MAIN MINERAL AGGREGATES

For the description of mineral aggregates, I use partially published Stepanov's classification, modified by our team. The generally accepted international classification completely adduced in C.Hill's and P.Forti's classical work, "Cave Minerals of the World", just like Maksimovich's popular classification with its several variants, have a number of serious errors with relation to the systematism of their construction, and therefore, they can not be successfully applied to Cupp- - Coutunn.

Maksimovich's classification is "too speleological". It outlines a group of stalactite classes that are almost similar in all aspects besides shape, which is influenced only by the rate of water inflow. At the same time, it denotes one group of "eccentrics", including all helictites, corallites, crystallictites and many other types of aggregates, each one includes more forms than the group stalactites does alone. Such a classification adequately defines the standard types of caves (Crimea, the Urals, Caucasus) but is absolutely unsuitable for the description of caves where the main way of solution supply differs from free current, and where calcite is not the only mineral. International classification, on the contrary, is "excessively mineralogical", with chemism as its main principle. Aggregates, differing from gravitational crusts, are too closely attached to minerals, which is not true in general cases. Thus, the antholites (Maleev's term) are directly associated with gypsum on the level of terminology (hence, "gypsum flower"), but at the same time there exist epsomite or ice antholites, which are visually indistinguishable from gypsum ones. This classification satisfactorily describes standard caves and also the "ore karst" caves, but it is not universal enough to apply to the Cupp- Coutunn System. Stepanov's classification principally differs from the two mentioned.

Terms of specific aggregates are not standardized in Stepanov's classification. The terms of this level, used below, were selected in descending order of their priority: - terms applied in publications by Stepanov and his followers. The terms define mostly aggregates of corallite and antholite crusts; - terms first used in Russia articles that were devoted to the genesis of a reported aggregate; - Maksimovich's classification terms (gravitational crust aggregates ); - terms from Hill and Forti's classification; - terms applied in foreign articles devoted to genesis of a reported aggregate; - terms applied in articles devoted to the morphology of a reported aggregate.

Corallite crusts. Aggregates of this class fundamentally differ from the above described formations and appear when the motion of thin films in the supplying solution is influenced more by capillary forces than by gravitational forces. These are dendrites, which consist of crystals (crystallictites) or of spherulites (corallites) and have a morphology acutely distinct from that of subaqueous dendrites. The first difference is that branches never intergrow, forming exactly multilevel bushes; secondly, there is an absence of crystallographic regularity in the branching of crystallictites. The fact of the controlling of the corallite and crystallictite growth exclusively by the physics of evaporation, which is always more active on surfaces with a small radius of curve (on ends, edges, and faces), is the reason for these differences. The difference in conditions of the formation of corallites proper and crystallictites is simply the rate of their growth. When the rate is low, crystallictites grow. When the rate is high, crystals start splitting and corallites form. Various intermediate forms also occur, such as dendrites consisting of curviedged crystals. Various transitional forms from gravitational crusts to corallites are often found, such as stalagmite-shaped bushes, that do not obtain enough solution from dripping water to allow the growth of normal stalagmites, but enough for the formation of a thin film spot, which provides local growth of corallites just under this point of dripping.

There is a group of important particular cases for corallite crusts. Absolutely different types of aggregates appear if more than one mineral is formed in a crust. Thus, by an exactly fixed proportion of magnesium in solution and enough intensive process of evaporation, the simultaneous growth of calcite and aragonite takes place. In accordance with the above reported model, aragonite growth occurs on the very edges as thin acicular crystals. In a small distance from the edge there is an inadequate amount of magnesium and the growth of the surrounding calcite crust proceeds.This crust, because of the speed of the extending of the film along the crystal has the morphology of a gravitational crust and prevents branching. This results in the formation of pseudohelictites, which have little similarity to dendrites, and have the appearances of occasionally branching and differently orientated "pencils" with thin aragonite crystal in the center.

It becomes more interesting if one considers the corallite crust of not just the noncarbonate minerals, but in addition, the highly soluble minerals (gypsum and particularly epsomite). The high solubility does not guarantee a stability and the microclimate system in the cave slowly changes. Naturally, the corallite crust becomes predominant for such minerals, but it is not enough. The lengthy existence of aggregates, and correspondingly, their large size, in any case seem to be less conditioned, but nevertheless, they exist. The trick consists of the prolonging of the aggregate's existence due to the brevity of the life of individuals. Large gypsum and all epsomite formations grow only in places with the intensive drawing of air. It is known that the so called "winter wind," from lower entrances to upper ones, and the "summer wind," from upper entrances to lower ones, exist in caves. Therefore, the seasonal fluctuations of wind cause the fluctuations of humidity near the entrances of the caves. The inward wind causes active evaporation to take place; the outward wind, allows condensation to proceed. According to the physics of evaporation and condensation, the former process is more active on the edges of the cave, and the latter prevails in the cavities. Thus, the crusts of soluble minerals undergo permanent recrystallization, corroding on one side and growing on the other. The crusts are separated from a substrate on the walls and the ceilings, being held on its roughnesses and sometimes falling down with the formation of "banks" up to a meter in size. Stalagmites rapidly turn into corallite crust formations which are hollow inside. Thus, the well-known 10m stalagmites of Khashm-Oyeek are up to 3m wide, and their walls are about 2 - 5cm thick. In particular cases, the process is so intensive that the crust that grows up during the dry period fall off in humid the period. Turchinov and I first described such "ephemerae" in the caves of Podoliya, and only after this, were they discovered in Cupp-Coutunn. It is notable that such aggregates before our publication were considered to form from the gas phase and it was even "proved" by the fact that in the Dzhurinskaya Cave on the barrer wall opposite to the dug out passage, gypsum bushes grew in a period of six months. Actually, this does not prove the transportation of gypsum by air, but attests instead to the role of wind and humidity in crystallization processes. To the point that the above mentioned gypsum chandeliers in Lechuguilla are also located where the lower humid levels of the system approach the canyon floor. It is interesting that as soon as the concept of permanent recrystallization was advanced, the gypsum massifs in the Cupp-Coutunn System immediately and with good results became considered as one of the most important exploration tools for substantial continuations of the cave system. During the mining exploitation, the caves were opened by several adits, which entirely reorganized the air circulation system. The gypsum massifs allow the reconstruction of old air flows, especially in places of their concentration ("necks" between slightly connected parts).

The antholite crusts are typical for noncarbonate highly soluble minerals and are formed at such degrees of drying, when the surface inflow of water is terminated entirely, yielding to the additional feeding exclusively through the pores from within the substrate. In the case of dense substrates with small pores, the filamentary crystals and their clusters are formed ("wool", "beards", flowers); in the case of clayey substrates with micropores, but with open joints of drying and with the inability to resist to crystalline pressure, needles and selenite interbeds appear. The distinct feature of growth of all such types of aggregates, entirely controlling their structure and morphology, is that they grow not on the free ends of crystals, but at the points of attachment, i.e., only the ends of the crystals that are located on the pores. Thus, the term "gypsum flower" is determined by the mechanism of splitting and twisting during the irregularity of the growth of the base.

The antholite crusts, as well as the noncarbonate corallites, are controlled by the seasonal cycle of humidity, but they may be controlled also by the cycles of humidity caused by floodings, which are sometimes irregular. The point is that the constant inflow through substrate pores is an absurdity, and in every case we come across the processes of the drying up of the periodically moistened substrate containing the required mineral. The moistening may occur very rarely. For example, I connect one-meter-needles of gypsum on clay massifs of the lower levels of the Cupp- Coutunn System with catastrophic floodings, appearing one or two times a century.

The mixing of corallite and antholite crusts is a usual phenomena for noncarbonate minerals. At a marked seasonal cycle, the fine-crystalline corallite crust occurs as a result, and it is sufficiently porous to serve as a buffer substrate for the growth of antholites during the peak of dryness every year. This is how the somewhat paradoxical crusts, separated from the wall, with flowers growing through are formed. Earlier, they were interpreted quite logically and intrinsically as three-generation forms, beginning from flowers through the crust to dissolution of crust with its removal from the wall. Nevertheless, all three generations proceed simultaneously, though in different phases during the cycle of the year.

The helictites (also called eccentric stalactites) are perhaps, the most enigmatic and unclassifiable aggregates, which represent occasionally branching calcitic or aragonitic "worms", uncontrolled by any evident processes. They are rare for typical caves, and therefore, since the first days of speleology as a science, the disputes about their morphology and genesis were very popular. Some scientists observed definite features, others, did not. Dozens of models, such as the models of the capillary channel, of the mutual crystalline pressure of three specially orientated individuals, of the growth from special film at particular chemism, and many others were advanced. The humorous fact is that everybody or almost everybody was right. In this case, we deal with a mineralogical analog of the convergency theory, i.e., with the effect of the essential external similarity of aggregates that possess different morphology and genesis. The capillary channel helictites are found often enough though the physical model of their genesis is not convincing. Nevertheless, the fact of solution inflow by the capillary channel is doubtless. The helictites of this type are most often found together with soda-straw. The soda-straw stalactite is a transition from gravitational to capillary form and represents unedged tubular monocrystals occurring more seldomly as twins, whose growth is conditioned by a very slow solution inflow and proceeds only along the perimeter of a hanging water drop. There are cases of such stalactite,in which capillary helictite grows, converting sometimes back into a soda-straw stalactites. The diameter of such secondary stalactites always differs from the original because of the changing of surface tension in proportion to crystallization. The capillary helictites do not transform back into stalactites in the areas of seasonal fluctuations of the humidity and stretch out toward dry wind. In this case, they are called anemolites.

The "spar" are also connected with soda-straw stalactites and represent short edged and twisted (sometimes into an ideal spiral-helicoid, which gave the designation to helictites) intergrowths of three crystals, whose mutual crystalline pressure caused this twisting. They also have a channel, but the linear cracks between individuals produce a part of solution onto the surface that provides an external edging. The pseudohelictites are a type of helictites, which actually are two-mineral corallites, as it was discussed above.

The other helictite types of the Cupp-Coutunn Caves are not studied in detail, though it is definitely known that a dozen types could be picked out among them with principally different genesis. For example, the helictites with a morphology extremely similar to channel forms are quite paradoxical, but growing only on the flowstone floor and amounting up to a meter high. The gravitationally orientated helictite bushes "flower beds," where every helictite is a stretched out, channelless spherulite cleaving along conchoidality and under every "flower bed" normal stalagmite grows, occurred in the presently destroyed Velikolepiye Hall of the Promeszutochnaya Cave, are obscured. Until present, no reasonable model has been proposed for straight aragonite helictites ("straw") which have a completely dissolved central channel, and the undissolved part of the crust is composed by crystals, forming a wooly surface and being identically directed relative to the axis. Some calcite helictites from the Glinyanaya Rechka section in the Promeszutochnaya Cave have an orientated overgrowing of gypsum that is, generally, a double absurdity, because the gypsum epitaxy over calcite is unknown, and the epitaxy of monocrystals on polycrystalline aggregates is impossible.

There are several classes of aggregates characteristic of the Cupp-Coutunn Cave System. Their genesis is controlled by so many distinct chemical features which are hardly expected in any other cave. The first class contains crystallictite crusts of fluorite originating in a very uncommon way connected with the double process in thin water films, through which hydrofluoric acid, if it is present in the air, reacts with calcite or gypsum. Thus, such crusts are not classified by solution inflow, because the solution is formed "in situ;" but as the dynamics of its circulation in proportion to the crystallization is controlled by capillary forces, the corallites and the crystallictites of common morphology grow. Corallites of other minerals exist which also grow from solution formed on the spot. In some cases it is simply the gypsum crust, that grows in places where sulfuric acid meets limestone. A detailed description of this mechanism will be given below.

In the second class are sulfide mirrors. The gigantic crystals of calcite (up to 2m) with inclusions of oxides and sulfides were left on the walls of the caves after the hydrothermal stage. These crystals underwent corrosion produced by the participation of hydrogen sulfide and sulfuric acid and with the removal of only soluble products by thin water films, during which the crystals were abraded up to the thickness of a few centimeters. The inclusions that existed in calcite emerged and underwent essential treatment by acids that resulted in the formations of metallic-lustrous "mirrors" on the dissolved surfaces.

The third class concerns almost all the aggregates of silicate minerals, the solutions for which were prepared "in situ", and the rate of crystallization from the prepared solution was so high (that is natural at almost neutral solubility) that it did not permit the gravitational or capillary forces of aggregates to develop, but only crystalline forces and also the components of the solution determined by the dynamics of the mixing process. In the already mentioned substance *4, whose dynamics of growth is highly reminiscent of a school experiment involving crystals of soluble salts in a silicate glue, we also considered the growth process in silica gel produced as the result of the treatment of montmorillonite from crystals of ferruginous and magnesial minerals by sulfuric acid.