No. Registros Solicitud 1 5614 colombia

DE - DESCRIPTORS: Antioquian-Batholith; batholiths-; Central-Cordillera; chemical-weathering; clastic-rocks; Colombia-; diorites-; erosion-; erosion-features; geomorphology-; granites-; granodiorites-; igneous-rocks; intrusions-; landforms-; plutonic-rocks; saprolite-; sedimentary-rocks; South-America; tonalite-; weathering-

CC - CATEGORY CODES: 23-Geomorphology; 05A-Igneous-and-metamorphic-petrology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N060000; N070000; LONG: W0743000; W0753000.

IL - ILLUSTRATION: Refs: 24; illus. incl. 4 tables, geol. sketch maps.

RF - REFERENCE SOURCE: GeoRef, Copyright 2003, American Geological Institute.

IS - ISSN: 0072-0992

CO - CODEN: GECBA7

AN - ACCESSION NUMBER: 2003-027123

UD - UPDATE CODE: 200309

Registro 401 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Edades K/ Ar en algunos cuerpos plutonicos del graben Cauca-Patia y norte de la Cordillera Occidental

Translated Title: K/ Ar ages of some plutonic bodies in the Cauca-Patia Graben and in the northern Cordillera Occidental.

AU - AUTHORS: Gonzalez-I-Humberto; Londono-G-Ana-Cristina

AF - AUTHOR AFFILIATION: Ingeominas, Medellin, Colombia

SO - SOURCE: Geologia Colombiana. 23; Pages 117-131. 1998.

PB - PUBLISHER: Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Geociencias. Bogota, Colombia. 1998.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 1998

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: The K/Ar dates obtained in the Sabanalarga and Buga batholiths and in the Cambumbia and Irra Stocks, confirm and make evident a plutonic event in the Albian and Cenomanian range, that affected the western flank of the Central Cordillera and the Cauca-Patia trough between the Central and the Occidental Cordillera of Colombia. This plutonism is calc-alkaline with type I granitoids. The Irra Stock intrudes basic volcanic rocks from the Barroso Formation, which confirms the late Cretaceous inferred age assigned to this unit, based on the paleontological evidences. Although the age obtained for the Amaime Gabbro is in the same range of the former event, seems to correspond better to a thermal and tectonic event, registered regional, than to the crystallization of the magmatic body. The ages of Mistrato and Nudillales stocks indicate that a Paleogene calc-alkaline plutonic event is present in the Occidental Cordillera, began with the Mande Batolit setting and related minor bodies, and extended from the late Paleocene to the Eocene. However, the Mistrato Stock is complex both structurally and lithologically, with gabbroic facies, and its spatial relationship with the basic volcanic rocks could be comagmatic; in this case, the obtained ages correspond to a thermal event that produced the isotopic recrystallization. Although the Buritica Andesite is spatially associate to the Buritica Stock, it is younger than the Stock, and also has an intensive hydrothermal alteration that is not characteristic of the Stock or its associated facies. For these reasons, the Andesite is considered genetically independent.

DE - DESCRIPTORS: absolute-age; Albian-; amphibole-group; Andes-; Anserma-Gabbro; batholiths-; biotite-; Buga-Batholith; Buritica-Andesite; calc-alkalic-composition; Cambumbia-Stock; Cauca-Patia-Graben; Cenomanian-; chain-silicates; clinoamphibole-; Colombia-; Cretaceous-; dates-; granites-; hornblende-; igneous-rocks; intrusions-; Irra-Stock; K-Ar; Lower-Cretaceous; Mesozoic-; mica-group; Mistrato-Pluton; Nudillales-Stock; plutonic-rocks; plutons-; Sabanalarga-Batholith; sheet-silicates; silicates-; South-America; Upper-Cretaceous; Western-Cordillera; whole-rock

CC - CATEGORY CODES: 03-Geochronology; 05A-Igneous-and-metamorphic-petrology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N050000; N060000; LONG: W0750000; W0760000.

IL - ILLUSTRATION: Refs: 28; illus. incl. 9 tables, geol. sketch maps.

RF - REFERENCE SOURCE: GeoRef, Copyright 2003, American Geological Institute.

IS - ISSN: 0072-0992

CO - CODEN: GECBA7

AN - ACCESSION NUMBER: 2003-027122

UD - UPDATE CODE: 200309

Registro 402 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Estudio de suelos con fines forenses por analisis fisicos, quimicos, mineralogicos y granulometricos

Translated Title: Forensic soil studies from physical, chemical, mineralogical and granulometric analysis.

AU - AUTHORS: Ballesteros-Maria-Ines; Molina-Carlos-Martin; Moreno-Betancourt-Jairo

AF - AUTHOR AFFILIATION: Universidad Nacional de Colombia, Departamento de Quimica, Bogota, Colombia

SO - SOURCE: Geologia Colombiana. 23; Pages 107-115. 1998.

PB - PUBLISHER: Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Geociencias. Bogota, Colombia. 1998.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 1998

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: Soils from two different taxonomic geographical areas from Funza and Zabrinsky in the borders of the Bogota Sabana were used to study and validate forensic analytical methods. The following analysis were used in this study: preliminary observation and test, color, pH, sieving, mechanical analysis, density gradient, X-ray diffraction and Scanning Electronic Microscopy (SEM). It was found that all these analysis but pH which yielded similar results for most of them were able to differentiate samples from both areas. It is recommended that the methods here described be analyzed as a set so they yield good results in the forensic field. It is also suggested they be applied in the following order: color, pH, density and mineralogic analysis.

DE - DESCRIPTORS: chemical-composition; Colombia-; color-; density-; forensic-geology; Funza-Colombia; granulometry-; mineral-composition; pH-; physical-properties; Sabana-de-Bogota; SEM-data; soil-mechanics; soils-; South-America; X-ray-data; X-ray-diffraction-data; Zabrinsky-Colombia

CC - CATEGORY CODES: 25-Soils

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 10; illus. incl. 2 tables.

RF - REFERENCE SOURCE: GeoRef, Copyright 2003, American Geological Institute.

IS - ISSN: 0072-0992

CO - CODEN: GECBA7

AN - ACCESSION NUMBER: 2003-027121

UD - UPDATE CODE: 200309

Registro 403 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Mapa de zonas sismogeneradoras en Cuba

Translated Title: Map of seismicity zones in Cuba.

AU - AUTHORS: Cotilla-Rodriguez-Mario-O; Alvarez-Gomez-Jose-Leonardo

AF - AUTHOR AFFILIATION: Universidad Complutense de Madrid, Departamento de Geofisica y Meteorologia, Madrid, Spain

SO - SOURCE: Geologia Colombiana. 23; Pages 97-106. 1998.

PB - PUBLISHER: Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Geociencias. Bogota, Colombia. 1998.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 1998

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: A new distribution of seismogenetic zones in Cuba is presented and discussed. Three main conditions are taken into account: tectonic-geological characteristics, geodynamic conditions and seismic activity of the Cuban block and surrounding areas. A new version of the classification system of Cuban seismogenetic zones is shown.

DE - DESCRIPTORS: Antilles-; Caribbean-region; classification-; Cuba-; geodynamics-; Greater-Antilles; neotectonics-; seismic-zoning; seismicity-; seismotectonics-; tectonics-; West-Indies

CC - CATEGORY CODES: 19-Seismology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 45; 3 tables, geol. sketch maps.

RF - REFERENCE SOURCE: GeoRef, Copyright 2003, American Geological Institute.

IS - ISSN: 0072-0992

CO - CODEN: GECBA7

AN - ACCESSION NUMBER: 2003-027120

UD - UPDATE CODE: 200309

Registro 404 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Acuiferos de la Formacion Tilata (Mioceno-Pliocene) en dos pozos del Suroeste de la Sabana de Bogota

Translated Title: Aquifers of the Tilata Formation (Miocene-Pliocene) from two wells in southwestern Sabana de Bogota.

AU - AUTHORS: Alvarez-Osejo-Alberto

AF - AUTHOR AFFILIATION: Universidad Nacional de Colombia, Departamento de Geociencias, Bogota, Colombia

SO - SOURCE: Geologia Colombiana. 23; Pages 79-95. 1998.

PB - PUBLISHER: Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Geociencias. Bogota, Colombia. 1998.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 1998

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: The Tilata Formation, with unconsolidated permeable layers, in the Bogota Sabana, are aquifers with important yields, relatively easy to drill. To know its lithology is useful for hydrogeological purposes. Two lithological columns of two water wells are presented. Its electrical resistivity ranges from 20 to 70 Ohm.m. The wells from the Tilata Formation could have specific capacities of 6,6 LPS/m. The transmissivity could be larger than 900 m (super 2) /day. The storage coefficient ranges from 2,2X10 (super -3) to 5,6X10 (super -4) in the two pumping tests, carried out with one observation well. Notions of well hydraulics are given in order to educate the ground water users, about hydrogelogic basic principles.

DE - DESCRIPTORS: aquifers-; Cenozoic-; Colombia-; discharge-; drawdown-; ground-water; hydraulic-conductivity; hydrodynamics-; key-beds; Miocene-; Neogene-; Pliocene-; pump-tests; Sabana-de-Bogota; South-America; storage-coefficient; Tertiary-; Tilata-Formation; transmissivity-; transport-; volume-; water-wells

CC - CATEGORY CODES: 21-Hydrogeology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N043000; N051500; LONG: W0734500; W0742000.

IL - ILLUSTRATION: Refs: 18; illus. incl. strat. cols., geol. sketch maps.

RF - REFERENCE SOURCE: GeoRef, Copyright 2003, American Geological Institute.

IS - ISSN: 0072-0992

CO - CODEN: GECBA7

AN - ACCESSION NUMBER: 2003-027119

UD - UPDATE CODE: 200309

Registro 405 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Estratigrafia del Cretacico Superior y Terciario Inferior en el Sector Norte de la Cuenca del Putumayo, Departamento del Caqueta, Colombia

Translated Title: Upper Cretaceous and lower Tertiary stratigraphy of the northern sector of the Putumayo River basin, Caqueta Department, Colombia.

AU - AUTHORS: Mora-Alejandro; Venegas-Diego; Vergara-Luis

AF - AUTHOR AFFILIATION: Universidad Nacional de Colombia, Departamento de Geociencias, Bogota, Colombia

SO - SOURCE: Geologia Colombiana. 23; Pages 31-77. 1998.

PB - PUBLISHER: Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Geociencias. Bogota, Colombia. 1998.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 1998

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: A new scheme of stratigraphic nomenclature is defined formally in the northern portion of the Putumayo basin. The Masaya Formation (new formation) represents the beginning of the Cretaceous sedimentation during the late Cenomanian, exhibiting fluvial deposits that rapidly grade up-section to intertidal deposits. Towards the NE, the unit onlaps the basement progressively, thus being diachronous. The Las Iglesias Formation (new formation) represents a regional episode of marine flooding during the Turonian and Coniacian, with a maximum flooding surface dated Santonian. After an erosion period that cannibalized Campanian rocks, intertidal sedimentation during the Maastrichtian to Paleocene took place. This is represented by the Rumiyaco Formation, which bears a fluvial member (El Neme) in its lower part. The Morelia Formation (new formation), whose stratigraphic position has not been reported previously, is a fluvial succession developed during the middle? to late Eocene. It is divided into two members. A shift in the sediment source occurred, from the previously shedding area of the Guyana Shield to the hinterland located to the NW of the area. The Pepino Formation (late Eocene) represents alluvial fans brought about by an uplift pulse of the ancestral Central Cordillera. Prior to this, the Morelia Formation was exposed and completely cannibalized to the SW of the study area. The sequence stratigraphic scheme comprises two supersequences and three sequences. Supersequence SKmi, with a late Albian to Santonian age, corresponds to the Masaya and Las Iglesias Formation. Within this supersequence two sequences are identified. Supersequence SKr formed during the early Maastrichtian to late Paleocene, encompasses the Rumiyaco Formation. The third order Sequence STm involves the Morelia Formation (middle?-late Eocene), being superseded by a younger sequence that begins at the base of the Pepino Formation.

DE - DESCRIPTORS: Albian-; algae-; Caqueta-Colombia; Cenozoic-; clastic-rocks; Colombia-; Cretaceous-; Dinoflagellata-; Foraminifera-; Invertebrata-; Las-Iglesias-Formation; lithostratigraphy-; Lower-Cretaceous; lower-Tertiary; Maestrichtian-; Masaya-Formation; Mesozoic-; microfossils-; Morelia-Formation; new-names; nomenclature-; palynomorphs-; Pepino-Formation; petrography-; Plantae-; Protista-; Putumayo-River-basin; Rumiyaco-Formation; sandstone-; Santonian-; sedimentary-rocks; Senonian-; sequence-stratigraphy; South-America; Tertiary-; Upper-Cretaceous

CC - CATEGORY CODES: 12-Stratigraphy; 06A-Sedimentary-petrology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N012000; N013500; LONG: W0754000; W0761000.

NN - ANNOTATION: Includes appendix.

IL - ILLUSTRATION: Refs: 37; illus. incl. sects., strat. cols., 4 plates, 2 tables, geol. sketch maps.

RF - REFERENCE SOURCE: GeoRef, Copyright 2003, American Geological Institute.

IS - ISSN: 0072-0992

CO - CODEN: GECBA7

AN - ACCESSION NUMBER: 2003-027118

UD - UPDATE CODE: 200309

Registro 406 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Primata, roedores e litopternas do Mio/ Plioceno da Amazonia Sul-Ocidental (Formacao Solimoes, Bacia do Acre), Brasil

Translated Title: Mio-Pliocene Primates, Rodentia and Litopterna from southwestern Amazonia (Solimoes Formation, Acre Basin), Brazil.

AU - AUTHORS: Bergqvist-Lilian-Paglarelli; Ribeiro-Ana-Maria; Bocquentin-Villanueva-Jean

AF - AUTHOR AFFILIATION: Universidade Federal do Rio de Janeiro, Departamento Geologia, Rio de Janeiro, Brazil

SO - SOURCE: Geologia Colombiana. 23; Pages 19-29. 1998.

PB - PUBLISHER: Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Geociencias. Bogota, Colombia. 1998.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 1998

LA - LANGUAGE: Portuguese

LS - LANGUAGE OF SUMMARY: English; Spanish

AB - ABSTRACT: The specimens studied belong to the fossil collection of the Federal University of Acre, Brazil. They were collected in two sites of Solimoes Formation: Patos (Acre river, at the border between Peru and Brazil) and Talisma (Purus river, State of Amazonas), both of late Miocene/Pliocene in age (Huayquerian-Montehermosan). The dental remains of Patos site are similar to the Litopterna-Proterotheriidae of "Mesopotamian" and Santacrucian. The calcanea were assigned to proterotheres based on the anterodorsal articular extension of the sustentacular facet and the presence of a navicular facet. The astragali with a deep medial face, trochlea extending onto the neck and distally bordered by a crest and sustentacular facet flat to convex, but lacking a concavity on the proximal third. The sum of these characters suggests a rodent affinity. The specimen of intermediate size between Agouti and Dasyprocta is more similar to the first, and thus is assigned to Agoutidae. The other astragalus is of appropriate size for Hydrochoerus, but differs from all extant rodents in its longer neck. Teeth of rodents of the family Neoepiblemidae are very common in the outcrop where the astragalus was collect and, since members of this family reached very large sizes, the specimen was tentatively assigned to the Neoepiblemidae. Another astragalus bears a trochlea larger distally than proximally and concave medial malleolar facet, placed at the distal end of the trochlea/proximal end of the neck; these are diagnostic features of primates. The flat outline of the trochlea with a deep medium concavity, and the similarity with Ateles, support the assignment of this specimen to the family atelidae.

DE - DESCRIPTORS: Acre-Basin; Acre-Brazil; Amazonas-Brazil; biostratigraphy-; Brazil-; Cenozoic-; Chordata-; Eutheria-; Huayquerian-; Litopterna-; Mammalia-; Miocene-; Montehermosan-; morphology-; Neogene-; Patos-Brazil; Pliocene-; Primates-; Purus-River; Rodentia-; Solimoes-Formation; South-America; Talisma-Brazil; taxonomy-; teeth-; Tertiary-; Tetrapoda-; Theria-; Vertebrata-

CC - CATEGORY CODES: 11-Vertebrate-paleontology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: S110000; S090000; LONG: W0683000; W0700000.

IL - ILLUSTRATION: Refs: 33; illus. incl. 1 plate, 3 tables, sketch map.

RF - REFERENCE SOURCE: GeoRef, Copyright 2003, American Geological Institute.

IS - ISSN: 0072-0992

CO - CODEN: GECBA7

AN - ACCESSION NUMBER: 2003-027117

UD - UPDATE CODE: 200309

Registro 407 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Los peces Devonicos del Macizo de Floresta (Boyaca, Colombia); consideraciones taxonomicas, bioestratigraficas, biogeograficas y ambientales

Translated Title: Devonian fish in the Floresta Massif (Boyaca, Colombia); taxonomic, biostratigraphic, biogeographic and environmental considerations.

AU - AUTHORS: Janvier-Philippe; Villarroel-Carlos-A

AF - AUTHOR AFFILIATION: Museum National d'Histoire Naturelle, Laboratoire de Paleontologie, Paris, France

SO - SOURCE: Geologia Colombiana. 23; Pages 3-18. 1998.

PB - PUBLISHER: Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Geociencias. Bogota, Colombia. 1998.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 1998

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: Fish remains are recorded from the Emsian-Eifelian Floresta Formation and the Late Devonian (? Frasnian) Cuche Formation of Boyaca, Colombia. The material from the Floresta Formation is associated to marine invertebrates and is referred to an indetermined arthrodire and probably a rhenanid. Several fish localities occur in the Late Devonian Cuche Formation. They have yielded an acanthodian, a chondrichthyan (Antarctilamna? sp.), placoderms (Bothriolepis sp., Asterolepis? sp. and an indetermined arthrodire), a stegotrachelid actinopterygian, and three sarcopterygians (a cosmine-covered form tentatively referred to an osteolepidid, the porolepiform Holoptychius sp., and the rhizodontid Strepsodus? sp.). This fish fauna of the Cuche Formation suggests a Late Frasnian age. By the presence of Asterolepis and Holoptychius, it is surprisingly similar to the Late Devonian vertebrate faunas found in the Old Red Sandstone of Europe and North America, although the presence of the chondrichthyan Antarctilamna can be regarded as a Gondwanan "signature". Such a mixture of Euramerican and Gondwana taxa suggests close geographical links between Euramerica and northern South America in Late Devonian times.

DE - DESCRIPTORS: Antarctilamna-; Asterolepis-; biogeography-; biostratigraphy-; Boyaca-Colombia; Chordata-; Colombia-; Cuche-Formation; Devonian-; Eifelian-; Emsian-; Floresta-Formation; Floresta-Massif; Holoptychius-; lithostratigraphy-; Lower-Devonian; Middle-Devonian; Osteichthyes-; paleogeography-; Paleozoic-; Pisces-; Placodermi-; South-America; taxonomy-; Vertebrata-

CC - CATEGORY CODES: 12-Stratigraphy; 11-Vertebrate-paleontology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N054000; N054500; LONG: W0730000; W0730500.

IL - ILLUSTRATION: Refs: 46; illus. incl. strat. col., sketch map.

RF - REFERENCE SOURCE: GeoRef, Copyright 2003, American Geological Institute.

IS - ISSN: 0072-0992

CO - CODEN: GECBA7

AN - ACCESSION NUMBER: 2003-027116

UD - UPDATE CODE: 200309

Registro 408 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Anotaciones geoquimicas para exploracion de Esmeraldas en la region Muzo-Coscuez con base en la relacion Na/ K y elementos traza

Translated Title: Geochemical indicators for emerald exploration in the Muzo-Coscuez region, based on Na/ K ratios and trace element contents.

AU - AUTHORS: Mendoza-Parada-Jaime-E

AF - AUTHOR AFFILIATION: Universidad Nacional de Colombia, Departamento de Geociencias, Bogota, Colombia

SO - SOURCE: Geologia Colombiana. 21; Pages 89-98. 1996.

PB - PUBLISHER: Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Geociencias. Bogota, Colombia. 1996.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 1996

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: This study covers the northwestern area of the emerald belt in the Muzo-Coscuez District located in the western edge of the Eastern Cordillera of Colombia, Departamento de Boyaca. The study includes sediments of Lower Cretaceous age, affected by fault systems and fractures which were accompanied by mineralizing events produced from fluid migration reacting with chromophores of the including rock, providing the emeralds' origin. The emerald mineralization is stratigraphically restricted to the shaly level of the carbonaceous-calcareous facies locked toward the top of Calcareous Shale member and base of the Carbonaceous Shale unit of Paja Formation. This shaly unit is mineralogically associated with rhombohedral calcite, pyrite, albite and pyrophyllite, which are minerals formed at low temperature conditions, as a result of post-magmatic hydrothermal-pneumatolitic processes and fluids provided by the including rock. Geochemically it is established that the albitization processes favor the emerald formation, meanwhile the potassic metasomatism related to regional metamorphism and dynamic tectonism inhibit the emerald mineralization as high temperatures are generated. The best indicators at local and regional considerations to conduct the geochemical exploration for emeralds are the behavior of chemical elements present in the water, active sediments, soil and rocks where the anomalous concentration of Na/K are higher than 1. The high anomalous concentrations of sodium and some elements in rare earths constitute also excellent indicators to conduit geochemical exploration.

DE - DESCRIPTORS: Andes-; beryl-; beryllium-ores; Boyaca-Colombia; chemical-composition; Colombia-; Coscuez-Colombia; Cretaceous-; Eastern-Cordillera; emerald-; fluvial-environment; gems-; geochemical-indicators; geochemical-methods; host-rocks; hydrothermal-alteration; Lower-Cretaceous; Mesozoic-; metal-ores; metals-; metasomatism-; mineral-composition; mineral-exploration; mineralization-; Muzo-Colombia; Paja-Formation; potassic-composition; rare-earths; ring-silicates; sediments-; silicates-; soils-; South-America; stream-sediments; water-

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