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150 New Data on Minerals. 2014. Vol. 49 MINERAL AGGREGATES IN THE PROMETHEUS CAVE IN WESTERN GEORGIA Elena N. Matvienko Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, [email protected] In 2011 near Kutaisi in the vicinity of Tsqaltubo city within the Lower Cretaceous limestones the Prometheus cave has been opened for visitors. The main types of mineral aggregates developed within the cave have been described. 7 photos, 6 references. Keywords: karst of Western Georgia, Tsqaltubo Plain, the Prometheus cave, mineral aggregates developed with- in the cave. In September 2012 the author was happy to Spa Resort located 9 km to the north-west from visit Georgia during the two-week tour with karst the Kutaisi city is known due to its thermal cave-bearing territories attending. waters and radon-bearing springs. Before the Due to the very often development of lime- 1990es Sataplya State Reserved Park existed stone strata belonging to the Cretaceous and here. It was found in 1935 and was famous with Upper Jurassic periods at the Caucasus (and dinosaurs traces and a small and attractive especially thick at the Southern slope of the Sataplya Cave (modest in compare with the Great Caucasus ridge), karst in Georgia is excel- Novoafonskaya Cave). lently revealed. In several regions of Georgia the In 1973 a new cave was discovered by the total thickness of karst-able rocks varies researchers of the karstological and speleologi- 1200–2600 m (Geology of the USSR, 1964). This cal laboratory of the Vashukhti Geographical fact as well as several other favourable regional Institute, Academy of Sciences of Georgia, in factors: hot and wet climate with abundant sedi- 9 km to the north-west from the Tsqaltubo in the ments, and active tectonic processes cause vast vicinity of the Kumistavi village. During further and various karst occurrence. Before 1990es investigation beside this cave the large system of more than 600 caves have been registered on the caves jointed together by an underground river Georgian territory – more than two third the all was discovered. In newest times the territory known caves on the territory of the Former received a grandiose governmental support of Soviet Union (Tintilozov, 1976). Most of caves tourism development in Western Georgia, and are situated at the Western Georgia. Large the Sataplya and Kumistavi caves have been Georgian limestone strip located in the interme- well-developed for tourist visits. In 2011 the cave diate place between the folded system of the was opened for visitors under the name “The Southern slope and the Georgian Block is attri- Prometheus cave”. buted to as a large speleological province (Geo- The entrance to the Prometheus cave is loca- logy of the USSR, 1964). Novoafonskaya among ted 100 meters above sea level. Its square is esti- the well-known caves of the Abkhazia one is the mated as 200–250 sq kilometers, and its depth most famous was discovered in 1961 and opened from the earth`s surface – 40 meters. As it was for visitors only in 1975. Within the scheme of shown during investigations, its full length of all speleological regioning this cave has been attri- coridors is about 20 kilometers. Now it is known buted to the subprovince of fore-mountainous that the cave consists of 17 halls, and 7 en- and low massifs as well as the caves of the Lower- trances-subcaves. Nowadays there is tourist Imeretinsky region. These caves are situated route with a length of 1.6 km that is finished near now at the territory of the modern Georgia (and the underground lake where all visitors take a the Tsqaltubo wavy plain, in particular) and simi- boat and sail out by the underground river to the lar in several features with them (Tintilozov, earth`s surface. Constant temperature in cave is 1976). The lowland consists predominantly of the +14°С. Bats live here as well as creations adap- Lower Cretaceous limestones. ted to live in darkness: freshwater mollusks, spi- Tsqaltubo karst region is situated at the ders, worms, crustaceans. Paths and stairs are eastern wavy and hilly vicinity of the Kol- arranged in such a way that tourists can visit five khidskaya lowland, in the valley of the Tsqal- large cave halls (up to 35 m length and 7 m in tubo River, to that from the north-east branches height) (Fig. 1). Artificial lighting sometimes are of the Sal`gural`sky ridge of the Great Cau- coloured, together with soft romantic music casus are attached. Tsqaltubo balneological evoke an atmosphere of mystery. Mineral aggregates in the Prometheus cave in Western Georgia 151 Fig. 1. Sight from the viewing platform. Fence 1 meter high. Photo: А. Lobachiov. Fig. 2. Stalactitic-stalag- mitic crust. Height of the «pagoda»attheright–3m. Photo: А. Lobachiov. Fig. 3. Stone «waterfall», 3 m high. Photo: А. Lobachiov. 152 New Data on Minerals. 2014. Vol. 49 Fig. 4. Stalactitic- stalagmitic crust coloured by terri- genic admixture. Height of the ceil- ing up to 2.5 m. Photo: А. Lobachiov. First of all, one may note the complicated and it was going without capture of terrigenic form of the karst cavity, feature of multiple (not material admixture belonging to streams perio- once) rock falls, distinct manifestation of stadia- dically fulfilling the cave. In places occurs lity of cave forms genesis when periods of mine- uneven colouring of cave forms by ferruginous ral formation alternated with stoppings-interrup- compounds in reddish-brown tones (Fig. 3), and tions, and apparently with periods of dissolution. locally – in yellow and merely bright (result of As a whole, these features as well as giant stalac- bacterial activity?) as well as in black colour with tite-stalagmitic formations (Fig. 2) are similar to metallic luster apparently due to the admixture the Novoafonskaya cave. of manganese compounds (vad MnO2·nH2O?). Viktor I. Stepanov has investigated the No- Stalactites (Fig. 5) here are very abundant, voafonskaya cave and described characteristics and more often than in the Novoafonskaya cave. of genetic stages of its development (Stepanov, There are many different forms: conical, cylindri- 1971). It was interesting for us to compare our cal, and flattened. During cave development cave observations with Stepanov notes and some stalactites were cut and in the centers of describe Prometheus mineral aggregates based stalactites cross-sections we can see feeding on the terms suggested by him and used during channels with continuing process of stalactite his work on “Caves” exposition in the Fersman formation droplets of sucking fluid (if there is a Mineralogical museum based on the material favourable lighting); as it may be often seen at from Central Asia caves. the edge of stalactite cross-section, it becomes As in the Novoafonskaya cave, very thick tuff the place of overgrowing by new generations of stalactite-stalagmitic crust is developed within small stalactites (Fig. 6). the Prometheus cave. In this case we mean the Linear ensembles of stalactites are very com- calc-tuff – pore calcitic rock forming the most mon if they are developed along cracks of the thick gravity cave formations (Stepanov, 1971; vault (Fig. 5, 6), as well as flattened stalactites – 1998). At the steep places of blocks obstructions products of linear sucking (Stepanov, 1998). tuff crust makes huge «waterfalls» formations Such natural mineralogical plumbs accurately (Fig. 3). following change of the location in space of the The reason of colouring of stalactite-stalag- feeding surface, became more complicated in mitic crust is terrigenic admixture (clayish, clay- their forms, and sometimes coalescence in place sand-bearing). And very often this admixture is forming fanciful bending drapes (Fig. 7). One not distributed evenly, and we can see fragments should note almost transparent strips that can be of pure-white translucent forms (Fig. 4) of more distinctly seen at the background of coloured by late generations in origin. the terrigenic clayish (Fig. 7b). Thus, in places one can observe calcitic sta- We can name these formations crystalactitic lactite-stalagmitic crust crystallization which similarly to translucent drapes at the “Caves” occurred more slowly than that of a tuff crust, exposition the translucent drapes at the exposi- Mineral aggregates in the Prometheus cave in Western Georgia 153 Fig. 5. Stalactites. Photo: E. Kislova. Fig. 6. Stalactites and stalagmites of the same generation. Photo: Т. Pavlova. tion “Caves” due to their coarse-grained texture They are similar to those developed in the No- (Stepanov, 1998). voafonskaya cave, with complicated surface Stalagmites are also very variable. Vastly relief that reflects multistadiality of their origin abundant are tuff stalagmitic crusts that arise (Fig. 2). Conical and cylindrical stalagmites in during the surface feeding (flat gravity stream) places overgrowth stalagmitic crust surface – (Stepanov, 1998). Typical crusts named “fried incrustations (Figs. 4, 6) often coloured due to eggs” (Fig. 3, at the front plan) forming at the the admixture of clay minerals. One may observe earliest stage of growth of the stalagmite itself white-snowy form with sparkling surface of during its axial feeding, before the moment numerous crystal faces. when geometric selection acts during the former Corallitic crust formed due to the evapora- growth. Large tuffo-calcitic stalagmites (in other tion of capillary thin films during «dry» periods is words, tufflagmites, according to Stepanov, well developed in the Novoafonskaya caves 1998) are very outstanding cave formations. (Stepanov, 1971) in side burrows, and secluded Fig. 7a, b. Stalactitic drapes: a – dimension up to 0.8 m. Red lighting. Photo: А. Lobachiov. b – Strips without terrigenic admixture, up to 4 cm wide. Photo: Т. Pavlova. a b 154 New Data on Minerals. 2014. Vol. 49 corners. In the Prometheus cave, when we wal- gous to the characteristics of live organisms ked along the main route, we have seen the over- (Slyotov, 1985).

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