MINERALS

At the present moment, the Cupp- Coutunn System yields only to the Tuya Muyun Cave (Uzbekistan) and SCS (Bulgaria) in the variety of known minerals. The list that is cited here includes three types of minerals: minerals which have been proven, minerals known from single reports (noted by a question mark), and non-determined minerals (noted by numerated asterisks). We would like to apologize for the term "residual clays", which we use here to denote the bright-colored fluffy covers on the walls and ceilings in the zones of intensive corrosion before we discovered that they were not just relic products of corrosion of limestone, but a quite complexly organized and very active mineral-bacterium substance. So, we are unable to offer brief and capacious enoughy term for it.

Native elements. Only sulfur in the form of rock fragments of thin powder was found. The source is unknown. Biogenic genesis is supposed, though the sulfur bacteria were not discovered in the bacteriologic samples.

Sulfates. Gypsum is distributed widely enough in modern speleothems. It has two origins. The first is the entry of rain water from residual rocks of the Gaurduck beds (the largest, but local massifs); The second origin is the biogenic sulfur cycle, which will be considered below. Recently it was discovered that in many cases (in dry areas) the formations (especially flowers) which were thought to be gypsum actually are composed of epsomite in aggregates typical for gypsum. It is interesting that the presence of epsomite was presupposed on the basis of the chemical composition of the water and searched for sighty during two years, but it was discovered in quite another place. Celestite occurs in many generations most often together with gypsum, and forms very specific isolated rosettes of crystals up to 2cm. There are some reports of the occurrence of single crystals of barite (?), but the results of analysis are absent. Possibly *1, found during the first passing on a calcite floor in a narrowness near the Vodopadnyi Hall in the form of bright green 2mm spherulites, is connected to sulfates. In Moscow the sample of *1 dissolved completely during an attempt to wash it . It was not possible to repeat sampling because the floor in this narrowness was filled up with clay just after the first expedition. The composition of water in the nearest pools indicated it to be most probably nickel sulfate.

Carbonates. Calcite is widely distributed both in modern speleothems and in relics of hydrothermal deposits ( where the temperature is up to 150 and 200 degrees centigrade according to single reports). In speleothem formations, calcite occurs together with ferrocalcite, manganocalcite, dolomite and high-magnesium calcite, from which it can not be visually distinguished. Calcite can be recognized by staining methods. Only the high-magnesium calcite has some specific aggregates, and dolomite occurs also in the form of a thin powder in altered residual clays. Aragonite is a main speleothem mineral in some parts of the caves. Sometimes its growth instead of calcite is controlled by magnesium , in other cases by lead. The latter causes the presence of cerussite inclusions in aragonite aggregates. The absolute absence of celestite, evenly distributed throughout the system, in areas with a developed aragonite mineralization and the almost total absence of strontium in aragonite itself allows one to suppose the occurrence of strontianite, visually similar to aragonite. Siderite occurs in the form of thin modern incrustations on the ancient crystals of hydrothermal calcite in poorly corroded areas of the cave. There are two minerals, which have not been diagnosed and supposedly also belonging to carbonates. Single crystals of *2 occur on calcite helectites. The form of the crystal conforms to aragonite, but the much more intensive luster and the tints after a coloring test correspond to dolomite. A specimen was not taken, because of the special beauty and special protection management of the areas where this mineral occurs, and during the clearing of the tracks (the only way to take a sample in such regions), it was not discovered. *3 also conforms to aragonite in its crystalline form, but it was not studied as a sample for the same reasons. It forms very specific aggregates which are not known for aragonite (coral-shaped dendrites having a honeycomb texture inherited from the second, now dissolved, mineral of parallel growth); it always has a bright yellow color and is confined to areas of nickelous sauconite distribution.

Hydromagnesite. In all the cases, hydromagnesite blooms on the ends of aragonite crystals and helictites.

Oxides and hydroxides. A detailed study was not carried out. The iron oxides and hydroxides are often found in residual clays on walls and ceilings in intensely corroded zones. Manganese oxides in some places cover calcite and gypsum speleothems and crystals and also form dendrites inside of calcite speleothems. Quartz occurs in residual clays in zones of corrosion of hydrotermally altered limestone (crystals up to 0.2mm) and also together with fluorite of the thermal phase (crystals up to 2mm).

Sulfides. Halena occurs in the form of fine (up to 0.05mm) inclusions in hydrothermal calcite. In the same places metacinnabar is found together with hydrothermal fluorite (crystals up to 1mm) and also as a powder on aragonite bushes together with manganese oxides . There are some reports about pyrite (?) occurrences in the form of powders on gypsum crystals, which are not confirmed by analysis. Sphalerite is not present, though zinc is widely distributed in some places of the cave. Nitrates. Saltpeter blooms are known in areas near the entrance of the cave, but they were almost not specially researched. Mixtures of other readily soluble minerals occur in effloresiences together with the saltpeter, though their sources are different. Saltpeter is formed from guano, but the preconditions for the deposition of soluble salts transported from salt-bearing gypsum relics takes place in the same area. In one case we observed epsomite, in another, halite. Halides. Fluorite is distributed as large quantities of veined mineral rock debris and as poorly colored crystals (up to 5cm) of the thermal phase (80-100 degrees centigrade of formation temperature) on the walls and also as modern dark violet crystals (up to 1mm) on calcite and gypsum speleothems.

Silicates. Montmorillonite is found not only in conjunction with other clay minerals, but also as monomineral aggregates in the form of amorphous separate globules up to 1cm in diameter situated along the fissures on calcite crusts and filling out cavities of dissolution from the inside of gypsum clowds. Sauconite and fraipontite are as a rule, colored green by nickel and occur in the same form in the western part of the Promeszutochnaya Cave. Some data on the presence of other zinc-bearing alumosilicates in this region is available. The nickel minerals providing the green coloring have not been studied yet, and the causes of their attraction to zinc-bearing alumosilicates are quite obscure. Substance *4, having a composition close to silicates and absolutely paradoxical features was found in the Vodopadnyi Hall. The substance fills coarse gypsum clowds dissolved from the inside and has a felted texture which is highly porous. It was discovered only because its fragments had poured off and fallen into a pool during our passing and were still floating there after a week. We had no time to finish our study, but the primary data showed it to be a mixture of two minerals - silicates of iron and magnesium. However, the range of temperature possible in the caves contradict to the presence of the latter. Perhaps the substance is a product of the sulfuric acid treatment of montmorillonite, which often occurs under gypsum clowds with the presence of iron and magnesium ions in solution.

Other minerals. There are some reports on finds of tuyamunite (?) in the Geophyzicheskaya Cave, which are probably true, because anomalies up to 300 microrentgen per hour are known for this cave. It is unlikely that the tuyamunite is of cave origin, being rather rock fragments from veins.

Discovered, but absolutely unstudied minerals. Although this is one of the most interesting divisions, the available information is so ambiguous that there is nothing to describe in most cases. I will adduce two inquisitive examples of absolutely new minerals for Cupp-Coutunn. Mineral *5, found as a single rosette of crystals (the largest is about 3cm length) in the OSKHI Gallery, is fully impenetrable for sampling without destroying the vast helictite bush. The crystals display a very intense luster, are well-edged and absolutely atypical for the caves, which attracts great interest. According to the latest reports by Korshunov, single inclusions of *6 as bright green transparent crystals (about 0.1mm in size) were found in the gypsum fragments of an ancient chandelier from the basement of the Baobab Hall.

Products of technogenic mineral formation. I discovered two years ago that in some areas of the cave metal objects (ladders, topographical bench-mark laths and others) left there before had undergone a very interesting influence from the atmosphere. Almost all the aluminum in the bench-mark laths had disappeared and clusters of glassy spherulites, solid in one cases and a semiliquid gel in another, hung in its place. Recently Korshunov's expedition (including students from Moscow State University) brought samples and is intensively researching them.

MAIN MINERAL AGGREGATES