scholarly journals Reviewing the Antioquia batholith and satellite bodies: a record of Late Cretaceous to Eocene syn- to post-collisional arc magmatism in the Central Cordillera of Colombia

2018 ◽  
Vol 46 (1) ◽  
pp. 82 ◽  
Author(s):  
José Duque-Trujillo ◽  
Camilo Bustamante ◽  
Luigi Solari ◽  
Álvaro Gómez-Mafla ◽  
Gloria Toro-Villegas ◽  
...  
Keyword(s):  
South America ◽  
Arc Magmatism ◽  
South American ◽  
South American Plate ◽  
Magmatic Arc ◽  
History Of ◽  
Formation Conditions ◽  
Early Interaction ◽  
Central Cordillera ◽  
Existing Data

The Antioquia batholith represents the magmatic record of the interaction between the Farallón and Caribbean plates with the NW part of the South American Plate during the Meso-Cenozoic. Several authors have reported zircon U-Pb ages and whole rock geochemistry in order to constrain the crystallization history of this batholith and its formation conditions. The present work aims to gather the existing data with new data obtained from the Ovejas batholith and La Unión stock, both genetically related to the main intrusion. Gathering our new data with information obtained in previous works, we conclude that the Antioquia batholith was constructed by successive pulses from ca. 97 to 58 Ma in an arc-related setting. The initial pulses are related to syn-collisional tectonics, during the early interaction between the Farallón plate and NW South America. The final pulses, that record Eocene ages, are related to a post-collisional setting, similar to that recorded in other plutons of the Paleogene magmatic arc of the Central Cordillera.

Geodynamic study of the north of the Andes block (Colombia, Panama, Ecuador and Venezuela) through gnss-gps: models of displacements, models of deformation and definition of local and regional geodynamic structures.

2020 ◽  
Author(s):  
Berrocoso Manuel ◽  
Del Valle Arroyo Pablo Emilio ◽  
Colorado Jaramillo David Julián ◽  
Gárate Jorge ◽  
Fernández-Ros Alberto ◽  
...  
Keyword(s):  
South America ◽  
Seismic Activity ◽  
Great Part ◽  
Velocity Model ◽  
South American ◽  
The South ◽  
South American Plate ◽  
Northern Andes ◽  
Velocity Models ◽  
The North

<p>The northwest of South America is conformed by the territories of Ecuador, Colombia and Venezuela. Great part of these territories make up the Northern Andes Block (BAN). The tectonic and volcanic activity in the northwest of South America is directly related to the interaction of the South American plate, and the Nazca and Caribbean plates, with the Maracaibo and Panama-Chocó micro plates. The high seismic activity and the high magnitude of the recorded earthquakes make any study necessary to define this complex geodynamic region more precisely. This work presents the velocity models obtained through GNSS-GPS observations obtained in public continuous monitoring stations in the region. The observations of the Magna-eco network (Agustín Codazzi Geographic Institute) are integrated with models already obtained by other authors from the observations of the GEORED network (Colombian Geological Service). The observations have been processed using Bernese software v.52 using the PPP technique; obtaining topocentric time series. To obtain the speeds, a process of filtering and adjustment of the topocentric series has been carried out. Based on this velocity model, regional structures have been defined within the Northern Andes Block through a differentiation process based on the corresponding speeds of the South American, Nazca and Caribbean tectonic plates. Local geodynamic structures within the BAN itself have been established through cluster analysis based on both the direction and the magnitude of each of the vectors obtained. Finally, these structures have been correlated with the most significant geodynamic elements (fractures, faults, subduction processes, etc.) and with the associated seismic activity.</p>

Cutaneous Myiasis from Panama, South America: Case Report and Review

2008 ◽  
Vol 12 (3) ◽  
pp. 133-138 ◽  
Author(s):  
Patricia T. Ting ◽  
Benjamin Barankin
Keyword(s):  
Case Report ◽  
South America ◽  
Group B Streptococcus ◽  
Left Knee ◽  
South American ◽  
History Of ◽  
Clinical Variants ◽  
Group B ◽  
Streptococcus A ◽  
Increasing Trends

Background: Myiasis is a cutaneous infestation with larvae of Diptera, the two-winged arthropod order. Eggs and/or larvae are transmitted directly from the environment or via arthropod vectors. Larvae are able to burrow into the dermis of intact skin or external body orifices. Three clinical variants of myiasis are furuncular, migratory (creeping), and infestation of wounds. Methods: A 35-year-old male presented with a 1-month history of worsening furuncles on the left knee and posterior thigh following his return from Panama, South America. Clinical examination revealed tender 6 cm and 2 cm erythematous to violaceous furuncles with surrounding desquamation and central puncta draining serosanguinous fluid. Five-millimeter punch biopsies and tissue swabs were performed. Results: All larvae were of the Dermatobia hominis species. The patient was empirically treated with cephalexin and ciprofloxacin for secondary bacterial cellulitis. Tissue swabs later cultured group B streptococcus. A tetanus booster was recommended. Conclusion: This case report describes a relatively rare cutaneous infestation with D. hominis, a Central and South American endemic larva of the human botfly. Increasing trends toward immigration and global travel to tropical and subtropic areas will likely increase the frequency of encounters with such parasitic cutaneous infestations in North American outpatient dermatology clinics.

scholarly journals Rudolf Schlechter's South-American orchids I. Historical and bibliographical background

Lankesteriana ◽  
2019 ◽  
Author(s):  
Carlos Ossenbach ◽  
Rudolf Jenny
Keyword(s):  
South America ◽  
Key Words ◽  
Historical Background ◽  
South American ◽  
Individual Country ◽  
History Of Botany ◽  
Tropical America ◽  
History Of ◽  
Flora Of South America ◽  
Complete Bibliography

This study represents the first part of a series dedicated to the work of Rudolf Schlechter on the orchid flora of South America. The historical background of Schlechter’s botanical activity is outlined, and salient aspects of his biography, as well as his main scientific relationships, in particular with Oakes Ames, and the origins of his interest in tropical America are discussed. We also present a complete bibliography relative to Schlechter’s production on the orchid floras of South American countries, with his network of orchid collectors, growers and other purveyors, and checklists of all the new taxa that he described from each individual country.   Key words: bibliography, biography, history of botany, Orchidaceae, South America

scholarly journals Ancient DNA reveals the lost domestication history of South American camelids in Northern Chile and across the Andes

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Paloma Diaz-Maroto ◽  
Alba Rey-Iglesia ◽  
Isabel Cartajena ◽  
Lautaro Núñez ◽  
Michael V Westbury ◽  
...  
Keyword(s):  
South America ◽  
Formative Period ◽  
Archaeological Sites ◽  
South American ◽  
Northern Chile ◽  
Spanish Conquest ◽  
Domestic Species ◽  
South American Camelids ◽  
History Of ◽  
Early Formative

The study of South American camelids and their domestication is a highly debated topic in zooarchaeology. Identifying the domestic species (alpaca and llama) in archaeological sites based solely on morphological data is challenging due to their similarity with respect to their wild ancestors. Using genetic methods also presents challenges due to the hybridization history of the domestic species, which are thought to have extensively hybridized following the Spanish conquest of South America that resulted in camelids slaughtered en masse. In this study, we generated mitochondrial genomes for 61 ancient South American camelids dated between 3,500 and 2,400 years before the present (Early Formative period) from two archaeological sites in Northern Chile (Tulán-54 and Tulán-85), as well as 66 modern camelid mitogenomes and 815 modern mitochondrial control region sequences from across South America. In addition, we performed osteometric analyses to differentiate big and small body size camelids. A comparative analysis of these data suggests that a substantial proportion of the ancient vicuña genetic variation has been lost since the Early Formative period, as it is not present in modern specimens. Moreover, we propose a domestication hypothesis that includes an ancient guanaco population that no longer exists. Finally, we find evidence that interbreeding practices were widespread during the domestication process by the early camelid herders in the Atacama during the Early Formative period and predating the Spanish conquest.

scholarly journals Cycling in South America, 1880-1920

2020 ◽  
Vol 48 (1) ◽  
pp. 287-325
Author(s):  
Matthew Brown
Keyword(s):  
South America ◽  
Social Innovation ◽  
South American ◽  
Global History ◽  
The South ◽  
American Experience ◽  
Its Analysis ◽  
History Of ◽  
The Media ◽  
Mode Of Transport

Historians have tended to ignore the South American experience of cycling. The continent’s diverse history of sports has been effaced by a popular and academic focus on soccer. The global history of cycling has therefore omitted South America from its analysis, perpetuating mistaken assumptions about the continent’s absence from technological and social innovation. This article analyses the sources located across the continent to demonstrate that cyclists raced, toured, and did acrobatics, often watched by thousands of spectators, attracting the attention of chroniclers and the media. The physical sensations of travelling through the environment on a pedal-powered machine were new and unexpected. With its focus on cycling as sport, recreation and mode of transport, this article inserts South America into the early global history of cycling.

scholarly journals The first fossil skull of an anteater (Vermilingua, Myrmecophagidae) from northern South America, a taxonomic reassessment of Neotamandua and a discussion of the myrmecophagid diversification

2019 ◽  
Author(s):  
Kevin Jiménez-Lara ◽  
Jhon González
Keyword(s):  
South America ◽  
Middle Miocene ◽  
Taxonomic Status ◽  
South American ◽  
Ecological Constraints ◽  
History Of ◽  
Northern South America ◽  
New Evidence ◽  
History Of The South ◽  
Species Inquirendae

AbstractThe evolutionary history of the South American anteaters, Vermilingua, is incompletely known as consequence of the fragmentary and geographically biased nature of the fossil record of this group. Neotamandua borealis is the only recorded extinct species from northern South America, specifically from the Middle Miocene of La Venta area, southwestern Colombia. A new genus and species of myrmecophagid for La Venta, Gen. et sp. nov., is here described based on a new partial skull. Additionally, given that the co-occurrent species of Gen. et sp. nov., N. borealis, was originally referred to as Neotamandua, the taxonomic status of this genus is revised. The morphological and taxonomic analyses of these taxa indicate that Gen. et sp. nov. may be related to Tamandua and that the justification of the generic assignments of the species referred to as Neotamandua is weak or insufficient. Two species previously referred to as Neotamandua (N. magna and N.? australis) were designated as species inquirendae and new diagnostic information for the redefined genus and its type species, N. conspicua, is provided. Together, these results suggest that the diversification of Myrmecophagidae was taxonomically and biogeographically more complex than what has been proposed so far. Considering the new evidence, it is proposed a synthetic model on the diversification of these xenartrans during the late Cenozoic based on the probable relationships between their intrinsic ecological constraints and some major abiotic changes in the Americas.

From Charles Darwin's Portfolio: An Early Essay on South American Geology and Species

1995 ◽  
Vol 14 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Sandra Herbert
Keyword(s):  
South America ◽  
Charles Darwin ◽  
South American ◽  
Geological Formation ◽  
History Of ◽  
Early Essay ◽  
Narrative Framework

This work is an analysis and edition of a previously unpublished essay by Charles Darwin entitled "Reflection on reading my Geological notes." The original draft of the essay appears to have been written in 1834, that is, during Darwin's voyage on H.M.S. Beagle (1831-1836). In the essay Darwin developed a theory of the geological formation of South America that included a narrative framework for the history of life on the continent. His treatment of the history of life is not yet transmutationist, but it is highly sequential.

Uplift history of the Western Ecuadorian Andes: new constraints from low-temperature thermochronology

2020 ◽  
Author(s):  
Audrey Margirier ◽  
Peter Reiners ◽  
Ismael Casado ◽  
Stuart Thomson ◽  
Alexandra Alvarado ◽  
...  
Keyword(s):  
Strike Slip ◽  
South American ◽  
South American Plate ◽  
Ridge Subduction ◽  
The North ◽  
Western Cordillera ◽  
Deformational History ◽  
History Of ◽  
Long Term Impact

<p>The Cenozoic growth of the Ecuadorian Andes has been strongly influenced by the compressional reactivation of inherited crustal anisotropies, strike-slip faulting and uplift, and the erosional effects of a wet tropical climate superposed on the deforming orogen. Some authors have linked uplift in the Western Cordillera to the interaction between the South American Plate and the subduction of the oceanic Carnegie Ridge. However, recent studies have alternatively suggested that the tectonic evolution of a northward-escaping crustal sliver in western Ecuador along the Pallatanga strike-slip zone may equally well explain mountain building and topographic growth in this region. While the importance of the Pallatanga Fault has been recognized in the context of seismic hazards, its long-term impact on the development of topography and relief has not been explored in detail. To evaluate the possible roles of oceanic ridge subduction and/or strike-slip motion in prompting the growth of the Western Cordillera, we present new thermochronological data to constrain the deformational history of the Western Cordillera at different latitudes. We focus on two sites in the vicinity of the Pallatanga strike-slip fault (3°S and 1°30’S) and a location farther to the north (0°30’N). Our apatite and zircon (U-Th-Sm)/He dates range from 26.0 ± 0.4 Ma to 3.9 ± 0.1 Ma and from 23.7 ± 0.3 to 5.9 ± 0.1 Ma, respectively. The three sampled sites record a clear age-elevation relationship. The inverse modeling of apatite and zircon (U-Th-Sm)/He dates and upcoming apatite fission-track data is expected to provide new constraints on the recent uplift and exhumation history of the Western Ecuadorian Andes and thus furnish information on the paleo-geographical evolution of the northern Andes.</p>

scholarly journals Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) in Argentina

2015 ◽  
Vol 73 (9) ◽  
pp. 751-754 ◽  
Author(s):  
Maximiliano A Hawkes ◽  
Miguel Wilken ◽  
Verónica Bruno ◽  
Virginia Pujol-Lereis ◽  
Guillermo Povedano ◽  
...  
Keyword(s):  
South America ◽  
Medical Records ◽  
Diagnostic Tests ◽  
Autosomal Dominant ◽  
European Ancestry ◽  
South American ◽  
Stroke Patients ◽  
External Capsule ◽  
Characteristic Imaging ◽  
History Of

CADASIL is the most common cause of hereditary stroke and vascular dementia. Published information about this disease in South America is scant. We describe clinical and demographic characteristics of 13 patients (10 families) with CADASIL from Argentina.Methods Medical records, diagnostic tests and family history of patients with CADASIL were reviewed.Results Thirteen patients with CADASIL (10 families) were included. All patients had European ancestry. Initial presentation was stroke in most patients (n = 11). Stroke patients later developed cognitive complaints (n = 9), migraine with aura (n = 1), apathy (n = 4) and depression (n = 6). External capsule and temporal lobe involvement on MRI were characteristic imaging findings. Two patients died after intracerebral hemorrhage.Conclusion This is the first report of non-related patients with CADASIL in South America addressing ancestry. Since European ancestry is not highly prevalent in all South American countries, there may be variable incidence of CADASIL within this region.

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