No. Registros Solicitud 1 5614 colombia



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UR - URL: (Full text) http://pubs.usgs.gov/prof/p1386i/

AN - ACCESSION NUMBER: 1999-042350

UD - UPDATE CODE: 199915

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

Registro 5404 de 5614 - GeoRef 1997-2001

TI - TITLE: New Paleo-proterozoic, Grenvillian, and Pan-African U-Pb zircon ages of boulders from the Coahuila Terrane; implications for the Pre-Cambrian tectonic history of northern Mexico.

AU - AUTHORS: Lopez-R; Cameron-K-L; Jones-N-W

AF - AUTHOR AFFILIATION: University of California at Santa Cruz, Santa Cruz, CA, United States

BK - BOOK TITLE: In: Geological Society of America, 1998 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Abstracts with Programs - Geological Society of America. 30; 7, Pages 354. 1998.

PB - PUBLISHER: Geological Society of America (GSA). Boulder, CO, United States. 1998.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1998

CN - CONFERENCE INFORMATION: Geological Society of America, 1998 annual meeting. Toronto, ON, Canada. Oct. 26-29, 1998.

LA - LANGUAGE: English

AB - ABSTRACT: The Coahuila terrane lies south of the Ouachita suture and was accreted to North America during the formation of Pangea. The age and character of the basement was unknown before this study. The terrane contains flysch deposits with clasts of Paleozoic arc rocks and a basal Mississippian conglomerate with Pre-Cambrian granitoid boulders. The Pre-Cambrian clasts reveal a tectonic history that includes approximately 1232-1217 Ma arc plutonism on approximately 1.8 Ga basement, approximately 1222 Ma to 1214 Ma late to post orogenic magmatism, and 579 Ma Pan-African plutonism. The boulders are separated based on texture, geochronology, and chemistry. These are 1) foliated granitoids, 2) banded gneisses, 3) non-foliated granitoids, and 4) a Pan-African granite. The foliated granitoids have arc-like trace element ratios, eNd(t) of +2.2 to +2.9, and 1232-1217 Ma zircon ages. The banded gneisses include a graphite-, K-feldspar paragneiss and six granitic gneisses. The latter have volcanic arc trace element ratios and eNd(t) of -1.3 to +1.3. One granite gneiss has a concordant zircon age of 1222 Ma with discordant fractions yielding an upper intercept age of approximately 1.85 Ga. Two others have discordant zircons with intercept ages within error of 1222 Ma and better constrained upper intercept ages of 1.85 Ga. The paragneiss also yields an age within error of 1222 Ma. The non-foliated granitoids have igneous-textures, eNd(t) of -2.3 to +0.6, and 1222-1214 Ma zircon ages. The Pan-African granite is concordant at 579 Ma and has arc-like trace element ratios and eNd(t) of -3.3. The foliated granitoids and banded gneisses are interpreted as a part of a Grenvillian arc that developed on approximately 1.8 Ga crust. The gneisses mark the end-stages of the arc and assimilated more basement. The non-foliated granitoids are the late to post orogenic intrusives, and the Pan-African granite is related to the Grenvillian boulders by Nd isotopes, model ages, and feldspar Pb isotopes. The feldspar Pb isotope ratios of all the Coahuila boulders lie below the S+K Pb evolution curve and are distinct from Laurentia Pb as defined by the Grenville Province and Texas. The Coahuila Pb isotope data overlap the fields for southern Mexico, Colombia, and some Grenville massifs in Georgia, U.S.A., which may also be exotic to North America. The Coahuila terrane Pre-Cambrian tectonic history outlined above coupled with the feldspar Pb isotope data preclude a Laurentian origin. Finally, the Coahuila Grenville rocks may be the unmetamorphosed equivalents of the granulite grade Grenville rocks that are exposed in eastern and southern Mexico.

DE - DESCRIPTORS: absolute-age; accretion-; assimilation-; clasts-; Coahuila-Terrane; dates-; facies-; geochemistry-; gneisses-; granites-; granulite-facies; Grenvillian-Orogeny; igneous-rocks; Laurentia-; magmas-; magmatism-; metamorphic-rocks; Mexico-; nesosilicates-; northern-Mexico; orthosilicates-; Paleoproterozoic-; Pan-African-Orogeny; Pangaea-; plutonic-rocks; Precambrian-; Proterozoic-; silicates-; tectonics-; textures-; trace-elements; U-Pb; upper-Precambrian; zircon-

CC - CATEGORY CODES: 16-Structural-geology; 03-Geochronology

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: 1999-039561

UD - UPDATE CODE: 199914

Registro 5405 de 5614 - GeoRef 1997-2001

TI - TITLE: RADARSAT images for assessment of the environments in the Amazon region.

AU - AUTHORS: Ardila-Torres-Myriam; Melo-Wilches-Hernando

AF - AUTHOR AFFILIATION: Instituto Geografico Agustin Codazi, Bogota, Colombia

BK - BOOK TITLE: In: RADARSAT for Amazonia; results of ProRADAR investigations.

BA - BOOK AUTHORS: Ahern-F-J (editor)

SO - SOURCE: Pages 15-22. 1998.

PB - PUBLISHER: Natural Resources Canada, Canada Centre for Remote Sensing. Ottawa, ON, Canada. 1998.

CP - COUNTRY OF PUBLICATION: Canada

PY - PUBLICATION YEAR: 1998

CN - CONFERENCE INFORMATION: Geomatics in the era of RADARSAT international conference. Ottawa, ON, Canada. May 25-30, 1997.

LA - LANGUAGE: English

AB - ABSTRACT: The usefulness of RADARSAT images S2 and S7 for the survey and assessment of the environment in the Amazon region was analyzed. The methodology included visual interpretation of RADARSAT data in analog format complemented by digital analysis. Geology, geomorphology and soil coverage and land use maps were used for elaboration. Interpretation was improved by combining RADARSAT data with LANDSAT or SPOT images. Finally, results allow us to conclude that RADARSAT images are very useful for surveying and assessing the biophysical environment in humid tropical zones.

DE - DESCRIPTORS: alluvial-plains; Amazon-Basin; Amazon-River; Amazonas-Colombia; Colombia-; digital-data; ecosystems-; environmental-analysis; fluvial-features; forests-; humid-environment; imagery-; interpretation-; land-use; Landsat-; Loreto-Peru; Radarsat-; remote-sensing; satellite-methods; soils-; South-America; SPOT-; terrestrial-environment; tropical-environment; wetlands-

CC - CATEGORY CODES: 22-Environmental-geology; 20-Applied-geophysics

DT - DOCUMENT TYPE: Book; Conference-Document

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: S040000; N030000; LONG: W0694200; W0704200.

IL - ILLUSTRATION: Refs: 6

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

AN - ACCESSION NUMBER: 1999-038534

UD - UPDATE CODE: 199914

Registro 5406 de 5614 - GeoRef 1997-2001

TI - TITLE: The Neogene depositional history of Darien, Panama.

AU - AUTHORS: Collins-Laurel-S; Coates-Anthony-G; Aubry-Marie-Pierre; Berggren-William-A

AF - AUTHOR AFFILIATION: Florida International University, Department of Geology, Miami, FL, United States

BK - BOOK TITLE: In: Geological Society of America, 1998 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Abstracts with Programs - Geological Society of America. 30; 7, Pages 26. 1998.

PB - PUBLISHER: Geological Society of America (GSA). Boulder, CO, United States. 1998.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1998

CN - CONFERENCE INFORMATION: Geological Society of America, 1998 annual meeting. Toronto, ON, Canada. Oct. 26-29, 1998.

LA - LANGUAGE: English

AB - ABSTRACT: The Darien Province bordering Colombia contains a northwest-southeast trending, Pacific depositional basin with Cretaceous to Miocene sediments. We present the first geological map and formal physical stratigraphy for the Neogene sediments of Darien. The new stratigraphic units, from base to top, are the Clarita, Tapaliza, Tuira and Chucunaque formations. The Neogene chronology and environmental history are described using planktonic and benthic foraminifera and calcareous nannoplankton from sections of the Chucunaque-Tuira and (to the southwest) Sambu river basins. Middle Miocene, cosmopolitan benthic foraminifera from the Clarita and Tapaliza formations (Chucunaque-Tuira basin) and coeval (early middle Miocene), unnamed Sambu beds indicate normal, well oxygenated, middle to upper bathyal waters. An unnamed, upper middle Miocene formation overlying the Tapaliza Formation contains a mixture of cosmopolitan and typical Pacific low-oxygen, upper bathyal benthic foraminifera. The late Miocene (nannoplankton Zone NN9, planktonic foraminiferal Zone N16) Tuira Formation of the Chucunaque-Tuira basin contains an outer neritic, low-oxygen facies with typical Pacific benthic foraminifera to the south, while to the north it is younger (N17), shallower (inner-middle neritic), and normal marine. Upper Miocene (NN11, N16 and 17) benthic foraminifera of the Chucunaque Formation (Chucunaque-Tuira basin) and unnamed beds of the Sambu basin are typical Pacific species indicative of low-oxygen, outer neritic to upper bathyal waters. In summary, Darien waters shallowed from middle bathyal to outer neritic depths from 16.4-15.6 Ma to 8.3-5.6 Ma. Benthic foraminifera were mostly cosmopolitan until about 12 Ma, when a typical eastern Pacific, low-oxygen biofacies was apparently established at upper bathyal depths, which suggests a cutoff from Caribbean circulation at upper bathyal and greater depths.

DE - DESCRIPTORS: algae-; benthonic-taxa; biofacies-; Cenozoic-; Central-America; Chuchunaque-Formation; Chucunaque-Tuira-River-basin; Clarita-Formation; Darien-; Foraminifera-; Invertebrata-; microfossils-; nannofossils-; Neogene-; paleo-oceanography; paleoenvironment-; Panama-; Plantae-; Protista-; Sambu-River-basin; Tapaliza-Formation; Tertiary-; Tuira-Formation

CC - CATEGORY CODES: 12-Stratigraphy

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: 1999-036468

UD - UPDATE CODE: 199913

Registro 5407 de 5614 - GeoRef 1997-2001

TI - TITLE: Reactivity of mercury from gold mining activities in darkwater ecosystems.

AU - AUTHORS: Meech-John-A; Veiga-Marcello-M; Tromans-Desmond

AF - AUTHOR AFFILIATION: University of British Columbia, Department of Mining and Mineral Process Engineering, Vancouver, BC, Canada

SO - SOURCE: Ambio. 27; 2, Pages 92-98. 1998.

PB - PUBLISHER: Royal Swedish Academy of Sciences. Stockholm, Sweden. 1998.

CP - COUNTRY OF PUBLICATION: Sweden

PY - PUBLICATION YEAR: 1998

LA - LANGUAGE: English

DE - DESCRIPTORS: Brazil-; Canada-; Colombia-; drainage-; Eastern-Canada; ecosystems-; gold-ores; mercury-; metal-ores; metals-; mining-; Northwest-Territories; Peru-; pollution-; Quebec-; South-America; tailings-; Venezuela-; waste-disposal

CC - CATEGORY CODES: 22-Environmental-geology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 68; illus. incl. 3 tables.

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

IS - ISSN: 0044-7447

CO - CODEN: AMBOCX

AN - ACCESSION NUMBER: 1999-035570

UD - UPDATE CODE: 199913

Registro 5408 de 5614 - GeoRef 1997-2001

BK - BOOK TITLE: Impacts of Colombia's current irrigation management transfer program.

BA - BOOK AUTHORS: Vermillion-Douglas-L; Garces-Restrepo-Carlos

BF - BOOK AUTHOR AFFILIATION: International Water Management Institute, Colombo, Sri Lanka

SO - SOURCE: Research Report - International Water Management Institute. 1998.

PB - PUBLISHER: International Water Management Institute IWMI. Colombo, Sri Lanka, International. Pages: 38. 1998.

CP - COUNTRY OF PUBLICATION: International

PY - PUBLICATION YEAR: 1998



LA - LANGUAGE: English

AB - ABSTRACT: This report deals with the results of a study conducted by the International Water Management Institute (IWMI) in collaboration with the National Institute for Land Development (INAT) to assess the impacts of the current national irrigation management transfer program in Colombia. In 1990, the Government of Colombia adopted a new national policy to transfer management of its irrigation districts to water users' associations (WUAs). This report examines the context of transfer, the basic transfer strategy, powers and functions devolved, and the impacts of transfer on irrigation management and irrigated agriculture in three sample irrigation districts. Two districts that were not transferred until 1995 and 1996 were also selected to enable comparison between schemes that had and had not yet been transferred during the period of historical analysis. Impacts measured include costs of irrigation to the government and the farmers, financial solvency of the irrigation districts, quality of irrigation operations and maintenance, and the agricultural and economic productivity of the irrigation systems. Data were collected through interviews with irrigation management staff and farmers, secondary data available from irrigation and agriculture departments, a sample survey of farmers, and direct inspection of irrigation networks. The national irrigation management transfer program in Colombia adopted in 1990 can be characterized as significant but only as a partial devolution of management to water users. The government maintained considerable advisory influence over the districts for several years, exercising some control over O&M plans and budgets, and resisting district attempts to release large numbers of staff. After adoption of the 1993 Land Development Law, in 1994, this control has been relaxed considerably as districts gained almost complete control over management. However, powers devolved do not include a formal water right or ownership of irrigation scheme infrastructure. Also, the government has not made it clear whose responsibility it will be, and under what terms and conditions to finance possible future costs of rehabilitation. Management transfer prompted a number of managerial changes aimed at improving management efficiency and accountability of district staff. Transfer resulted in a significant shift in the burden of cost from the government to farmers, which has generally been accepted by farmers. But transfer has not had substantial impacts on the performance of operations and maintenance, or on the agricultural and economic productivity of irrigated land or water, neither improving negative performance nor causing detriment where performance is positive. This report raises concerns about how lack of a comprehensive devolution policy for the irrigation subsector can discourage farmers from investing in the long-term sustainability of their irrigation schemes. More attention is needed toward using the transfer process to create local management self-reliance and ensuring that needed support systems for local management are in place prior to implementation of irrigation management transfer programs.

DE - DESCRIPTORS: agriculture-; Colombia-; economics-; environmental-effects; evapotranspiration-; financing-; hydrology-; irrigation-; land-use; programs-; rainfall-; seasonal-variations; South-America; water-balance; water-management; water-resources; water-rights; water-supply; water-use

CC - CATEGORY CODES: 21-Hydrogeology

DT - DOCUMENT TYPE: Serial; Report

BL - BIB LEVEL: Monograph

IL - ILLUSTRATION: Refs: 15; illus. incl. 12 tables, sketch map.

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

IS - ISSN: 1026-0862

RN - REPORT NUMBER: 25

AN - ACCESSION NUMBER: 1999-035148

UD - UPDATE CODE: 199912

Registro 5409 de 5614 - GeoRef 1997-2001

TI - TITLE: Strengthening and retrofitting of reinforced concrete buildings.

AU - AUTHORS: Rendon-Jorge

AF - AUTHOR AFFILIATION: Josue Galvis Ramos and Associates, Manizales, Colombia

SO - SOURCE: Individual Studies by Participants at the International Institute of Seismology and Earthquake Engineering. 34; Pages 189-201. 1998.

PB - PUBLISHER: International Institute of Seismology and Earthquake Engineering. Tokyo, International. 1998.

CP - COUNTRY OF PUBLICATION: International

PY - PUBLICATION YEAR: 1998

LA - LANGUAGE: English

AB - ABSTRACT: This study deals with the general principles which should govern the structural rehabilitation of a building damaged by an earthquake focusing principally on the columns as the most important structural members. First, some basic factors that affect the degree of damage to buildings are given, as well as the importance of the relationship between strength and ductility when evaluating the seismic capacity of buildings. The Japanese Capacity Evaluation Method is applied to an existing building in Colombia and the results are verified with a dynamic response spectrum analysis. Then the damage pattern in reinforced concrete columns is explained, and finally three methods of retrofitting, concrete jacketing, steel jacketing and continuous fiber wrapping, are investigated.

DE - DESCRIPTORS: buildings-; damage-; earthquakes-; geologic-hazards; preventive-measures; reinforced-materials; seismic-response

CC - CATEGORY CODES: 30-Engineering-geology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 8; illus.

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

IS - ISSN: 0074-6606

CO - CODEN: ISEIAM

AN - ACCESSION NUMBER: 1999-033867

UD - UPDATE CODE: 199912

Registro 5410 de 5614 - GeoRef 1997-2001

TI - TITLE: Building a constrained tecto-sedimentologic model of continental sedimentation; evolving Tertiary paleogeography of the Middle Magdalena Valley Basin, Colombia.

AU - AUTHORS: Gomez-Elias; Jordan-Teresa-E; Baquero-Edgar; Kelley-Shari

AF - AUTHOR AFFILIATION: Cornell University, Department of Geological Sciences, Ithaca, NY, United States

BK - BOOK TITLE: In: Geological Society of America, 1998 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Abstracts with Programs - Geological Society of America. 30; 7, Pages 339. 1998.

PB - PUBLISHER: Geological Society of America (GSA). Boulder, CO, United States. 1998.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1998

CN - CONFERENCE INFORMATION: Geological Society of America, 1998 annual meeting. Toronto, ON, Canada. Oct. 26-29, 1998.

LA - LANGUAGE: English

AB - ABSTRACT: The oil producing Middle Magdalena Valley Basin of Colombia (MMVB) contains a thick record of Tertiary continental sedimentation that locally reaches 8,000 m in thickness. We investigate the combined sedimentary and structural Cenozoic histories of this region and demonstrate that its transformation into an intermontane basin began in the Paleogene and not during the Neogene as previously interpreted. Supporting this interpretation is the discrimination of preorogenic, synorogenic and postorogenic packages of sediments based on diagnostic stratal geometries, which are illustrated by seismic and structural sections. Growth relations between sediment wedges and folds, as well as crosscutting relations, prove to be key elements with which to determine ages of deformation. Analysis of facies, provenance trends, geochemical data and zircon fission-track chronology further constrains our conclusions. Continental sedimentation coupled with deformation of multiple source areas shaped the architecture of the MMVB. Deformation of the Central Cordillera, the western border of the MMVB, produced an angular unconformity that separates Paleocene-age regressive delta or coastal plain facies from younger sediments. The oldest Paleogene strata (Eocene) that onlapped this unconformity came from the Eastern Cordillera, whose deformation partially isolated the incipient MMVB from the Llanos Foothills Basin to the east. Sedimentary environments included sinuous channels with varying degrees of braiding surrounded by flood plains subjected to pedogenesis, which prevailed during the sedimentation of the rest of the Paleogene rocks. Late Paleogene (Oligocene?) sedimentation was contemporaneous with continued deformation of the Eastern Cordillera as shown by stratal growth geometries and progressive unconformities related to fold-limb rotation. Braided streams flowing towards the north deposited the Neogene sediments of the MMVB. The last uplift event of the Eastern Cordillera resulted from out-of-sequence reverse faulting and is younger than 6.2+ or -0.8 Ma.In contrast to current sequence stratigraphic models of the MMVB, our work highlights the importance of synsedimentary deformation for interpreting the stratal packages and tectonic history.

DE - DESCRIPTORS: basins-; Cenozoic-; Central-Cordillera; Colombia-; dates-; deformation-; deltaic-environment; fission-track-dating; fluvial-environment; geochronology-; intermontane-basins; lithofacies-; Llanos-; Middle-Magdalena-Valley-Basin; models-; nesosilicates-; orthosilicates-; paleogeography-; petroleum-; provenance-; regression-; sea-level-changes; sedimentation-; sequence-stratigraphy; silicates-; South-America; Tertiary-; thickness-; zircon-

CC - CATEGORY CODES: 12-Stratigraphy; 16-Structural-geology

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: 1999-024554

UD - UPDATE CODE: 199909

Registro 5411 de 5614 - GeoRef 1997-2001

TI - TITLE: Geological history of the NW Oaxacan Complex in Mexico; a central piece of the Grenville Orogen?.

AU - AUTHORS: Solari-Luigi-A; Keppie-J-Duncan; Ortega-Gutierrez-Fernando; Lopez-Robert; Cameron-Kenneth-L

AF - AUTHOR AFFILIATION: Universidad Nacional Autonoma de Mexico, Instituto de Geologia, Mexico City, Mexico

BK - BOOK TITLE: In: Geological Society of America, 1998 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Abstracts with Programs - Geological Society of America. 30; 7, Pages 354. 1998.

PB - PUBLISHER: Geological Society of America (GSA). Boulder, CO, United States. 1998.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 1998

CN - CONFERENCE INFORMATION: Geological Society of America, 1998 annual meeting. Toronto, ON, Canada. Oct. 26-29, 1998.

LA - LANGUAGE: English

AB - ABSTRACT: The Oaxacan Complex consists of polydeformed para- and ortho-gneisses metamorphosed at granulite facies (720-750 degrees C and 7-8 kbar metamorphic peak), in places retrogressed to lower grades. In the northwestern, it is composed of five lithotectonic units (bottom to top): (1) foliated anorthosite and gabbro; (2) mafic orthogneiss; (3) migmatite, which yielded nearly concordant U-Pb ages between ca. 1185 and 1000 Ma; (4) paragneisses; (5) orthogneiss, pelitic schists, charnockites which have yielded nearly concordant U-Pb ages between 1155 Ma and 1045 Ma, and hornblende syenites. Granitic pegmatites intruded many of the units at various stages during and after the high-grade deformation. The structural history of the Oaxacan Complex includes: (1) development of a foliation at granulite facies; (2) SE-vergent, recumbent folding with an axial planar foliation, a strong NNW-trending stretching lineation that is parallel to fold hinges formed at granulite metamorphism; a late syntectonic pegmatite yielded a concordant U/Pb age of 980 Ma; (3) amphibolite to greenschist facies SE-vergent shear zones display NNW-trending stretching lineations and mylonitic to blastomylonitic fabric: the age of an amphibolite facies shear zone is bracketed by a nearly concordant U-Pb ages of ca. 1125 Ma and 976 Ma from a pre- or syn-tectonic pegmatite and a post-tectonic pegmatite, respectively; (4) upright NNW-trending folds, which display upper greenschist facies C-S fabric in their steep limbs; (5) brittles shearing some of which probably formed during the Laramide Orogeny. The Oaxacan Complex was dextrally sheared over the Acatlan Complex to the W in the Devonian, and near the eastern margin was thrust over Cretaceous rocks. The ca. 980 Ma age of the granulite facies deformation maybe equivalent to the Rigolet deformational phase, the last phase of deformation in the type Grenville Orogeny. Comparisons of lithologies, P-T-t cooling curves, geological history and Pb isotopic data suggest that the Oaxacan Complex is most similar to the Adirondack Highlands, some of the Appalachian basement massifs, and the Colombian massifs.


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