What does a stalactite look like? How are karst caves formed? Stalactites and stalagmites, other rock formations
Many people confuse these two concepts. Our educational program will put everything in its place.
As children, many people loved to climb caves, if they managed to take advantage of such an opportunity and found strange stone icicles sticking out of the floor or ceiling. These are stalactites and stalagmites, but who is who - what is the difference between them?
There is a science that deals with the study of caves - speleology. According to speleological studies in caves, as a result of a long time, where rocks of limestone, chalk, gypsum, salt and water are present, mineral formations protruding from the floor are formed in spaces washed out by water, growths - stalagmites, as well as hanging like icicles or drop-like mineral growths - stalactites.
Stalagmites, translated from Greek, means drop. It is a process emerging from the floor of the cave. It is formed when a drop of water flows from the ceiling and hits one point on the floor, forming a thick, spreading growth similar to a cone. Since the temperature on the floor is lower than above, a drop of water freezes faster, and therefore stalagmites can “grow” faster.
Stalactites, translated from Greek as flowing drop by drop, are stone formations hanging in the form of a needle. When a drop of water slowly drains from the ceiling and the temperature is low, the drop of water freezes, forming a stone build-up in the form of an icicle or a thick needle.
The frequency and fragility of rock formations depends on the composition of the rock, the time of formation of growths and the volume in the cave.
How are karst caves formed? Stalactites and stalagmites - what are they? Main breed Crimean mountains- limestone. Rocks riddled with cracks easily absorb moisture. Rain and melt water with dissolved carbon dioxide flows through them deep into the mountain. This very weak carbonic acid interacts with limestone (calcium carbonate), transforms it into a soluble state (calcium bicarbonate), and over the course of many millennia it washes and erodes its bed. This creates a growing, flooded cave. Over time, the underground river may find a new crack and descend another one, two, three, or even all six floors, as in Kizil-Kobe (Red Caves). The lower “wet” caves continue to grow, while the upper ones retain their original shape.
Stages of formation of karst caves
- Rain and melt water seeps through capillaries through the soil with rocks and absorbs carbon dioxide. Small streams gather along cracks into an underground river.
- Water (weak carbonic acid) continues to wash its channel. The limestone becomes soluble and is washed out of the rocks, making the water hard.
- In the middle of the cave, the water goes into a crack and begins to create another channel for itself. In an abandoned cave (already free from the river) stalactites grow.
- The river is washing a completely new channel. Large stalactites grow in the cave.
How are stalactites formed?
Hard water drips from the cave roofs. These are sediments transformed into rocks that seeped from the surface of the earth through the “roof”, and the cave’s own condensate. A reverse reaction takes place on the surface of the stone. Calcium bicarbonate dissolved in water turns back into carbonate, releasing carbon dioxide. In everyday life, a similar process leads to the appearance of plaque in bathrooms, scale in pots and radiators.
First, a ring appears on the rock, then a growing tube. Until the hole becomes clogged, water drips from it, and a sharp, straight stone icicle gradually grows - stalactite. If the water flow is good, if there are no neighboring drops, the stalactite will be single and can grow large. Where there has been constant rain for centuries, a whole forest of stalactites grows, usually of different lengths and thicknesses, sometimes of different colors. If the droplet is very small, dense thickets of “straws” may appear, more than a meter long and several millimeters thick, transparent, shining in the light of a lantern, like an exquisite underground chandelier.
What are seasonal stalactite rings?
Outwardly, they look like tree rings. They can also be used to determine age, weather in times distant from us by thousands and even millions of years. To do this, determine the isotopic and chemical composition of the desired “ring”. It’s important not to make a mistake, because there are so many rings!
A modern ion mass spectrometer allows you to take samples from layers one hundredth of a millimeter thick - this corresponds to an analysis accuracy of one year.
How long does it take for stalactites to grow?
The growth rate of cave stalactites varies greatly. This depends on the amount and composition of water flowing from the “ceiling”, on the temperature and humidity of the air in the cave. It is difficult to even talk about any average values. In some caves, meter-high stalactites grow in a thousand years, in others - in five thousand years. But in any case, a broken “stone icicle” is irreparable damage to nature. The trace of a moral crime is like killing an animal for fun.
Stalagmites, stalagnates and other sinter formations
What other forms do sinter formations in caves have? In the place where the drop falls, first a speck appears, then a bump of insoluble salts (mostly the same calcium carbonate). The tubercle grows and turns into a stone stump - sometimes pointed, but more often flat or rounded by the random splashing of hard water. This is how it is formed stalagmite. Usually it is larger, thicker and stronger than a stalactite, because water flows down its walls and all the released carbonate is used for construction. And also because a stalactite sooner or later breaks off under its own weight, but a stalagmite never does.
If the movement of water is not disturbed, the stalactite fuses with the stalagmite. The strongest underground column is formed - stalagnate From now on, nothing threatens it except earthquakes, so stalagnates can grow to gigantic proportions.
Flowing down the inclined vaults of the cave, hard water leaves behind not specks, but stripes of calcium carbonate. These stripes grow in thickness and eventually turn into thin flat ones. sail. They can be smooth and wavy, like the edges of a tablecloth, they can cover the entire wall to the ground, or they can remain in the form of pasties, forming a “cornice” or “chandelier”, and then grow like ordinary stalactites. Everything depends on the movement of a whimsical, capricious, “lazy” water drop, which always chooses the easiest and most profitable path for itself. Usually scallops ring when you tap them with a stick, so walls covered with scallops are called xylophones or authorities.
The most interesting and unusual of karst deposits - helictites, or eccentrics. Starting to grow like stalactites, they bend strangely and bizarrely. Sometimes these are stalactites of the second order; they grow like branches on a tree trunk. Why do stalactites begin to grow to the sides, like druses of crystals, or even twist into a spiral, turning into helictites? Science doesn't give an exact answer. The mechanics and chemistry of helictite growth are borderline phenomena between two forms: sinter and crystalline. Helictites were found in the caves “200 years of Simferopol”, Nizhny Bair.
Helictites form in places where the air is still; there the same calcium bicarbonate, dissolved not in the water dripping from the vaults, but in the moisture of the air, turns into a solid state.
Underground waterfalls also leave behind traces of limestone. It grows in a dense natural layer and will remain a decoration for tens and hundreds of thousands of years. Even after the unlucky river leaves the upper floors of the cave, we see frozen stone waterfalls…
Drops and streams flow into the baths, along the edges of which a limestone ridge grows - gurova dam. The gur baths have their own life: stone “water lilies” and “lotuses” with rounded “buds” and flat “leaves” lying in the water grow.
Matures in some baths cave pearls. Is not gem, but the composition of sea and cave pearls is the same. It is generally accepted that a grain of sand falling into a bath is rotated by a water flow and is gradually enveloped in limestone (which in its pure form is transparent, like glass). But pearls are also formed in very quiet backwaters...
Wet, soft, shapeless mass white, sometimes with a bluish tint, called moon milk. This is still the same calcium carbonate. Moon milk decorates the caves in its own way, and when dried, it crumbles into a fine powder when pressed. How moon milk is formed, the true mystery of karst caves, is something that only vague assumptions are made about. Nothing in nature except calcite exists in this state. Moon milk can be dry and wet, liquid and dense, viscous and fluid. In reality, this substance is neither solid nor liquid, it is not at all clear what it is... Scientists avoid this topic, leaving exotic lovers a clear field for thought and imagination.
Aragonite crystals
When the water leaves, the growth of the cave stops, but its interior continues to be enriched with new decorations. Air humidity in deep stone cavities approaches 100%. Water vapor is saturated with calcium bicarbonate ions, and crystals grow on stones (usually along cracks).
The whimsicality and capriciousness of the figures of aerosol crystallization is incomparable to any deposits: created according to the laws of the microcosm, they depend on the composition and concentration of ions, on the paths of movement of water molecules, on the rules for constructing crystal lattices with all their additions and deviations. Aragonite is a hard type of calcite. It is formed at fairly low temperatures, most often underground - in caves, ore deposits, and cold springs.
In the caves you can find tiny crystals of aragonite. When there are a lot of them, they glow in the lantern’s beam, like celestial stars. Sometimes large, acute-angled crystals grow, and nearby there are small ones, collected into “twigs”, into “fluffs”, into “snowflakes”. These can be sharp-spined “hedgehogs”, “thriving” stalactites of various shades, individual “cave flowers” collected in inflorescences of different colors and unimaginable shapes.
The most interesting and varied underground decorations grow as a result of the combined action of liquid water and an ion-rich aerosol. Graceful anthropomorphic figurines, little animals, “hairy Agos”, “jellyfish” with a fringe of “tentacles” along the edges, “anemones”... In a word, get your camera ready, open your notebook, fantasize! But everything will be poor, everything will be wrong: we are mere mortals, and the caves were created by her majesty Nature. Unequal.
" ~- ~- ~- ~" ~&~" ~- ~- ~- ~"
Aqueous chemogenic cave deposits are formed by precipitation from flowing or standing water. They are represented by all sorts of forms of sinter formations.
Stalactites(from the Greek stalaktós - dripping) - drip-drip (usually calcareous in karst caves) formations hanging in the form of conical icicles, draperies, curving fringes or hollow tubes from the vaults and upper parts of the walls of karst caves or other underground voids (eng. : Speleothem). This is the most widely known form of manifestation of gravitational textures of mineral aggregates. The terms “stalactite” and “stalagmite” were introduced into literature in 1655 by the Danish naturalist Ole Worm.
Stalactites arise as a result of the precipitation of calcium carbonate during the decomposition of calcium bicarbonate in a solution with the formation of less soluble calcium carbonate and CO 2, and the removal of carbon dioxide from water saturated with it. The solubility of carbonates depends on the presence of CO 2 in solution. Once the CO2 limit in the pore solution is used up, carbonate dissolution will cease. When the solution is close to saturation - in some parts common system filtration-diffusion will cause dissolution, and in others - precipitation of carbonate. In this case, dissolution can occur on the walls of thin pores and cracks, and sedimentation can occur on individual crystallization nuclei in an open cavity.
There are also gypsum and salt stalactites formed due to an increase in the saturation of the solution during the evaporation of the solvent (water).
Under certain conditions, stalactites grow from the bottom of caves and other underground karst cavities towards stalactites. stalagmites in the form of cones, and merging stalactite and stalagmite form columnar columns called stalagnate. On stalactites or stalagmites, partially submerged by underground waters in caves, growing take care(aggregates that crystallize in a horizontal plane at the water-air boundary from the edges of the solid phase), as a result of which complex ensembles of mushroom-shaped aggregates are formed.
Gury, or calcite dams damming underground lakes - are found mainly in limestone and much less often in dolomite cavities. They are formed in horizontal and inclined passages as a result of the precipitation of calcium carbonate from solution, which is associated with the release of carbon dioxide due to the turbulence of the water flow and/or changes in its temperature when moving through the underground gallery. The outlines of the dams, which usually have the appearance of a regular or curved arc, are determined mainly by the original shape of the projections of the cave floor. Based on morphological characteristics, gurs are divided into areal and linear. The latter are developed mainly in narrow passages with underground streams, which they divide into separate reservoirs. water flow not only creates calcite dams, but also destroys them. When flow rates and salinity change groundwater Under the influence of erosion and corrosion, holes, breaks and cuts are formed in the gourds. This leads to the formation of dry gours that are unable to retain water. As a result of further dissolution and erosion, only heavily corroded protrusions remain in place of the calcite dams, marked on the floor and walls of the cavity.
"Icicles" of ice as in ice caves, and on the surface of the Earth, are also stalactites. According to the classification of V.I. Stepanova, the following types of stalactites are distinguished for karst caves:
with strictly axial feeding, tubular stalactites (pasta) appear, characterized by a constant channel diameter and a structure controlled by geometric selection as a drop grows on the meniscus;
with combined areal and axial feeding, conical stalactites appear. They cannot be considered simply as tubular stalactites overgrown with a spherulite crust, since synchronous fouling affects the morphology of the meniscus;
with linear feeding, draperies occur;
ensembles of stalactites and draperies are extremely characteristic;
Tuphlactites can be especially distinguished - stalactites growing in conditions of high supersaturation, consisting of calcareous tuff, and thereby lacking the structure specified by geometric selection. The separation of concepts also removes the conflict between the common definition that tubular stalactites are always single-crystalline, and the existence of tubular tuphlactites, characteristic, for example, of the adits of the Khaidarkan deposit.
Stalactite-stalagmite crust, as well as the tuff stalactite-stalagmite crust [Stepanov, 1971], essentially consist of aggregates of extremely similar structures and textures that have the same characteristic symmetry. At the same time, the specific compositions of these crusts in aggregates can vary significantly. There are caves with a sharp predominance of stalagmite forms, and also vice versa. In most cases, as shown in [Maksimovich, 1965], the ratio of the number of stalactite and stalagmite forms is controlled solely by the degree of water content in the cave.
According to V.A. Maltsev, “The existing division of stalactites into feeding types (external-internal) does not correspond to their morphology, their structure, or the real mechanisms of their feeding. In true stalactites, which crystallize as a result of degassing of the solution or cooling of the melt, the central channel is not the cause, but the consequence, and the “feeding” observed in some tubular stalactites through the channel is secondary.”
Described as stalactites, stalactite-like aggregates of chalcedony, quartz, goethite, and many minerals from the secretions of effusive and sedimentary rocks and from the voids of ore veins, upon careful study, almost always turn out to be pseudostalactites or other stalactite-like forms of aggregates.
Travertine(travertine terraces) are formed by the precipitation of calcite and/or aragonite from solutions containing calcium bicarbonate. This process occurs, in particular, when pressure drops during the release of groundwater to the earth's surface. As a result, a chemical reaction occurs, during which water-insoluble calcium carbonate is released. In the presence of carbon dioxide in geothermal water, CaCO3 dissolves in the form of calcium bicarbonate:
CaCO3 + CO2 + H2O = Ca(HCO3)2
With the release of geothermal water to the surface of the Earth, the partial pressure of CO2 decreases and the carbonate-calcium equilibrium in it shifts towards the formation of the solid phase: Ca(HCO3)2 = CaCO3↓ + CO2 + H2O.
When the carbonate-calcium balance is disturbed in geothermal water, a suspension of CaCO3 crystals up to 10 microns in size or more is formed. The amount of suspended matter formed in this case ranges from 4 to 25 mg/l. The main share is made up of particles less than 1 µm in size. Some of them, falling into the laminar sublayer, settle on hard surfaces forming deposits. Depending on the speed of water flow relative to the deposition surface, deposits of varying densities are formed on it.
Literature:
Maksimovich G.A. Genetic series of sinter deposits of caves (carbonate speleolithogenesis) // Caves, issue 5(6). Perm, 1965.
Maltsev V.A. Minerals of the Cap-Koutan karst cave system (southeast of Turkmenistan) // "World of Stones", 1993, No. 2 (Russian/English).
Maltsev V.A. Once again about stalactites with “internal” and “external” nutrition // Full version in English: V.A. Maltsev. Stalactites with "internal" and "external" feeding, Proc. Univ. Bristol Spel. Soc., 1998, 21(2), 149-158
Stepanov V.I. Periodicity of crystallization processes in karst caves // Proceedings of Min. museum named after Fersman. Moscow, 1971, issue 20, p. 161-171.
Stepanov V.I. Structures and textures of mineral aggregates formed in the free space of voids
C. Hill, P. Forti. Cave minerals of the world. NSS, 1986, 238 p.
Their growth is determined by water flowing down a thin cavity located inside the stalactite, as well as by the flow of calcite material along the surface of the deposit. Often the internal cavity is located eccentrically. From the opening of these tubes every 2–3 minutes. dripping clear water. The sizes of cone-shaped stalactites, located mainly along cracks and well indicating them, are determined by the conditions of calcium carbonate supply and the size of the underground cavity. Typically, stalactites do not exceed 0.1–0.5 m in length and 0.05 m in diameter. Sometimes they can reach 2–3, even 10 m in length () and 0.5 m in diameter. Interesting spherical (onion-shaped) stalactites formed as a result of blockage of the tube opening. Aberration thickenings and patterned growths appear on the surface of the stalactite. Spherical stalactites are often hollow due to the secondary dissolution of calcium by water entering the cave. Anemolites - curved stalactites
In some caves where there is significant air movement, curved stalactites are found - anemolites, the axis of which is deviated from the vertical.
The formation of anemolytes is determined by the evaporation of hanging drops of water on the leeward side of the stalactite, which causes it to bend in the direction of the air flow. The bending angle of individual stalactites can reach 45°. If the direction of air movement periodically changes, then zigzag anemolites. Curtains and draperies hanging from the ceiling of caves have a similar origin to stalactites. They are associated with infiltration water seeping along a long crack. Some curtains, composed of pure crystalline calcite, are completely transparent. In their lower parts there are often stalactites with thin tubes, at the ends of which droplets of water hang. Calcite deposits can look like petrified waterfalls. One of these waterfalls is noted in the Tbilisi grotto of the New Athos (Anakopia) cave. Its height is about 20 m and its width is 15 m. - These are complexly constructed eccentric stalactites, included in the subgroup of anomalous stalactite formations. They are found in various parts of karst caves (on the ceiling, walls, curtains, stalactites) and have the most varied, often fantastic shapes: in the form of a curved needle, a complex spiral, a twisted ellipse, a circle, a triangle, etc. Needle-shaped helictites reach 30 mm in length and 2–3 mm in diameter. They are a single crystal, which, as a result of uneven growth, changes orientation in space. There are also polycrystals grown into one another. In the section of needle-shaped helictites, which grow mainly on the walls and ceilings of caves, no central cavity can be traced. They are colorless or transparent, their ends are pointed. Spiral-shaped helictites develop predominantly on stalactites, especially thin-tubular ones. They consist of many crystals. Inside these helictites, a thin capillary is found through which the solution reaches the outer edge of the aggregate. Water droplets formed at the ends of helictites, unlike tubular and conical stalactites, do not come off for a long time (many hours). This determines the extremely slow growth of helictites. Most of them belong to the type of complex formations that have a bizarre and intricate shape. 
The complex mechanism of helictite formation is currently not well understood. Many researchers (N.I. Krieger, B. Zheze, G. Trimmel) associate the formation of helictites with blockage of the growth channel of thin-tubular and other stalactites. The water entering the stalactite penetrates the cracks between the crystals and comes out to the surface. This is how the growth of helictites begins, due to the predominance of capillary forces and crystallization forces over gravity. Capillarity appears to be the main factor in the formation of complex and spiral-shaped helictites, the direction of growth of which initially largely depends on the direction of intercrystalline cracks. 
F. Chera and L. Mucha (1961) experimental physicochemical studies proved the possibility of calcite precipitation from the air of caves, which causes the formation of helictites. Air with a relative humidity of 90–95%, supersaturated with tiny droplets of water with calcium bicarbonate, turns out to be an aerosol. Droplets of water falling on the ledges of walls and calcite formations quickly evaporate, and calcium carbonate falls out as sediment. The highest growth rate of a calcite crystal occurs along the main axis, causing the formation of needle-shaped helictites. Consequently, under conditions where the dispersion medium is a substance in a gaseous state, helictites can grow due to the diffusion of a dissolved substance from the surrounding aerosol. Helictites created in this way (“aerosol effect”) are called “cave frost.” 
Along with the colmatage of the feed channel of individual thin-tubular stalactites and the “aerosol effect,” the formation of helictites, according to some researchers, is also influenced by the hydrostatic pressure of karst waters (L. Yakuch), features of air circulation (A. Vikhman) and microorganisms. These provisions, however, are not sufficiently reasoned and, as research has shown, recent years, are largely debatable. Thus, the morphological and crystallographic features of eccentric sinter forms can be explained either by capillarity or the influence of aerosol, as well as a combination of these two factors. The most colorful photos of caves containing stalactites and stalagmites. These usually limestone formations hanging from the ceiling or growing out of the ground are simply mesmerizing. How old are they supposed to be? Many millions, as tour guides classically claim, or can they grow in a shorter period of time?
(Stalactites photo No. 1.1)
(Stalactites photo No. 1.2)
What are stalactites and stalagmites? The water that seeps into the cave contains particles of limestone or other minerals. When a drop of water flows through the gap and falls, the mineral dissolved in it remains on the ceiling of the cave. Then, drop by drop, these deposits grow downwards and after a long or short time a stalactite is formed on the ceiling of the cave - a solid icicle made of stone or salt. Below, under it, a stalagmite grows, from falling drops from the stalactite. After some time, both limestone formations grow, meet and unite into a single column
(Stalactites photo No. 2.1)
(Stalactites photo No. 2.2)
“Caves are formed under the influence of groundwater, but we don’t know how this happens,” say evolutionary scientists. But judging by new data, it turns out that sulfuric acid influences the formation of at least 10% of caves in the Guadalupe Mountains in New Mexico and Texas. This means that caves could have formed much faster than in millions of years
(Stalactites photo No. 3.1)
(Stalactites photo No. 3.2)
The world's tallest stalagmite is located in Arman Cave in France. According to scientists, its growth rate is 3 mm per year. Then this stalagmite should have reached its height of 38 m in 12,700 years. Such data are not consistent with the age of the stalagmite, which was established by radiometric dating (millions of years). Is the method wrong?
(Stalactites photo No. 4.1)
(Stalactites photo No. 4.2)
At Cape Levin in Western Australia there is a water wheel, which is simply overgrown with stones. And this happened in less than 65 years. This suggests that such natural growths can form quite quickly. But why then, according to evolutionists, do stalactites and stalagmites, whose age is unknown, form over thousands or even millions of years?
(Stalactites photo No. 5.1)
(Stalactites photo No. 5.2)
With discoveries about the rapid growth of stalactites now known, we can say that the growth of the stalactites we see in the most beautiful limestone caves did not require entire eons. These beautiful formations could have grown very quickly in just a few thousand years during the cataclysmic global Flood.
(Stalactites photo No. 6.1)
(Stalactites photo No. 6.2)
Often a stalagmite connects with a stalactite and a column appears. The largest stone column in Carlsbad is more than 30 meters high. The ceilings of some caves are hung with short stalactites, like fringes. In other caves they shine stone stalactites in the form of needles on the walls. There are stalactites that grow to the sides and even upwards.
(Stalactites photo No. 7.1)
(Stalactites photo No. 7.2)
In October 1953, National Geographic magazine published a photograph of a bat that fell onto a stalagmite in the famous Carlsbad Caverns, New Mexico, and became solidified there. The stalagmite grew so quickly that it was able to preserve the bat before the animal began to decompose.
(Stalactites photo No. 8.1)
(Stalactites photo No. 8.2)
In the Jenolan Caves and various other places you can see stalactites and stalagmites that grew directly in structures built by man. Like the Lincoln Memorial, Jenolan structures contain cement mortar that is highly permeable, allowing these formations to grow quickly. Unfortunately, the grown formations are very porous and brittle.
(Stalactites photo No. 9.1)
(Stalactites photo No. 9.2)
In Philadelphia, anyone can see many bridges in which stalactites grow. The length of some of them is more than 30 cm. We conclude, based on the age of the bridges, that all these stalactites are less than 56 years old. That's speed!
(Stalactites photo No. 10.1)
(Stalactites photo No. 10.2)
The world of stalactites and stalagmites is beautiful and mysterious. These bright photos tell us about God’s amazing laws in the world of geology, about our history, which is not millions of years old, but only 5-6 thousand. And these majestic natural formations tell us about the greatness of their Creator
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