Borate Deposits of Turkey and Argentina; A Summary and Geological Comparison
Abstract
1
Borate Deposits of Turkey and Argentina; A Summary and
Geological Comparison
CAH‹T HELVACI1 & RICARDO N. ALONSO2
1 Dokuz Eylül Üniversitesi, Mühendislik Fakültesi, Jeoloji Mühendisli¤i Bölümü, 35100 Bornova, ‹zmir - TURKEY
(e-mail: chelvaci@izmir.eng.deu.edu.tr)
2 Universidad Nacional de Salta and CONICET, Buenos Aires 177, 4400 Salta, ARGENTINA
Abstract: Turkey has the largest borate reserves in the world and Argentina is in third place. Both countries have
calcium and sodium borate deposits where colemanite, ulexite and borax are the principal minerals. We present
here a comparison of the main borate deposits interlayered in continental Miocene volcaniclastic rocks of the
Anatolian plateau (Turkey) and those of the Puna high plateau (Argentina).
The main borate deposits of Turkey are at Emet, Bigadiç, Kestelek and K›rka. Emet is in the western part of
the Kütahya province. In Emet, a sedimentary lacustrine sequence rich in tuffaceous materials hosts the colemanite
section. There are limestones and marl layers at the base and top of the borate section. Arsenic minerals (realgar
and orpiment) are very abundant and spatially related to the borates, indicating a common genetic origin. The
principal borate mineral is colemanite with minor ulexite, hydroboracite, meyerhofferite, and rarer species such as
veatchite-A, tunellite, teruggite and cahnite. Colemanite occurs as nodules of different sizes, agglomerated in thick
beds.
Bigadiç has borates interbedded with tuffs, clay and limestone layers. The borate minerals are formed in two
distinct zones, lower and upper, separated by thick tuff beds. Colemanite and ulexite predominate in both borate
zones. Other borates include howlite, probertite and hydroboracite in the lower zone, and inyoite, meyerhofferite,
pandermite (priceite), terschite, hydroboracite, howlite, tunellite and rivadavite in the upper borate zone.
The Kestelek deposit is 27 km southeast of the town of Mustafa Kemalpafla in the province of Bursa. The
borate zone consists of marl, limestone, tuffaceous limestone, tuff and borate layers. The borate minerals occur
interbedded with clay minerals. Colemanite is present as masses from nodule to boulder size (up to 1 m in
diameter), and as thin layers of fibrous and euhedral crystals. Colemanite, ulexite and probertite predominate and
sparse hydroboracite is also present locally.
The K›rka stratigraphic succession comprises borates that are intimately interbedded with and penetrating
marls, claystones, zeolitized tuff and tuffaceous epiclastic material in the lacustrine sedimentary rocks. The main
boron mineral is borax with lesser amounts of colemanite, ulexite and other borate minerals.
The volcano-sedimentary rock units in the Sultançay›r deposit include borate-bearing gypsum intercalated in a
sandy claystone unit. Calcium borates, mainly pandermite (priceite) and howlite, but also colemanite and bakerite,
are interspersed within the Sultançay›r gypsum.
The borates in all of these districts occur in older playa lake deposits of Miocene age that rest unconformably
on a Paleozoic and Mesozoic basement that is comprised of ophiolites, marbles and schists.
Argentina has lacustrine borate deposits restricted to 1) Sijes hill in the Los Andes districts of the Salta
province, 2) the Loma Blanca deposits of the Jujuy province and 3) the Tincalayu deposit located on the
northwestern margin of the Hombre Muerto Salar. There are also several borate occurrences within salars of the
Andes region.
Sijes hill is a topographically positive area of Miocene rocks, 30 km long, along the eastern border of the
Pastos Grandes salt pan. Borates occur as interbeds in a very thick lacustrine volcaniclastic sequence. Several
evaporitic members, with halite at the bottom and borate and gypsum at the middle and top, are interlayered with
tuffs and tuffaceous materials. Colemanite is the main borate mineral at the Monte Verde, Esperanza and Santa
Rosa mines. Other deposits are composed principally of mainly hydroboracite, the principal borate mineral in the
Sijes district. Colemanite occurs as spherules agglomerated in beds less than 1 m thick and is accompanied by
hydroboracite, inyoite and ulexite.
Predominantly borax and trace amounts of colemanite, ulexite and other borate minerals are also present in
the Loma Blanca deposit of the Jujuy province, and in the Tincalayu deposit.
Key Words: Borate, Colemanite, Turkey, Argentina, Anatolian Plateau, Puna High Plateau
... The presence of boron salt residues within the claystonedominated succession was initially reported by Ercan et al. (1983). Helvacı and Alonso (2000) suggested that these calcified pseudomorphs might originate from hawlite and colemanite. The limestones and dolomitic limestones that form the upper part of the unit are thick-bedded, whitish gray and well-consolidated. ...
In a re‐examination of the Neogene stratigraphy of the Uşak, Güre, and Selendi basins of western Anatolia, western Turkey, the stratigraphic position of the previously defined İnay Group is revised, which was previously considered to be of the Middle Miocene age. Based on mammalian biochronology and stratigraphic relationships, two sequences are identified, separated by conformable/transitional contacts within the former group: the Middle Miocene Güre Group is composed of the Fakılı Formation, characterized by alluvial fan deposits, and the lacustrine Derbent Formation. Radiometric dating of alkaline volcanics laterally associated with Güre Group sediments in the Uşak and Güre basins, and mammalian fossils re‐evaluated into the MN5‐6 biozones in the Selendi Basin, indicate early Middle Miocene. Considering the stratigraphic relationship with the overlying early Late Miocene İnay Group as redefined, we estimate that the Güre Group was deposited in the Middle Miocene. The İnay Group is characterized by a lateral–vertical transition from alluvial deposits of the Ahmetler Formation to the overlying lacustrine Ulubey Formation. An MN9‐10 fauna, containing deinotheres, was found within the latter formation.
Saline‐alkaline lakes are common in tectonically active, semi‐arid regions, resulting from the interplay between tectonic, hydrothermal, surface processes and climate. This study investigates their contribution to the evolution of the saline‐alkaline succession in the intramontane Ibar Basin (Southern Serbia). The succession is investigated using detailed sedimentological analysis, in situ U–Pb geochronology of carbonates acquired by laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS), major and trace element geochemistry and fluid inclusion analysis. Dominantly clastic sedimentation is represented by alluvial fan, flood plain, delta and marginal and profundal lake facies associations. Microbialite and littoral to sublittoral oil shales formed in the areas protected from clastic input. The stratigraphic succession shows a transition from alluvia to a hydrologically open and closed lacustrine environment. U–Pb geochronology of microbialite of a close lake phase (~17 Ma) suggests basin evolution during the Early to Middle Miocene age. The hydrologically closed lake phase is marked by borate‐rich facies, which comprise mainly colemanite overgrown by secondary ulexite within profundal lake facies associations. The textural features suggest that colemanite initially precipitated at or below the sediment/water interface. The subsequent growth, as observed from the primary fluid inclusions in colemanite and calcite, indicates precipitation from the evolving bittern brine under evaporitic, redox conditions, which during diagenesis reached temperatures of 200–220°C. High Ca²⁺/Na⁺ ratios in the brine favour colemanite precipitation. Gradual Ca²⁺ depletion and clay breakdown (dewatering) lead to ulexite and borax precipitates. The results imply that B, Ca and Na were mobilised and transported into the basin by hydrothermal fluids that previously leached bedrock and/or by streams carrying products of the volcanic rocks' weathering. However, brine saturation and syndepositional precipitation were initiated by an arid climate through evaporation, while further growth was driven by reflux of fluids during diagenesis. This study highlights the importance of the tectonics of the collisional orogens and associated processes, arid climate and basin hydrological regime on the deposition of B, Ca‐rich deposits in saline‐alkaline lakes.
Western Anatolia, Türkiye, is renowned for its diverse geothermal resources, encompassing high, medium, and low enthalpy systems. While these systems are valuable for energy production and economic development, they are also associated with significant environmental challenges, particularly high concentration arsenic and boron contamination. This study highlights critical hotspots, including Sandıklı (27 mg/L) and Banaz-Hamamboğazı (95.64 mg/L), with arsenic levels far exceeding the World Health Organization’s (WHO) maximum permissible limit of 10 ppb. Such contamination poses significant risks to water quality, agriculture, and public health, especially in major agricultural provinces like Aydın and Manisa. To address these challenges, machine learning models were applied to classify arsenic concentrations. Ensemble methods, including AdaBoost (ABC) and Extra Trees (ETC) classifiers, consistently outperformed others, showing high accuracy of about 97% in distinguishing geochemical signatures and predicting arsenic levels. In contrast, the k-Nearest Neighbors Classifier (KNNC) proved less effective, with frequent misclassifications. The combination of machine learning and meta-analysis provided a robust framework for identifying spatial and temporal patterns of contamination, offering valuable insights for environmental monitoring. This approach not only enhanced the understanding of arsenic distribution in geothermal systems but also provided actionable insights for mitigating contamination risks. The findings underscore the importance of combining computational techniques with environmental geochemistry to improve the management of geothermal wastewater. Future research should expand these methodologies to other regions and contaminants, leveraging machine learning to develop more effective environmental protection strategies. This study demonstrates the potential of data-driven approaches to address critical environmental issues and supports sustainable development in geothermal-rich areas.
Volcano-sedimentary (VS) deposits represent a relatively poorly studied and still underdeveloped type of Li resource. These deposits consist of mixed volcanic-sedimentary successions deposited in closed basins developed in felsic magmatic provinces. The Li ore in VS systems includes complex mineralogical assemblages dominated by phyllosilicates, borosilicates, and phosphates. In this paper we review the geologic features of VS Li deposits with the goal of providing a generalized deposit model, as well as an updated classification scheme, which can be used to aid a better understanding of this unconventional ore type and inform mineral exploration of VS-fertile geologic terranes. We focus on several key characteristics of VS deposits, including the following: (1) tectonic and climatic settings of VS-endowed districts, (2) geochemical footprint of Li-fertile magmatic rocks found in VS deposits, (3) mechanisms of transport and enrichment of Li from the primary igneous rocks to the critical zone, (4) physical and structural features of the geologic trap, (5) triggers for the Li deposition in the secondary ore assemblages, and (6) preservation and aging behavior of VS deposits, with implications for mineral exploration. These aspects are discussed based on published available data and also by presenting new observations on representative VS deposits from the western United States, eastern Europe, and elsewhere.
Lithium distribution in Bigadiç Borate Deposit and lithium-borate relations
In this work, the arsenic (As2O3) amount in colemanite ore was reduced from 4551 to 425 ppm using decrepitation. The crystal and amorphous states of products were determined by XRD measurements and the thermodynamic properties of samples were examined by DSC-TGA analysis. Elemental arsenic was analyzed using an ICP-ES/MS analyzer. As a result of the characterizations, a majority of the arsenic mass was found in the waste material for all temperatures. It was concluded that arsenic is carried on the surface of gangue minerals in the calcination process. Moreover, the decrepitated arsenic compounds tend to accumulate back on solid surfaces thus the amount of arsenic was found to be higher than the amount found in literature which is lower than 100 ppm. Therefore the affinity of arsenic compounds to montmorillonite and colemanite surfaces were further studied comparatively using molecular dynamics (MD) and Monte Carlo (MC) simulations. The resulting energy and density profiles show that the arsenic compounds have a higher affinity towards the montmorillonite surface. The simulation results reflect the decrease of accumulation amount on the surfaces with increasing temperature in parallel with the experimental measurements.
The Harmancık Basin, in the north-easternmost Miocene graben in western Anatolia, hosts a 12.6-m-thick coal seam located in the Keles coalfield, in which coals are being exploited by open-cast mining methods. Syngenetic clinoptilolite/heulandite-type zeolite formation in the upper part of coal seam and carbonaceous clayey diatomite as a roof rock have been identified for the first time, and the palaeoenviromental reconstruction of the coal seam was conducted using a multidisciplinary approach. The coal facies and palynological data show that vegetation and depositional changes took place during the middle Miocene, which resulted in vertical variations in elemental and mineralogical compositions. During the initial stages of mire development woody vegetation (e.g. pollen with affinity to Cupressaceae) prevailed, telmatic conditions were common, and preservation of organic matter was high due to anoxic conditions. Thus, relatively low-ash yield was observed in the lower and middle parts of the coal seam. Furthermore, the presence of kaolinite and smectite-type clay mineral aggregates in these parts of the coal seam suggests that alteration of synchronous volcanic inputs took place under weak acidic to neutral conditions. In contrast, limnotelmatic conditions prevailed during the late stages of peat-accumulation, and macrophytes coinciding with herbaceous peat-forming vegetation (e.g. Osmundaceae, Polypodiaceae, and Nymphaeaceae) were dominant. The elevated Gelification Index (GI) values in the uppermost parts of the coal seam could be related to development of alkaline conditions in the palaeomires, which also caused formation of syngenetic clinoptilolite/heulandite-type zeolite from the alkaline activations of synchronous volcanic inputs. Even though palynological data points to the prevalence of freshwater conditions during peat-accumulation, B enrichments along Sr/Ba ratio higher than 1.0 could point to possible marine influence; however, no Neogene marine deposits have been identified in the Harmacik Basin. Nevertheless, the SEM-EDX data show the presence of traceable Ba and Sr in clinoptilolite/heulandite grains, and Sr-bearing barite around feldspar grains in the studied samples from the upper parts of the coal seam. This implies K-feldspars and K-rich alkali-feldspars, derived from synchronous volcanic ash fall, altered under alkaline conditions. Moreover, alginite proportions increased towards the upper parts of the seam, while relatively high Hydrogen Index (HI) values were reached in the uppermost part of coal seam and carbonaceous clayey diatomite roof-rock sample. Furthermore, palynolgical data imply that vegetation changes towards the roof of the coal seam reflect the progressive development of more humid conditions and nutrient-rich surface waters, which favoured increased algal activity.
The Emet borate deposits are shown to be older and mineralogically more complex than was previously thought, and to have formed within the muds of playa lakes during the Middle Oligocene. The borate minerals formed in two geochemically distinct sedimentary basins, and are interbedded with marls, volcanic tuffs and clays, which appear to have been derived mostly from a volcanic terrain. Colemanite predominates, but other borates include meyerhofferite, ulexite, tunellite, teruggite, cahnite, hydroboracite and a form of veatchite. Reserves are ample, but the presence of arsenic in both the sulphite and borate phases can present problems during mineral processing.
A-ct -Borate minerals, such as colemanite, ulexite and borax, have been reported in Tertiary continental basins of West Anatolia, Turkey, and Samos Island, Greece. Tuffaceous rocks interbedded with the borates are rich in authigenic silicate minerals such as zeolites, potassium feldspar and opal-CT, all of which have a genetic association with the borates. Chemical analyses of the tuffaceous rocks show variation in major elements due to the varying per-centage of carbonaceous, detrital, and volcanic derived material. The volcanic activity in the vicinity of each particular lacustrine basin created ion-rich fluids from which a series of borates were precipitated under arid climate. Additionally, the We-alkaline character of these fluids was responsible for the diagenesis of the silicic glass of the tuffaceous rocks, altering them to silicates and silica polymorphs.
We have analyzed the boron isotope composition of 80 borate minerals (major minerals: borax, colemanite, and ulexite; minor minerals: veatchite-A, tunellite, kernite, terrugite, probertite, meyer-hofferite, inderite, inyoite, hydroboracite, howlite, and pandermite) from the main deposits (Kirka, Bigadiç, and Emet) and two smaller deposits (Kestelek and Sultançayir) in the western Turkish borate deposits. Forty-three samples were also analysed for their Sr isotope composition. The data span a wide range in δ11B values from -1.6%o to -25.3%o. The δ11B values of the main borate minerals are largely controlled by their mineralogy and the pH of the brines from which they precipitated. An inverse correlation between the average δ11B and ratios of colemanite in the different deposits suggests there is some variation in the sources of boron and Sr to the deposits. Emet has the highest contribution from aluminosilicates and Kirka the highest contribution from Eocene carbonates, with Bigadiç occupying an intermediate position. The δ11B values of the minor borate minerals distinguish between those which are primary precipitates from the original brines (or formed from primary borates without boron loss from the system) and those which formed from alteration of preexisting borate minerals with substantial loss of boron from the system.
Metamorphic basement complex are unconformably overlain by the Triassic Dışkaya (Karakaya) formation which is intruded by the Paleocene Çataldağ granidiorite unit. Lower Miocene andesite-aglomera and tuff unit rest top of all these older unit with unconformity, Midle-Upper Miocene sediments overly all the older units, and contents in ascending order, basement conglomarate, lower limestone, sandy claystone and upper limestone units.
According to the petrographic studies, metamorphic basement complex are composed of amphibolite and quartz -muscovite schist, whereas Dışkaya formation are composed of neomorphic limestone blocks, shale and lithareniüc sandstones, Sandstones taken from basement conglomerate unit show feldspatic litharenite composition. Boratiferous gypsum beds varying 10 to 15 meter in thicknesses, occur within the sandy claystone unit. Nodular pandermite and howlite minerals are present within these gypsum horizons. Chemical analysis shows that pandermite and howlite minerals have 46.49% and 40.69% B2O3 mean values respectively, It is estimated that the reserve of the Sultançayır borate deposit is approximately 1 million metric tons. However, a great amount of this reserve was mined out by the French and English companies during the period between the years of 1865 and 1955. In addition, probable distributions of gypsum beds are determined and 300 million ton geologic reserve arc calculated. These gypsum beds have 34% SO3 mean value and the properties of gypsum beds are suitable for the cement industry.
ÖZ : Çalışma alanında Permiyen yaşlı metamorfik temel karmaşığını ve üzerine uyumsuzlukla oturan Triyas yaşlı Dışkaya (Karakaya) formasyonunu Paleosen yaşlı Çataldağ granodiyorit birimi keserek yüzey lemistir. Bu birimleri Alt Miyosen yaşlı andezit-aglomera ve tüf birimi uyumsuzlukla örtmüştür. Tüm bu birimler üzerinde uyumsuz olarak yeralan Orta-Üst Miyosen çökelleri alttan üste doğru sırasıyla taban çakıltaşı, alt kireçtaşı, kumlu kiltaşı ve üst kireçtaşı birimlerinden oluşur.
Petrografik çalışmalar sonucu metamorfik temel karmaşığının amfibolit ve kuvars-muskovit şistlerden oluştuğu belirlenmiştir. Dışkaya formasyonu, feldispatik kumtaşı, şeyi ve kumtaşı, şeyi içinde yeralan neomorfik kireçtaşı bloklarından oluşmaktadır. Taban çakıltaşı biriminden alınan kumtaşları feldispatik litarenit bileşimler göstermektedir. Kumlu kiltaşı birimi içinde, kalınlığı 10-15 metre arasında değişen boraüı jipsler gözlenmiştir. Bu jipsler içinde modüler şekilli pandermit ve havlit mineralleri bulunmaktadır. Yapılan analizlerde pandermitlerin % 46.49 B2O3 ve havlitlerin % 40.69 B2O3 içerdikleri belirlenmiştir. Sultançayır borat yatağının tahminen 1 milyon ton rezervi olduğu sanılmaktadır. Ancak, yatağın büyük bir bölümü 1865-1955 yılları arasında Fransız ve İngiliz şirketleri tarafından işletilmiştir. Ayrıca, olası yayılımları belirlenen jipslerin 300 milyon ton jeolojik rezervi olabileceği hesaplanmıştır. Bu jipslerin SO3 oranları %34'ün üzerinde olup çimento sanayii için aranan özelliklere uygundur.
The Neogene borate deposits of Anatolia have thin sedimentary covers and have never been deeply buried. The major rockforming, calcium-bearing borates are colemanite and ulexite. Under progressive evaporation, borate precipitation occurred in a number of settings, from stable playas to perennial lakes, the latter evolving to shallow lakes and playa lakes. In all these lakes, shallow ing-upward cycliclty is common. Colemanite faciès occupy the margins, and ulexite faciès the centers of the basins; this mineral zonation is depositional and cannot be ascribed to diagenetic processes. Colemanite and ulexite formed mainly as interstitial growths under synsedimentary conditions, and as mineralogically primary, displacive and/or cementing lithofacies, which were affected by progressive compaction. Heliothermal conditions might have favored the precipitation of colemanite in some lakes; in others, subaerial (playa) conditions seem to have been appropriate. Locally, some colemanite is secondary and proceeds from the (macroscopic) replacement of precursor ulexite; this replacement occurred during either early diagenesis or (more probably) late diagenesis. Minor evidence exists for colemanite formation from replacement of precursor inyoite (?).
The Green River Formation of Wyoming was deposited in a large lake, Lake Gosiute, during Eocene time. Throughout Lake Gosiute's existence, nearby volcanism supplied debris to the lake basin. Tuffs are abundant and widespread in the formation and were highly reactive units. Reaction between glass and the lake waters produced authigenic clay minerals, mordenite or clinoptilolite, analcime, and potassium feldspar. Some tuffs are almost entirely replaced by authigenic aluminosilicate minerals. The alteration of the tuffs shows a systematic pattern with the clay mineral and zeolite alteration restricted to facies formed in relatively fresh water, and the feldspar alteration is confined to a hypersaline facies. We infer that the lake water ranged from fresh or brackish (SiO2 = 10 ppm, K = 50 ppm, Na = 1,000 ppm) at a pH of 8.0 during the "fresh-water stage" to hypersaline (SiO2 = 1,000 ppm, K = 5,000 ppm, Na = 100,000 ppm) at a pH of 9.0 to 10.0 during the most saline and alkaline stage. Brines were formed primarily by evaporative concentration. Organisms, reflected by abundant high-yield oil shales, thrived during the freshwater episodes, but were apparently absent or of minor significance during the hypersaline episodes; this is reflected by the presence of thick beds of trona and halite.
The major element chemistry and the rare earth element (REE) distribution of sedimentary smectite and diagenetic clinoptilolite from the lacustrine volcanic-sedimentary succession near Bigadic in northwestern Anatolia, Turkey, suggest a constant influx of volcanogenic material into the basin with, especially, a systematic negative Eu anomaly. This is supported by the Sr isotope chemistry which shows slight differences in the87Sr/86Sr of the sedimentary phases (carbonates and smectites) with values between 0.70835±7and0.70859±9 and the diagenetic clinoptilolite with values between0.70861±8and0.70893±17.This lacustrine volcanic-sedimentary succession is Early to Middle Miocene in age, with KAr values for the biotite and hornblende of the basal volcanic rocks showing an average age of ∼22 Ma. The KAr data of the clinoptilolite are strongly dependent on the permeability of the tuffaceous host rocks. They suggest an age of ∼14 Ma for the end of the diagenetic recrystallization of the clinoptilolite in impermeable rocks, and further chemical exchange with the interstitial fluids in the permeable rocks. This latter process induced a loss of radiogenic40Ar and REE out of the zeolites from the permeable tuffs, and might have had an influence on their chemical composition.
Ezcurrite (2NaaO.5B20s.7HaO) is a new sodium borate mineral discovered at the Tincalayu borax mine in the Province of Salta, Argentina. The mineral is associated with borax and kernite; tilexite and inderite also occur in the borate sediments. Tincalconite occurs as a weathering product of borax. Ezcurrite looks like kernite and has the following properties: Sp. Gr. = 2.153; ns (Na) a = 1.472, j8= 1.506, 7= 1.526; biaxial negative; 2V (calc) 73}°; Z A elongation 42.6°. It contains: B208, 58.21%; Na20, 20.73%; H20, 21.06%. The X-ray powder pattern shows the three most prominent d spacings to be 6.94A, 3.08A, and 2.77A.. The results of the differential thermal analysis are given. The deposit in which ezcurrite occurs has been deformed and is predominantly massive re-crystallized borax. The borax was probably recrystallized during the deformation and some of it dehydrated under elevated temperatures to form kernite. Ezcurrite, which is less hydrous, was probably also formed at about the same time by crystallizing from solutions released by the dehydration of borax or kernite perviously formed. The temperature necessary to form ezcurrite might or might not have been higher than that for forming kernite. If the temperature was high enough, metakernite might have been formed. Some evidence indicates that the inderite at the deposit is primary. The mineral is named for Sr. Juan Manuel de Ezcurra, manager of the Cia. Productora de Boratos, S.A., owner of the Tincalayu mine.