HOME





Santa Teresa Formation, Colombia
The Santa Teresa Formation (, Tist, Pgst) is a geological formation of the western Eastern Ranges of the Colombian Andes, west of the Bituima Fault, and the southern Middle Magdalena Valley. The formation spreads across the western part of Cundinamarca and the northern portion of Tolima. The formation consists of grey claystones intercalated by orange quartz siltstones and sandstones of small to conglomeratic grain size. The thickness at its type section has been measured to be and a maximum thickness of suggested. In the formation, dated on the basis of its fossil content to the Late Oligocene, many leaf imprints and mollusks were found, suggesting a lacustrine to deltaic depositional environment with periodical marine incursions. Etymology The formation was defined by De Porta in 1966 and named after the vereda Santa Teresa, San Juan de Rioseco.Acosta & Ulloa, 2001, p.64 Description The Santa Teresa Formation is the youngest unit outcropping in the Jerusalén-Guadu ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Late Oligocene
The Chattian is, in the geologic timescale The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochron ..., the younger of two age (geology), ages or upper of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/Series (stratigraphy), Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (stage), Aquitanian (the lowest stage of the Miocene). Stratigraphic definition The Chattian was introduced by Austrian palaeontologist Theodor Fuchs in 1894. Fuchs named the stage after the Chatti, a Germanic peoples, Germanic tribe.Berry, Edward W"The Mayence Basin, a Chapter of Geologic History" ''The Scientific Monthly'', Vol. 16, No. 2, February 1923. pp. 114. Retrieved March 18, 2020. The original type locality (geology), type l ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Claystone
Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone and shale. Most of the particles of which the stone is composed are less than and are too small to study readily in the field. At first sight, the rock types appear quite similar; however, there are important differences in composition and nomenclature. There has been a great deal of disagreement involving the classification of mudrocks. A few important hurdles to their classification include the following: # Mudrocks are the least understood and among the most understudied sedimentary rocks to date. # Studying mudrock constituents is difficult due to their diminutive size and susceptibility to weathering on outcrops. # And most importantly, scientists accept more than one classification scheme. Mudrocks make up 50% of the sedimentary rocks in the geologic record and are easily the most widespread deposits on Earth. Fine sediment is ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Quebrada
Quebrada may refer to: Places Argentina * Quebrada de Las Flechas, a valley in the province of Salta in northern Argentina * Quebrada de Humahuaca, World Heritage, a valley in the province of Jujuy in northern Argentina * Quebrada de Luna, village in Argentina Bolivia * Quebrada Honda, a fossil site in southern Bolivia Brazil * Canoa Quebrada, a seaside resort in northeastern Brazil Chile * Quebrada del Nuevo Reino, a village in Pichilemu, Chile Colombia * Quebrada Limas, a small river in Bogotá Costa Rica * Quebrada Grande, village in Guanacaste, Costa Rica Puerto Rico * Quebrada, Camuy, Puerto Rico, a barrio * Quebrada, San Lorenzo, Puerto Rico, a barrio * Quebrada Arenas, Las Piedras, Puerto Rico, a barrio *Quebrada Arenas, Maunabo, Puerto Rico, a barrio * Quebrada Arenas, San Lorenzo, Puerto Rico, a barrio *Quebrada Arenas, Toa Alta, Puerto Rico, a barrio * Quebrada Arenas, Vega Baja, Puerto Rico, a barrio *Quebrada Arenas, San Juan, Puerto Rico, a barrio * Quebrada ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Syncline
In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed smaller folds. Synclines are typically a downward fold (synform), termed a synformal syncline (i.e. a trough), but synclines that point upwards can be found when strata have been overturned and folded (an antiformal syncline). Characteristics On a geologic map, synclines are recognized as a sequence of rock layers, with the youngest at the fold's center or ''hinge'' and with a reverse sequence of the same rock layers on the opposite side of the hinge. If the fold pattern is circular or elongate, the structure is a basin. Folds typically form during crustal deformation as the result of compression that accompanies orogenic mountain building. Notable examples * Powder River Basin, Wyoming, US * Sideling Hill roadcut along Inters ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  




Guaduas
Guaduas () is a municipality and town in Colombia, in the Lower Magdalena Province department of Cundinamarca Department, Cundinamarca, about 117 km from Bogotá. It is an agricultural and tourist center of some importance with a population of about 33,000 in the municipality. Its name refers to a type of Guadua, bamboo cane. It is one of the cities on the Bogotá-Medellín highway. Its main plaza is featured on the Colombian ten-thousand Colombian peso, pesos bill, and is one of the seats of the Roman Catholic Diocese of La Dorada–Guaduas History The early inhabitants of the "Valley of the Guaduas" were the indigenous Panche people. It was an important stop on the road from Santafé de Bogotá to Honda, located in a small, fertile valley. The town proper was founded on April 20, 1572 by Andrés Díaz Venero de Leiva. It was abandoned after its foundation until December 13, 1610, when Fray Tomas de Morales founded the Franciscan monastery of ''La Soledad'' on the same ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Jerusalén, Cundinamarca
Jerusalén is a municipality and town of Colombia in the department of Cundinamarca. Climate See also * Jerusalén, El Salvador Jerusalén is a municipality in the La Paz department of El Salvador. It was founded by the Cordova family. They were Sephardi Jew Jews (, , ), or the Jewish people, are an ethnoreligious group and nation, originating from the Isra ... References Municipalities of Cundinamarca Department {{Cundinamarca-geo-stub ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Depositional Environment
In geology, depositional environment or sedimentary environment describes the combination of physical, chemical, and biological processes associated with the deposition of a particular type of sediment and, therefore, the rock types that will be formed after lithification, if the sediment is preserved in the rock record. In most cases, the environments associated with particular rock types or associations of rock types can be matched to existing analogues. However, the further back in geological time sediments were deposited, the more likely that direct modern analogues are not available (e.g. banded iron formations). Types of depositional environments Continental * – type of Fluvial deposit. Caused by moving water in a fan shape (Alluvial Fan) and containing mostly impermeable and nonporous sediments well sorted. * . Often in deserts and coastal regions and well sorted, large scale cross-beds * – processes due to moving water, mainly streams. Common sediments are g ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

River Delta
A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creation of a river delta occurs at the '' river mouth'', where the river merges into an ocean, a sea, or an estuary, into a lake, a reservoir, or (more rarely) into another river that cannot carry away the sediment supplied by the feeding river. Etymologically, the term ''river delta'' derives from the triangular shape (Δ) of the uppercase Greek letter delta. In hydrology, the dimensions of a river delta are determined by the balance between the watershed processes that supply sediment and the watershed processes that redistribute, sequester, and export the supplied sediment into the receiving basin. River deltas are important in human civilization, as they are major agricultural production centers and population centers. They can provide ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Lacustrine
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from the ocean, although they may be connected with the ocean by rivers. Lakes, as with other bodies of water, are part of the water cycle, the processes by which water moves around the Earth. Most lakes are fresh water and account for almost all the world's surface freshwater, but some are salt lakes with salinities even higher than that of seawater. Lakes vary significantly in surface area and volume of water. Lakes are typically larger and deeper than ponds, which are also water-filled basins on land, although there are no official definitions or scientific criteria distinguishing the two. Lakes are also distinct from lagoons, which are generally shallow tidal pools dammed by sandbars or other material at coastal regions of oceans or large ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Grain Size
Grain size (or particle size) is the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. This is different from the crystallite size, which refers to the size of a single crystal inside a particle or grain. A single grain can be composed of several crystals. Granular material can range from very small colloidal particles, through clay, silt, sand, gravel, and cobbles, to boulders. Krumbein phi scale Size ranges define limits of classes that are given names in the Wentworth scale (or Udden–Wentworth scale named after geologists Chester K. Wentworth and Johan A. Udden) used in the United States. The Krumbein ''phi'' (φ) scale, a modification of the Wentworth scale created by W. C. Krumbein in 1934, is a logarithmic scale computed by the equation :\varphi=-\log_2, where :\varphi is the Krumbein phi scale, :D is the diameter In geometry, a diameter of a circle i ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Conglomerate (geology)
Conglomerate () is a sedimentary rock made up of rounded gravel-sized pieces of rock surrounded by finer-grained sediments (such as sand, silt, or clay). The larger fragments within conglomerate are called clasts, while the finer sediment surrounding the clasts is called the matrix. The clasts and matrix are typically cemented by calcium carbonate, iron oxide, silica, or hardened clay. Conglomerates form when rounded gravels deposited by water or glaciers become solidified and cemented by pressure over time. They can be found in sedimentary rock sequences of all ages but probably make up less than 1 percent by weight of all sedimentary rocks. They are closely related to sandstones in origin, and exhibit many of the same types of sedimentary structures, such as tabular and trough cross-bedding and graded bedding.Boggs, S. (2006) ''Principles of Sedimentology and Stratigraphy.'', 2nd ed. Prentice Hall, New York. 662 pp. Friedman, G.M. (2003) ''Classification of sediments and s ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]