Quantitative paleoparasitology applied to archaeological sediments

Three techniques to extract parasite remains from archaeological sediments were tested. The aim was to improve the sensibility of recommended paleoparasitological techniques applied in archaeological remains. Sediment collected from the pelvic girdle of a human body found in Cabo Vírgenes, Santa Cruz, Argentina, associated to a Spanish settlement founded in 1584 known as Nombre de Jesús, was used to search for parasites. Sediment close to the skull was used as control. The techniques recommended by Jones, Reinhard, and Dittmar and Teejen were used and compared with the modified technique presented here, developed to improve the sensibility to detect parasite remains. Positive results were obtained only with the modified technique, resulting in the finding of Trichuris trichiura eggs in the sediment

Environmental controls and facies architecture of a jurassic carbonate episode La Manga Formation), Mendoza Province, Neuquén Basin

La Manga Formation is a vast carbonate system developed in the Neuquén Basin. The age is based in ammonite faunas, ranging from Early Callovian (Bodenbenderi-Proximum Zone) to Middle Oxfordian (Cordatum Standard Zone to Transversarium Standard Zone, and probably to the lower part of the Bifurcatus Standard Zone). A stratigraphical and sedimentological analysis, in the outcrops exposed in the south of Mendoza province, enabled the recognition of five facies associations of a carbonate ramp corresponding to (1) distal outer ramp, (2) proximal outer to distal middle ramp, (3) proximal middle ramp, (4) inner ramp deposits (shoreface, shoal, patch reef, shallow subtidal lagoon and tidal flat) and (5) paleokarstic facies. These facies correspond to homoclinal to distally steepened carbonate ramp. The facies associations are included into three third-order depositional sequences (DS-1, DS-2, DS-3) represented by transgressive and highstand systems tracts with sequence boundaries of regional character. Different controlling factors can be recognised in the deposition of this unit. The abrupt changes of facies, as well as paleokarst and epikarst discontinuity surfaces in the successions provide important evidence in terms of depositional environment and vertical evolution of the carbonate ramp. Facies patterns are variable across the outcrop area and vertically through time because of a combination of ramp morphology, siliciclastic supply, sea level changes and tectonic effects. In the southern sections, siliciclastic influx influenced the deposition of proximal middle ramp facies later overlain by scleractinian patch reefs which grew up throughout progressive stages from aggradational to progradational facies in response to climate controls and nutrient levels influence. In northern outcrops, tectonic controls affected the ramp topography and influenced the development of distal deep marine facies. Shallow subtidal and peritidal cycles indicate a combination of allocyclic and autocyclic processes controlling accommodation space and sediment accumulation.Fil: Palma, Ricardo Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Bressan, Graciela Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Riccardi, Alberto Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: López Gómez, José. Universidad Complutense de Madrid; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Martín Chivelet, Javier. Consejo Superior de Investigaciones Científicas; España. Universidad Complutense de Madrid; Españ