Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone and gypsum. It is characterized by underground drainage systems with sinkholes and caves and it has been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes, the English word karst was borrowed from German Karst in the late 19th century. The German word came into use before the 19th century, according to the prevalent interpretation, the term is derived from the German name for the Karst region, a limestone plateau above the city of Trieste in the northern Adriatic. Scholars disagree, however, on whether the German word was borrowed from Slovene, the Slovene common noun kras was first attested in the 18th century, and the adjective form kraški in the 16th century. The Slovene words arose through metathesis from the reconstructed form *korsъ, the word is of Mediterranean origin, believed to derive from some Romanized Illyrian base.
It has been suggested that the word may derive from the Proto-Indo-European root karra- rock, the name may be connected to the oronym Karsádios oros cited by Ptolemy, and perhaps to Latin Carusardius. The development of karst occurs whenever acidic water starts to break down the surface of bedrock near its cracks, as the bedrock continues to degrade, its cracks tend to get bigger. As time goes on, these fractures will become wider, if this underground drainage system does form, it will speed up the development of karst formations there because more water will be able to flow through the region, giving it more erosive power. The carbonic acid that causes karstic features is formed as rain passes through the atmosphere picking up carbon dioxide, once the rain reaches the ground, it may pass through soil that can provide much more CO2 to form a weak carbonic acid solution, which dissolves calcium carbonate. The oxidation of sulfides leading to the formation of acid can be one of the corrosion factors in karst formation.
As oxygen -rich surface waters seep into deep anoxic karst systems, they bring oxygen, sulfuric acid reacts with calcium carbonate, causing increased erosion within the limestone formation. This chain of reactions is, This reaction chain forms gypsum, the karstification of a landscape may result in a variety of large- or small-scale features both on the surface and beneath. On exposed surfaces, small features may include solution flutes, limestone pavement, medium-sized surface features may include sinkholes or cenotes, vertical shafts, disappearing streams, and reappearing springs. Large-scale features may include limestone pavements and karst valleys, mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers, or haystack/eggbox landscapes. Beneath the surface, complex underground systems and extensive caves. Some of the most dramatic of these formations can be seen in Thailands Phangnga Bay, calcium carbonate dissolved into water may precipitate out where the water discharges some of its dissolved carbon dioxide.
Rivers which emerge from springs may produce tufa terraces, consisting of layers of calcite deposited over extended periods of time, in caves, a variety of features collectively called speleothems are formed by deposition of calcium carbonate and other dissolved minerals
A stalagmite is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings. Stalagmites may be composed of amberat, minerals, peat, sand, the corresponding formation hanging down from the ceiling of a cave is a stalactite. Mnemonics have been developed for which word refers to type of formation, one is that stalactite has a C for ceiling. The most common stalagmites are speleothems, which form in limestone caves. This stalagmite formation occurs only under certain pH conditions within the underground cavern and they form through deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions. Limestone is the form of calcium carbonate rock, which is dissolved by water that contains carbon dioxide. If stalactites – the ceiling formations – grow long enough to connect with stalagmites on the floor and dirt from human contact can stain the formation and change its color permanently.
Another type of stalagmite is formed in lava tubes while lava is still active inside, the mechanism of formation is similar to that of limestone stalagmites. A key difference with lava stalagmites is that once the lava has ceased flowing and this means if the stalagmite were to be broken it would never grow back. Stalagmites in lava tubes are rarer than their stalactite counterparts because during formation the dripping material falls onto still-moving lava floors that absorb or carry the material away, the generic term lavacicle has been applied to lava stalactites and stalagmites indiscriminately, and evolved from the word icicle. A common stalagmite found seasonally or year round in many caves is the ice stalagmite, commonly referred to as icicles, water seepage from the surface will penetrate into a cave and if temperatures are below freezing temperature, the water will collect on the floor into stalagmites. Deposition may directly from the freezing of water vapor. Similar to lava stalagmites, ice stalagmites form very quickly within hours or days, unlike lava stalagmites however, they may grow back as long as water and temperatures are suitable.
Ice stalagmites are more common than their stalactite counterparts because warmer air rises to the ceilings of caves, ice stalactites may form corresponding stalagmites below them, and given time, may grow together to form an ice column. Stalactites and stalagmites can form on concrete ceilings and floors, calcium carbonate deposition as a stalagmite occurs when the solution carries the calcium laden leachate solution to the ground under the concrete structure. Carbon dioxide is absorbed into the alkaline solution, which facilitates the chemical reactions to deposit calcium carbonate as a stalagmite. These stalagmites rarely grow taller than a few centimetres, secondary deposits, which create stalagmites, flowstone etc, outside the natural cave environment, are referred to as “calthemites”. These concrete derived secondary deposits can’t be referred to as “speleothems” due to the definition of the word, the largest known stalagmite in the world exceeds 70 metres in height and is located in Sơn Đoòng Cave, Vietnam
Mammals are any vertebrates within the class Mammalia, a clade of endothermic amniotes distinguished from reptiles by the possession of a neocortex, three middle ear bones and mammary glands. All female mammals nurse their young with milk, secreted from the mammary glands, Mammals include the largest animals on the planet, the great whales. The basic body type is a quadruped, but some mammals are adapted for life at sea, in the air, in trees. The largest group of mammals, the placentals, have a placenta, Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale. With the exception of the five species of monotreme, all modern mammals give birth to live young, most mammals, including the six most species-rich orders, belong to the placental group. The largest orders are the rodents and Soricomorpha, the next three biggest orders, depending on the biological classification scheme used, are the Primates, the Cetartiodactyla, and the Carnivora. Living mammals are divided into the Yinotheria and Theriiformes There are around 5450 species of mammal, in some classifications, extant mammals are divided into two subclasses, the Prototheria, that is, the order Monotremata, and the Theria, or the infraclasses Metatheria and Eutheria.
The marsupials constitute the group of the Metatheria, and include all living metatherians as well as many extinct ones. Much of the changes reflect the advances of cladistic analysis and molecular genetics, findings from molecular genetics, for example, have prompted adopting new groups, such as the Afrotheria, and abandoning traditional groups, such as the Insectivora. The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade, the early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period, this group diverged from the line that led to todays reptiles. Some mammals are intelligent, with some possessing large brains, self-awareness, Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals and echolocation. Mammals can organize themselves into fission-fusion societies and hierarchies, most mammals are polygynous, but some can be monogamous or polyandrous.
They provided, and continue to provide, power for transport and agriculture, as well as commodities such as meat, dairy products, wool. Mammals are hunted or raced for sport, and are used as model organisms in science, Mammals have been depicted in art since Palaeolithic times, and appear in literature, film and religion. Defaunation of mammals is primarily driven by anthropogenic factors, such as poaching and habitat destruction, Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is accepted, McKenna & Bell and Wilson & Reader provide useful recent compendiums. Though field work gradually made Simpsons classification outdated, it remains the closest thing to a classification of mammals
Cave paintings are painted drawings on cave walls or ceilings, mainly of prehistoric origin, to some 40,000 years ago in Eurasia. The exact purpose of the Paleolithic cave paintings is not known, evidence suggests that they were not merely decorations of living areas since the caves in which they have been found do not have signs of ongoing habitation. They are located in areas of caves that are not easily accessible. Some theories hold that cave paintings may have been a way of communicating with others, the paintings are remarkably similar around the world, with animals being common subjects that give the most impressive images. Humans mainly appear as images of hands, mostly hand stencils made by blowing pigment on a hand held to the wall. The earliest known cave paintings/drawings of animals are at least 35,000 years old and are found in Pettakere cave on the island of Sulawesi in Indonesia, previously it was believed that the earliest paintings were in Europe. The earliest non-figurative rock art dates back to approximately 40,000 years ago, nearly 340 caves have now been discovered in France and Spain that contain art from prehistoric times.
But subsequent technology has made it possible to date the paintings by sampling the pigment itself, the choice of subject matter can indicate chronology. For instance, the reindeer depicted in the Spanish cave of Cueva de las Monedas places the drawings in the last Ice Age. The oldest date given to a cave painting is now a pig that has a minimum age of 35,400 years old at Pettakere cave in Sulawesi. Indonesian and Australian scientists have dated other non-figurative paintings on the walls to be approximately 40,000 years old, the method they used to confirm this was dating the age of the stalactites that formed over the top of the paintings. The art is similar in style and method to that of the Indonesian caves as there were hand stencils and this date coincides with the earliest known evidence for Homo sapiens in Europe. Because of the cave arts age, some scientists have conjectured that the paintings may have made by Neanderthals. The earliest known European figurative cave paintings are those of Chauvet Cave in France and these paintings date to earlier than 30,000 BCE according to radiocarbon dating.
Some researchers believe the drawings are too advanced for this era, the radiocarbon dates from these samples show that there were two periods of creation in Chauvet,35,000 years ago and 30,000 years ago. In 2009, cavers discovered drawings in Coliboaia Cave in Romania, an initial dating puts the age of an image in the same range as Chauvet, about 32,000 years old. Some caves probably continued to be painted over a period of thousands of years. This was created roughly between 10,000 and 5,500 years ago, and painted in rock shelters under cliffs or shallow caves, though individual figures are less naturalistic, they are grouped in coherent grouped compositions to a much greater degree
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate. The Mohs scale of hardness, based on scratch hardness comparison. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite, aragonite will change to calcite at 380–470 °C, and vaterite is even less stable. Calcite is derived from the German Calcit, a term coined in the 19th century from the Latin word for lime and it is thus etymologically related to chalk. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, prisms, or various scalenohedra. Calcite exhibits several twinning types adding to the variety of observed forms and it may occur as fibrous, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form and its fracture is conchoidal, but difficult to obtain. It has a defining Mohs hardness of 3, a gravity of 2.71.
Color is white or none, though shades of gray, orange, green, violet, calcite is transparent to opaque and may occasionally show phosphorescence or fluorescence. A transparent variety called Iceland spar is used for optical purposes, acute scalenohedral crystals are sometimes referred to as dogtooth spar while the rhombohedral form is sometimes referred to as nailhead spar. Single calcite crystals display an optical property called birefringence and this strong birefringence causes objects viewed through a clear piece of calcite to appear doubled. The birefringent effect was first described by the Danish scientist Rasmus Bartholin in 1669, at a wavelength of ~590 nm calcite has ordinary and extraordinary refractive indices of 1.658 and 1.486, respectively. Between 190 and 1700 nm, the refractive index varies roughly between 1.9 and 1.5, while the extraordinary refractive index varies between 1.6 and 1.4. Calcite, like most carbonates, will dissolve with most forms of acid, calcite can be either dissolved by groundwater or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved ion concentrations.
Although calcite is fairly insoluble in water, acidity can cause dissolution of calcite. Ambient carbon dioxide, due to its acidity, has a slight solubilizing effect on calcite, calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures. On a landscape scale, continued dissolution of calcium carbonate-rich rocks can lead to the expansion and eventual collapse of cave systems, high-grade optical calcite was used in World War II for gun sights, specifically in bomb sights and anti-aircraft weaponry
Brazil, officially the Federative Republic of Brazil, is the largest country in both South America and Latin America. As the worlds fifth-largest country by area and population, it is the largest country to have Portuguese as an official language. Its Amazon River basin includes a vast tropical forest, home to wildlife, a variety of ecological systems. This unique environmental heritage makes Brazil one of 17 megadiverse countries, Brazil was inhabited by numerous tribal nations prior to the landing in 1500 of explorer Pedro Álvares Cabral, who claimed the area for the Portuguese Empire. Brazil remained a Portuguese colony until 1808, when the capital of the empire was transferred from Lisbon to Rio de Janeiro, in 1815, the colony was elevated to the rank of kingdom upon the formation of the United Kingdom of Portugal and the Algarves. Independence was achieved in 1822 with the creation of the Empire of Brazil, a state governed under a constitutional monarchy. The ratification of the first constitution in 1824 led to the formation of a bicameral legislature, the country became a presidential republic in 1889 following a military coup détat.
An authoritarian military junta came to power in 1964 and ruled until 1985, Brazils current constitution, formulated in 1988, defines it as a democratic federal republic. The federation is composed of the union of the Federal District, the 26 states, Brazils economy is the worlds ninth-largest by nominal GDP and seventh-largest by GDP as of 2015. A member of the BRICS group, Brazil until 2010 had one of the worlds fastest growing economies, with its economic reforms giving the country new international recognition. Brazils national development bank plays an important role for the economic growth. Brazil is a member of the United Nations, the G20, BRICS, Mercosul, Organization of American States, Organization of Ibero-American States, CPLP. Brazil is a power in Latin America and a middle power in international affairs. One of the worlds major breadbaskets, Brazil has been the largest producer of coffee for the last 150 years and it is likely that the word Brazil comes from the Portuguese word for brazilwood, a tree that once grew plentifully along the Brazilian coast.
In Portuguese, brazilwood is called pau-brasil, with the word brasil commonly given the etymology red like an ember, formed from Latin brasa and the suffix -il. As brazilwood produces a red dye, it was highly valued by the European cloth industry and was the earliest commercially exploited product from Brazil. The popular appellation eclipsed and eventually supplanted the official Portuguese name, early sailors sometimes called it the Land of Parrots. In the Guarani language, a language of Paraguay, Brazil is called Pindorama
The Pleistocene is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the worlds most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period, the Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. In the ICS timescale, the Pleistocene is divided into four stages or ages, all of these stages were defined in southern Europe. In addition to this subdivision, various regional subdivisions are often used. Charles Lyell introduced the term pleistocene in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today and this distinguished it from the older Pliocene Epoch, which Lyell had originally thought to be the youngest fossil rock layer. The Pleistocene has been dated from 2.588 million to 11,700 years before present and it covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold spell.
The end of the Younger Dryas has been dated to about 9640 BC, the IUGS has yet to approve a type section, Global Boundary Stratotype Section and Point, for the upper Pleistocene/Holocene boundary. The proposed section is the North Greenland Ice Core Project ice core 75°06 N 42°18 W, the lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama chronozone, isotopic stage 103. Above this point there are notable extinctions of the calcareous nanofossils, Discoaster pentaradiatus, the Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has, in the past, been used to mean the last ice age. The revised definition of the Quaternary, by pushing back the date of the Pleistocene to 2.58 Ma. Pleistocene climate was marked by repeated glacial cycles in which continental glaciers pushed to the 40th parallel in some places and it is estimated that, at maximum glacial extent, 30% of the Earths surface was covered by ice.
In addition, a zone of permafrost stretched southward from the edge of the sheet, a few hundred kilometres in North America. The mean annual temperature at the edge of the ice was −6 °C, during interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions. The effects of glaciation were global, antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene. The Andes were covered in the south by the Patagonian ice cap, there were glaciers in New Zealand and Tasmania. The current decaying glaciers of Mount Kenya, Mount Kilimanjaro, glaciers existed in the mountains of Ethiopia and to the west in the Atlas mountains. In the northern hemisphere, many glaciers fused into one, the Cordilleran ice sheet covered the North American northwest, the east was covered by the Laurentide
Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate, about 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, most cave systems are through limestone bedrock. The first geologist to distinguish limestone from dolomite was Belsazar Hacquet in 1778, like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids and these organisms secrete shells made of aragonite or calcite, and leave these shells behind when they die. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragment, some limestones do not consist of grains at all, and are formed completely by the chemical precipitation of calcite or aragonite, i. e. travertine.
Secondary calcite may be deposited by supersaturated meteoric waters and this produces speleothems, such as stalagmites and stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance, the primary source of the calcite in limestone is most commonly marine organisms. Some of these organisms can construct mounds of rock known as reefs, below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone typically does not form in deeper waters. Limestones may form in lacustrine and evaporite depositional environments, calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits a characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors, especially with weathered surfaces, Limestone may be crystalline, granular, or massive, depending on the method of formation.
Crystals of calcite, dolomite or barite may line small cavities in the rock, when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams, particularly there are waterfalls. Calcium carbonate is deposited where evaporation of the leaves a solution supersaturated with the chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls, coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the building process, limestone recrystallizes into marble
Caving — traditionally known as spelunking in the United States and Canada and potholing in the United Kingdom and Ireland — is the recreational pastime of exploring wild cave systems. In contrast, speleology is the study of caves and the cave environment. Cave diving is a distinct, and more hazardous, sub-speciality undertaken by a minority of technically proficient cavers. Sometimes categorized as a sport, it is not commonly considered as such by long-time enthusiasts. Many caving skills overlap with those involved in canyoning, Caving is often undertaken for the enjoyment of the outdoor activity or for physical exercise, as well as original exploration, similar to mountaineering or diving. Physical or biological science is an important goal for some cavers, virgin cave systems comprise some of the last unexplored regions on Earth and much effort is put into trying to locate and survey them. In well-explored regions, the most accessible caves have already been explored, Caving, in certain areas, has been utilized as a form of eco and adventure tourism.
Tour companies have established a leading and guiding tours into. Depending on the type of cave and the type of tour, in many areas, there are tours led through lava tubes by a guiding service. Some however consider the assistance cavers give each other as a team sport activity. Too much emphasis on the labeling of caving as a sport can narrow the goals of caving as a whole, Caving often puts the needs and welfare of a cave before those of the active participants. Clay Perry, an American caver of the 1940s, wrote about a group of men and this group referred to themselves as spelunkers, a term derived from the Latin spēlunca cave, den, itself from the Greek σπῆλυγξ spēlynks cave. This is regarded as the first use of the word in the Americas, throughout the 1950s, spelunking was the general term used for exploring caves in US English. It was used freely, without any positive or negative connotations, in the 1960s, the terms spelunking and spelunker began to be considered déclassé among experienced enthusiasts.
This sentiment is exemplified by bumper stickers and T-shirts displayed by some cavers, Cavers rescue spelunkers, outside the caving community and spelunkers predominately remain neutral terms referring to the practice and practitioners, without any respect to skill level. Potholing refers to the act of exploring potholes, a word originating in the north of England for predominantly vertical caves, the base term caving comes from the Latin cavea or caverna, meaning simply, a cave. He developed his own based on ropes and metallic ladders. Martel visited Kentucky and notably Mammoth Cave National Park in October 1912, robert de Joly, Guy de Lavaur and Norbert Casteret were prominent figures of that time, surveying mostly caves in Southwest France
Minas Gerais is a state in the north of Southeastern Brazil. It ranks as the second most populous, the third by gross domestic product, Minas Gerais is the state with the largest number of Brazilian presidents. With an area of 586,528 square kilometres —larger than Metropolitan France—it is the fourth most extensive state in Brazil. In the south, the tourist points are the mineral spas, such as Caxambu, Lambari, São Lourenço, Poços de Caldas, São Thomé das Letras, Monte Verde. The landscape of the State is marked by mountains, valleys, in the Serra do Cipó, Sete Lagoas and Lagoa Santa, the caves and waterfalls are the attractions. Some of Brazils most famous caverns are located there, in recent years, the state has emerged as one of the largest economic forces of Brazil, exploring its great economic potential. Two interpretations are given for the origin of the name Minas Gerais and it comes from Minas dos Matos Gerais, the former name of the colonial province. Another explanation is that this ignores the two large geographical spaces which conformed the state in its history, the region of the mines, and these corresponded to the areas of Sertão which were farther and hard to access from the mining spots.
The confusion comes from the fact that the term Gerais is taken as an adjective to Minas in the first version, Minas Gerais is in the north of the southeastern subdivision of Brasil, which contains the states of São Paulo, Rio de Janeiro and Espírito Santo. It borders on Bahia, Goiás, Mato Grosso do Sul, the states of São Paulo and Rio de Janeiro and it shares a short boundary with the Distrito Federal. Minas Gerais is situated between 14°1358 and 22°5400 S latitude and between 39°5132 and 51°0235 W longitude and it is larger in area than Metropolitan France or Spain. Minas Gerais features some of the longest rivers in Brazil, most notably the São Francisco, the Paraná and to a lesser extent, the state holds many hydroelectric power plants, including Furnas. The most notable one is the Pico da Bandeira, the third highest mountain in Brazil at 2890 m, the state has huge reserves of iron and sizeable reserves of gold and gemstones, including emerald and aquamarine mines. Emeralds found in location are comparable to the best Colombia-origin emeralds.
Each region of the state has a character, geographically. The central and eastern area of the state is hilly and rocky, around Lagoa Santa and Sete Lagoas a typical Karst topography with caves and lakes is found. Some of the mountains are almost entirely iron ore, which led to extensive mining, recent advances in environmental policy helped to put limits to mining. Vale do Aços largest cities are Ipatinga, Coronel Fabriciano and Timóteo, now that mining is restricted large areas of forest are being removed for timber, charcoal and to clear land for cattle ranching
Belo Horizonte is the sixth largest city in Brazil, the thirteenth largest city in South America and the eighteenth largest city in the Americas. The metropolis is anchor to the Belo Horizonte metropolitan area, ranked as the third most populous area in Brazil. Belo Horizonte is the capital of the state of Minas Gerais and it is the first planned modern city in Brazil. The region was first settled in the early 18th century, but the city as it is today was planned and constructed in the 1890s. The city features a mixture of contemporary and classical buildings, and is home to several modern Brazilian architectural icons, in planning the city, Aarão Reis and Francisco Bicalho sought inspiration in the urban planning of Washington, D. C. The city has employed notable programs in urban revitalization and food security, the city is built on several hills and is completely surrounded by mountains. There are several parks in the immediate surroundings of Belo Horizonte. The Mangabeiras Park, located 6 km south-east from the city centre in the hills of Curral Ridge, has a view of the city.
It has an area of 2.35 km2, of which 0.9 km2 is covered by the native forest, the Jambeiro Woods nature reserve extends over 912 hectares, with vegetation typical of the Atlantic forest. More than one hundred species of birds inhabit the reserve, as well as ten different species of mammals, Belo Horizonte was one of the host cities of the 1950 and the 2014 FIFA World Cup. Additionally, the city shared the host of the 2013 FIFA Confederations Cup, the term Grande BH denotes any of various definitions for the metropolitan area of Belo Horizonte. The legally defined Metropolitan Region of Belo Horizonte consists of 34 municipalities in total, the intense process of urbanization that is taking place in the metropolitan region has made some of the political boundaries between municipalities in the region obsolete. Belo Horizonte lies on a region of contact between different geological series of the Proterozoic, the geology largely comprises various crystalline rocks, which give rise to the varied morphology of the landscape.
The archean rocks members of Belo Horizonte complex and supracrustal sequences of the Paleoproterozoic is predominant, the metasedimentary rocks has its area of occurrence on the south of Ribeirão Arrudas pipeline, constituting about 30% of the area of Belo Horizonte. The characteristics of this area are lithological diversities and rugged topography, which has its maximum expression in the Serra do Curral, the hills of Belo Horizonte are part of the Espinhaço Mountains and belong to the larger Itacolomi mountain chain. The highest point in the municipality is in the Serra do Curral, Belo Horizontes latitude at 1955South places it in the tropical zone. Yearly temperatures average between 9 and 35 °C, the Köppen climate classification of the region is tropical savanna climate and it borders on a humid subtropical climate. Belo Horizonte is located about 300 kilometres from the sea, even though inter-seasonal differences are not as pronounced as they are in temperate places, there is a contrast between spring and summer, and between fall and winter
A stalactite is a type of formation that hangs from the ceiling of caves, hot springs, or manmade structures such as bridges and mines. Any material which is soluble, can be deposited as a colloid, or is in suspension, or is capable of being melted, Stalactites may be composed of amberat, minerals, peat, pitch and sinter. A stalactite is not necessarily a speleothem, though speleothems are the most common form of stalactite because of the abundance of limestone caves, the corresponding formation on the floor of the cave is known as a stalagmite. The most common stalactites are speleothems, which occur in limestone caves and they form through deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions. Limestone is the form of calcium carbonate rock which is dissolved by water that contains carbon dioxide. When the solution comes into contact with air the chemical reaction that created it is reversed, the reversed reaction is, Ca 2 → CaCO3 + H 2O + CO2 An average growth rate is 0.13 mm a year.
The quickest growing stalactites are formed by a constant supply of slow dripping water rich in calcium carbonate and carbon dioxide. The drip rate must be enough to allow the CO2 to degas from the solution into the cave atmosphere. Too fast a drip rate and the solution, still carrying most of the CaCO3, falls to the floor where degassing occurs. All limestone stalactites begin with a single drop of water. When the drop falls, it deposits the thinnest ring of calcite, each subsequent drop that forms and falls deposits another calcite ring. Eventually, these form a very narrow, hollow tube commonly known as a soda straw stalactite. Soda straws can grow long, but are very fragile. If they become plugged by debris, water flowing over the outside, depositing more calcite. The same water drops that fall from the tip of a stalactite deposit more calcite on the floor below, unlike stalactites, stalagmites never start out as hollow soda straws. Given enough time, these formations can meet and fuse to create pillars of calcium carbonate known as a column, another type of stalactite is formed in lava tubes while lava is still active inside.
The mechanism of formation is similar to that of limestone stalactites, a key difference with lava stalactites is that once the lava has ceased flowing, so too will the stalactites cease to grow. This means that if the stalactite were to be broken it would never grow back, the generic term lavacicle has been applied to lava stalactites and stalagmites indiscriminately and evolved from the word icicle