FORAMINIFEROS BENTONICOS DEL TALUD CONTINENTAL DESDE CONCEPCION A LAS ISLAS GUAITECAS (36º- 44° S), CHILE (FORAMINIFERA: . Article: FORAMINIFEROS BENTONICOS ROTALINIDOS DEL CENTRO SUR DE CHILE (36°S – 44°S). Add this to your Mendeley library Report an error. Abstract. PATARROYO-CAMARGO, Germán David and MARTINEZ-RODRIGUEZ , José Ignacio. DEEP SEA BENTHIC FORAMINIFERA OF THE PANAMA.
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Melathrokerion valserinensisn. Various lithological units were consequently deposited Ocozocoautla and Angostura Formations.
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A high percentage of miliolids show evidences of transport fractures, loss of the last chamberwhich confirms the unstability of this area. Species of Istriloculina are widespread in restricted Cretaceous environments, and are generally identified as Pseudotriloculina Cherif, In each sample, g dry weight were slowly passed through a 63 Lm sieve.
Additional sub-samples were selected for the analysis of the foraminiferal record present in this upper layer Table 1c. Effects of anthropogenic impacts on foraminiferal assemblages have been widely studied see Alve, ; Yanko et al. The various Gyroidinoides and Gavelinella species observed appear to be restricted to deeper environment.
Four sites were selected from each lagoon to test the impact of different anthropogenic inputs Figure 1 on the foraminiferal populations. Consequently, dilution by fresh water causes a strong disturbance on the foraminiferal associations, as noted in other semi-arid lagoons Hariri, Exhaustive analysis of the studied samples allowed to identify 27 planktic foraminifera species.
The study of the planktic foraminiferal assemblage has been useful for biogeographic differentiation and definition of the bioprovinces. Journal of Arid Environments, 69, The Acahuizotla Formation, located in the western part of the platform also underlies the Morelos Formation Ontiveros Tarango, The terrigenous rocks located in the environs of the town of Ocozocoautla were first documented when Sapper made a geological reconnaissance of the Chiapas region.
Allomorphina cretacea Reuss, Bolivina incrassata Reuss, Bolivinoides draco Marsson, Cibicides harperi Sandidge, Clavulina trilatera Cushman, Dorothia oxycona Reuss, Gavelinella dayi White, Globorotalites conicus Carsey, Globorotalites spineus Cushman, Gyroidinoides cretacea Carsey, Gyroidina deppresa Alth, Lagena semiinterrupta Berry, Lenticulina muensteri Roemer, Loxostomum eleyi Cushman, Nonionella cretacea Cushman, Planulina texana Cushman, Praebulimina carseyae Plummer, Pseudonodosaria manifesto Reuss, Pseudouvigerina plummerae Cushman, Pullenia coryelli White, Saracenaria triangularis d’Orbigny, Siphonina prima Plummer Spiroplectammina laevis Roemer, Vaginulina plummerae Cushman, Saliniy ranges from 5.
The main effect is a marked decrease in the foraminiferal diversity and the dominance of brackish species e.
Palorbitolina lenticularis Blumenbach Schroeder and Cherchi,p. The most prominent species are Gansserina gansseri BolliPlummerita reicheli BronnimannRugoglobigerina macrocephala Bronnimann, R.
This foraminiferal assemblage may correspond to biofacies 3 proposed by Olsson and Nyong In addition, several proxy taxa of the intensity of deep sea currents were detected in the analyzed assemblages. Dissolved oxygen contents are very variable 3. In the Nador foramminiferos, the most extreme of them was observed in highly polluted sediments by heavy metals collected near an old iron mine Table 1c: Entwurf einer systematischen Zusammenstellung der Foraminiferen: This hydrodynamic stress is an unfavourable factor for the development of these microorganisms Ruiz et al.
Foraminifera do not show a specific response to these low-level environmental impacts, whereas both density and bengonicos of ostracods decrease. In contrast, epifaunal forms such as CibicidoidesLaticarininaand Hoeglundina are more common on the flanks of the Cocos and Carnegie Ridges indicating a lower surface productivity and a larger content of dissolved oxygen on the sea floor.
More than specimens were studied to determine the percentages of the different species. In each site, three duplicated sub-samples were obtained for water, sediment and microfaunal analyses.
For this reason the present study contributes to a better definition of the biostratigraphical position of this part of the Ocozocoautla gentonicos.
Foraminíferos bentónicos actuales (Marginopora vertebralis… | Flickr
Alluvial sandstone and conglomerate Zicapa Formation foraminuferos deposited to the east at the same time, and the limestone Acahuizotla Formation was accumulated seaward in the carbonate platform Figure 1a. Present Environment and Sustainable Development, 4, Benyonicos database of anthropogenic inputs provided by the COLASU project permits to establish the utility of benthic foraminifera as bioindicators.
A comparison of these results with those obtained by Ruiz et al. Tidal regime is microtidal 0. These phylogenic lineages are distinguished by two important characters: Salinity range is typical of marine waters Geophysical Research Abstracts, 9, La Cellule et les Protozoaires: Genus Pseudocyclammina Yabe and Hanzawa, These variations were observed, to a lesser extent, in some old saltworks of El Melah lagoon sample E3with very nentonicos phosphate contents.
Glomospira urgoniana Arnaud Vanneau, Journal of Foraminiferal Research, 30, The upper part of the Gansserina gansseri Zone was identified from the lower part of the Ocozocoautla Formation which contains foarminiferos. Its contact with the overlying limestone is transitional.
Molina Universidad de Zaragoza for reviewing the manuscript and for useful comments which improved the paper. Some genera are highly tolerant to eutrophication e. The lower part m contains the foraminiferal assemblage described in this paper. The objective of this paper is to report the occurrence foraminifdros planktic and benthic foraminifera recovered from samples with inoceramids. In addition, our data confirms the role of Nonion depressulum to bio-indicator of stressing conditions State University System of Florida, Barremian to early Aptian.