A prominent example, the Dereli barite deposit, has been completely depleted and abandoned following open-pit mining operations.

3.1.2. The Karacaören (Mesudiye/Ordu) Deposit

The Karacaören barite deposit is hosted within Eocene-aged andesitic stocks, approximately 3 km northeast of Karacaören Village in the Mesudiye district and about 60 km from the Black Sea coast. The barite body exhibits a lenticular geometry, measuring 220 m in length and 70 m in width, and is oriented N35° E. The barite displays characteristics of clearly hydrothermal vein formation, with white to grey coloration and a steep, nearly vertical orientation.

The mineralization occurs at an elevation of 2300 m at the summit of the Black Sea Mountains. Due to challenging topographic conditions, no beneficiation plant has been constructed at the site. To date, approximately 400,000 tons of barite ore—suitable for use in paint and drilling applications—has been extracted via open-pit mining and sold without further processing. Minor occurrences of galena, sphalerite, and hematite are associated with the barite. The second most abundant mineral within the vein is coarse-grained quartz. The Güzelyurt gold deposit is located approximately 5 km south of the barite occurrences.

3.1.3. The Kızılcaören (Beylikova/Eskişehir) F + Ba + REE + Th Deposit

The Kızılcaören deposit represents a unique rare earth element (REE) mineralization in Anatolia and shows similarities with ore mineralogy and geochemistry to the Bayan Obo deposit in China and the Mountain Pass deposit in the USA. The banded F–Ba–REE–Th ore consists primarily of barite, fluorite, bastnäsite, calcite, and Mn-rich calcite. Barite-rich banded ore forms isolated mineralized bodies located at the center of the deposit (Figure 2).

The deposit was discovered in 1959 through aerial gamma-ray spectrometry surveys, which detected thorium-associated radioactivity [45]. According to an earlier reserve report by the General Directorate of Mineral Research and Exploration (MTA) of Türkiye [46], the deposit contains several tens of millions of tons of barite reserves.

The Kızılcaören F–Ba–REE–Th deposit is hosted within a Triassic-aged mélange series and is interpreted to have formed during the late Oligocene to early Miocene, approximately 24–25 million years ago [43,47]. The deposit has been variously classified as a carbonatite [43,44,48,49,50] or as a pegmatite [14]. Although extensive research has been conducted on the geology of the Kızılcaören deposit [43,44,45,46,47,48,49,50,51,52], no previous studies have identified distinct ore types or clarified their genetic relationships. In this study, we conducted detailed geological mapping of the deposit, classified the ore types, and performed mineralogical and geochemical analyses on the different ore types.

The Kızılcaören deposit occurs within Triassic lithic tuff units and partially metamorphosed and silicified sedimentary rocks, including conglomerate, sandstone, shale, and limestone. These form a northward-dipping, thrust-bound sedimentary succession. Both the lithic tuff and the weakly metamorphosed sedimentary series host the F–Ba–REE–Th mineralization. The sedimentary sequence contains large, crystallized limestone blocks, some exceeding several hundred meters in size (Figure 2). The presence of these exogenic limestone blocks within the sandstone supports the interpretation of a mélange-type origin for the sedimentary sequence.

Three phonolitic necks intrude into serpentinized ultramafic rocks, forming a dome-like structure aligned along E–W-trending lineaments. Feldspar from the phonolites has been dated to approximately 23 Ma using the K–Ar geochronological method [41], indicating a late Oligocene age. Several researchers (e.g., [43,49]) have associated these phonolitic intrusions and related alkaline magmatism with the formation of the mineralization.

The Ore Geometry and Types

The layered ore represents the primary ore type throughout the deposit and includes several varieties: (Figure 3a) silicate-rich banded ore, (Figure 3b) manganese oxide-rich banded ore, (Figure 3c) barite-rich banded ore, and (Figure 3d) fluorite-rich banded ore. These banded ore levels can reach up to 20 m in thickness and generally display a chemical zonation from bottom to top. The basal unit begins with fluorite–barite–bastnäsite ore, which gradually transitions into banded manganese oxide ore, and finally into a manganoan calcite-rich upper unit. The manganese oxide- and barite-rich layers can individually reach up to 10 m thick and contain minor amounts of fluorite and bastnäsite. The carbonate-rich uppermost level is well-laminated, with bedding thicknesses ranging from 0.5 to 5 cm. This fine layering is interpreted as the result of carbonic, gas-rich fluid accumulation near the top of the ore sill emplacement. This stratified ore is shown in both the geological map and cross sections (Figure 4). The presence of ore and host rock fragments aligned parallel to the banding suggests a close genetic relationship with fluid flow. These fragments likely originated from deeper parts of the system, were transported vertically, and then reoriented into a horizontal position (Figure 4).

The layered ores are relatively soft and exhibit gentle dips, in contrast to the massive ore bodies, which are steeply dipping and nearly vertical. The banded ores also show evidence of mineral fragmentation related to fluid flow, as well as rounded mineral grains including sanidine, K-feldspar, calcite, barite, fluorite, and bastnäsite. Phlogopite flakes occur in all ore types, typically as elongated euhedral crystals aligned along the banding planes.

The ore minerals of the massive ore are fine-grained, relatively hard, and homogeneous. A weak mineral orientation related to fluid flow is also observed in the massive feeder ore body, as revealed by petrographic studies (Figure 5). Based on these characteristics, the massive vein is interpreted as a feeder system for the layered ores. Cross-cutting relationships between the feeder veins and the layered ore bodies suggest polyphase mineralization, dominated by successive pulses of Ba, Si, Mn, F, and REEs.

3.2. Passive Margin Deposits (PMH) (From Sedimentary to Vein Type)

The Arabian plate and the southern margin of the Anatolide plate represent passive margin tectonic settings in Türkiye [32,53]. These regions contain thick sedimentary sequences—exceeding 10 km in thickness—ranging from the Cambrian to the Eocene, and they host the most significant barite deposits in Türkiye.

3.2.1. The Şarkikarağaç (Isparta) and Hüyük (Konya) Deposit

The Şarkikaraağaç and Hüyük regions are among the most important barite-producing areas in Türkiye, with total reserves estimated at approximately 17 million tons [54]. The main barite body is exposed in the largest open pit of the Şarkikaraağaç deposit, where it extends conformably along the contact between Cambrian–Devonian-aged schists and limestones of the Sultandede Formation.

The origin of the barite formations in this region has been widely discussed by numerous geologists; [54,55,56,57,58] proposed an exhalative–sedimentary and/or diagenetic origin for the barites. In contrast, [25] suggested that the mineralization is related to submarine volcanism, while [26,54] argued that the deposits closely resemble Mississippi Valley-type (MVT) mineralization and may be genetically associated with an underlying magmatic body.

In addition to this major deposit—which produces approximately 247,000 metric tons of barite annually—numerous smaller barite bodies occur within schist units and along schist–calc-schist contacts, oriented parallel to the schistosity. These mineralizations extend from Şarkikaraağaç to Hüyük, comprising more than 30 occurrences aligned along a N45° W–SE trend. Barite layers and pods typically strike N40–50° W, with dips of approximately 50° NE, and range in thickness from 0.5 to 8 m (Figure 6a). Approximately 90% of the region’s barite production is derived from the Şarkikaraağaç deposit, while the remaining 10% comes from the Hüyük deposit. Although this barite zone is crosscut by faults, a consistent structural trend is evident in the field. The barite layers are interbedded with and alternated by host rock, indicating a stratiform–stratabound style of mineralization. Both white and grey barite ores are extracted from the deposit, which also contains minor amounts of galena, chalcopyrite, and pyrite, along with rare occurrences of malachite, azurite, limonite, calcite, quartz, and siderite. Field observations suggest that this deposit is primarily sedimentary in origin, as the barite beds occur parallel to the schistosity planes. Similarly, Ref. [57] proposed a syn-sedimentary origin for the Dinek region barites, located between Şarkikaraağaç and Hüyük. The barite mineralization likely formed contemporaneously with the host rocks and later experienced metamorphism under greenschist facies conditions. Despite this metamorphic overprint, primary depositional structures remain visible within the barite layers and lenses. The barites are stratabound and typically exhibit a stratiform geometry, although signs of deformation—including secondary veins, folding, and brecciation—are also present in the study area [58].

3.2.2. The Tordere (Feke/Adana) Region Deposits

There are three main barite occurrences in this region—Kuştepe, Çebişderesi, and Sinanlı—from north to south, along with several abandoned mining sites situated between Sinanlı and Çebişderesi. The Tordere (Feke–Adana) barite deposit, hosted by Cambrian limestones of the Koruk Formation, displays epigenetic characteristics. The vein and replacement-type ore bodies exhibit a NE trend in the southern sites (Sinanlı and Çebişderesi) and a NW trend in the northern Kuştepe area. At the Kuştepe location, barite veins were mined along fault zones trending N60° W/60° SW and N80° W/66° NE, with vein thicknesses ranging from 3 to 5 m. In the Sinanlı area, barite was extracted along N20° E/60° SE and N80° W/66° NE-trending faults, reaching depths of up to 45 m below the adit entrance. In the southern part of the region, additional production occurred from N28° E/50° NW and N20° E/60° NW-dipping veins. The ore bodies are up to 5 m thick and are characterized by brecciation and sharp vein–host rock contacts (Figure 6b). Notably, no alteration zones are observed around the ore bodies.

Several adits have been opened along these veins, and underground mining continues in some areas. The region currently produces approximately 10,000 metric tons of barite annually. Barite veins are commonly associated with hematite, and to a lesser extent with galena, chalcopyrite, pyrite, and malachite. In addition, a nearby vein-type fluorite-barite mineralization, known as the Akkaya occurrence, is located close to the Tordere deposit and is also interpreted to have formed epigenetically from formation waters [59].

3.2.3. The Karalar (Gazipaşa/Antalya) Deposit

The Karalar galena–barite deposit is a vein-type mineralization hosted within the limestones of the Permian Bıçkıcı Formation. Galena and barite mineralizations are found in the Boyalık and Suluocak localities, referred to as the Boyalık, Büyük Ocak, and Sulu Ocak occurrences, respectively. At the Büyük Ocak site, the primary vein trends N85° W and dips 35° SW, while the host limestone layers trend N60° W with dips of 60–70° NE. The ore vein is unconformable to the limestone bedding and exhibits a reverse dip. The vein thickness ranges from 50 cm to 2.5 m. Notably, substantial limestone breccias occur within the ore vein, likely formed during faulting events. A second vein, trending N70° W and dipping 85–89° NE, is also vein-type in nature and has a thickness of 30 cm to 1.0 m. The third vein trends N85° E/85° NW and has a thickness of approximately 20 cm. This vein contains significant amounts of calcite in addition to barite. Exploration and production activities at the Boyalık mine have been conducted via open-pit methods within the ore zone. The mineralization developed along a thrust zone between the Permian Bıçkıcı Formation and the overlying Triassic Çamlıca Formation. It is generally discordant with the host rocks and is interpreted as epigenetic in origin [60].

The ore veins are composed primarily of barite (80%–85%) and galena (10%–15%), with minor amounts of sphalerite, pyrite, fahlore, limonite, quartz, and calcite as gangue minerals [27]. Meanwhile, ref. [61] proposed an exhalative–sedimentary model for the deposit, and [25,62] suggested a syn-sedimentary origin. However, the ore zones do not follow bedding or schistosity planes, and the fault-controlled nature of the mineralization clearly supports an epigenetic origin. According to [28,63], barium and lead were leached from Ordovician–Triassic basement rocks by deeply circulating meteoric waters during post-Triassic time, while barium and sulfur may have been mobilized from basement rocks by shallower heated fluids.

3.2.4. The Aydıncık–Silifke Region (Mersin) Deposits

The barite mineralizations in this region were initially studied under the scope of a project conducted by the General Directorate of Mineral Research and Exploration (MTA) of Türkiye [29]. These include the Koçaşlı and Aydıncık (Sarıyar) deposits in Aydıncık (Mersin) and the Gökbelen and Çılbayır deposits in Silifke (Mersin) (Figure 6c,d). The Koçaşlı and Aydıncık (Sarıyar) barite occurrences developed within the Middle–Late Cambrian-aged Çaltepe Formation and Devonian-aged limestones belonging to the Geyikdağ Unit of the Taurides. The Koçaşlı barite mineralization is located southeast of Koçaşlı village, within recrystallized Devonian limestones. It trends N10° W and dips 60° SW. The Aydıncık–Sarıyar barite mineralization is hosted within Devonian recrystallized limestones, forming a lens up to 8 m thick and 40 m long. The barite ore is gray to dark gray in color and occurs as thin layers and lenses at multiple stratigraphic levels, conformable with the bedding of the host carbonate rocks. The Gökbelen barite deposit is located north of Gökbelen village, within limestone zones of the Cambrian–Ordovician limestone–shale succession of the Seydişehir Formation. The ore vein trends N35° W and dips 15° NE [29,64]. The mineralized zone is 1.5 to 3 m thick. Barite is the principal mineral, accompanied by hematite, limonite, goethite, and minor quartz. The ore zone is generally iron-rich. The Çilbayır barite mineralization formed in limestones along a N30° E-trending fracture zone, north of Çilbayır village. Additionally, N–S oriented barite veins inclined 26° W and with thicknesses between 15 and 20 cm are observed along this line. The mineralization occurs within a zone varying in width from 2 to 8 m.

3.2.5. The Önsen Region (Kahramanmaraş) Deposit

In this region, three barite occurrences—Çilekli, Çınaraltı, and Dadağlı—are aligned from south to north. The northernmost Çilekli barite zone extends along a fault zone with a N15° E/90° NW orientation. The Çınaraltı barite zone, located centrally, exhibits similar structural characteristics with a N39° E/65° NW trend. The southernmost Dadağlı barite zone trends N80° E/90°. The nearly monomineralic barite ore occurs as irregular veins, pods, stockworks, and disseminations, formed primarily through hydrothermal filling and replacement processes. The Cambrian-aged host carbonates exhibit intense karstification, much of which is infilled with brownish terra rossa. The barite mineralization is hosted both in stockworks and in brecciated limestone, forming high-grade ore zones that are a few meters thick and extend approximately 300 m in length, bounded by fault zones (Figure 6e).

Barite mineralizations occur as isolated lenses and pockets, with an estimated reserve of 8000–10,000 tons. Mining activities in all three zones include both open-pit and underground operations.

3.2.6. The Şekeroba Region (Kahramanmaraş) Deposit

The barite deposits in the Şekeroba region are highly scattered, with an annual production ranging between 50,000 and 80,000 metric tons of ore. From north to south, the main deposits include Beyoğlu, Şekeroba, and Yıldız [29]. This region holds the distinction of being the first barite production district in Türkiye, with mining activities dating back to 1960.

The Şekeroba deposit contains the highest-quality barite in Türkiye and is operated by Barit Maden Turk A.S. (Istanbul, Türkiye). Annual production is approximately 40,000 metric tons of ultra-white barite ore (Figure 6f). The ore zone of the Şekeroba deposit trends N10° E/65° SE and extends up to 300 m in length. On average, it is 100 m wide and 15 m thick, occurring within Ordovician–Silurian-aged metasandstone and metashale of the Seydişehir Formation (Figure 7). The ore consists of coarse-grained, nearly monomineralic barite exhibiting a cataclastic texture. In addition to barite veins, uneconomic quartz veins are also present.

Petrographic studies indicate that the barite is highly deformed. Recrystallization originates along cleavage surfaces of large euhedral barite grains, resulting in the formation of fine-grained, subhedral secondary barite crystals. Textural evidence indicates that chalcopyrite is replacing barite in some parts of the deposit (Figure 8a). Additionally, lamprophyric dyke and sill intrusions are accompanied by the barites in the underground gallery.

The Beyoğlu deposit occurs as a steeply dipping vein trending N40° E/85° SE, with a thickness of 2–3 m. It is hosted in brownish quartzite of the Akçadağ Formation. The main Şekeroba barite deposit forms a roughly N–S-trending vein system. Active production continues from a vein at the Şekeroba deposit that reaches up to 20 m in thickness and extends several hundred meters in length. More than 10 million tons of barite have been produced from this vein; however, mining was halted due to increased overburden (stripping) requirements.

The Yıldız deposit is characterized by nearly E–W/30–60° N-trending veins hosted in alternating quartzite and shale layers of the Akçadağ Formation, with a maximum thickness of 4 m. These veins are frequently offset by faults and may reach lengths of 60–80 m. Barite occurs as red-colored, irregular lenses due to the presence of abundant hematite in the paragenesis. This deposit has not yet been exploited due to licensing issues. The red coloration is one of the most distinctive features of mineralization in this region.

3.2.7. The Hasköy (Muş) Deposit

Barite occurrences in the Muş region are hosted within the Middle to Upper Devonian-aged Meydan Formation of the Mutki Group, part of the Bitlis Metamorphics, which represents the older basement unit of the Anatolides. The barite mineralization is predominantly observed as fracture-filling veins that crosscut the stratification. Economically significant barite deposits have been exploited in several locations, including Hasköy, Azıklı, Elmabulak, Toprakkale, Kasor, and Kızılkilise.

The mineral assemblage associated with these occurrences includes barite, pyrite, chalcopyrite, sphalerite, galena, chalcocite, covellite, malachite, azurite, hematite, limonite, and quartz [65,66]. It is suggested that barium was transported by circulating seawater, which leached elements from the underlying rocks. A granitic intrusion likely played a key role in the mineralization process by acting as a heat source [31].

3.2.8. The Karakaya (Hakkari) Deposit

The Karakaya stratiform barite deposit occurs within the Triassic limestone–limestone shale alternating sedimentary sequence of the passive margin Paleozoic–Mesozoic carbonates of the Arabian Platform. Permian carbonates consisting of thick-bedded and black cherty limestone (Tanin Group) locally include vein-type barite-bearing Pb-Zn deposits (Kurşuntepe, Akkaya, Tanintanin, and Deştan). Mesozoic formations begin with Early Triassic shales (Çığlı Group) and gradually pass to carbonate–shale alternating shallow marine sediments (Cudi Group). The most important Pb-Zn deposits (Meskantepe, Üzümcü, Armutlu, Karakaya) occur in this group, especially in the thick-bedded dolomitic limestone layers (Figure 9). White-gray barite shows bandings up to 15 m and white feeder vein bodies up to 20 m. These large, newly discovered barite deposits occur approximately 300 m above the SEDEX-type Zn-Pb deposits [63,67]. Barites that are both stratiform (Figure 10) and vein-type (feeder veins) are monomineralic. Vein-type barites are formed in the feeder zone, while stratiform barites are formed on the seafloor [33].

4. Analytical Methods

Whole-rock analysis of barite samples was performed at Bureau Veritas Mineral Laboratories in Canada under the Group LF202 analytical package. The major oxides and several minor elements were determined for a 0.2 g sample using inductively coupled plasma (ICP) emission spectrometry, following lithium metaborate/tetraborate fusion and diluted nitric acid digestion. The loss on ignition (LOI) was measured by weight difference after heating the samples at 1000 °C. Rare earth and refractory elements were analyzed by ICP mass spectrometry following lithium metaborate/tetraborate fusion and nitric acid digestion of a 0.2 g sample. Additionally, a separate 0.5 g split was digested in aqua regia and analyzed by ICP mass spectrometry to determine the base metals.

Sulfur isotope analysis (δ³⁴S) of barites was performed by elemental analysis–isotope ratio mass spectrometry EA-IRMS in the Iso-Analytical Laboratory (UK). IA-R061 (barium sulphate, δ³⁴SV-CDT = +20.33‰) IA-R061, IA-R025 (barium sulphate, δ³⁴SV-CDT = +8.53‰), and IA-R026 (silver sulfide, δ³⁴SV-CDT = +3.96‰) references were used for the calibration and ¹⁸O correction to SO⁺ ion irradiation.

Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) of barites were determined at Middle East Technical University Laboratories. Isotope ratios were determined by taking the average of the measurements held in a serial manner. The ⁸⁷Sr/⁸⁶Sr data are presented as normalized to ⁸⁶Sr/⁸⁸Sr = 0,1194. During measurements, the NBS 987 Sr isotope standard was measured and, if significant, a bias correction was made. Analytical uncertainties are presented at the 2 sigma level. According to the long-term measurement results from the Middle East Technical University Laboratories, the Sr SRM987 standard gives an average value of 0.710250 ± 10 (n = 90).

Oxygen (δ¹⁸O) isotope analysis of barites was performed at the GNS Science (New Zealand) Stable Isotope Laboratory. Measurement of δ¹⁸O in sulfate minerals was performed using mass spectrometry (isotope ratio mass spectrometry (IRMS)). The barites were pyrolyzed at 1450 °C in silver capsules on a HEKA tech high-temperature element analyzer coupled with a GV Instruments IsoPrime mass spectrometer. All measurements were repeated three times. All results are reported in terms of reported values of +12.0‰ and −11.3‰ for δ¹⁸O values and VSMOW normalized to the IAEA-SO-5 and IAEA-SO-6 international standards. The analytical accuracy of these measurements is 0.5‰. Oxygen (δ¹⁸O) and carbon (δ¹³C) isotope analyses of Mesozoic barites were carried out at the Middle East Technical University Central Laboratory using the stable isotope ratio mass spectrometry analysis method. The δ¹³C and δ¹⁸O isotope ratios of carbonate samples were determined by gas bench continuous flow isotope ratio mass spectrometry (DeltaPlus XP Isotope Ratio Mass Spectrometer—ThermoFinnigan, Somerset, NJ, USA). The standard “NBS19 Limestone (NIST)” (δ¹³C: 1.95‰ and δ18O: −2.20‰) was analyzed in each set of experiments together with the samples and used to convert the crude isotopic ratios of the samples determined by the device into real isotopic values. The results were determined according to VPDB (Vienna Pee Dee Belemnite) in per mil (‰). The 1σ margins of error for δ¹³C and δ¹⁸O isotope ratios do not exceed 0.2‰.

Mineral chemistry analyses were conducted using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) at the Geochronology and Geochemistry Laboratory of Istanbul University—Cerrahpaşa (IUC-GGL), Department of Geological Engineering. Sample and standard reference materials (SRM) underwent ablation with an irradiance of approximately 5 joules per square centimeter, a spot diameter of 60 μm, and a laser pulse rate of 10 Hz. Plasma power was set at 1200, with helium utilized as the sample gas at a flow rate of 0.6 L/min and argon introduced as a make-up gas at the same flow rate. All isotopes were examined at low resolution, encompassing five samples within a 20% mass window and a total dwell time of 30 ms per element. For external calibration, the glass reference NIST612 was measured following every ten sample analyses utilizing the values provided by [68]. Data quality assurance involved the analysis of USGS reference glasses BCR-2G and AGV-2G [69] concurrently with the samples. The reduction of data was carried out using the ICPMSDataCal 12 software package [69].

5. Ore Geochemistry

5.1. Major and Trace Element Geochemistry

As a result of the high-grade nature of the analyzed barites, the concentrations of major oxides are very low (

Table 2. Whole-rock average major oxide composition of barite samples from deposits in Türkiye.

Deposit	SiO2	Al2O3	Fe2O3	MgO	MnO	CaO	Na2O	K2O	BaSO4	References for Table 2, Table 3 and Table 4
Kirazören (n:3)	6.33	1.78	3.78	<0.01	<0.01	0.03	0.08	0.05	80.99	this study
Kızılcaören (n:2) *	4.38	1.04	1.985	0.465	1.54	30.35	0.075	0.84	38.28
Şarkikaraağaç (n:18)	2.36	0.04	0.26	0.77	0.251	1.82	0.01	0.02	94	[54]
Hüyük (n:21)	0.12	0.02	0.02	0.01	0.005	0.47	0.01	0.01	94
Aydıncık (n:2)	2.94	0.12	0.09	<0.01	<0.01	<0.01	<0.01	0.03	95.45	this study
Tordere (n:3)	0.77	0.06	0.37	0.07	<0.01	1.95	<0.01	0.01	96.51	[30]
Önsen (n:3)	1.42	<0.01	<0.04	<0.01	<0.01	0.04	<0.01	<0.01	97.04
Şekeroba (n:7)	0.28	<0.01	0.07	0.02	<0.01	0.05	<0.01	<0.01	97.68
Hasköy (n:13)	3.71	0.16	0.89	3.39	0.07	4.53	0.26	0.01	43.5	[65]
Karakaya (n:3)	0.17	0.05	0.06	0.07	<0.01	2.27	0.02	<0.01	93.79	this study

* Additionally, Kızılcaören barites have 20% F composition. P₂O₅ and Cr₂O₃ values of all deposits < 0.01.

).

Table 3. Whole-rock average trace element composition of barite samples from deposits in Türkiye (ppm).

Deposit	Sr	Hf	Zr	Y	Cu	Pb	Zn	Ni	As	Cd	Sb	Hg
Kirazören (n:3)	8793.4	2.4	17	3.9	82.3	980.8	34.3	<20	995	0.4	1300	0.62
Kızılcaören (n:2)	5515	0.6	42.5	549	2	633	212.5	77	122.5	0.9	10	0.07
Şarkikaraağaç (n:18)	>10,000	-	-	-	27.3	20.9	343.7	<20	<5	-	6.9	-
Hüyük (n:21)	>10,000	-	-	-	<10	<5	353.8	<20	<5	-	2.35	-
Aydıncık (n:2)	16,292.5	2.05	2.85	1.8	2.65	0.75	3	0.25	0.6	<0.1	0.7	0.065
Tordere (n:3)	13,756.5	1.50	1.50	1.63	39.23	29.87	4.00	1.33	12.00	<0.1	17.20	4.19
Önsen (n:3)	15,205.2	2.0	0.5	1.3	25.2	0.3	2.0	0.1	<0.5	<0.1	0.8	0.3
Şekeroba (n:7)	10,923.6	2.2	0.9	1.7	22.8	0.8	3.0	0.6	0.8	<0.1	0.7	0.2
Karakaya(n:3)	24,448.1	1.9	1.1	2.2	5.9	1334.2	13.5	10.4	2.6	241.4	0.4	0.637

Table 3. Whole-rock average trace element composition of barite samples from deposits in Türkiye (ppm).

Deposit	Sr	Hf	Zr	Y	Cu	Pb	Zn	Ni	As	Cd	Sb	Hg
Kirazören (n:3)	8793.4	2.4	17	3.9	82.3	980.8	34.3	<20	995	0.4	1300	0.62
Kızılcaören (n:2)	5515	0.6	42.5	549	2	633	212.5	77	122.5	0.9	10	0.07
Şarkikaraağaç (n:18)	>10,000	-	-	-	27.3	20.9	343.7	<20	<5	-	6.9	-
Hüyük (n:21)	>10,000	-	-	-	<10	<5	353.8	<20	<5	-	2.35	-
Aydıncık (n:2)	16,292.5	2.05	2.85	1.8	2.65	0.75	3	0.25	0.6	<0.1	0.7	0.065
Tordere (n:3)	13,756.5	1.50	1.50	1.63	39.23	29.87	4.00	1.33	12.00	<0.1	17.20	4.19
Önsen (n:3)	15,205.2	2.0	0.5	1.3	25.2	0.3	2.0	0.1	<0.5	<0.1	0.8	0.3
Şekeroba (n:7)	10,923.6	2.2	0.9	1.7	22.8	0.8	3.0	0.6	0.8	<0.1	0.7	0.2
Karakaya(n:3)	24,448.1	1.9	1.1	2.2	5.9	1334.2	13.5	10.4	2.6	241.4	0.4	0.637

Table 4. Whole-rock average rare earth element composition of barite samples from deposits in Türkiye (ppm).

Deposit	La	Ce	Pr	Nd	Sm	Eu	Gd	Tb	Dy	Ho	Er	Tm	Yb	Lu
Kirazören (n:3)	6.57	5.47	0.55	2.40	0.7	*	3.87	0.20	0.81	0.16	0.36	0.03	0.22	0.03
Kızılcaören (n:2)	>10,000	>10,000	>1000	5140	599.5	140	317.5	34.8	128.9	17.52	35.05	3.75	19.95	2.49
Şarkikaraağaç (n:18)	0.36	<0.1	0.08	<0.1	<0.1	0.98	<0.1	<0.1	<0.1	<0.1	<0.1	<0.05	<0.1	<0.04
Hüyük (n:21)	0.16	<0.1	0.16	<0.1	<0.1	1.8	0.2	<0.1	<0.1	<0.1	<0.1	<0.05	<0.1	<0.04
Aydıncık (n:2)	2.55	0.75	0.09	0.35	0.26	*	2.71	0.04	0.17	<0.02	<0.03	<0.01	0.10	0.015
Tordere (n:3)	2.17	1.10	0.15	0.75	0.28	1.68	2.16	0.05	0.28	<0.02	0.06	0.02	0.20	0.03
Önsen (n:3)	1.8	0.2	<0.02	<0.3	0.2	<0.02	2.7	0.03	0.2	<0.02	<0.03	<0.01	0.1	0.01
Şekeroba (n:7)	2.1	0.3	0.1	0.5	0.2	<0.02	3.0	0.04	0.1	<0.03	0.05	0.02	0.2	0.03
Karakaya (n:3)	2.3	0.77	0.17	0.35	0.06	*	2.46	0.35	0.29	0.02	0.09	0.02	0.12	0.01

* These values could not be read due to high interference of other elements.

Table 4. Whole-rock average rare earth element composition of barite samples from deposits in Türkiye (ppm).

Deposit	La	Ce	Pr	Nd	Sm	Eu	Gd	Tb	Dy	Ho	Er	Tm	Yb	Lu
Kirazören (n:3)	6.57	5.47	0.55	2.40	0.7	*	3.87	0.20	0.81	0.16	0.36	0.03	0.22	0.03
Kızılcaören (n:2)	>10,000	>10,000	>1000	5140	599.5	140	317.5	34.8	128.9	17.52	35.05	3.75	19.95	2.49
Şarkikaraağaç (n:18)	0.36	<0.1	0.08	<0.1	<0.1	0.98	<0.1	<0.1	<0.1	<0.1	<0.1	<0.05	<0.1	<0.04
Hüyük (n:21)	0.16	<0.1	0.16	<0.1	<0.1	1.8	0.2	<0.1	<0.1	<0.1	<0.1	<0.05	<0.1	<0.04
Aydıncık (n:2)	2.55	0.75	0.09	0.35	0.26	*	2.71	0.04	0.17	<0.02	<0.03	<0.01	0.10	0.015
Tordere (n:3)	2.17	1.10	0.15	0.75	0.28	1.68	2.16	0.05	0.28	<0.02	0.06	0.02	0.20	0.03
Önsen (n:3)	1.8	0.2	<0.02	<0.3	0.2	<0.02	2.7	0.03	0.2	<0.02	<0.03	<0.01	0.1	0.01
Şekeroba (n:7)	2.1	0.3	0.1	0.5	0.2	<0.02	3.0	0.04	0.1	<0.03	0.05	0.02	0.2	0.03
Karakaya (n:3)	2.3	0.77	0.17	0.35	0.06	*	2.46	0.35	0.29	0.02	0.09	0.02	0.12	0.01

* These values could not be read due to high interference of other elements.

The results of whole-rock trace element analyses are presented in Table 3. Due to the predominantly monomineralic nature of the barite samples, trace element concentrations are generally very low, with most values falling below the detection limit. Elements below this threshold are not included in the table.

Among the analyzed samples, the Kirazören deposit, along with Kızılcaören, displays distinct trace element signatures. Kirazören barites contain 1.5 ppm Sn, 0.3 ppm Rb, 1.9 ppm Th, 5.4 ppm U, 27 ppm V, 0.4 ppm Cd, and 15 ppm Mo. In contrast, barites from passive margin settings exhibit trace element concentrations that are mostly below the detection limit.

In addition to whole-rock analyses (see Table 2, Table 3 and Table 4) conducted on powdered samples, mineral chemistry analyses were also performed on individual barite grains, with the average values summarized in

Table 5. Average trace element composition (ppm) from mineral chemistry analyses of barite samples from various deposits in Türkiye. PMH = passive margin-hosted.

Deposit	Kızılcaören (n:44)	Kirazören (n:26)	Cenozoic PMH (Karakaya) (n:31)	Paleozoic PMH
				Tordere (n:9)	Önsen (n:12)	Hasköy (n:12)	Mean PMH (n:33)
Sc	0.15	2.53	0.06	0.03	0.03	0.05	0.04
V	2.78	12.06	0.82	0.84	0.11	0.03	0.28
Cr	4.18	20.79	0.44	0.02	0.20	0.13	0.13
Co	0.05	0.05	0.04	0.07	0.02	0.02	0.03
Ni	0.49	1.21	0.69	0.30	0.18	2.14	0.92
Ga	1.00	0.75	0.05	0.04	0.02	0.02	0.02
Ge	1.03	0.58	0.98	0.68	0.63	0.47	0.59
Rb	0.21	0.10	0.10	0.07	0.04	0.06	0.05
Sr	9123.38	14,587.19	44,720.26	30,874.79	19,722.82	26,640.41	25,294.30
Y	18.81	14.00	16.71	13.52	14.55	13.59	13.92
Zr	0.69	12.20	0.18	0.01	0.03	0.01	0.02
Nb	0.22	0.37	0.00	0.001	0.003	0.002	0.00
Cs	0.10	0.04	0.03	0.02	0.05	0.09	0.06
La	37.90	6.17	2.05	3.63	3.18	4.14	3.65
Ce	38.15	4.34	0.15	0.52	0.44	0.28	0.40
Pr	3.92	0.29	0.01	0.04	0.004	0.10	0.05
Nd	12.14	1.86	0.56	1.64	1.32	1.85	1.60
Sm	2.24	0.64	0.49	0.83	0.71	0.77	0.76
Eu	29.22	21.39	16.06	40.69	36.17	46.78	41.26
Gd	2.48	0.98	0.74	1.05	0.99	1.12	1.06
Tb	0.12	0.01	0.00	0.002	0.0004	0.002	0.00
Dy	0.61	0.11	0.00	0.01	0.0013	0.01	0.01
Ho	0.11	0.02	0.00	0.002	0.0047	0.002	0.00
Er	0.27	0.08	0.01	0.03	0.01	0.02	0.02
Tm	0.03	0.01	0.00	0.01	0.01	0.01	0.01
Yb	0.17	0.10	0.01	0.02	0.02	0.03	0.02
Lu	0.04	0.03	0.05	0.03	0.03	0.03	0.03
Hf	1.04	1.15	2.00	1.07	1.09	1.14	1.10
Ta	0.01	0.04	0.00	0.001	0.002	0.001	0.00
Pb	0.34	76.86	6.18	0.56	0.13	0.56	0.40
Th	15.02	0.94	0.00	0.05	0.005	0.02	0.02
U	1.20	1.04	0.04	0.05	0.03	0.01	0.03
Zn	1291.45	1336.82	1680.12	1024.76	1202.43	1053.34	1099.76

. This method allowed for the detection of elements that were below the detection limit in whole-rock analysis, such as Sc, V, Cr, Co, U, and Th. Notably, the Kirazören barites are characterized by comparatively elevated concentrations of Sc, V, Cr, and Zr in the mineral chemistry results.

Notable trace element enrichments are observed in several barite deposits: Kirazören barite shows elevated concentrations of Au (up to 1 ppm in one sample), Cu, Pb, As, and Sb; Karakaya barite exhibits higher Pb, Zn, and Cd values; and one barite sample from Tordere is characterized by increased Cu, Pb, As, Sb, and Hg concentrations.

SrO composition of barites was calculated from Sr values. SrO compositions were analyzed as 1.4–2.04 in Tordere barites, 0.6%–2.6% in Sekeroba barites, 1.1%–1.99% in Önsen barites, 1.8%–2.1% in Aydıncık barites, 1.1%–3.7% in Karakaya barites, and 0.91%–1.1% in the Kirazören deposit. These values are similar to those of SrO compositions of hydrothermal deposits.

5.2. Rare Earth Element (REE) Geochemistry

The results of rare earth element (REE) analysis are presented in Table 4, and the chondrite-normalized REE distribution diagram [70] is shown in Figure 11. The total rare earth element (TREE) content of barite samples from Türkiye generally is low, with the notable exception of the Kızılcaören carbonatite-hosted F–REE–Ba deposit. This deposit contains several million tons of barite resources [44], and the barite-rich banded ores exhibit elevated TREE concentrations, particularly enriched in light REEs (LREEs).

The steep downward trend from LREEs to heavy REEs (HREEs) indicates pronounced fractionation, consistent with high-temperature formation conditions and the strong complexation and mobilization behavior of HREEs. A weak positive Ce anomaly is observed in the Kızılcaören barite, whereas barites from other deposits display distinct negative Ce anomalies. The negative Ce anomaly has been attributed to the influence of seawater-derived components in the ore-forming hydrothermal fluids [71,72,73].

A weak negative Ce anomaly observed in the volcanic arc-hosted Kirazören deposit suggests limited seawater involvement in the hydrothermal system responsible for transporting Ba²⁺ and SO₄²⁻ ions. These barites also display a negative Eu anomaly alongside a positive Gd anomaly. The presence of a positive Gd anomaly has been previously documented in modern oceanic barite formations [4], Permian carbonates in Iran [74], and Paleozoic carbonates in southeastern Bosnia [75].

In terms of total rare earth element (TREE) content, the deposits can be ranked in decreasing order as follows: the carbonatite-hosted Kızılcaören deposit; the volcanic arc-hosted Kirazören deposit (both magmatism-associated); and sedimentary-hosted deposits such as Karakaya, Şekeroba, Tordere, Aydıncık, and Önsen (classified as passive margin-hosted, or PMH deposits). This trend in REE enrichment shows an inverse relationship with radiogenic character: deposits with higher TREE contents exhibit lower radiogenic signatures, while those with lower TREE contents display higher radiogenic character.

Eu values could not be detected in the whole-rock analyses due to significant interference from other elements. This is likely because Eu²⁺ can substitute for Ba²⁺ in the barite structure owing to their identical charge and similar ionic radii [76,77,78]. However, mineral chemistry analyses reveal relatively high Eu concentrations (Table 5, Figure 12). Europium can also be strongly concentrated in plagioclase feldspar and subsequently mobilized by hydrothermal fluids, similar to barium. Positive Eu anomalies have been frequently reported in modern deep-sea hydrothermal systems [79,80,81], where hot hydrothermal fluids are particularly enriched in Eu compared to other rare earth elements [82,83,84].

5.3. Isotope Geochemistry (S, O, D, Sr)

Due to its similar atomic radius to barium, strontium is commonly incorporated into the barite structure and provides valuable information about the source and evolution of barium in the system. The ⁸⁷Sr/⁸⁶Sr isotopic ratio is widely used for stratigraphic correlation and absolute dating [85]. To compare the isotopic signatures of various deposits, ⁸⁷Sr/⁸⁶Sr isotope analyses were conducted on 20 barite samples from different locations. The results, along with corresponding δ¹⁸O and δ³⁴S (‰) values, are presented in

Table 6. ⁸⁷Sr/⁸⁶Sr, δ¹⁸O (‰), and δ³⁴S (‰) values of barite samples from Türkiye.

Deposit	87Sr/86Sr	δ18O (‰)	δ34S (‰)
Kirazören1	0.70717	6.3	17.08
Kirazören 2	0.70688	7.0	7.73
Kızılcaören1	0.70598	8.6	5.90
Kızılcaören3	0.70605	9.6	5.61
Kızılcaören5	0.70608	7.5	5.78
Şarkikaraağaç *	0.714	13.6	27.9
Hüyük *	0.7105	13,2	28.5
Aydıncık	0.71884	13.1	35.48
Aydıncık 2	0.71761	12.7	32.10
Tordere Feke	0.71283	16.6	31.46
Tordere Feke2	0.71109	15.8	32.01
Önsen	0.71213	11.5	20.70
Önsen Dadağlı	0.71111	11.1	21.14
Önsen Çınaraltı	0.71052	11.3	19.98
Şekeroba	0.71183	11.6	28.93
Şekeroba	0.71213	9.1	40.44
Şekeroba	0.71259	10.2	34.59
Sekeroba Beyoğlu	0.71273	10.8	29.46
Şekeroba Yıldız	0.7157	10.3	32.68
Şekeroba Yıldız	0.71373	12.8	31.80
Hasköy *	0.71311	14.04	38.18
Karakaya 2	0.70831	14.3	24.19
Karakaya 3	0.709	13.9	23.05

* Şarkikaraağaç value is the mean value of 22 samples. Hüyük value is the mean value of 13 samples [54]. Hasköy value is the mean value of 22 samples from [65]. Tordere, Şekeroba, and Önsen values are from [30].

.

Comparing the Sr isotope ratios of barites, the Kızılcaören F + Ba + REE + Th complex ore reveals the lowest radiogenic value (0.706‰), and it is obviously associated with a young magmatic source. This low radiogenic Sr isotope ratio is compatible with the Oligocene carbonatite magma emplacement into the Triassic metasediments, which hosts the deposit. The following Sr isotope ratio belongs to the Kirazören barite deposit (0.707‰) which is located in the Upper Cretaceous volcano sedimentary succession of the Pontides. These two magmatism-associated deposits are remarkable with their comparatively lower ⁸⁷Sr/⁸⁶Sr ratios as well as δ ³⁴S and δ¹⁸O.

The ⁸⁷Sr/⁸⁶Sr ratios of the Karakaya stratiform barite deposit, found within Jurassic limestones, are consistent with its age, measuring 0.709‰. Other deposits, such as the Tordere (0.712‰), Şekeroba, and Önsen deposits (0.713‰), exhibit elevated radiogenic values, though none are as high as the Aydıncık deposit (0.718‰). Beyond the eastern Taurides, Paleozoic passive margin-hosted barite deposits in Türkiye display varying ratios: Hüyük barites in the central Taurides range from 0.709 to 0.710, while Şarkikaraağaç barites range from 0.711 to 0.718 [54]. These data indicate that the ⁸⁷Sr/⁸⁶Sr ratios in the eastern Taurides are generally more radiogenic than those in the central Tauride region, with the Aydıncık deposit notably presenting the highest radiogenic value. Furthermore, Muş barites exhibit ⁸⁷Sr/⁸⁶Sr ratios ranging from 0.711 to 0.714‰ [65], which are more radiogenic than coeval seawater. This elevated radiogenicity is attributed to the interaction of Devonian seawater with the continental crust, leading to the mobilization of Sr and Ba [31].

The Kızılcaören and Kirazören deposits are notable for their comparatively lower δ³⁴S and δ¹⁸O ratios. When plotted on the diagram of δ³⁴S values for sulfur-bearing minerals in hydrothermal systems [86], the isotopic signature of the magmatism-associated Kızılcaören and Kirazören barites suggests that the ore-forming fluids likely originated from a magmatic source. In contrast, the δ³⁴S values of passive margin-hosted barite deposits clearly indicate seawater–sediment interaction.

In addition to these isotope analyses, oxygen and hydrogen (δ¹⁸O and δD (²H)) isotope analyses were performed on three quartz samples from veins accompanying barite veins in the Şekeroba deposit [30]. δ¹⁸O and δD values of the fluid inclusions in quartz samples were analyzed using the isotope fluorination method to determine the nature of ore-forming fluids. The results show that the δ¹⁸O values of quartz are similar to those of barites. The mean δ¹⁸O value for quartz is 15.8‰, and the δD value is −67‰. These values align with those metamorphic waters, which typically exhibit a wide range of δ¹⁸O values between 5‰ and 25‰, and δD values between −70‰ and −20‰ [87,88].

6. Discussion

Barite deposits in Türkiye exhibit diverse geological origins, geochemical characteristics, and isotopic compositions, reflecting the complex interplay of tectonic evolution and varied fluid sources across the region. These deposits are broadly classified into two main groups: magmatism-associated deposits and passive margin-hosted deposits, each possessing distinctive features.

6.1. Geological Environment

Magmatism-associated barite deposits, exemplified by those at Kızılcaören, Kirazören, and Karacaören, are typically found within volcanic, volcaniclastic rocks, and carbonatites. Their genesis is directly linked to Late Cretaceous to Miocene magmatic activity in the Pontide arc and the extensional tectonic regimes of western Anatolia [38,39,40,42,43,47]. Notably, the Kızılcaören deposit is hosted by Oligocene carbonatite intrusions [43,44], sharing mineralogical characteristics with well-known REE-barite deposits like Bayan Obo (China) and Mountain Pass (USA).

In contrast, passive margin-hosted barite deposits, including Şarkikaraağaç, Hüyük, Şekeroba, Önsen, Tordere, Aydıncık, Hasköy, and Karakaya, occur within Paleozoic–Mesozoic sedimentary sequences across the Taurides and the Arabian Plate [25,26,27,28,29,30,31,33,54,55,56,57,58,59,60,61,62,63,64,65,66,67]. These deposits encompass both stratiform and vein-type occurrences, frequently hosted by limestone, dolostone, or schist. Their textures and morphologies are consistent with sedimentary–diagenetic or low-temperature hydrothermal processes.

6.2. Trace Element Geochemistry

Whole-rock and in situ analyses reveal distinct trace element profiles distinguishing the two deposit types. Kirazören and Kızılcaören barites are significantly enriched in elements such as Pb, Zn, Mo, U, Th, and rare earth elements (REEs), indicating hydrothermal fluids with a prominent magmatic component. Conversely, passive margin-hosted deposits generally exhibit low concentrations of trace elements, with notable exceptions like Tordere and Karakaya. In these instances, a slight enrichment in base metals suggests either fault-controlled fluid flow or interaction with Pb–Zn systems [33].

The carbonatite-hosted Kızılcaören deposit in particular displays exceptionally high total REE (TREE) contents, characterized by a steep light rare earth element (LREE)/heavy rare earth element (HREE) pattern and a positive Ce anomaly. This geochemical signature is consistent with high-temperature fluids derived from carbonatitic sources [43,46,70]. In stark contrast, passive margin-hosted barites typically show flat to slightly LREE-enriched patterns and negative Ce anomalies, which are interpreted to reflect low-temperature seawater–sediment interaction and diagenetic precipitation [4,30,70,71,72,73].

6.3. Isotopic Signatures

A genetic approach to determining the source of barium has been undertaken using its sulfur, oxygen, and strontium isotopic compositions. Barite precipitation can occur through several mechanisms: directly from the seawater column (marine barite); at the oxic–anoxic boundary within marine sediments where barium-rich pore waters migrate upwards and react with sulfate-rich seawater (diagenetic barite); or from hot hydrothermal solutions (hydrothermal barite) [89].

Sulfur isotope values (δ³⁴S) provide further insight: magmatism-associated deposits such as Kızılcaören and Kirazören, exhibit relatively low δ³⁴S values (5.6‰–17‰). These values are consistent with magmatic or mixed sulfur sources [86,89]. In contrast, δ³⁴S values for passive margin barites are notably higher, often exceeding 30‰ (e.g., Şekeroba, Aydıncık). Oxygen isotopes (δ¹⁸O) further support these trends: magmatic barites typically display lower δ¹⁸O values (6‰–9‰), while sedimentary-hosted barites show elevated values (up to 16.6‰) [30,33,54,67]. This suggests lower-temperature fluid evolution and greater influence from marine pore waters.

The δ³⁴S, δ¹⁸O (‰), and ⁸⁷Sr/⁸⁶Sr isotope values of the studied barites were plotted on a diagram adapted from [90] to facilitate comparison with various environmental settings [89,90,91,92,93,94,95,96,97,98,99] (Figure 13). Magmatism-associated barites plot in the lower-left quadrant of the diagram, indicating slightly lower values than marine hydrothermal barites. Conversely, passive margin-hosted barites occupy a large area on the right side of the diagram (Figure 13a), clustering at the intersection of marine cold seep, diagenetic barites, marine hydrothermal, and continental barite fields.

The cold seep formation model has also been proposed for barites from other regions, including the Sea of Okhotsk [92,100,101], Selwyn Basin [15], and the Gulf of Mexico [93,102]. This aligns with the typical diagenetic source and formation characteristics observed in passive margin-hosted barite deposits in Türkiye. In contrast, magmatism-associated deposits (Kızılcaören and Kirazören) strongly suggest a possible magmatic contribution and/or associated hydrothermal processes. Furthermore, the δ³⁴S and ⁸⁷Sr/⁸⁶Sr isotope values of the magmatism-associated barites again show slightly lower values compared to marine hydrothermal barites, while passive margin-hosted barite deposits exhibit isotopic signatures more akin to continental barites (Figure 13b).

While δ³⁴S values of the Mesozoic passive margin-hosted Karakaya barite deposit closely resembles seawater composition (Figure 13 and Figure 14a), Paleozoic passive margin-hosted deposits exhibit greater enrichment in heavy sulfur isotopes. Previous research by [103,104] interpreted the highly positive δ³⁴S values in pyrites as an indication of intensified diagenetic fluids driven by hydrothermal convection.

Unlike other Paleozoic passive margin-hosted deposits, the Mesozoic Karakaya barite deposit is distinct due to the presence of a large Pb-Zn deposit located over 300 m below its uppermost barite zone. Furthermore, it uniquely preserves both stratiform and feeder vent complex structures. This deposit was thus classified as a vent-proximal SEDEX-type deposit by [33]. Similar preserved feeder and vent complexes have been documented by various researchers (e.g., [105,106,107,108,109]) and are often defined as shale-hosted massive sulfide (SHMS) deposits. However, some studies [109,110,111,112,113] have also indicated that these deposits may lack clear exhalative features, instead showing evidence of subsurface or replacement-style mineralization, frequently replacing earlier barite. Nevertheless, given that the Pb-Zn-Ba deposits of the Karakaya (Hakkari) region are hosted within a carbonate series, it is more accurate to classify this deposit as a sediment-hosted massive sulfide (SMS) deposit.

Figure 14. (a) δ³⁴S isotope evolution curve [114], (b) ⁸⁷Sr/⁸⁶Sr isotopic change in seawater over geological time [115] and positions of the studied barite deposits in Türkiye.

Figure 14. (a) δ³⁴S isotope evolution curve [114], (b) ⁸⁷Sr/⁸⁶Sr isotopic change in seawater over geological time [115] and positions of the studied barite deposits in Türkiye.

Passive margin-hosted barites typically exhibit more radiogenic ⁸⁷Sr/⁸⁶Sr ratios, ranging from 0.710 to 0.718. These elevated ratios indicate significant interaction with either radiogenic continental crust or highly evolved marine fluids, as further summarized in Figure 15, which presents these characteristics in accordance with their host rock features and tectonic setting. Notably, the Aydıncık barite (0.71884) records the highest radiogenic value among all deposits investigated in this study, potentially reflecting extensive leaching of crustal material [30,54]. Furthermore, lead (Pb) isotope data corroborate these findings, also pointing to highly radiogenic Pb sourced from old continental crust [30,33].

Such a significant influx of radiogenic Pb, Sr, and Ba from the continent into the marine environment, particularly during the Ordovician and Devonian, could theoretically result in primary hydrogenous or sedimentary barite deposition. However, the rapid transfer of such a large quantity of barium from land to sea within a short timeframe is geologically improbable. Therefore, a substantial amount of Sr and Ba must have been dissolved and transported into seawater from the thick sedimentary sequence characteristic of a passive margin setting.

Conversely, diagenetic barite deposits can form within marine sediments through the infiltration of barium-rich seawater. High biological productivity influences barium mobility and deposition. Enhanced biological productivity and subsequent organic matter decay lead to the development of anoxic conditions. Under these conditions, barium can dissolve from marine sediments, mobilize into oxic environments, and precipitate as BaSO_4. The migration of Ba²⁺ typically occurs from anoxic to sub-oxic or oxic conditions, with its pathway (upward or downward) depending on the distribution of anoxic sediments. Generally, however, organic matter-rich productive period sediments and their associated anoxic conditions are found below, with oxic sediments above. Methanogenesis within the anoxic sediments promotes the dissolution of Ba, Sr, and other divalent cations, facilitating their upward migration. These ions then encounter sulfate ions in oxic sediments or at the sediment-seawater interface, leading to barite precipitation. The presence of organic debris-rich black shale units at the bottom of the primary ore zone in the Şekeroba, Tordere, and Şarkikaraağaç deposits strongly indicates past productive marine conditions followed by anoxia linked to organic material decay.

Primary diagenetic–sedimentary barite deposits, having undergone subsequent orogenic movements, likely experienced dissolution and remobilization of barium from their original sites. This mobilized barium was then redeposited as vein and replacement-type mineralization within quartzites, shales, and limestones. However, the precise timing of this re-precipitation remains undefined. The absence of barite deposits in Triassic rocks suggests two possibilities: either the barite formed exclusively prior to the Triassic, or hydrothermal fluids did not reach shallow Triassic stratigraphic levels.

The barite ores consistently exhibit significant tectonic deformation and brecciation. Stable oxygen isotope data from quartz coexisting with Şekeroba barites do not indicate a signature related to seawater or rifting. Instead, the deformed nature of the ore, its low-angle geometry associated with thrusting, and the metamorphic oxygen–hydrogen isotope signatures [30] collectively suggest that deeply circulated lateral fluid movements played a major role in the secondary barium deposition. This regeneration phenomenon has also been discussed for Moroccan barite deposits by [118,119], who proposed that syn-sedimentary barites formed during the Cambrian were subsequently regenerated during Triassic rifting, concurrent with the opening of the Tethyan Ocean.

7. Conclusions

Türkiye holds a significant position as a global barite producer, contributing approximately 10% of the world’s total production and possessing resources estimated at several tens of millions of tons. These barite deposits serve both the dyeing and drilling industries, with an annual export volume of 200,000 tons. Barite occurrences in Türkiye are broadly categorized into two main groups based on their genesis: magmatism-associated and passive margin-hosted deposits. The latter group, characterized by relatively larger reserves, represents the primary source of barite production in the country. The general characteristics of these two distinct deposit types are summarized below:

Passive Margin-Hosted Barite Deposits:

• Primarily found within passive continental margin deposits of Lower Paleozoic age (e.g., Şarkikaraağaç, Tordere, Aydıncık, Hasköy), exhibiting either stratiform or vein geometries.
• Characterized by a relatively low abundance of trace elements, but high radiogenic ⁸⁷Sr/⁸⁶Sr and δ³⁴S values.
• Barite-forming solutions represent a mixture of seawater, diagenetic waters, or deep-circulating continental crustal waters.
• Share similarities in age and origin with the Atlas Mountains barite deposits (Moroccan deposits).

Magmatism-Associated Barite Deposits:

These deposits, exemplified by Kızılcaören, Kirazören, and Karacaören, exhibit the following general characteristics:

• Hosted in arc volcanics within the Pontides or in post-collisional Oligocene-aged carbonatites in NW Anatolia.
• Display higher concentrations of trace elements (e.g., Zn, Pb, As, Ag, Au, and REEs) compared to passive continental margin deposits.
• Exhibit low radiogenic Sr isotope values (⁷Sr/⁸⁶Sr) and moderate δ³⁴S values relative to passive continental margin deposits, clearly indicating an igneous (magmatic) source.