No. Registros Solicitud 1 5614 colombia

UD - UPDATE CODE: 200424

Registro 9 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Efecto de la meteorizacion en las propiedades dinamicas de un suelo gabroico

Translated Title: Weathering effects and the dynamic properties of gabbroic soils.

AU - AUTHORS: Otalvaro-Calle-Ivan-Fernando; Cano-Martinez-Carlos-Andres; Osorio-Mora-Rodrigo-Ivan; Hincapie-Aguilar-Jaime-Eduardo

AF - AUTHOR AFFILIATION: Universidad Nacional de Colombia, COL, Colombia

SO - SOURCE: Revista Universidad Eafit. 40; 133, Pages 120-132. 2004.

PB - PUBLISHER: Escuela de Administracion y Finazas. Medellin, Colombia. 2004.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 2004

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: This work shows the variation of the shear modulus (G) and the damping fraction (beta ) in accordance with the confinement level and the degree of weathering valued in field in a soil profile made up basically by gabbro saprolite, that belongs to the Gabbro of San Diego unit that outcrops in the Aburra valley towards the east of the city of Medellin, (Colombia). For such study unaltered samples extracted from a manual excavation of 18,0 meters were used, these were evaluated through cyclic triaxial compression tests and resonant column in non drained condition. Finally, the study is concluded carrying out an analysis of the seismic response of the terrain through a uni-dimensional wave propagation model.

DE - DESCRIPTORS: Aburra-Valley; classification-; Colombia-; compressibility-; confining-pressure; drainage-; dynamic-properties; elastic-constants; exploration-; gabbros-; grain-size; granulometry-; igneous-rocks; Medellin-Colombia; metamorphic-rocks; mineral-composition; models-; moisture-; parent-materials; plutonic-rocks; propagation-; properties-; San-Diego-Gabbro; saprolite-; seismic-response; shear-modulus; soils-; South-America; triaxial-tests; variations-; weathering-

CC - CATEGORY CODES: 25-Soils

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N054500; N070000; LONG: W0750000; W0760000.

IL - ILLUSTRATION: Refs: 16; illus. incl. 1 table, sketch map.

RF - REFERENCE SOURCE: GeoRef, Copyright 2004, American Geological Institute.

IS - ISSN: 0120-341X

AN - ACCESSION NUMBER: 2004-083648

UD - UPDATE CODE: 200424

Registro 10 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Small-scale curvatures in thrust belts; linking sub-decollement basement structures with thin-skinned.

AU - AUTHORS: Bayona-German; Thomas-William-A

AF - AUTHOR AFFILIATION: University of Kentucky/Corporacion Geologica ARES, Bogota, Colombia

BK - BOOK TITLE: In: Geological Society of America, 2003 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Abstracts with Programs - Geological Society of America. 35; 6, Pages 603. 2003.

PB - PUBLISHER: Geological Society of America (GSA). Boulder, CO, United States. 2003.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 2003

CN - CONFERENCE INFORMATION: Geological Society of America, 2003 annual meeting. Seattle, WA, United States. Nov. 2-5, 2003.

LA - LANGUAGE: English

AB - ABSTRACT: The assumption of a low-angle, hinterlandward-dipping basal slope of the critical wedge eliminates consideration of the effects of an irregularly shaped basal detachment surface in the evolution of thrust belts. Geometry and kinematics of structural styles in the thin-skinned, unmetamorphosed Appalachian thrust belt of Alabama and Georgia may be directly and indirectly related to sub-decollement basement structures and the pre-deformational stratal architecture of the unit that hosts the regional decollement. In the leading and intermediate imbricates of Georgia and the leading imbricates in Alabama, low-amplitude fault-related anticlines form where depth to basement is shallow. Folds and faults in intermediate imbricates have local strike deviations which are not transmitted to either leading or trailing thrust sheets. In the intermediate imbricates in Alabama, high-amplitude fault-related anticlines form where the regional decollement is deep within the Birmingham basement graben; detachment folds nucleate above down-to-southeast basement faults with moderate vertical separation; and a mushwad (ductile duplex) evolves above a broad, deep graben containing a large volume of weak strata (i.e., thick shale-dominated succession). Small-scale curvatures of the thrust belt are also related to differences in basement elevation across basement transverse faults. Small-scale salients of the Helena Fault and Gadsden mushwad are very abrupt, and they are related to a transverse basement fault that separates a narrow Birmingham Graben on the northeast from a wider and deeper graben on the southwest. This observation suggests that a transverse basement fault primarily controlled the geometry of small-scale salients of the Rome, eastern Coosa, and Talladega faults. Abrupt curvatures are confined in transverse zones suggesting that distribution of northwest-striking basement faults and related differences in elevation of the top of basement exerted a primary role in the location of transverse structures in the thrust belt.

DE - DESCRIPTORS: Alabama-; Appalachians-; basement-tectonics; Coosa-Fault; decollement-; duplexes-; faults-; fold-and-thrust-belts; geometry-; Georgia-; grabens-; imbricate-tectonics; kinematics-; North-America; Rome-Fault; Southern-Appalachians; systems-; Talladega-Fault; tectonics-; thin-skinned-tectonics; thrust-faults; transverse-faults; United-States

CC - CATEGORY CODES: 16-Structural-geology

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

BL - BIB LEVEL: Analytic

RF - REFERENCE SOURCE: GeoRef, Copyright 2004, 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: 2004-083411

UD - UPDATE CODE: 200424

Registro 11 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Recent crustal deformation and the earthquake cycle along the Ecuador-Colombia subduction zone.

AU - AUTHORS: White-Scott-M; Trenkamp-Robert; Kellogg-James-N

AF - AUTHOR AFFILIATION: University of South Carolina, Department of Geological Sciences, Columbia, SC, United States

SO - SOURCE: Earth and Planetary Science Letters. 216; 3, Pages 231-242. 2003.

PB - PUBLISHER: Elsevier. Amsterdam, Netherlands. 2003.

CP - COUNTRY OF PUBLICATION: Netherlands

PY - PUBLICATION YEAR: 2003

LA - LANGUAGE: English

AB - ABSTRACT: Recent results from Global Positioning System (GPS) measurements show deformation along the coast of Ecuador and Colombia that can be linked to the rupture zone of the earthquake in 1979. A 3D elastic boundary element model is used to simulate crustal deformation observed by GPS campaigns in 1991, 1994, 1996, and 1998. Deformation in Ecuador can be explained best by 50% apparent locking on the subduction interface. Although there have not been any historic large earthquakes (M (sub w) >7) south of the 1906 earthquake rupture zone, 50% apparent elastic locking is necessary to model the deformation observed there. In Colombia, only 30% apparent elastic locking is occurring along the subduction interface in the 1979 earthquake rupture zone (M (sub w) 8.2), and no elastic locking is necessary to explain the crustal deformation observed at two GPS sites north of there. There is no evidence from seismicity or plate geometry that plate coupling on the subduction zone is reduced in Colombia. However, simple viscoelastic models suggest that the apparent reduction in elastic locking can be explained entirely by the response of a viscous upper mantle to the 1979 earthquake. These results suggest that elastic strain accumulation is occurring evenly throughout the study area, but postseismic relaxation masks the true total strain rate.

DE - DESCRIPTORS: Andes-; boundary-element-analysis; Colombia-; coupling-; crust-; cycles-; earthquakes-; East-Pacific; Ecuador-; Global-Positioning-System; Pacific-Ocean; plate-tectonics; postseismic-processes; relaxation-; South-America; strain-; subduction-; subduction-zones

CC - CATEGORY CODES: 19-Seismology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

IL - ILLUSTRATION: Refs: 35; illus. incl. sketch maps.

RF - REFERENCE SOURCE: GeoRef, Copyright 2004, American Geological Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands

IS - ISSN: 0012-821X

CO - CODEN: EPSLA2

AN - ACCESSION NUMBER: 2004-082868

UD - UPDATE CODE: 200424

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

TI - TITLE: Anomalias geobotanicas espectrales asociadas con los cambios en litologia; su uso para la cartografia geologica de las rocas ultrabasicas, en terrenos totalmente vegetados de la costa pacifica colombiana

Translated Title: Spectral geobotanical anomalies associated with lithologic changes; geological mapping of ultramafic rocks in highly vegetated terrains of Colombia's Pacific coast.

AU - AUTHORS: Villegas-V-H

AF - AUTHOR AFFILIATION: INGEOMINAS, Bogota, Colombia

SO - SOURCE: Boletin de Geologia (Bucaramanga). 22; 37, Pages 68-76. 2000.

PB - PUBLISHER: Universidad Industrial de Santander. Bucaramanga, Colombia. 2000.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 2000

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: It has long been known that soils developed on ultramafic rocks inhibit the growth of vegetation. Taking into account this, digital processing was carried out in a Colombian Pacific Coast Landsat TM subscene, where the Guapi Ultrabasic Lithodeme outcrops. The ratio TM4/TM3 image proved to be powerful for identifying spectral geobotanical anomalies of sparse vegetation, related to a NS to NE-SW trending ultramafic belt exposed throughout the study area. The contrast stretched TM4 image allowed to diferentiate another two ultramafic lensoid boudins different from the belt, which seem to have the same lithology.

DE - DESCRIPTORS: Cauca-Colombia; climate-; coastal-environment; coastal-plains; Colombia-; data-processing; digital-data; geobotanical-methods; geochemical-anomalies; Guapi-River; igneous-rocks; imagery-; Landsat-; Llantin-River; mapping-; Pacific-Ocean; remote-sensing; satellite-methods; South-America; spectra-; thematic-mapper; ultramafic-composition; vegetation-

CC - CATEGORY CODES: 02A-General-geochemistry; 20-Applied-geophysics

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N020000; N030000; LONG: W0763000; W0780000.

IL - ILLUSTRATION: Refs: 12; sketch maps.

RF - REFERENCE SOURCE: GeoRef, Copyright 2004, American Geological Institute.

IS - ISSN: 0120-0283

CO - CODEN: UISBAV

AN - ACCESSION NUMBER: 2004-082832

UD - UPDATE CODE: 200424

Registro 13 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Criterios para la clasificacion y descripcion de movimientos en masa

Translated Title: Mass movement classification and description criteria.

AU - AUTHORS: Vargas-Cuervo-G

AF - AUTHOR AFFILIATION: Calle 45 No. 38a-47 Int. 2 Apto. 804, Bogota, Colombia

SO - SOURCE: Boletin de Geologia (Bucaramanga). 22; 37, Pages 39-67. 2000.

PB - PUBLISHER: Universidad Industrial de Santander. Bucaramanga, Colombia. 2000.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 2000

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: A mass movement may be defined as any lithologic or debris material displacement downwards (vertical or in the direction of a slope foot), caused by gravity. In common language, there are other synonymous words such as: landslide, collapse and terrain movement. The occurrence of a mass movement develops some characteristic geomorphologic and morphometric features. The morphologic elements may be associated to displaced mass or surrounding intact terrain. Among these morphologic elements are the crown, the main scarp, the rupture surface, the body, the flanks, the front and the foot. Mass movements have been internationally classified in eight basic types: falls, flows, landslides, lateral propagation, collapses, reptation, torrential floods, avalanches and complex mass movements. Nevertheless, they may be described or classified under many points of view, including: relative displacement, velocity or movement rate, type and size of involved material, relative activity, relative dimension, grade of development, transport mechanism, genesis and detonate agent. Mass movements may be quantified for their magnitude in relation to the volume, activity, velocity and intensity according to damages occasioned.

DE - DESCRIPTORS: avalanches-; bedrock-; causes-; characterization-; classification-; description-; erosion-; eruptions-; faults-; geologic-hazards; geometry-; geomorphology-; land-subsidence; landforms-; landslides-; mass-movements; morphometry-; nomenclature-; properties-; regolith-; rupture-; sedimentation-; soils-; solifluction-; tectonics-; volcanism-; volcanoes-

CC - CATEGORY CODES: 23-Geomorphology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

NN - ANNOTATION: Includes appendices.

IL - ILLUSTRATION: Refs: 33; illus. incl. 11 tables.

RF - REFERENCE SOURCE: GeoRef, Copyright 2004, American Geological Institute.

IS - ISSN: 0120-0283

CO - CODEN: UISBAV

AN - ACCESSION NUMBER: 2004-082831

UD - UPDATE CODE: 200424

Registro 14 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Brechas de atricion y mineralizaciones auriferas en las minas de Miraflores (Quinchia, Risaralda) y su relacion con un cuerpo tipo "brecha-pipe"

Translated Title: Breccias and gold mineralization at Quinchia and Risaralda (Miraflores, Colombia); field relationships with breccia pipe body.

AU - AUTHORS: Carrillo-Lombana-V-M

AF - AUTHOR AFFILIATION: Carrera 93 No. 24-40, Santa Fe de Bogota, Colombia

SO - SOURCE: Boletin de Geologia (Bucaramanga). 22; 37, Pages 28-38. 2000.

PB - PUBLISHER: Universidad Industrial de Santander. Bucaramanga, Colombia. 2000.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 2000

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: Gold bearing veins hosted at the walls of attrition breccias are now in exploitation at the Miraflores mines and these breccias look younger than a breccia pipe body outcropping just at the eastern sector of them. The gold bearing veins are of epithermal type and even though its width is centimetric they develop locally high gold concentrations (ore shoots or bonanzas), important for small-scale mining. Only at the places of La Balastrera (which correspond with an implosion breccia) and at La Calichera (a typical crackle breccia), the basalt that host the breccias and the veins show gold bearing mineralizations. The breccia pipe observed at the surface and at the first meters of two tunnels is apparently barren but there are reasons to think that it is possible to find, new gold ores capable to support medium scale or bulk mining exploitations.

DE - DESCRIPTORS: Barroso-Formation; breccia-; Cenozoic-; Colombia-; deformation-; gold-ores; intrusions-; La-Balastrera-Deposit; La-Calichera-Deposit; metal-ores; metallogeny-; mineral-deposits,-genesis; mineral-exploration; mineralization-; mines-; mining-; mining-geology; Miraflores-Colombia; pipes-; Quinchia-Colombia; rhyolitic-composition; Risaralda-Colombia; Romeral-Fault; South-America; stress-; systems-; tectonics-; Tertiary-; underground-mining; veins-

CC - CATEGORY CODES: 27A-Economic-geology,-geology-of-ore-deposits

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N050000; N053000; LONG: W0754500; W0761500.

IL - ILLUSTRATION: Refs: 6; illus. incl. geol. sketch map.

RF - REFERENCE SOURCE: GeoRef, Copyright 2004, American Geological Institute.

IS - ISSN: 0120-0283

CO - CODEN: UISBAV

AN - ACCESSION NUMBER: 2004-082830

UD - UPDATE CODE: 200424

Registro 15 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Composicion quimica y mineralogia de las biotitas metamorficas del sector central del macizo de Santander, Colombia

Translated Title: Chemical and mineralogical composition of metamorphic biotites, central Santander Massif, Colombia.

AU - AUTHORS: Garcia-Ramirez-C-A; Campos-Alvarez-N-O

AF - AUTHOR AFFILIATION: Universidad Industrial de Santander, Escuela de Geologia, Bucaramanga, Colombia

SO - SOURCE: Boletin de Geologia (Bucaramanga). 22; 37, Pages 18-27. 2000.

PB - PUBLISHER: Universidad Industrial de Santander. Bucaramanga, Colombia. 2000.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 2000

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: The metamorphic biotites of the Neis de Bucaramanga, Silgara and Ortoneis formations in the Central Part of the Santander Massif correspond to the eastonite-siderophilite and annite series. The chemical composition of the biotite in metapelites depends on the temperature and pressure, while in quartz feldspathic and mafic rocks it is controlled by the bulk rock composition of the protolith.

DE - DESCRIPTORS: annite-; biotite-; chemical-composition; Colombia-; complexes-; Devonian-; eastonite-; FTIR-spectra; geochemistry-; geologic-thermometry; infrared-spectra; intrusions-; mafic-composition; major-elements; Mesozoic-; metamorphic-rocks; metamorphism-; metapelite-; metasedimentary-rocks; mica-group; microscope-methods; mineral-assemblages; mineral-composition; minor-elements; Neis-de-Bucaramanga-Formation; Ortoneis-Formation; Paleozoic-; petrography-; plutons-; protoliths-; Santander-Colombia; Santander-Massif; SEM-data; sheet-silicates; siderophilite-; Silgara-Formation; silicates-; South-America; spectra-; X-ray-diffraction-data

CC - CATEGORY CODES: 05A-Igneous-and-metamorphic-petrology; 02C-Geochemistry-of-rocks,-soils,-and-sediments

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N071900; N072100; LONG: W0754900; W0755100.

IL - ILLUSTRATION: Refs: 5; illus. incl. 1 table, geol. sketch map.

RF - REFERENCE SOURCE: GeoRef, Copyright 2004, American Geological Institute.

IS - ISSN: 0120-0283

CO - CODEN: UISBAV

AN - ACCESSION NUMBER: 2004-082829

UD - UPDATE CODE: 200424

Registro 16 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Analisis de variables morfometricas de Toxaster roulini Agassiz (Echinoides; Toxasteriidae) de la formacion Rosa Blanca, Municipio de Zapatoca (Santander, Colombia)

Translated Title: Morphometric variables analysis of Toxaster roulini Agassiz (Echinoides, Toxasteriidae) of the Rosa Blanca Formation, Zapatoca Municipality (Santander, Colombia).

AU - AUTHORS: Cruz-Guevara-L-E; Jerez-Jaimes-J-H; Navaez-Parra-E-X; Franco-Blanco-R-A

AF - AUTHOR AFFILIATION: Universidad Industrial de Santander, Escuela de Geologia, Santander, Colombia

SO - SOURCE: Boletin de Geologia (Bucaramanga). 22; 37, Pages 7-17. 2000.

PB - PUBLISHER: Universidad Industrial de Santander. Bucaramanga, Colombia. 2000.

CP - COUNTRY OF PUBLICATION: Colombia

PY - PUBLICATION YEAR: 2000

LA - LANGUAGE: Spanish

LS - LANGUAGE OF SUMMARY: English

AB - ABSTRACT: In the outcrop sequence of the Rosa Blanca Formation on the highway Zapatoca--the Platanalito Mines, 188 specimens of Toxaster roulini Agassiz of the Aptiano (Camacho, 1979) were gathered directly from the strata that contained them. The respective measurements of the variable morphometrics of the collected specimens of Toxaster roulini Agassiz were carried out: long 1, long 2, width, high, high anus, distance of the mouth, with the purpose of evaluating the type of growth of these individuals and the influence of this variables in their deformation during the fossilization process. These data were processed applying lineal regressions and correlation using the program STATISTICA version 4.0. In the sampling place the individuals that prevailed (74.4%) between 20 and 33 mm in length, between 17 and 30 mm in width, and between 11 and 18 mm in height, showing this way that this is the size common of the sampling population. The variables high anus and distance of the mouth constituted specific areas that were not modified during the growth of the individuals, which confirms from the low correlationship values that present these two variables morphometrics with the other ones. The results of the regressions and correlations indicate that the T. roulini growth is isometric and alteration exists in the variable height very probably induced by the pressure of the superior strata during the fossilization process. We think about a hypothesis for the distribution in the habitat of T. roulini Agassiz in which the individuals of smaller sizes inhabited the surface of the marine bottom and the biggest individuals were totally buried in the marine bottom, based on the position of the anus for the first one the anus it is located bellow half of each individual's total height and for the biggest the anus it is located above half of the total height of these.

DE - DESCRIPTORS: Aptian-; benthonic-taxa; Colombia-; Cretaceous-; dimensions-; Echinodermata-; Echinoidea-; Echinozoa-; fossilization-; Invertebrata-; Lower-Cretaceous; marine-environment; Mesozoic-; morphology-; morphometry-; paleoenvironment-; Rosa-Blanca-Formation; Santander-Colombia; sedimentary-rocks; South-America; Toxaster-; Toxasteriidae-; Zapatoca-Colombia

CC - CATEGORY CODES: 10-Invertebrate-paleontology

DT - DOCUMENT TYPE: Serial

BL - BIB LEVEL: Analytic

MC - MAP COORDINATES: LAT: N063000; N070000; LONG: W0731500; W0733000.

IL - ILLUSTRATION: Refs: 5; illus. incl. 2 tables, sketch map.

RF - REFERENCE SOURCE: GeoRef, Copyright 2004, American Geological Institute.

IS - ISSN: 0120-0283

CO - CODEN: UISBAV

AN - ACCESSION NUMBER: 2004-082828

UD - UPDATE CODE: 200424

Registro 17 de 5614 - GeoRef : 2002-2004/12

TI - TITLE: Planktonic Foraminifera record of the mid Albian sea level rise, upper Magdalena Valley, Colombia.

AU - AUTHORS: Leon-Rodriguez-Lizette

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

BK - BOOK TITLE: In: Geological Society of America, 2003 annual meeting.

BA - BOOK AUTHORS: Anonymous

SO - SOURCE: Abstracts with Programs - Geological Society of America. 35; 6, Pages 87. 2003.

PB - PUBLISHER: Geological Society of America (GSA). Boulder, CO, United States. 2003.

CP - COUNTRY OF PUBLICATION: United-States

PY - PUBLICATION YEAR: 2003

CN - CONFERENCE INFORMATION: Geological Society of America, 2003 annual meeting. Seattle, WA, United States. Nov. 2-5, 2003.

LA - LANGUAGE: English

AB - ABSTRACT: Micropaleontological descriptions and analysis of three sections from a lower Cretaceous unit in southern Colombia named "Tetuan Limestone", has allowed the comparison between the stratigraphic distribution (range) of the planktic foraminifera and the ammonites collected from the same samples. This appraisal presents for the first time in Colombia the recognition and calibration with other fossil groups of two planktic foraminifera interval zones: Ticinella primula and Biticinella breggiensis, with late mid Albian and early late Albian ages respectively. The "Tetuan Limestone" belongs to a great sedimentary succession that extends along the Upper Magdalena Valley (Huila Department), and is described as intercalations of micritic limestones and micritic concretions of thin to middle size, tabular and cuneiform beds with interbedded dark gray, laminated, calcareous claystones with common imprints of ammonites, bivalves and fish. Presence of marine planktic microfauna within the claystones of the "Tetuan Limestone", immediately above the mainly arenaceous and barren of planktic microfauna Caballos Limestone, is understood as a marine transgression marker at the end of mid Albian. Slow increase of planktic foraminifera like Ticinella primula, T. aff. albiana, T. caronae, T. madecassiana, T. roberti, Biticinella breggiensis, Hedbergella delrioensis, H. gorbachikae, H. simplex, Favusella washitensis, etc. is in contrast to those ones of benthic life trough the studied interval, the former showing a constant sea level rise, at least up to the late Albian to early Cenomanian. At the same time, planktic foraminifera change from initial trocospiral forms of ticinellids and hedbergellids to predominant subconic, planispiral and robust trocospiral forms of heterohelicids, globigerinelloids and whiteinellids. The residing water masses that occupied the accumulation enclosure were mostly warm; nevertheless, abundant and punctual presence of species like Whiteinella baltica indicate temporal incursions of cold currents. Planktic foraminifera associations exhibit greater geographic affinities with those from Mexico and Texas and in minor proportion with the Tethys realm. On the other hand, benthonic foraminifera are very similar to those reported for the Albian in Trinidad.