Stratigraphy is a branch of geology which studies rock layers and layering. It is primarily used in the study of sedimentary and layered volcanic rocks, stratigraphy has two related subfields, lithologic stratigraphy or lithostratigraphy, and biologic stratigraphy or biostratigraphy. The first practical application of stratigraphy was by William Smith in the 1790s. Another influential application of stratigraphy in the early 19th century was a study by Georges Cuvier, variation in rock units, most obviously displayed as visible layering, is due to physical contrasts in rock type. This variation can occur vertically as layering, or laterally, and these variations provide a lithostratigraphy or lithologic stratigraphy of the rock unit. Key concepts in stratigraphy involve understanding how certain geometric relationships between rock layers arise and what these geometries imply about their original depositional environment. The basic concept in stratigraphy, called the law of superposition, states, in a stratigraphic sequence.
Chemostratigraphy studies the changes in the proportions of trace elements and isotopes within. Carbon and oxygen isotope ratios vary with time, and researchers can use those to map subtle changes that occurred in the paleoenvironment and this has led to the specialized field of isotopic stratigraphy. Biostratigraphy or paleontologic stratigraphy is based on evidence in the rock layers. Strata from widespread locations containing the fossil fauna and flora are said to be correlatable in time. Biologic stratigraphy was based on William Smiths principle of succession, which predated. It provides strong evidence for the formation and extinction of species, the geologic time scale was developed during the 19th century, based on the evidence of biologic stratigraphy and faunal succession. One important development is the Vail curve, which attempts to define a global historical sea-level curve according to inferences from worldwide stratigraphic patterns, stratigraphy is commonly used to delineate the nature and extent of hydrocarbon-bearing reservoir rocks and traps of petroleum geology.
Chronostratigraphy is the branch of stratigraphy that places an absolute age, a gap or missing strata in the geological record of an area is called a stratigraphic hiatus. This may be the result of a halt in the deposition of sediment, the gap may be due to removal by erosion, in which case it may be called a stratigraphic vacuity. It is called a hiatus because deposition was on hold for a period of time, a physical gap may represent both a period of non-deposition and a period of erosion. A geologic fault may cause the appearance of a hiatus, magnetostratigraphy is a chronostratigraphic technique used to date sedimentary and volcanic sequences
Capra is a genus of mammals, the goats or wild goats, composed of up to nine species, including the wild goat, the markhor, and several species known as ibex. The domestic goat is a subspecies of the wild goat. Evidence of goat domestication dates back more than 8,500 years, wild goats are animals of mountain habitats. They are very agile and hardy, able to climb on bare rock, the Rocky Mountain goat is in a separate genus, Oreamnos. All members of the Capra genus are bovids, and more specifically caprids, as such they are ruminants, meaning they chew the cud, and have four-chambered stomachs which play a vital role in digesting and redigesting their food. The genus has sometimes taken to include Ovis and Ammotragus. In this smaller genus, some authors have recognized two species, the markhor on one side and all other forms included in one species on the other side. Recent studies based on mitochondrial DNA suggest that the Siberian ibex and the Nubian ibex represent distinct species, the Alpine ibex forms a group with the Spanish ibex.
The West Caucasian tur appears to be closely related to the wild goat than to the East Caucasian tur. The markhor is relatively separated from other forms—previously it had been considered to be a separate branch of the genus. Almost all wild species are allopatric —the only geographical overlaps are the wild goat with the East Caucasian tur. In both cases, the species do not usually interbreed in the wild, but in captivity, all Capra species can interbreed. Along with sheep, goats were among the first domesticated animals, the domestication process started at least 10,000 years ago in what is now northern Iran. Easy human access to hair and milk were the primary motivations. Goat skins were used until the Middle Ages for water and wine bottles when traveling and camping. Evidence of the ibex is widely present in the record, particularly in the Near East. Ibex motifs are common on cylinder seals and pottery, both painted and embossed. Excavations from Minoan Crete at Knossos, for example, have yielded specimens from about 1800 BC, from the similar age a gold jewelry ibex image was found at the Akrotiri archaeological site on Santorini in present-day Greece
The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals and they are used primarily to grind food during chewing. The name molar derives from Latin, molaris dens, meaning tooth, from mola and dens. Molars show a great deal of diversity in size and shape across mammal groups, in humans, the molar teeth have either four or five cusps. Adult humans have twelve molars, in four groups of three at the back of the mouth, the third, rearmost molar in each group is called a wisdom tooth. It is the last tooth to appear, breaking through the front of the gum at about the age of twenty, ethnicity can affect the age at which this occurs, with statistical variations between groups. In some cases, it may not even erupt at all, the human mouth contains upper and lower molars. They are, maxillary first molar, maxillary second molar, maxillary third molar, mandibular first molar, mandibular second molar, in mammals, the crown of the molars and premolars are folded into a wide range of complex shapes.
The basic elements of the crown are the more or less conical projections called cusps, the cusps contain both dentine and enamel, whereas minor projections on the crown, called crenullations, are the result of different enamel thickness. Cusps are occasionally joined to form ridges and expanded to form crests, cingula are often incomplete ridges that pass around the base of the crown. It is generally agreed that therian mammals evolved from an ancestor with tribosphenic cheek teeth, with three main cusps arranged in a triangle. Each major cusp on an upper molar is called a cone and is identified by a dependent on its relative location on the tooth, proto-, para-, meta-, hypo-. Suffixes are added to names, -id is added to cusps on a lower molar. A shelf-like ridge on the part of the crown is called a cingulum, the same feature on the lower molar a cingulid, and a minor cusp on these, for example. The design that is considered one of the most important characteristics of mammals is a shape called a tribosphenic molar.
This molar design has two important features, the trigonid, or shearing end, and the talonid, or crushing heel, in modern tribosphenic molars, the trigonid is towards the front of the jaw and the talonid towards the rear. The tribosphenic tooth is found in insectivores and young platypuses, upper molars look like three-pointed mountain ranges, lowers look like two peaks and a third off to the side. The tribosphenic design appears primitively in all groups of mammals, some Jurassic mammals, such as Shuotherium and Pseudotribos, have reversed tribosphenic molars, in which the talonid is towards the front
It extends from the earliest known use of stone tools, probably by Homo habilis initially,2.6 million years ago, to the end of the Pleistocene around 10,000 BP. The Paleolithic era is followed by the Mesolithic, the date of the Paleolithic–Mesolithic boundary may vary by locality as much as several thousand years. During the Paleolithic period, humans grouped together in small societies such as bands, the Paleolithic is characterized by the use of knapped stone tools, although at the time humans used wood and bone tools. Other organic commodities were adapted for use as tools, including leather and vegetable fibers, due to their nature, surviving artifacts of the Paleolithic era are known as paleoliths. About 50,000 years ago, there was a increase in the diversity of artifacts. For the first time in Africa, bone artifacts and the first art appear in the archaeological record, the first evidence of human fishing is noted, from artifacts in places such as Blombos cave in South Africa. The new technology generated an explosion of modern humans which is believed to have led to the extinction of the Neanderthals.
Humankind gradually evolved from members of the genus Homo—such as Homo habilis. The climate during the Paleolithic consisted of a set of glacial and interglacial periods in which the climate periodically fluctuated between warm and cool temperatures, by c. 50,000 – c. 40,000 BP, the first humans set foot in Australia. By c. 45,000 BP, humans lived at 61°N latitude in Europe, by c. 30,000 BP, Japan was reached, and by c. 27,000 BP humans were present in Siberia, above the Arctic Circle. At the end of the Upper Paleolithic, a group of humans crossed Beringia, the term Paleolithic was coined by archaeologist John Lubbock in 1865. It derives from Greek, παλαιός, old, and λίθος, stone, human evolution is the part of biological evolution concerning the emergence of anatomically modern humans as a distinct species. The Paleolithic Period coincides almost exactly with the Pleistocene epoch of geologic time and this epoch experienced important geographic and climatic changes that affected human societies.
During the preceding Pliocene, continents had continued to drift from possibly as far as 250 km from their present locations to positions only 70 km from their current location. South America became linked to North America through the Isthmus of Panama, most of Central America formed during the Pliocene to connect the continents of North and South America, allowing fauna from these continents to leave their native habitats and colonize new areas. Africas collision with Asia created the Mediterranean Sea, cutting off the remnants of the Tethys Ocean, climates during the Pliocene became cooler and drier, and seasonal, similar to modern climates. The formation of an Arctic ice cap around 3 million years ago is signaled by a shift in oxygen isotope ratios and ice-rafted cobbles in the North Atlantic. Mid-latitude glaciation probably began before the end of the epoch, the global cooling that occurred during the Pliocene may have spurred on the disappearance of forests and the spread of grasslands and savannas
Archaeology, or archeology, is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, biofacts or ecofacts, Archaeology can be considered both a social science and a branch of the humanities. In North America, archaeology is considered a sub-field of anthropology, archaeologists study human prehistory and history, from the development of the first stone tools at Lomekwi in East Africa 3.3 million years ago up until recent decades. Archaeology as a field is distinct from the discipline of palaeontology, Archaeology is particularly important for learning about prehistoric societies, for whom there may be no written records to study. Prehistory includes over 99% of the human past, from the Paleolithic until the advent of literacy in societies across the world, Archaeology has various goals, which range from understanding culture history to reconstructing past lifeways to documenting and explaining changes in human societies through time.
The discipline involves surveying and eventually analysis of data collected to learn more about the past, in broad scope, archaeology relies on cross-disciplinary research. Archaeology developed out of antiquarianism in Europe during the 19th century, Archaeology has been used by nation-states to create particular visions of the past. Nonetheless, archaeologists face many problems, such as dealing with pseudoarchaeology, the looting of artifacts, a lack of public interest, the science of archaeology grew out of the older multi-disciplinary study known as antiquarianism. Antiquarians studied history with attention to ancient artifacts and manuscripts. Tentative steps towards the systematization of archaeology as a science took place during the Enlightenment era in Europe in the 17th and 18th centuries, in Europe, philosophical interest in the remains of Greco-Roman civilization and the rediscovery of classical culture began in the late Middle Age. Antiquarians, including John Leland and William Camden, conducted surveys of the English countryside, one of the first sites to undergo archaeological excavation was Stonehenge and other megalithic monuments in England.
John Aubrey was a pioneer archaeologist who recorded numerous megalithic and other monuments in southern England. He was ahead of his time in the analysis of his findings and he attempted to chart the chronological stylistic evolution of handwriting, medieval architecture and shield-shapes. Excavations were carried out in the ancient towns of Pompeii and Herculaneum and these excavations began in 1748 in Pompeii, while in Herculaneum they began in 1738. The discovery of entire towns, complete with utensils and even human shapes, prior to the development of modern techniques, excavations tended to be haphazard, the importance of concepts such as stratification and context were overlooked. The father of archaeological excavation was William Cunnington and he undertook excavations in Wiltshire from around 1798, funded by Sir Richard Colt Hoare. Cunnington made meticulous recordings of neolithic and Bronze Age barrows, one of the major achievements of 19th century archaeology was the development of stratigraphy.
The idea of overlapping strata tracing back to successive periods was borrowed from the new geological and paleontological work of scholars like William Smith, James Hutton, the application of stratigraphy to archaeology first took place with the excavations of prehistorical and Bronze Age sites
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
The Swabian Jura, sometimes named Swabian Alps in English, is a mountain range in Baden-Württemberg, extending 220 km from southwest to northeast and 40 to 70 km in width. It is named after the region of Swabia, the Swabian Jura occupies the region bounded by the Danube in the southeast and the upper Neckar in the northwest. In the southwest it rises to the mountains of the Black Forest. The highest mountain of the region is the Lemberg, the areas profile resembles a high plateau, which slowly falls away to the southeast. The northwestern edge is an escarpment, while the top is flat or gently rolling. In economic and cultural terms, the Swabian Jura includes regions just around the mountain range and it is a popular recreation area. The geology of the Swabian Jura is mostly limestone, which formed the seabed during the Jurassic period, the sea receded 50 million years ago. Three layers of different limestones are stacked over each other to form the range, Black Jurassic, Brown Jurassic, White Jurassic may be as pure as 99% calcium carbonate.
Since limestone is soluble in water, rain seeps through cracks everywhere, thus there are hardly any rivers, lakes or other forms of surface water on the plateau. In some places, former volcanic activity has left traces, such as maars, in the west, the Zollerngraben sometimes causes mild earthquakes. The Nördlinger Ries is a meteorite crater. Tertiary relicts can be found at the part of Swabian Jura. Famous locations are known in the Ulm area, constant rain and other weather influences are slowly dissolving the entire range. Each year, it recedes approximately 2 mm, some millions of years ago, the mountains reached as far as Stuttgart. In some places, the limestone was more resistant to decay, the omnipresent caves are great tourist spots and not very crowded. Many different types can be found, from dry dripstone caves to caves that can only be entered by boat, sometimes the discharge of the water from subterranean rivers can be spectacular, too, e. g. the Blautopf, a source for a tributary of the Danube.
Also because of the limestone, the Danube nearly disappears near Immendingen. Most of the water lost by the Danube resurfaces in the Aachtopf, the soil is not very fertile, the humus is often as thin as 10 cm
Neanderthals, or more rarely Neandertals, were a species or subspecies of archaic humans in the genus Homo that became extinct about 40,000 years ago. Neanderthals and modern humans share 99. 7% of their DNA and are closely related. Neanderthals left bones and stone tools in Eurasia, from Western Europe to Central, from the 1950s to the early 1980s, Neanderthals were widely considered a subspecies of Homo sapiens and a minority of scholars still hold this view. Several cultural assemblages have been linked to the Neanderthals in Europe, the earliest, the Mousterian stone tool culture, dates to about 160,000 years ago. Late Mousterian artifacts were found in Gorhams Cave on the south-facing coast of Gibraltar, male Neanderthals had cranial capacities averaging 1600 cm3, females 1300 cm3, extending to 1736 cm3 in Amud 1. This is notably larger than the 1250–1400 cm3 typical of modern humans, males stood 164–168 cm and females 152–156 cm tall. Recent studies show that a few Neanderthals began mating with ancestors of modern humans long before the out of Africa migration of present day non-Africans.
Claims that Neanderthals deliberately buried their dead, and if they did, the debate on deliberate Neanderthal burials has been active since the 1908 discovery of the well-preserved Chapelle-aux-Saints 1 skeleton in a small hole in a cave in southwestern France. In 2013, scientists sequenced the genome of a Neanderthal for the first time. The genome was extracted from the bone of a 50. In 2016, elaborate constructions of rings of broken stalagmites made by early Neanderthals around 176,000 years ago were discovered 336 m inside Bruniquel Cave in southwestern France and this would have required a more advanced social structure than previously known for Neanderthals. Thal is a spelling of the German word Tal, which means valley. Nevertheless, Kings name had priority over the proposal put forward in 1866 by Ernst Haeckel, the practice of referring to the Neanderthals and a Neanderthal emerged in the popular literature of the 1920s. The German pronunciation of Neanderthaler or Neandertaler is in the International Phonetic Alphabet, in British English, Neanderthal is pronounced with the /t/ as in German, but different vowels.
In laymans American English, Neanderthal is pronounced with a /θ/ and /ɔ/ instead of the longer British /aː/, during the early 20th century the prevailing view was heavily influenced by Arthur Keith and Marcellin Boule, who wrote the first scientific description of a nearly complete Neanderthal skeleton. During the 1930s scholars Ernst Mayr, George Gaylord Simpson and Theodosius Dobzhansky reinterpreted the existing fossil record, Neanderthal man was classified as Homo sapiens neanderthalensis - an early subspecies contrasted with what was now called Homo sapiens sapiens. The obviously unbroken succession of fossil sites of both subspecies in Europe was considered evidence that there was a slow and gradual evolutionary transition from Neanderthals to modern humans, contextual interpretations of similar excavation sites in Asia lead to the hypothesis of multiregional origin of modern man in the 1980s. Current scientific ideas hold that both evolved from a common African ancestor, Homo erectus
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