No. Registros Solicitud 1 5614 colombia

DE - DESCRIPTORS: Archosauria-; biogeography-; bipedalism-; Chordata-; Colombia-; Degenhardt,-Carl; Diapsida-; dinosaurs-; history-; occurrence-; paleoecology-; Reptilia-; Saurischia-; South-America; Tetrapoda-; Theropoda-; tracks-; Vertebrata-

CC - CATEGORY CODES: 11-Vertebrate-paleontology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 23; sketch map.

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute.

IS - ISSN: 0037-9409

AN - ACCESSION NUMBER: 2000-033298

UD - UPDATE CODE: 200011

Registro 5242 de 5614 - GeoRef 1997-2001

TI - TITLE: Water discharge and sediment load from the western slopes of the Colombian Andes with focus on Rio San Juan.

AU - AUTHORS: Restrepo-Juan-D; Kjerfve-Bjorn

AF - AUTHOR AFFILIATION: University of South Carolina, Marine Science Program, Columbia, SC, United States

SO - SOURCE: Journal of Geology. 108; 1, Pages 17-33. 2000.

PB - PUBLISHER: University of Chicago Press. Chicago, IL, United States. 2000.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 2000

LA - LANGUAGE: English

AB - ABSTRACT: Small rivers draining high-rainfall basins and mountainous terrain west of the Cordilleras in South America have disproportionately high water discharge and sediment load. Fifteen rivers in western Colombia discharge a combined 254 km (super 3) yr (super -1) or 8020 m (super 3) s (super -1) of water into the Pacific. Sediment yield is strongly correlated with basin area (R (super 2) = 0.97), and sediment load is correlated with water discharge (R (super 2) = 0.73). Rio San Juan occupies a 16,465-km (super 2) basin with a mean annual rainfall of 7277 mm. It has the highest water discharge (2550 m (super 3) s (super -1) ), sediment load (16X10 (super 6) t yr (super -1) ), and basin-wide sediment yield (1150 t km (super -2) yr (super -1) ) on the entire west coast of South America. Rio Patia drains a 23,700-km (super 2) basin with a mean annual rainfall of 2821 mm. Its water discharge, sediment load, and basin-wide sediment yield are 1291 m (super 3) s (super -1) , 14 t yr (super -1) , and 972 t km (super -2) yr (super -1) , respectively. Rio San Juan and Rio Patia deliver 30X10 (super 6) t of suspended sediment annually into the Pacific. Analysis of data for an additional 22 rivers in Colombia that drain into the Caribbean Sea indicates that the Pacific rivers have at least twice the sediment yield compared with the larger Rio Magdalena. Our results confirm that the Pacific rivers of Colombia need to be accounted for in global sediment budgets.

DE - DESCRIPTORS: Andes-; bedload-; Colombia-; discharge-; drainage-basins; fluvial-sedimentation; hydrology-; measurement-; models-; Northern-Andes; rainfall-; rivers-and-streams; San-Juan-River; sediment-transport; sediment-yield; sedimentation-; slopes-; South-America; stream-transport

CC - CATEGORY CODES: 21-Hydrogeology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N033000; N053000; LONG: W0754500; W0772000.

IL - ILLUSTRATION: Refs: 74; illus. incl. 2 tables, sketch maps.

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute.

IS - ISSN: 0022-1376

CO - CODEN: JGEOAZ

AN - ACCESSION NUMBER: 2000-026992

UD - UPDATE CODE: 200009

Registro 5243 de 5614 - GeoRef 1997-2001

TI - TITLE: Large volume recycling of oceanic lithosphere over short time scales: geochemical constraints from the Caribbean Large Igneous Province.

AU - AUTHORS: Hauff-F; Hoernle-K; Tilton-G; Graham-D-W; Kerr-A-C

AF - AUTHOR AFFILIATION: GEOMAR Research Center, Kiel, Federal Republic of Germany

SO - SOURCE: Earth and Planetary Science Letters. 174; 3-4, Pages 247-263. 2000.

PB - PUBLISHER: Elsevier. Amsterdam, Netherlands. 2000.

RP - RESEARCH PROGRAM: DSDP (Deep Sea Drilling Project)

CP - COUNTRY OF PUBLICATION: Netherlands

PY - PUBLICATION YEAR: 2000

LA - LANGUAGE: English

AB - ABSTRACT: Oceanic flood basalts are poorly understood, short-term expressions of highly increased heat flux and mass flow within the convecting mantle. The uniqueness of the Caribbean Large Igneous Province (CLIP, 92-74 Ma) with respect to other Cretaceous oceanic plateaus is its extensive sub-aerial exposures, providing an excellent basis to investigate the temporal and compositional relationships within a starting plume head. We present major element, trace element and initial Sr-Nd-Pb isotope composition of 40 extrusive rocks from the Caribbean Plateau, including onland sections in Costa Rica, Colombia and Curacao as well as DSDP Sites in the Central Caribbean. Even though the lavas were erupted over an area of approximately 3X10 (super 6) km (super 2) , the majority have strikingly uniform incompatible element patterns (La/Yb = 0.96+ or -0.16, n = 64 out of 79 samples, 2sigma ) and initial Nd-Pb isotopic compositions (e.g. (super 143) Nd/ (super 144) Nd (sub in) = 0.51291+ or -3, epsilon (sub Ndi) =7.3+ or -0.6, (super 206) Pb/ (super 204) Pb (sub in) = 18.86+ or -0.12, n = 54 out of 66, 2sigma ). Lavas with endmember compositions have only been sampled at the DSDP Sites, Gorgona Island (Colombia) and the 65-60 Ma accreted Quepos and Osa igneous complexes (Costa Rica) of the subsequent hotspot track. Despite the relatively uniform composition of most lavas, linear correlations exist between isotope ratios and between isotope and highly incompatible trace element ratios. The Sr-Nd-Pb isotope and trace element signatures of the chemically enriched lavas are compatible with derivation from recycled oceanic crust, while the depleted lavas are derived from a highly residual source. This source could represent either oceanic lithospheric mantle left after ocean crust formation or gabbros with interlayered ultramafic cumulates of the lower oceanic crust. High (super 3) He/ (super 4) He in olivines of enriched picrites at Quepos are approximately 12 times higher than the atmospheric ratio suggesting that the enriched component may have once resided in the lower mantle. Evaluation of the Sm-Nd and U-Pb isotope systematics on isochron diagrams suggests that the age of separation of enriched and depleted components from the depleted MORB source mantle could have been < or =500 Ma before CLIP formation and interpreted to reflect the recycling time of the CLIP source. Mantle plume heads may provide a mechanism for transporting large volumes of possibly young recycled oceanic lithosphere residing in the lower mantle back into the shallow MORB source mantle.

DE - DESCRIPTORS: Antilles-; Atlantic-Ocean; basalts-; Caribbean-region; Caribbean-Sea; Carribbean-Large-Igneous-Province; Central-America; chemical-composition; chemical-ratios; Colombia-; concentration-; Costa-Rica; crust-; Curacao-; Deep-Sea-Drilling-Project; DSDP-Site-151; DSDP-Site-152; geochemistry-; igneous-rocks; isotope-ratios; isotopes-; lead-; Leg-15; Lesser-Antilles; lithosphere-; major-elements; mantle-; metals-; mid-ocean-ridge-basalts; mineral-composition; Nd-144-Nd-143; neodymium-; Netherlands-Antilles; North-Atlantic; oceanic-crust; Pb-206-Pb-204; radioactive-isotopes; rare-earths; South-America; stable-isotopes; trace-elements; volcanic-rocks; West-Indies

CC - CATEGORY CODES: 18-Solid-earth-geophysics; 02D-Isotope-geochemistry

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

NN - ANNOTATION: Includes appendix.

IL - ILLUSTRATION: Refs: 53; illus. incl. 1 table, geol. sketch map.

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands

IS - ISSN: 0012-821X

CO - CODEN: EPSLA2

AN - ACCESSION NUMBER: 2000-012960

UD - UPDATE CODE: 200005

Registro 5244 de 5614 - GeoRef 1997-2001

TI - TITLE: Crustal controls on volcanism; an arc-scale view of volcano and fault interaction in the Northern Andes, Colombia and Ecuador.

AU - AUTHORS: Wessels-Rick-Lee; Williams-Stanley-N; Hall-Minard-L; Wood-Charles-A

AF - AUTHOR AFFILIATION: Arizona State University Department of Geology, Tempe, AZ, United States

BK - BOOK TITLE: In: AGU 1999 fall meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Eos, Transactions, American Geophysical Union. 80; 46, Suppl., Pages 959. 1999.

PB - PUBLISHER: American Geophysical Union. Washington, DC, United States. 1999.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1999

CN - CONFERENCE INFORMATION: American Geophysical Union 1999 fall meeting. San Francisco, CA, United States. Dec. 13-17, 1999.

LA - LANGUAGE: English

DE - DESCRIPTORS: Andes-; Carnegie-Ridge; Cenozoic-; Colombia-; crust-; East-Pacific; Ecuador-; faults-; fractures-; Holocene-; island-arcs; lithosphere-; mafic-composition; mineral-composition; Northern-Andes; Pacific-Ocean; plate-tectonics; Quaternary-; slabs-; South-America; stress-fields; strike-slip-faults; subduction-; volcanic-centers; volcanic-features; volcanism-; volcanoes-; volcanology-

CC - CATEGORY CODES: 18-Solid-earth-geophysics

DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute.

IS - ISSN: 0096-3941

CO - CODEN: EOSTAJ

UR - URL: (Full text) http://www.public.asu.edu/~wessels1/

AN - ACCESSION NUMBER: 2001-079981

UD - UPDATE CODE: 200124

XURL - URLs, etc : URL; URL-ITEM (UR)

Registro 5245 de 5614 - GeoRef 1997-2001

BK - BOOK TITLE: Remote sensing and tectonic analysis of active volcanoes in continental arcs.

BA - BOOK AUTHORS: Wessels-Rick-Lee

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1999

DG - DEGREE GRANTED: Doctoral

DI - DEGREE GRANTING INSTITUTION: Arizona State University. Tempe, AZ, United States. Pages: 153. 1999.

LA - LANGUAGE: English

DE - DESCRIPTORS: aerial-photography; Andes-; Colombia-; digital-terrain-models; Ecuador-; errors-; extension-tectonics; fault-zones; faults-; fractures-; geologic-hazards; geophysical-surveys; Global-Positioning-System; lava-; lithosphere-; magmas-; Northern-Andes; orientation-; patterns-; remote-sensing; South-America; spatial-distribution; strike-slip-faults; subduction-; surveys-; tectonics-; textures-; topography-; variations-; volatiles-; volcanoes-

CC - CATEGORY CODES: 24-Quaternary-geology; 20-Applied-geophysics

DT - DOCUMENT TYPE: Thesis-or-Dissertation

BL - BIB LEVEL: Monograph

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute.

AV - AVAILABILITY: University Microfilms, Ann Arbor, MI, United States

AN - ACCESSION NUMBER: 2001-079863

UD - UPDATE CODE: 200124

Registro 5246 de 5614 - GeoRef 1997-2001

BK - BOOK TITLE: Middle Paleogene palynology of Colombia, South America; biostratigraphic, sequence stratigraphic, and diversity implications.

BA - BOOK AUTHORS: Jaramillo-Carlos-Alberto

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1999

DG - DEGREE GRANTED: Doctoral

DI - DEGREE GRANTING INSTITUTION: University of Florida. Gainesville, FL, United States. Pages: 417. 1999.

LA - LANGUAGE: English

DE - DESCRIPTORS: Andes-; biostratigraphy-; Cenozoic-; chronostratigraphy-; Colombia-; correlation-; Llanos-; middle-Paleogene; miospores-; models-; Paleogene-; paleotemperature-; palynomorphs-; pollen-; provenance-; sequence-stratigraphy; South-America; species-diversity; spores-; subsidence-; Tertiary-; tropical-environment; variations-

CC - CATEGORY CODES: 12-Stratigraphy

DT - DOCUMENT TYPE: Thesis-or-Dissertation

BL - BIB LEVEL: Monograph

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute.

AV - AVAILABILITY: University Microfilms, Ann Arbor, MI, United States

AN - ACCESSION NUMBER: 2001-074146

UD - UPDATE CODE: 200123

Registro 5247 de 5614 - GeoRef 1997-2001

TI - TITLE: A petrological model for oceanic impact melting and the origin of komatiites.

AU - AUTHORS: Jones-A-P; Price-G-D; Claeys-P

BK - BOOK TITLE: In: Oceanic impacts; mechanisms and environmental perturbations; ESF-IMPACT workshop.

BA - BOOK AUTHORS: Gersonde-Rainer (editor); Deutsch-Alexander (editor)

SO - SOURCE: Berichte zur Polarforschung. 343; Pages 41-42. 1999.

PB - PUBLISHER: Kamloth. Bremerhaven, Federal Republic of Germany. 1999.

CP - COUNTRY OF PUBLICATION: Federal-Republic-of-Germany

PY - PUBLICATION YEAR: 1999

CN - CONFERENCE INFORMATION: Workshop on "Oceanic impacts; mechanisms and environmental perturbations. Bremerhaven, Federal Republic of Germany. April 15-17, 1999.

LA - LANGUAGE: English

DE - DESCRIPTORS: breccia-; clastic-rocks; Colombia-; East-Pacific; genesis-; glasses-; Gorgona-Island; igneous-rocks; impactite-; impacts-; komatiite-; marine-environment; melting-; metamorphism-; Pacific-Ocean; plutonic-rocks; sedimentary-rocks; shock-metamorphism; South-America; ultramafics-; volcanic-rocks

CC - CATEGORY CODES: 05A-Igneous-and-metamorphic-petrology

DT - DOCUMENT TYPE: Serial; Conference-Document

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 3

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. Reference includes data from Geoline, Bundesanstalt fur Geowissenschaften und Rohstoffe, Hanover, Germany

IS - ISSN: 0176-5027

CO - CODEN: #52114

AN - ACCESSION NUMBER: 2001-060230

UD - UPDATE CODE: 200119

Registro 5248 de 5614 - GeoRef 1997-2001

TI - TITLE: Analisis y tendencia asintotica en fenomenos hidrologicos de multiples escalas en redes hidrograficas

Translated Title: Analysis and asymptotic trend in hydrologic phenomena of multiple scale in hydrographic networks.

AU - AUTHORS: Gupta-Vijay-K

AF - AUTHOR AFFILIATION: University of Colorado, Department of Civil and Environmental Engineering, USA, United States

SO - SOURCE: Dyna (Medellin, Colombia). 128; Pages 53-61. 1999.

PB - PUBLISHER: Universidad Nacional de Colombia, Facultad Nacional de Minas. Medellin, Colombia. 1999.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 1999

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: River networks are discrete nested branching patterns which span about four decades in their spatial scales. They aggregate water, sediments, nutrients, and biogeochemical variables such as carbon and nitrogen from small to larger subbasins. A foundational understanding of water and energy balances in river networks requires suitable formulations, solutions and tests of appropriate conservation equations. Solutions of these conservation laws for discrete networks also require an understanding of the geometry and statistics of branching patterns and of the bio-physical processes which appear in these equations. A link-based mass Conservation equation is taken as an example to review recent developments which have used self-similarity as an umbrella to deal with the multiscale nature of the problem. The role of channel network theories is illustrated in this context, and recent developments in analytical network theories are reviewed. Analytical results have very often required the use of asymptotics. It leads to universality which does not depend on all the details of a model.

DE - DESCRIPTORS: drainage-basins; drainage-patterns; energy-balance; energy-conservation; geometry-; hydrodynamics-; hydrographs-; mathematical-models; nutrients-; sediments-; surface-water; water-balance

CC - CATEGORY CODES: 21-Hydrogeology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 29; illus.

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute.

IS - ISSN: 0012-7353

CO - CODEN: DYNAAU

AN - ACCESSION NUMBER: 2001-054922

UD - UPDATE CODE: 200117

Registro 5249 de 5614 - GeoRef 1997-2001

BK - BOOK TITLE: A spatial analysis of emergy of an internationally shared drainage basin and the implications for policy decisions.

BA - BOOK AUTHORS: Howington-Tonya

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1999

DG - DEGREE GRANTED: Doctoral

DI - DEGREE GRANTING INSTITUTION: University of Florida. Gainesville, FL, United States. Pages: 232. 1999.

LA - LANGUAGE: English

DE - DESCRIPTORS: biomass-; Catatumbo-River-basin; Colombia-; decision-making; drainage-basins; geographic-information-systems; information-systems; international-cooperation; policy-; soils-; South-America; Venezuela-; water-management; water-quality; water-resources; watersheds-

CC - CATEGORY CODES: 21-Hydrogeology

DT - DOCUMENT TYPE: Thesis-or-Dissertation

BL - BIB LEVEL: Monograph

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute.

AV - AVAILABILITY: University Microfilms, Ann Arbor, MI, United States

AN - ACCESSION NUMBER: 2001-050195

UD - UPDATE CODE: 200116

Registro 5250 de 5614 - GeoRef 1997-2001

TI - TITLE: Biosteering in BP Amoco; more bang for your bug.

AU - AUTHORS: Jones-Robert; Lowe-Stephen; Milner-Paul; Heavey-Peter; Payne-Simon; Ewen-David

AF - AUTHOR AFFILIATION: BP-Amoco, Sunbury-on-Thames, United Kingdom

BK - BOOK TITLE: In: Geological Society of America, 1999 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Abstracts with Programs - Geological Society of America. 31; 7, Pages 356. 1999.

PB - PUBLISHER: Geological Society of America (GSA). Boulder, CO, United States. 1999.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1999

CN - CONFERENCE INFORMATION: Geological Society of America, 1999 annual meeting. Denver, CO, United States. Oct. 25-28, 1999.

LA - LANGUAGE: English

DE - DESCRIPTORS: Andrew-Field; Arabian-Peninsula; Asia-; Atlantic-Ocean; biosteering-; biostratigraphy-; carbonate-rocks; case-studies; chalk-; Chalk-Fields; Colombia-; cost-; Cretaceous-; Cusiana-Field; depositional-environment; geophysical-methods; high-resolution-methods; lithofacies-; marine-environment; Mesozoic-; microfacies-; microfossils-; monitoring-; North-Atlantic; North-Sea; oil-and-gas-fields; oil-wells; palynomorphs-; petroleum-; petroleum-exploration; reservoir-rocks; sedimentary-rocks; seismic-methods; shallow-water-environment; South-America; submarine-fans; thin-sections; United-Arab-Emirates

CC - CATEGORY CODES: 12-Stratigraphy; 29A-Economic-geology,-geology-of-energy-sources

DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States

IS - ISSN: 0016-7592

CO - CODEN: GAAPBC

AN - ACCESSION NUMBER: 2001-049860

UD - UPDATE CODE: 200116

Registro 5251 de 5614 - GeoRef 1997-2001

TI - TITLE: Emeralds; recent developments and projected changes in supply.

AU - AUTHORS: Schwarz-Dietmar

AF - AUTHOR AFFILIATION: Guebelin Gem Lab, Lucerne, Switzerland

BK - BOOK TITLE: In: Proceedings of the third international gemological symposium.

BA - BOOK AUTHORS: Keller-Alice (chairperson); Kimmel-Kathryn (chairperson)

SO - SOURCE: Gems and Gemology. 35; 3, Pages 62-63. 1999.

PB - PUBLISHER: Gemological Institute of America. Santa Monica, CA, United States. 1999.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1999

CN - CONFERENCE INFORMATION: Third international gemological symposium. San Diego, CA, United States. June 21-24, 1999.

LA - LANGUAGE: English

DE - DESCRIPTORS: Afghanistan-; Africa-; Asia-; Brazil-; Colombia-; Commonwealth-of-Independent-States; East-Africa; economics-; emerald-; gems-; Indian-Ocean-Islands; Indian-Peninsula; Madagascar-; mineral-exploration; mineralization-; Pakistan-; production-; ring-silicates; silicates-; South-America; Southern-Africa; Urals-; Zambia-; Zimbabwe-

CC - CATEGORY CODES: 28A-Economic-geology,-geology-of-nonmetal-deposits

DT - DOCUMENT TYPE: Serial; Conference-Document

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 7; illus.

RF - REFERENCE SOURCE: GeoRef, Copyright 2002, American Geological Institute.

IS - ISSN: 0016-626X

CO - CODEN: GEGEA2

AN - ACCESSION NUMBER: 2001-045361

UD - UPDATE CODE: 200114

Registro 5252 de 5614 - GeoRef 1997-2001

TI - TITLE: Three-dimensional kinematic model of evolution of the northern portion of the eastern thrust front of the Eastern Cordillera, Colombia; interaction between thin-skinned and basin inversion.

AU - AUTHORS: Corredor-Freddy

AF - AUTHOR AFFILIATION: Harvard University, Department of Earth and Planetary Sciences, Cambridge, MA, United States

BK - BOOK TITLE: In: Geological Society of America, 1999 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Abstracts with Programs - Geological Society of America. 31; 7, Pages 268. 1999.

PB - PUBLISHER: Geological Society of America (GSA). Boulder, CO, United States. 1999.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1999

CN - CONFERENCE INFORMATION: Geological Society of America, 1999 annual meeting. Denver, CO, United States. Oct. 25-28, 1999.

LA - LANGUAGE: English

AB - ABSTRACT: The eastern front of the Eastern Cordillera is a large east-verging fold and thrust belt. A detailed structural analysis and interpretation of recently acquired seismic data, surface geology and remote-sensing images along the northern portion of this belt suggests that at least three phases of deformation have occurred during the Tertiary, giving rise to varying structural geometries at different locations along the mountain front. The earliest phase of deformation, occurred during the late Eocene-early Oligocene, formed an east vergent thin skinned imbricate fan, which was eroded and covered by early Oligocene deposits. A later middle Miocene phase of deformation reactivated some of the previously formed faults and created new ones, thereby forming a passive-roof duplex triangle zone, where the early Oligocene unconformity served as the roof thrust. It is likely that positive basin inversion just to the west drove this fault-fold system. A final late Pliocene-early Pleistocene stage of deformation occurred when the inversion affected the eastern border of the fold belt, deforming and folding the preexisting passive-roof duplex and its frontal monocline. The geometry of the structures in the eastern thrust front is highly complicated in three-dimensions as several tectonic events have occurred during their evolution. A three-dimensional model of this thrust front has been developed using two-dimensional information to show the complex variations that occur on all the thrust imbricates that form this fold belt.

DE - DESCRIPTORS: Andes-; Cenozoic-; Colombia-; deformation-; duplexes-; Eastern-Cordillera; Eocene-; faults-; fold-and-thrust-belts; folds-; geometry-; geophysical-methods; geophysical-surveys; imagery-; imbricate-tectonics; interpretation-; kinematics-; lower-Oligocene; models-; Oligocene-; Paleogene-; reactivation-; remote-sensing; seismic-methods; South-America; surveys-; tectonics-; Tertiary-; thin-skinned-tectonics; three-dimensional-models; thrust-faults; triangle-zones; two-dimensional-models; unconformities-; variations-