DE - DESCRIPTORS: Acrisols-; Alisols-; Amazon-Basin; Caqueta-Basin; classification-; Colombia-; drainage-; Ferralsols-; horizon-differentiation; land-use; morphology-; parent-materials; pedogenesis-; principal-components-analysis; soil-profiles; soils-; South-America; statistical-analysis; textures-
CC - CATEGORY CODES: 25-Soils; 22-Environmental-geology
DT - DOCUMENT TYPE: Serial
BL - BIB LEVEL: Analytic
MC - MAP COORDINATES: LAT: S013000; S002500; LONG: W0704000; W0723000.
NN - ANNOTATION: Includes an appendix.
IL - ILLUSTRATION: Refs: 81; illus. incl. 5 tables, sketch maps.
RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands
IS - ISSN: 0016-7061
CO - CODEN: GEDMAB
AN - ACCESSION NUMBER: 1996-074570
UD - UPDATE CODE: 199623
Registro 4679 de 5614 - GeoRef Disc 4: 1993-1996
TI - TITLE: Onset of the Little Ice Age at the Columbia Icefield, Canadian Rockies, as recorded in lateral moraines of the Stutfield Glacier.
AU - AUTHORS: Osborn-Gerald
AF - AUTHOR AFFILIATION: University of Calgary, Department of Geology and Geophysics, Calgary, AB, Canada
BK - BOOK TITLE: In: AMQUA 1996; program and abstracts of the 14th biennial meeting; Global warming; interglacials, interstadials, climatic optima, and other events.
BA - BOOK AUTHORS: Anonymous
SO - SOURCE: Program and Abstracts - American Quaternary Association. Conference. 14; Pages 181. 1996.
PB - PUBLISHER: American Quaternary Association. Seattle, WA, United States. 1996.
CP - COUNTRY OF PUBLICATION: United-States
PY - PUBLICATION YEAR: 1996
CN - CONFERENCE INFORMATION: AMQUA 1996; 14th biennial meeting of the American Quaternary Association. Flagstaff, AZ, United States. May 20-22, 1996.
LA - LANGUAGE: English
DE - DESCRIPTORS: Canada-; Canadian-Rocky-Mountains; Cenozoic-; clastic-sediments; Colombia-Icefield; debris-flows; glacial-geology; glaciers-; Holocene-; ice-movement; igneous-rocks; mass-movements; moraines-; Neoglacial-; North-America; pyroclastics-; Quaternary-; Rocky-Mountains; sediments-; Stutfield-Glacier; till-; unconformities-; volcanic-rocks; Western-Canada
CC - CATEGORY CODES: 24-Quaternary-geology
DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document
BL - BIB LEVEL: Analytic
RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute.
IS - ISSN: 0741-059X
CO - CODEN: AMQUAM
AN - ACCESSION NUMBER: 1996-081570
UD - UPDATE CODE: 199624
Registro 4680 de 5614 - GeoRef Disc 4: 1993-1996
TI - TITLE: Late Cenozoic tectonics and paleomagnetism of North Cauca Basin intrusions, Colombian Andes; dual rotation modes.
AU - AUTHORS: MacDonald-W-D; Estrada-J-J; Sierra-G-M; Gonzalez-H
AF - AUTHOR AFFILIATION: State University of New York at Binghamton, Department of Geological Sciences, Binghamton, NY, United States
SO - SOURCE: Tectonophysics. 261; 4, Pages 277-289. 1996.
PB - PUBLISHER: Elsevier. Amsterdam, Netherlands. 1996.
RP - RESEARCH PROGRAM: IGCP (International Geological Correlation Programme)
CP - COUNTRY OF PUBLICATION: Netherlands
PY - PUBLICATION YEAR: 1996
LA - LANGUAGE: English
AB - ABSTRACT: Further paleomagnetic results are reported from 18 sites in Late Tertiary hypabyssal igneous rocks adjacent to the Romeral fault system which forms the eastern boundary of the North Cauca Basin. The paleomagnetic directions in these massive igneous intrusions are distributed in vertical planes parallel to the adjacent Romeral suture zone. Two modes of rotation, involving non-coherent rotations about horizontal rotation axes and coherent rotations about vertical rotation axes, can explain the observed remanence patterns. The paleovectors have been rotated variably (non-coherently), both upwards and downwards, through up to nearly 90 degrees , about horizontal axes which are perpendicular to the prevailing structural trend. These horizontal axis rotations are believed to be associated with shear gradients operating on rough projections or "asperities" on otherwise approximately lenticular bodies. These give rise to torques which cause variable horizontal axis rotation along splay faults of the Romeral and adjacent systems. In addition, the north segment of the zone of intrusions has been rotated coherently, i.e. through uniform angles, of about 30 degrees counterclockwise, about vertical axes relative to the southern zone. The change in declination trend corresponds to a major change in trend of the Romeral suture zone. The vertical-axis rotations are believed to represent regional-scale kinking of vertical lenti-laminar fault panels of crust accreted to the paleocontinental margin along the Romeral suture. It is hypothesized that oblique transpression has pressed the zone of intrusions into the Caldas Re-entrant in the paleocontinental margin.
DE - DESCRIPTORS: Andes-; Cauca-Basin; Cenozoic-; Colombia-; fault-zones; faults-; hypabyssal-rocks; IGCP-; igneous-rocks; intrusions-; neotectonics-; Northern-Andes; paleomagnetism-; Romeral-Fault; rotation-; South-America; suture-zones; tectonics-; terranes-; Tertiary-; transpression-; upper-Cenozoic; upper-Tertiary
CC - CATEGORY CODES: 16-Structural-geology
DT - DOCUMENT TYPE: Serial
BL - BIB LEVEL: Analytic
MC - MAP COORDINATES: LAT: N051500; N160000; LONG: W0753000; W0760000.
NN - ANNOTATION: IGCP Project No. 345.
IL - ILLUSTRATION: Refs: 31; illus. incl. sect., block diags., 1 table, geol. sketch maps.
RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands
IS - ISSN: 0040-1951
CO - CODEN: TCTOAM
AN - ACCESSION NUMBER: 1997-004175
UD - UPDATE CODE: 199701
Registro 4681 de 5614 - GeoRef Disc 4: 1993-1996
TI - TITLE: Assessing the impact of trajectory on wells drilled in an overthrust region.
AU - AUTHORS: Last-Nigel-C; McLean-Michael-R
AF - AUTHOR AFFILIATION: BP Exploration Colombia, COL, Colombia
SO - SOURCE: JPT. Journal of Petroleum Technology. 48; 7, Pages 620-626. 1996.
PB - PUBLISHER: American Institute of Mining, Metallurgical and Petroleum Engineers. Dallas, TX, United States. 1996.
CP - COUNTRY OF PUBLICATION: United-States
PY - PUBLICATION YEAR: 1996
LA - LANGUAGE: English
DE - DESCRIPTORS: anisotropy-; bedding-; boreholes-; Casanare-Colombia; Colombia-; Cupiagua-Field; Cusiana-Field; drilling-; faults-; horizontal-drilling; oil-and-gas-fields; petroleum-engineering; planar-bedding-structures; sedimentary-structures; South-America; stability-; strength-; stress-; thrust-faults; well-logs; wells-
CC - CATEGORY CODES: 29A-Economic-geology,-geology-of-energy-sources
DT - DOCUMENT TYPE: Serial
BL - BIB LEVEL: Analytic
MC - MAP COORDINATES: LAT: N043000; N053000; LONG: W0720000; W0730000.
NN - ANNOTATION: SPE paper 30465; first presented at the 1995 SPE annual tech. conf. and exhibition, Dallas, TX, Oct. 22-25, 1995; includes appendix.
IL - ILLUSTRATION: Refs: 21; illus. incl. block diag., sects., sketch maps.
RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute.
IS - ISSN: 0149-2136
CO - CODEN: JPTJAM
AN - ACCESSION NUMBER: 1997-004648
UD - UPDATE CODE: 199702
Registro 4682 de 5614 - GeoRef Disc 4: 1993-1996
TI - TITLE: Temporal change in coda Q at Nevado del Ruiz Volcano, Colombia.
AU - AUTHORS: Londono-John-Makario
AF - AUTHOR AFFILIATION: Kyoto University, Kyoto, Japan
SO - SOURCE: Journal of Volcanology and Geothermal Research. 73; 1-2, Pages 129-139. 1996.
PB - PUBLISHER: Elsevier. Amsterdam, Netherlands. 1996.
CP - COUNTRY OF PUBLICATION: Netherlands
PY - PUBLICATION YEAR: 1996
LA - LANGUAGE: English
AB - ABSTRACT: An analysis of coda Q (Q (sub c) ), intrinsic Q (Q (sub i) ), scattering Q (Q (sub s) ) and total Q (Q (sub t) ), was made at Nevado del Ruiz Volcano (NRV) for local earthquakes recorded during 1992-1994. Coda Q has been calculated for the first time at Nevado del Ruiz Volcano (NRV) using the single-scattering model proposed by Aki and Chouet (1975). Estimations of Q (sub c) were made for five frequency bands centred at 1.5, 3.0, 6.0, 12.0 and 24.0 Hz. The estimated Q (sub c) varies from around 60 at 1.5 Hz to around 980 at 24 Hz, depending on the frequency with Q (sub c) = 30+ or -1.2f (super 1.03+ or -0.001) . In general, Q (sub c) values at NRV are rather similar to those obtained in other volcanic areas in the world. A steady trend in Q (sub c) (super -1) was found from January 1992 to January 1994. This variation is coincident with the stability in the volcanic activity since the last phreato -magmatic eruption on 1 September 1989. In the middle of April 1994, a new activity started at NRV and a small volcanic crisis occurred. Continuous increasing was observed in Q (sub c) (super -1) around two months before the crisis. This suggests a possibility that the temporal variation of Q (sub c) can be useful for monitoring the volcanic activity at NRV. Q (sub i) and Q (sub s) were separated from Q (sub t) by using a multiple-scattering model called "Multiple Lapse Time Window Analysis", MLTWA (Fehler et al., 1992). Estimations for Q (sub i) , Q (sub s) and Q (sub t) were made for four frequency bands, 3.0, 6.0, 12.0 and 24.0 Hz. Q (sub i) values were found to be near to those of Q (sub c) for frequencies higher than 6.0 Hz. For low frequencies Q (sub s) values were near to Q (sub c) values. This can suggest that the intrinsic absorption could be the predominant attenuation phenomenon in the NRV area at frequencies higher than 6 Hz and the scattering phenomenon is predominant for low frequencies; therefore the change in Q (sub c) at high frequencies is considered to reflect variations in the inner conditions of the volcano, such as changes in temperature, movement of fluids, and so on.
DE - DESCRIPTORS: attenuation-; coda-waves; Colombia-; elastic-waves; Nevado-del-Ruiz; Q-; seismic-waves; South-America; surface-waves; temporal-distribution; volcanism-; volcanoes-; wave-dispersion
CC - CATEGORY CODES: 19-Seismology
DT - DOCUMENT TYPE: Serial
BL - BIB LEVEL: Analytic
MC - MAP COORDINATES: LAT: N045300; N045300; LONG: W0752200; W0752200.
IL - ILLUSTRATION: Refs: 47; illus. incl. 1 table.
RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands
IS - ISSN: 0377-0273
CO - CODEN: JVGRDQ
AN - ACCESSION NUMBER: 1997-005048
UD - UPDATE CODE: 199702
Registro 4683 de 5614 - GeoRef Disc 4: 1993-1996
TI - TITLE: Crustal thickness variations beneath the Peninsular Ranges, Southern California.
AU - AUTHORS: Ichinose-Gene-A; Day-Steven; Magistrale-Harold; Prush-Ted; Vernon-Frank-L; Edelman-Adam
AF - AUTHOR AFFILIATION: San Diego State University, Department of Geological Sciences, San Diego, CA, United States
SO - SOURCE: Geophysical Research Letters. 23; 22, Pages 3095-3098. 1996.
PB - PUBLISHER: American Geophysical Union. Washington, DC, United States. 1996.
CP - COUNTRY OF PUBLICATION: United-States
PY - PUBLICATION YEAR: 1996
LA - LANGUAGE: English
DE - DESCRIPTORS: Argentina-earthquake-1994; California-; Cenozoic-; Colombia-earthquake-1994; crust-; earthquakes-; Kuril-Islands-earthquake-1994; North-America; Peninsular-Ranges; Peninsular-Ranges-Batholith; Salton-Trough; Southern-California; tectonics-; teleseismic-signals; Tertiary-; thickness-; United-States; Vanuatu-earthquake-1994; velocity-structure
CC - CATEGORY CODES: 18-Solid-earth-geophysics
DT - DOCUMENT TYPE: Serial
BL - BIB LEVEL: Analytic
MC - MAP COORDINATES: LAT: N324000; N331000; LONG: W1160000; W1170000.
IL - ILLUSTRATION: Refs: 20; illus. incl. 1 table, sketch map.
RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute.
IS - ISSN: 0094-8276
CO - CODEN: GPRLAJ
AN - ACCESSION NUMBER: 1997-008965
UD - UPDATE CODE: 199703
Registro 4684 de 5614 - GeoRef Disc 4: 1993-1996
TI - TITLE: Mise en evidence d'une tectonique compressive eocene-oligocene dans l'ouest de la Cordillere orientale de Colombie, d'apres la structure en duplex des gisements d'emeraude de Muzo et de Coscuez
Translated Title: Evidence for Eocene-Oligocene compressive tectonics in the western Eastern Cordillera of Colombia, based on the structure of the Muzo and Coscuez emerald deposits.
AU - AUTHORS: Laumonier-B; Branquet-Y; Lopes-B; Cheilletz-A; Giuliani-G; Rueda-F
AF - AUTHOR AFFILIATION: Ecole des Mines de Nancy, Nancy, France
SO - SOURCE: Comptes Rendus de l'Academie des Sciences, Serie II. Sciences de la Terre et des Planetes. 323; 8, Pages 705-712. 1996.
PB - PUBLISHER: Gauthier-Villars. Montrouge, France. 1996.
CP - COUNTRY OF PUBLICATION: France
PY - PUBLICATION YEAR: 1996
LA - LANGUAGE: French
LS - LANGUAGE OF SUMMARY: English
AB - ABSTRACT: The structures of the emerald deposits of the western part of Eastern Cordillera of Colombia (thrusts, ramps, duplexes, tear faults) have been formed by three deformational events forming a single thrust-tectonics phase, synchronous with the emerald-forming hydrothermalism. As this hydrothermalism is Late Eocene-Early Oligocene in age, it is also the age of the thrust tectonics.
DE - DESCRIPTORS: Andean-Orogeny; Andes-; beryl-; Cenozoic-; Colombia-; compression-tectonics; Coscuez-Deposit; Eastern-Cordillera; emerald-; Eocene-; faults-; folds-; gems-; mineral-deposits,-genesis; mineralization-; Muzo-Deposit; Oligocene-; Paleogene-; ring-silicates; silicates-; South-America; structural-controls; syntectonic-processes; tectonics-; Tertiary-; thrust-faults
CC - CATEGORY CODES: 28A-Economic-geology,-geology-of-nonmetal-deposits
DT - DOCUMENT TYPE: Serial
BL - BIB LEVEL: Analytic
IL - ILLUSTRATION: Refs: 10
RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data from PASCAL, Institute de l'Information Scientifique et Technique, Vandoeuvre-les-Nancy, France
IS - ISSN: 1251-8050
AN - ACCESSION NUMBER: 1997-014909
UD - UPDATE CODE: 199705
Registro 4685 de 5614 - GeoRef Disc 4: 1993-1996
TI - TITLE: The Venezuelan foredeeps; Part II, Structure.
AU - AUTHORS: Audemard-Felipe; Lugo-Jairo
AF - AUTHOR AFFILIATION: Intevep, Caracas, Venezuela
BK - BOOK TITLE: In: American Association of Petroleum Geologists 1996 annual convention.
BA - BOOK AUTHORS: Anonymous
SO - SOURCE: Annual Meeting Abstracts - American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists. 5; Pages 7. 1996.
PB - PUBLISHER: American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists. Tulsa, OK, United States. 1996.
CP - COUNTRY OF PUBLICATION: United-States
PY - PUBLICATION YEAR: 1996
CN - CONFERENCE INFORMATION: American Association of Petroleum Geologists 1996 annual convention. San Diego, CA, United States. May 19-22, 1996.
LA - LANGUAGE: English
AB - ABSTRACT: A series of seismic reflection profiles document the evolution of the foredeeps where NNE-trending Jurassic half grabens were developed in a back-arc setting on pre-existing Paleozoic folded-belts. These units were onlapped by a Cretaceous-Tertiary passive margin succession, which in turn was cannibalized by a complex folded-belt evolving from west to east. The northern Perija, a predominantly east-vergent basement-involved folded-belt, was first emplaced along the northwestern corner of Venezuela in Eocene times. Coeval to this event is the emplacement of most of the Lara nappes along north-central Venezuela, which override the passive margin for more than 200 km. In Oligocene times, the western Serrania del Interior reached the vicinity of its present position in central Venezuela. During Late Oligocene-Middle Miocene most of the eastern Serrania del Interior was emplaced. At this time, the Perija Ranges were reactivated as part of the northern extension of the Eastern Cordillera of Colombia. During the Middle Miocene-Recent, the folded belts migrated eastward to the position of Trinidad to join the Barbados accretionary prism. To the west, the Venezuelan Andes evolved as a northwest-vergent basement-involved folded belt overriding the Maracaibo Basin.
DE - DESCRIPTORS: accretionary-wedges; Andes-; Antilles-; back-arc-basins; Barbados-; basement-tectonics; basins-; Caribbean-region; Cenozoic-; Colombia-; Cretaceous-; Eastern-Cordillera; Eocene-; evolution-; folds-; geophysical-methods; geophysical-profiles; half-grabens; Jurassic-; Lara-Nappes; Lesser-Antilles; Maracaibo-Basin; Mesozoic-; Oligocene-; Paleogene-; Paleozoic-; passive-margins; plate-tectonics; reactivation-; reflection-methods; seismic-profiles; Serrania-del-Interior; Sierra-de-Perija; South-America; tectonics-; Tertiary-; Trinidad-; Trinidad-and-Tobago; Venezuela-; West-Indies
CC - CATEGORY CODES: 16-Structural-geology
DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document
BL - BIB LEVEL: Analytic
RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States
IS - ISSN: 0094-0038
CO - CODEN: APGAB2
AN - ACCESSION NUMBER: 1997-016392
UD - UPDATE CODE: 199706
Registro 4686 de 5614 - GeoRef Disc 4: 1993-1996
TI - TITLE: Geological evaluation of Radarsat data; plans and preliminary results.
AU - AUTHORS: Berger-Zeev; Irving-R-E-L; Hughes-D; Thompson-M-D
AF - AUTHOR AFFILIATION: Image Interpretation Technologies, Calgary, AB, Canada
BK - BOOK TITLE: In: American Association of Petroleum Geologists 1996 annual convention.
BA - BOOK AUTHORS: Anonymous
SO - SOURCE: Annual Meeting Abstracts - American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists. 5; Pages 14-15. 1996.
PB - PUBLISHER: American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists. Tulsa, OK, United States. 1996.
CP - COUNTRY OF PUBLICATION: United-States
PY - PUBLICATION YEAR: 1996
CN - CONFERENCE INFORMATION: American Association of Petroleum Geologists 1996 annual convention. San Diego, CA, United States. May 19-22, 1996.
LA - LANGUAGE: English
AB - ABSTRACT: Radarsat, the Canadian synthetic aperture radar satellite to be launched in September 1995, is anticipated to become the prime active imaging system for geological mapping of tropical areas and other humid areas. Radarsat will provide adequate spatial resolution, stereo capabilities and relatively low incidence angles to reduce the geometric distortions of geological structures due to layover effects. As part of the Radarsat user development program of the Canadian Space Agency, it has been proposed to conduct an evaluation program of the terrain surface mapping capabilities of Radarsat and its application to hydrocarbon exploration, coal develoment, geological hazard mapping and environmental monitoring. The evaluation program will be carried out in three test sites: 1) Western Canadian Basin (a mature exploration area in Alberta with a range of geology/topography), 2) Andean Foothills (frontier tropical sedimentary basins in Columbiam representing prototype active exploration areas), and 3) Philippine volcanic region (frontier tropical earthquake-prone geohazard area of Philippine wrench fault system on Luzon Island, in a typical structural setting of the sedimentary basins of southeast Asia). The paper will include the project plans, illustrate the structural setting and the relationships between surface and subsurface structures for each of the three test sites, and present a preliminary evaluation of simulated and actual Radarsat data as compared to data from ERS-1, airborne SAR, Landsat thematic mapper and SPOT. The preliminary application of Radarsat for exploration will be discussed.
DE - DESCRIPTORS: Andes-; Asia-; basins-; coal-; Colombia-; development-; earthquakes-; evaluation-; Far-East; geologic-hazards; mapping-; monitoring-; North-America; organic-residues; petroleum-; petroleum-exploration; Philippine-Islands; radar-methods; RADARSAT-; remote-sensing; SAR-; satellite-methods; sedimentary-basins; sedimentary-rocks; South-America; Western-Canada-Basin
CC - CATEGORY CODES: 29A-Economic-geology,-geology-of-energy-sources; 20-Applied-geophysics
DT - DOCUMENT TYPE: Abstract; Serial; Conference-Document
BL - BIB LEVEL: Analytic
RF - REFERENCE SOURCE: GeoRef, Copyright 2000, American Geological Institute. Reference includes data supplied by American Association of Petroleum Geologists, Tulsa, OK, United States
IS - ISSN: 0094-0038
CO - CODEN: APGAB2
AN - ACCESSION NUMBER: 1997-016432
UD - UPDATE CODE: 199706
Registro 4687 de 5614 - GeoRef Disc 4: 1993-1996
TI - TITLE: Three-dimensional geometry and kinematics of the western thrust front of the Eastern Cordillera, Columbia.
AU - AUTHORS: Corredor-Freddy-O
AF - AUTHOR AFFILIATION: Occidental de Colombia, Bogota, Colombia
BK - BOOK TITLE: In: American Association of Petroleum Geologists 1996 annual convention.
BA - BOOK AUTHORS: Anonymous
SO - SOURCE: Annual Meeting Abstracts - American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists. 5; Pages 29-30. 1996.
PB - PUBLISHER: American Association of Petroleum Geologists and Society of Economic Paleontologists and Mineralogists. Tulsa, OK, United States. 1996.
CP - COUNTRY OF PUBLICATION: United-States
PY - PUBLICATION YEAR: 1996
CN - CONFERENCE INFORMATION: American Association of Petroleum Geologists 1996 annual convention. San Diego, CA, United States. May 19-22, 1996.
LA - LANGUAGE: English
AB - ABSTRACT: The western thrust front of the Eastern Cordillera of Colombia consists of a series of west verging thrusts, reverse faults and associated folds and faults. This faulted and folded belt is limiting the east flank of the middle Magdalena Basin and the western flank of the Eastern Cordillera fold belt of Colombia. The interpretation of digital Landsat-TM data using the ERDAS/Imagine software package and the use of the axial surface mapping technique (Shaw et al., 1994) on seismic reflection data has allowed to establish the three-dimensional geometry and kinematics of a small portion of this belt in detail. Satellite data interpretation has provided a new view of the geological features outcopping in the area. The thrust front geometries are illustrated by several parallel balanced cross sections linked with the satellite images that have been constructed using geometric relations (Suppe, 1983 and Jones, 1987) and the techniques of the modern structural geology. The fold belt geometry is being controlled by both, NE-SW and a NW-SE strike slip components and a compressional stress field in direction NW-SE. Four major deformational events have been interpreted in the geological time: Paleocene, middle Eocene, Miocene and Pleistocene time events. The geometry and kinematics of the structures related to the western thrust front of the Eastern Cordillera can be explained by fault slip changes along the strike over a detachment level (thin skin tectonic). The Lower Cretaceous shales of the Villeta Formation are proposed as the main detachment level for this fold belt. The geometry of this thrust front might be explained by changes in the thrust angles and depths along the dip and strike too (thick skin tectonic). The deformation of this portion of the Eastern Cordillera fold belt has resulted in a minimum of 15 km of horizontal shortening.
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