No. Registros Solicitud 1 5614 colombia
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CC - CATEGORY CODES: 26B-Economic-geology,-general,-economics DT - DOCUMENT TYPE: Serial; Conference-Document BL - BIB LEVEL: Analytic IL - ILLUSTRATION: Refs: 18; illus. incl. 2 tables. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 1324-6240 CO - CODEN: #03621 AN - ACCESSION NUMBER: 2000-052881 UD - UPDATE CODE: 200017 Registro 5288 de 5614 - GeoRef 1997-2001 TI - TITLE: Riprap at bridge piers. AU - AUTHORS: Duarte-C-A; Sainz-J-A AF - AUTHOR AFFILIATION: National University of Colombia, School of Civil Engineering, Bogota, Colombia SO - SOURCE: Journal of Hydraulic Research = Journal de Recherches Hydrauliques. 37; 3, Pages 291-302. 1999. PB - PUBLISHER: International Association for Hydraulic Research. Delft, International. 1999. CP - COUNTRY OF PUBLICATION: International PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: English LS - LANGUAGE OF SUMMARY: French AB - ABSTRACT: The influence that protective riprap have on the scour holes that develop near bridge piers has been studied in clear water conditions with circular and rectangular piers. Non-dimensional graphs, relating the characteristic dimensions of the scour holes with the riprap elevation above bed level and its width, are presented. Also, the necessary minimum width of riprap, deduced from tests, is compared to criteria proposed by various authors. DE - DESCRIPTORS: bridges-; channels-; piers-; riprap-; rivers-and-streams; testing- CC - CATEGORY CODES: 30-Engineering-geology DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic IL - ILLUSTRATION: Refs: 18; illus. incl. 1 table. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 0022-1686 CO - CODEN: IHSBAS AN - ACCESSION NUMBER: 2000-052018 UD - UPDATE CODE: 200017 Registro 5289 de 5614 - GeoRef 1997-2001 TI - TITLE: Acid mine drainage (AMD) treatment by sulphate reducing bacteria. AU - AUTHORS: Estrada-Rendon-C-M; Amara-G; Leonard-P; Tobin-J; Roussy-J; Degorce-Dumas-J-R AF - AUTHOR AFFILIATION: Universidad Nacional de Columbia, Medellin, Colombia BK - BOOK TITLE: In: Biohydrometallurgy and the environment toward the mining of the 21st century; proceedings of the International biohydrometallurgy symposium IBS'99, Part B, Molecular biology, biosorption, bioremediation. BA - BOOK AUTHORS: Amils-R (editor); Ballester-A (editor) SO - SOURCE: Process Metallurgy. 9, Part B; Pages 577-585. 1999. PB - PUBLISHER: Elsevier. Amsterdam, Netherlands. 1999. CP - COUNTRY OF PUBLICATION: Netherlands PY - PUBLICATION YEAR: 1999 CN - CONFERENCE INFORMATION: International biohydrometallurgy symposium IBS'99. Madrid, Spain. June 20-23, 1999. LA - LANGUAGE: English DE - DESCRIPTORS: acid-mine-drainage; arsenic-; bacteria-; bioremediation-; Carnoules-Mine; dams-; Europe-; France-; Gard-France; heavy-metals; iron-; lead-; manganese-; metals-; mines-; pH-; pollution-; precipitation-; remediation-; sulfate-ion; tailings-dams; Western-Europe; zinc- CC - CATEGORY CODES: 22-Environmental-geology DT - DOCUMENT TYPE: Serial; Conference-Document BL - BIB LEVEL: Analytic IL - ILLUSTRATION: Refs: 10; illus. incl. 5 tables. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IB - ISBN: 0-444-50193-2 CO - CODEN: #05123 AN - ACCESSION NUMBER: 2000-049810 UD - UPDATE CODE: 200016 Registro 5290 de 5614 - GeoRef 1997-2001 TI - TITLE: An archaeological perspective of the Pleistocene/ Holocene boundary in northern South America. AU - AUTHORS: Gnecco-Cristobal AF - AUTHOR AFFILIATION: Universidad del Cauca, Departamento de Antropologia, Popayan, Colombia BK - BOOK TITLE: In: The Pleistocene/ Holocene transition and human occupation in South America. BA - BOOK AUTHORS: Zarate-Marcelo-A (editor) SO - SOURCE: Quaternary International. 53-54; Pages 3-9. 1999. PB - PUBLISHER: Pergamon. Oxford, United Kingdom. 1999. CP - COUNTRY OF PUBLICATION: United-Kingdom PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: English DE - DESCRIPTORS: archaeology-; Calima-River; Cenozoic-; chronology-; climate-; ecosystems-; Ecuador-; glacial-environment; Holocene-; human-activity; interglacial-environment; lower-Holocene; Orinoco-River; paleoclimatology-; Pleistocene-; Quaternary-; Santa-Elena-Peninsula; South-America; stratigraphic-boundary; upper-Pleistocene; Venezuela- CC - CATEGORY CODES: 24-Quaternary-geology DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic MC - MAP COORDINATES: LAT: S020000; N150000; LONG: W0650000; W0850000. IL - ILLUSTRATION: Refs: 61; sketch map. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 1040-6182 AN - ACCESSION NUMBER: 2000-046037 UD - UPDATE CODE: 200015 Registro 5291 de 5614 - GeoRef 1997-2001 TI - TITLE: Seismic risk mitigation project for Pereira, Dosquebradas and Santa Rosa de Cabal, Department of Risaralda (Colombia). AU - AUTHORS: Garcia-Ana-Campos AF - AUTHOR AFFILIATION: Corporacion Autonoma Regional de Risaralda, Risaralda, Colombia SO - SOURCE: Bulletin of the International Institute of Seismology and Earthquake Engineering. 33; Pages 131-145. 1999. PB - PUBLISHER: International Institute of Seismology and Earthquake Engineering. Tokyo, Japan. 1999. CP - COUNTRY OF PUBLICATION: Japan PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: English AB - ABSTRACT: The carrying out of a coordinated group of activities for the reduction of seismic risk in Pereira, Dosquebradas and Santa Rosa de Cabal, it is supported in natural, socio-economical, cultural and historic aspects that indicate the existence of serious problems that can affect the development of these cities in the case of the occurrence of possible earthquake. The project through the identification and analysis of the group of variables that intervene in seismic phenomenon as a whole and its consequences, pretend to minimize of human, social and economical losses in Pereira, Dosquebradas and Santa Rosa, by means of establishing planning policies for the improvement of seismic risk reduction programs and emergency attention by the responsible government agencies. Following the partial advances are presented, showing a general look related with the seismic regional hazard, the local answer, the physical vulnerability of constructions and the scenario of losses for earthquake. DE - DESCRIPTORS: Colombia-; Dosquebradas-Colombia; earthquakes-; geologic-hazards; mitigation-; Pereira-Colombia; preventive-measures; Risaralda-Colombia; Santa-Rosa-de-Cabal-Colombia; seismic-risk; seismicity-; South-America CC - CATEGORY CODES: 30-Engineering-geology DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic MC - MAP COORDINATES: LAT: N044800; N044800; LONG: W0754100; W0754100. IL - ILLUSTRATION: Refs: 10; illus. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 0074-655X CO - CODEN: IISBB2 AN - ACCESSION NUMBER: 2000-045560 UD - UPDATE CODE: 200015 Registro 5292 de 5614 - GeoRef 1997-2001 TI - TITLE: Earthquake complex response and stability analysis of natural slopes. AU - AUTHORS: Escorcia-C-Gustavo-E AF - AUTHOR AFFILIATION: O.V.B.B., Civil Engineers, Meta, Colombia SO - SOURCE: Individual Studies by Participants at the International Institute of Seismology and Earthquake Engineering. 35; Pages 181-194. 1999. PB - PUBLISHER: International Institute of Seismology and Earthquake Engineering. Tokyo, International. 1999. CP - COUNTRY OF PUBLICATION: International PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: English AB - ABSTRACT: By considering local geology, soil site, topography, and seismic response, a stability problem of natural slope at a site of Colombia was studied using numerical methods. Basically this study contains two kinds of analyses: 1) Response Analysis, following the methodology developed by Lysmer, Udaka, Seed and Hwang and summarized as code FLUSH, which in an approximate manner takes in to account the strong non-linearity of soils subject to strong earthquake motion. 2) Stability Analysis, based on Inertial Method, where strengths of soils used are obtained from static laboratory test but additional dynamic stresses computed in the previous analysis can be considered in judgement of slope stability. This procedure might be expected to use for the wide range of earthquake engineering practices. DE - DESCRIPTORS: Colombia-; earthquakes-; geologic-hazards; numerical-analysis; preventive-measures; seismic-response; slope-stability; slopes-; South-America; stability- CC - CATEGORY CODES: 30-Engineering-geology DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic IL - ILLUSTRATION: Refs: 9; illus. incl. 2 tables. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 0074-6606 CO - CODEN: ISEIAM AN - ACCESSION NUMBER: 2000-045523 UD - UPDATE CODE: 200015 Registro 5293 de 5614 - GeoRef 1997-2001 TI - TITLE: Seismic hazard assessment in the Northern Andes (PILOTO Project). AU - AUTHORS: Dimate-Cristina; Drake-Lawrence; Yepez-Hugo; Ocola-Leo; Rendon-Herbert; Gruenthal-Gottfried; Giardini-Domenico AF - AUTHOR AFFILIATION: Instituto de Investigaciones en Geociencias, Mineria y Quimica, Santafe de Bogota, Colombia BK - BOOK TITLE: In: The Global Seismic Hazard Assessment Program (GSHAP) 1992-1999. BA - BOOK AUTHORS: Giardini-Domenico (editor) SO - SOURCE: Annali di Geofisica. 42; 6, Pages 1039-1055. 1999. PB - PUBLISHER: Istituto Nazionale di Geofisica. Rome, Italy. 1999. CP - COUNTRY OF PUBLICATION: Italy PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: English AB - ABSTRACT: Five Andean countries (Bolivia, Peru, Ecuador, Colombia, Venezuela) and four European countries (Italy, Spain, Holland, Germany) cooperated in the PILOTO program ("Test area for earthquake monitoring and seismic hazard assessment"), launched under GSHAP and sponsored by the European Union (Ct.94-0103) to produce a unified SHA for the Andean region. Activities included the integration of national earthquake catalogues and source zonings in common regional databases and joint technical workshops for the assessment of the regional hazard, expressed in terms of expected peak ground acceleration with 10% exceedance probability in 50 years. DE - DESCRIPTORS: Andes-; cartography-; earthquakes-; geologic-hazards; monitoring-; Northern-Andes; PILOTO-Project; programs-; risk-assessment; seismic-risk; seismicity-; South-America; UN-IDNDR CC - CATEGORY CODES: 19-Seismology; 22-Environmental-geology DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic IL - ILLUSTRATION: Refs: 19; illus. incl. 3 tables, geol. sketch maps. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 0365-2556 CO - CODEN: AGFRAI AN - ACCESSION NUMBER: 2000-043690 UD - UPDATE CODE: 200014 Registro 5294 de 5614 - GeoRef 1997-2001 TI - TITLE: Body wave inversion of the 1970 and 1963 South American large deep-focus earthquakes. AU - AUTHORS: Estabrook-Charles-H AF - AUTHOR AFFILIATION: GeoForschungsZentrum, Potsdam, Federal Republic of Germany SO - SOURCE: Journal of Geophysical Research, B, Solid Earth and Planets. 104; 12, Pages 28,751-28,768. 1999. PB - PUBLISHER: American Geophysical Union. Washington, DC, United States. 1999. CP - COUNTRY OF PUBLICATION: United-States PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: English DE - DESCRIPTORS: body-waves; Colombia-earthquake-1970; deep-focus-earthquakes; earthquakes-; elastic-waves; focus-; functions-; inverse-problem; moment-tensors; Nazca-Plate; Peru-Bolivia-earthquake-1963; plate-tectonics; rupture-; seismic-moment; seismic-waves; subduction-; teleseismic-signals; time-factor CC - CATEGORY CODES: 19-Seismology DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic MC - MAP COORDINATES: LAT: S400000; N100000; LONG: W0500000; W0900000. IL - ILLUSTRATION: Refs: 79; illus. incl. 3 tables, geol. sketch maps. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 0885-3401 AN - ACCESSION NUMBER: 2000-040340 UD - UPDATE CODE: 200013 Registro 5295 de 5614 - GeoRef 1997-2001 TI - TITLE: Actividad sismica y tasa de deformacion sismotectonica en la zona del Viejo Caldas, Colombia Translated Title: Seismic activity and seismotectonic strain rate in the Viejo Caldas region, Colombia. AU - AUTHORS: Tabares-Ocampo-Lina-Maria; Mora-Paez-Hector; Salcedo-Hurtado-Elkin-de-Jesus AF - AUTHOR AFFILIATION: INGEOMINAS, Unidad Operativa Observatorio Vulcanologico y Sismologico, Manizales, Colombia SO - SOURCE: Revista de la Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. 23; 88, Pages 359-373. 1999. PB - PUBLISHER: Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. Bogota, Colombia. 1999. CP - COUNTRY OF PUBLICATION: Colombia PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: Spanish LS - LANGUAGE OF SUMMARY: English AB - ABSTRACT: The Viejo Caldas Region, affected by the Nazca Plate subduction underneath the South American Plate, is characterized by the occurrence of deep and destructive earthquakes. This paper evaluates the seismic activity and the seismotectonic strain rate on the basis of existing empirical relationships, using deep seismological information and focal mechanism solutions. The results obtained, that are in agreement with those from the geodetic measurements carried out in the GPS CASA campaigns, show that under the Viejo Caldas Region the Nazca Plate has extensional stress, and is moving 41 mm/yr with an azimuth of 133 degrees , factors that generate high seismic activity and possibility of occurrence of an earthquake with magnitude m (sub b) > or =7,4. DE - DESCRIPTORS: active-faults; Atlantic-Ocean; Caribbean-Sea; Colombia-; depth-; earthquake-prediction; earthquakes-; faults-; focal-mechanism; moment-tensors; Nazca-Plate; North-Atlantic; numerical-models; offshore-; plate-tectonics; rates-; seismicity-; seismotectonics-; South-America; South-American-Plate; strain-; subduction-; subduction-zones; tectonics-; Viejo-Caldas-Colombia CC - CATEGORY CODES: 18-Solid-earth-geophysics DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic IL - ILLUSTRATION: Refs: 29; illus. incl. 4 tables. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 0370-3908 CO - CODEN: RCCFAO AN - ACCESSION NUMBER: 2000-040131 UD - UPDATE CODE: 200013 Registro 5296 de 5614 - GeoRef 1997-2001 TI - TITLE: Algunas observaciones acerca de la geologia del sudoeste del Caqueta Translated Title: Some observations about the geology of southwestern Caqueta. AU - AUTHORS: Galvis-V-Jaime; Pinto-R-Hernando SO - SOURCE: Revista de la Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. 23; 88, Pages 347-358. 1999. PB - PUBLISHER: Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. Bogota, Colombia. 1999. CP - COUNTRY OF PUBLICATION: Colombia PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: Spanish LS - LANGUAGE OF SUMMARY: English AB - ABSTRACT: In the area comprised between Florencia and Fraguita hamlet, of southwestern Caqueta Department there is completely different lithology than that of the Upper Magdalena Valley. The geologic events are completely different in these areas. In southwestern Caqueta there were episodes of magmatism not registered before in the geologic literature of Colombia. There are in Caqueta many wrench faults which put in contact pieces of territory which present different lithologic assemblages. The number and thickness of the phanerozoic geologic units diminish to the East. DE - DESCRIPTORS: areal-geology; Caqueta-Colombia; Colombia-; faults-; geochronology-; landform-evolution; lithostratigraphy-; magmatism-; mineral-resources; Phanerozoic-; Precambrian-; South-America; tectonics-; wrench-faults CC - CATEGORY CODES: 13-Areal-geology DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic MC - MAP COORDINATES: LAT: N003000; N014500; LONG: W0743000; W0754500. IL - ILLUSTRATION: Refs: 13; illus. incl. strat. cols., 4 plates, geol. sketch map. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 0370-3908 CO - CODEN: RCCFAO AN - ACCESSION NUMBER: 2000-040130 UD - UPDATE CODE: 200013 Registro 5297 de 5614 - GeoRef 1997-2001 TI - TITLE: Estudio de sismicidad historica en la region de Bucaramanga (Colombia) Translated Title: Study of the history of seismicity in the Bucaramanga region, Colombia. AU - AUTHORS: Salcedo-Hurtado-Elkin-de-Jesus AF - AUTHOR AFFILIATION: Universidad del Valle, Departamento de Geografia, Cali, Colombia SO - SOURCE: Revista de la Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. 23; 87, Pages 233-248. 1999. PB - PUBLISHER: Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. Bogota, Colombia. 1999. CP - COUNTRY OF PUBLICATION: Colombia PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: Spanish LS - LANGUAGE OF SUMMARY: English AB - ABSTRACT: In spite of the fact that Bucaramanga is a seismoactive region of Colombian territory that in recent years shows the major production of earthquakes, it does not have historical studies that reveal its seismic activity in the preinstrumental period. As a contribution to fill this vacuum, the present study, using the intensivist and extensivist methods, begins with the systematic revision of newspaper sources, in order to intensify the knowledge of the catalogued earthquakes, on one hand, and to get the major quantity of new seismic notices, on the other hand. As an initial result of this research it is possible to tell that until now the Bucaramanga region has not been the scene of catastrophic earthquakes, whose effects can be unhappily remembered by the population; also it is important to emphasize that from 1930, on average every 5 years, at least 2 quakes are sensed in Bucaramanga city, and that in a period of 26 years, between 1950 and 1976, about 45 earthquakes occurred. In spite of exhaustive search, the results presented in this paper must be considerate as preliminary and urge to continue this study, with one fundamental goal, the assessment of the degree of intensity for every recognized earthquake. DE - DESCRIPTORS: active-faults; Bucaramanga-Colombia; Cenozoic-; Colombia-; earthquakes-; faults-; history-; Holocene-; modern-; Quaternary-; Santander-Colombia; seismic-intensity; seismicity-; South-America CC - CATEGORY CODES: 19-Seismology DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic MC - MAP COORDINATES: LAT: N070000; N075000; LONG: W0723000; W0731500. NN - ANNOTATION: Includes appendices.. IL - ILLUSTRATION: Refs: 14; illus. incl. 3 tables. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 0370-3908 CO - CODEN: RCCFAO AN - ACCESSION NUMBER: 2000-033581 UD - UPDATE CODE: 200011 Registro 5298 de 5614 - GeoRef 1997-2001 TI - TITLE: Rocas grenvillianas en la regiode Puerto Berrio-Antioquia Translated Title: Grenvillian rocks in the Puerto Berrio-Antioquia region. AU - AUTHORS: Ordonez-Carmona-Oswaldo; Pimentel-Marcio-M; de-Moraes-Renato; Restrepo-Jorge-Julian AF - AUTHOR AFFILIATION: Universidad de Brasilia, Instituto de Geociencias, BRA, Brazil SO - SOURCE: Revista de la Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. 23; 87, Pages 225-232. 1999. PB - PUBLISHER: Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. Bogota, Colombia. 1999. CP - COUNTRY OF PUBLICATION: Colombia PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: Spanish LS - LANGUAGE OF SUMMARY: English AB - ABSTRACT: In the El Vapor creek (Puerto Berrio-Antioquia), mylonitic rocks were identified. The geochemical data for the mylonites reveal high SiO (sub 2) content (65.7 to 80.9 wt %) and a peraluminous character. A Rb-Sr isochron for these mylonites yielded an age of 894+ or -36 Ma, with an initial (super 87) Sr/ (super 86) Sr ratio of ca. 0.71785. This date is interpreted here as a metamorphic resetting age in response to the Grenvillian orogeny. The high initial ratio suggests a long crustal residence period. This interpretation is confirmed with T (sub DM) model ages of 1757 and 1829 Ma and zircon evaporation age of 1.1 Ga. DE - DESCRIPTORS: absolute-age; Antioquia-Colombia; Colombia-; dates-; evaporation-; geochemistry-; Grenvillian-Orogeny; metamorphic-rocks; metamorphism-; mylonites-; Neoproterozoic-; nesosilicates-; orthosilicates-; peraluminous-composition; petrography-; Precambrian-; Proterozoic-; Puerto-Berrio-Colombia; silicates-; Sm-Nd; South-America; Rb-Sr; upper-Precambrian; zircon- CC - CATEGORY CODES: 05A-Igneous-and-metamorphic-petrology; 03-Geochronology DT - DOCUMENT TYPE: Serial BL - BIB LEVEL: Analytic MC - MAP COORDINATES: LAT: N062300; N063800; LONG: W0742000; W0744200. IL - ILLUSTRATION: Refs: 27; illus. incl. 3 tables, geol. sketch map. RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. IS - ISSN: 0370-3908 CO - CODEN: RCCFAO AN - ACCESSION NUMBER: 2000-033580 UD - UPDATE CODE: 200011 Registro 5299 de 5614 - GeoRef 1997-2001 TI - TITLE: Vulcanitas cenozoicas en el piedemonte suroriental de la Sierra Nevada de Santa Marta en la Serrania de Perija Translated Title: Cenozoic volcanites in the southeastern piedmont of the Sierra Nevada de Santa Marta, Serrania de Perija. AU - AUTHORS: Galvis-Vergara-Jaime; de-la-Espriella-Ricardo AF - AUTHOR AFFILIATION: Cra. 48G, No. 95-19, Santafe de Bogota, Colombia SO - SOURCE: Revista de la Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. 23; 87, Pages 213-224. 1999. PB - PUBLISHER: Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. Bogota, Colombia. 1999. CP - COUNTRY OF PUBLICATION: Colombia PY - PUBLICATION YEAR: 1999 LA - LANGUAGE: Spanish LS - LANGUAGE OF SUMMARY: English AB - ABSTRACT: Rocks originating during three magmatic events, clearly different in age and genesis, are present in the southeastern portion of the Sierra Nevada de Santa Marta. The first event took place during Triassic-Jurassic time, is related to the rifting process, and produced alkaline siliceous magmatism interbedded with red sediments. The second one originated later, during Jurassic time by submarine vulcanism, and its composition is basic and intermediate. The third event produced acid vulcanites--rhyolites and rhyodacites--in a wide SWW-NEE belt which outcrops from the southeastern foothills of the Sierra Nevada to extensive areas on the Serrania de Perija; the hypothesis of its age as Cenozoic is the subject of this paper. Yüklə 20,82 Mb. Dostları ilə paylaş:
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