Geología de la formación clay pebble beds del grupo Ancón (eoceno medio), acantilado del área Concepción, Ancón, provincia de Santa Elena.
Fecha
2021-03
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Facultad de Ciencias Naturales. Universidad de Guayaquil
Resumen
La Dormación Clay Pebble Beds perteneciente al al Grupo Ancón (Eoceno Medio) se encuentra sobreyaciendo a la Formación Socorro, las mismas que forman parte del campo petrolero de Ancón. Dentro del Área Concepción, se interpretaron diez afloramientos, seis secciones delgadas de rocas y catorce muestras bioestratigráficas, para determinar litologías, composición mineralógica, petrotectónica, bioestratigrafía y paloambiente de las formaciones Clay Pebble Beds y Socorro. Además, se identificaron secuencias turbiditicas incompletas (Te; Tb - Te y Tc - e), truncadas incompletas (Tb y Tb - c) y las litofacies A, C, y F; estructuras sedimetarias (canales)y estructuras sensidimentarias. En base a los radiolarios Lamptonium pennatun, Theocampe mongolfieri, Lythocyclia ocellus, Spongatractus pochystylus y Cenosphaera sp., se determinó la edad Eoceno Temprano tardío-Eoceno Medio temprano para Formación Clay Pebble Beds. Además, se identificó la presencia de la Formación Socorro por la identificación de radiolarios Cenosphaera melitoma, Lithocyclia ocellus y Lychnocanoma cf. bellum, que determinaron la edad Eoceno Medio temprano - Eoceno Medio medio; een relación con la presencia de foraminíferos bentónicos Bathysiphon eocénica, Nodosaria sp.. Bolivina sp y Lenticulina sp., se determinó el ambiente de Marino de plataforma externa a Talud Superior para ambas formaciones. Las rocas en relación con sus componentes esenciales (Q: 76.25%. L: 21.26& y F: 2.49%) fueron clasificadas como Sublitarenitas y Litarenitas y en relación con los componentes monocristalinos (Qm: 69.55%, Lt: 27.34 y F: 3.11%) y policristalinos (Qp: 50.99%, Ls: 39.23 y Lv: 9.78%), se determinó el origen tectónico de depositación correspondiente a Orógeno reciclado y orógeno de colisión cuarzosa, según los diagramas de procedencia.
Within the Concepción Area, ten outcrops, six rock thin sections and fourteen biostratigraphic samples were interpreted to determine lithology, mineralogical composition, petrotectonics, biostratigraphy and paleoenvironment of tthe Clay Pebble Beds and Socorro formations. In addition, incomplete turbiditic sequences (Te; Tb - Te and Tc - e), incomplete truncated (Tb and Tb - c) and lithofacies A, C, and F; sedimentary strcutures (channels) and synsedimetary structures were identified. Based on the radiolarians Lamptonium pennatun, Theocampe mongolfieri, Lythocyclia ocellus, Spongatractus pochystylus and Cenosphaera sp. Early Eocene - earrly Middle Eocene age was determined for the Clay Pebble Beds Formation; in adition, the presence of the Socorro Formation was identified by the presence of radiolarians Cenosphaera melitoma, Lithocyclia ocellus and Lychnocanoma cf. bellum determined the early Middle Eocene - middle Middle Eocene age; in relation to the presence of benthic foraminifera Bathysiphon eocenic, Nodosarria sp. Boliviana sp. and Lenticulina sp., the outer shelf to upper slope marine environment was determined for both formations. the rocks in relation to their essential components (Q: 76.25%, L: 21.26& and F: 2.49%) were classified as Sublitarenites and Litarenites and in reñation to the monocrystalline (Qm: 69.55%, Lt: 27.34 and F: 3. 11%) and polycrystalline (Qp: 50.99%, Ls: 39.23 and Lv: 9.78%), the tectonic origin of deposition was determined corresponding to recyycled orogen and quartzose collision orogen, accordingg to provenance diagrams.
Within the Concepción Area, ten outcrops, six rock thin sections and fourteen biostratigraphic samples were interpreted to determine lithology, mineralogical composition, petrotectonics, biostratigraphy and paleoenvironment of tthe Clay Pebble Beds and Socorro formations. In addition, incomplete turbiditic sequences (Te; Tb - Te and Tc - e), incomplete truncated (Tb and Tb - c) and lithofacies A, C, and F; sedimentary strcutures (channels) and synsedimetary structures were identified. Based on the radiolarians Lamptonium pennatun, Theocampe mongolfieri, Lythocyclia ocellus, Spongatractus pochystylus and Cenosphaera sp. Early Eocene - earrly Middle Eocene age was determined for the Clay Pebble Beds Formation; in adition, the presence of the Socorro Formation was identified by the presence of radiolarians Cenosphaera melitoma, Lithocyclia ocellus and Lychnocanoma cf. bellum determined the early Middle Eocene - middle Middle Eocene age; in relation to the presence of benthic foraminifera Bathysiphon eocenic, Nodosarria sp. Boliviana sp. and Lenticulina sp., the outer shelf to upper slope marine environment was determined for both formations. the rocks in relation to their essential components (Q: 76.25%, L: 21.26& and F: 2.49%) were classified as Sublitarenites and Litarenites and in reñation to the monocrystalline (Qm: 69.55%, Lt: 27.34 and F: 3. 11%) and polycrystalline (Qp: 50.99%, Ls: 39.23 and Lv: 9.78%), the tectonic origin of deposition was determined corresponding to recyycled orogen and quartzose collision orogen, accordingg to provenance diagrams.
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CLAY PEBBLE BEDS, ORÓGENO RECICCLADO, ARENISCAS, TALUD SUPERIOR