Arqueología y etnohistoria de la región metropolitana : las sociedades indígenas de Buenos Aires

Fil: Bonomo, Mariano. División Arqueología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Latini, Sergio. Sección Etnohistoria. Instituto de Ciencias Antropológicas. Facultad de Filosofía y Letras. Universidad de Buenos Aire

The Holocene marine depositional event in the historical centre of Palermo

Studi recenti hanno indicato come al di sopra della classica sequenza del Quaternario marino della Piana di Palermo ricorra, in alcunisiti del Centro Storico, un limitato spessore di depositi marini di età post-tirreniana. Con lo scopo di precisare l’età di tali depositi sonostate studiate le associazioni di microfossili di campioni provenienti da sondaggi geognostici. Utilizzando lo schema ecobiozonale anannofossili calcarei recentemente proposto per l’ultima deglaciazione nel Mediterraneo centrale (Canale di Sicilia) detti depositi contengononannoflore attribuibili all’Olocene. Un'analisi al radiocarbonio ha confermato tale attribuzione, limitando alla parte bassadell'Olocene la pertinenza stratigrafica di tali depositi.Recent data have pointed out that, above the classical depositional sequence of the Quaternary marine sediments of the PalermoCoastal plain, post-Tyrrhenian sediments occur. In order to determine the age of these sediments and to confirm the deposition of arecent sedimentary cycle, microfossil assemblage of several samples, coming from geognostic drillings, have been analysed. Usingthe calcareous nannofossil ecobiozone scheme recently proposed for the last deglaciation of the central Mediterranean (SicilyChannel), examined sediments can be ascribed to the Holocene. Radiocarbon analysis confirmed such an attribution providing a moreaccurate stratigraphic determination

Arqueología y etnohistoria de la región metropolitana: las sociedades indígenas de Buenos Aires

En los últimos siglos la región metropolitana de Buenos Aires no solo ha sufrido grandes modificaciones y pérdidas de entornos naturales, sino también profundos e irreversibles cambios sociales e históricos que concluyeron con la desaparición de sus habitantes originarios. Para poder conocer cómo vivían los pueblos indígenas en la zona donde hoy se emplaza la Capital Federal y sus alrededores, debemos estudiar los conjuntos arqueológicos y los escritos de los primeros europeos que arribaron al Río de la Plata. A partir de las investigaciones iniciadas en el siglo XIX, los materiales arqueológicos hallados en Buenos Aires y los partidos aledaños fueron atribuidos a los indígenas que describieron los exploradores que llegaron desde el Viejo Mundo. Con estos materiales, sobre todo en base a la decoración, forma y función de los recipientes de alfarería, se intentaban identificar a dos grupos étnicos con economías distintas que aparecían en los documentos de la conquista habitando diferentes ambientes: los cazadores de las llanuras denominados querandíes o los agricultores guaraníes de las islas del Paraná. Las fuentes escritas señalan que el área también fue ocupada y recorrida por los charrúas y distintas parcialidades de los chaná-timbú (chaná, mbeguá, chaná-mbeguá), aunque en general estas poblaciones no trataron de ser reconocidas en el registro arqueológico.Facultad de Ciencias Naturales y Muse

CALCAREOUS PLANKTON HIGH RESOLUTION BIOSTRATIGRAPHY (FORAMINIFERA AND NANNOFOSSILS) OF THE UPPERMOST LANGHIAN – LOWER SERRAVALLIANRAS IL-PELLEGRIN SECTION (MALTA)

Results of an integrated biostratigraphic (calcareous nannofossils and planktonic foraminifers) study of the uppermost Langhian/lower Serravallian Ras il-Pellegrin section (Fomm ir-Rih Bay – Malta) are presented. This high resolution study allowed us to recognise several useful lower Serravallian bio-events in the Mediterranean and to provide a detailed distribution pattern of the recognised taxa. The astrochronological calibration, reported in a different paper of this volume, provided absolute ages of the bio-events of the studied section. The LO (Last Occurrence) of Globorotalia peripheroronda at 13.39 Ma, the Paragloborotalia partimlabiata FO (First Occurrence) at 12.62 Ma and the Paragloborotalia mayeri FCO (First Common Occurrence) at 12.34 Ma among the planktonic foraminifera, and the Sphenolithus heteromorphus LO at 13.59 Ma, the Cyclicargolithus floridanus LCO (Last Common Occurrence) at 13.39 Ma, the Reticulofenestra pseudoumbilicus FCO at 13.32 Ma, the Calcidiscus macintyrei FO at 12.57 Ma and the Calcidiscus premacintyrei LCO at 12.51 Ma among the calcareous nannofossils, were recorded. Moreover, our results confirm the LO of S. heteromorphus as a fairly synchronous event in the Mediterranean and in the Atlantic and Pacific Oceans. Therefore, we suggest a lithological level near or coincident with this event for the definition of the GSSP of the Serravallian. The Ras il-Pellegrin section may be considered a good candidate for this definition.&nbsp

Natural Biocides to Prevent the Microbial Growth On Cultural Heritage

Many historic, cultural and artistic objects and buildings are made of stone. Like all materials, stone is subject to inexorable deterioration. Along with chemical and physical weathering factors, microbial growth plays an important role in this process. Stones type and local climatic differences have a great impact on the biodeterioration process and their outcomes. Microbial metabolism results in deteriorating agents such as organic and inorganic acid, chelating agents, enzymes and extracellular polymeric substances (EPS) causing e.g. biocorrosion and biomineralization; furthermore phototropic and heterotropic microorganism (ex. Firmicutes and fungi) are able to penetrate into stone mineral [1,2,3]. In addition to structural damage, rock biofilms cause aesthetic damage. In general the biocides used to prevent the growth of microbes are mostly based by using chemical methods, but they show a restricted efficiency and can cause discolorations and severe damages to the cultural heritage and ,also, they affect higher organisms including humans. Recently, the biotechnology and the applied microbiology (the use of antagonistic organisms or their metabolites products against the biodeteriorating agents) offers a wide range of new procedures for the cleaning and conservation of the artistic substrata [4-9]. The case of the study regards two historical bridges: the “San Vito Bridge” located in Potenza and “Della Vecchia Bridge” located in Campomaggiore, a little village near Potenza. The bacteria isolated belong to a wide variety of phylogenetic group being closely related to species of 10 genera within the Proteobacteria, the Firmicutes and the Actinobacteria; the number of fungi was slightly lower than those of bacteria. The fungi isolated on two bridges belong to Aspergillus, Penicillium and Stemphylium genera. In this work secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga) ICMP 11096 strain and glycoalkaloids derived from Solanacee extracts, were used against bacteria and fungi isolated. Results show that all secondary metabolites inhibited in vitro and in vivo the growth of these colonising confirming that the application of biopesticides will be is a promising alternative to synthetic pesticides over traditional technologies. In fact, the use of these natural substances consents a more homogeneous removal of the surface deposits without compromising the substrata structure and the preservation of patina noble ; in addition, bio-cleaning has proven to be more selective than chemicals

CALCAREOUS PLANKTON BIO-EVENTS IN THE MIOCENECASE PELACANI SECTION (SOUTH-EASTERN SICILY, ITALY)

The upper Serravallian-Lower Tortonian Case Pelacani section in Sicily is represented by the epipelagic sediments of the Tellaro Formation. Along the section, which was sampled in four easily correlatable segments, a more or less continuous sequence of lithologic couplets, with whitish marls and blackish levels in the lower part and whitish marls and whitish more indurated levels in the upper part are present. The distribution of the most common taxa of planktonic foraminifera and calcareous nannofossils was quantitatively estimated in 316 samples, collected every 20 cm along the section which is 66.35 m thick. This allowed to identify eleven planktonic foraminifera (but only the eight marker events were quantitatively estimated) and five calcareous nannofossil bio-events.  Their astrochronology is reported by correlation with the cyclostratigraphic results obtained for this section in a different paper. The ages are well comparable with the ages published for the same events in other Mediterranean sections. Paleomagnetic analysis along 30 meters in the central part of the section gave puzzling results and therefore no reliable magnetostratigraphy could be obtained. The Case Pelacani section, straddling the stratigraphic interval between slightly below the first occurrence and slightly above the first regular occurrence of Neogloboquadrina acostaensis , is a good candidate for the definition of the GSSP (Global Stratigraphic Section and Point) of the Tortonian. Independently from the selected section, we suggest to define the Serravallian/Tortonian boundary in a level coincident or near the last occurrence of Paragloborotalia siakensis, as already proposed, or coincident with or near the last common occurrence of Globigerinoides subquadratus. This latter level virtually coincides with the first common occurrence of Globigerinoides obliquus obliquus and is slightly above the last common occurrence of Discoaster kugleri, which occurs only 2.25 meters (and 3 precessional cycles) below in the studied section.&nbsp

Lo stato dell’ambiente marino nell’area del Canale di Sicilia in prossimità del SIN di Gela.

Viene illustrata in questa nota l’attuale condizione in cui si trova lo stato dell’ambiente marino nell’area del Canale di Sicilia immediatamente a ridosso della costa merdionale delle Sicilia dal Golfo di Gela alla costa iblea. Lo stato dell’ambiente in oggetto viene valutato in base alla distribuzione di alcuni metalli in tracce normalmente ritenuti fra i più significativi per gli scopi prefissati, esaminati lungo la colonna d’acqua e nei sedimenti superficiali di fondale. I risultati ottenuti, illustrati anche attraverso un’indagine statistica multivariata, indicano un arricchimento superficiale della colonna d’acqua in lantanio che può essere ascritto tanto ad un’origine litogenica, quanto ad input antropico. Nei sedimenti al naturale raggruppamento fra elementi in tracce in tracce basato su analogie comportamentali di carattere geochimica sfugge il Ni che mostra di provenire da una fonte differente per la quale non si può escludere la natura antropica. Tale ipotesi di esiti di antropizzazione trova conforto nei raffronti condotti con il chimismo del particolato atmosferico desunto da dati di letteratura

AN INTEGRATED CALCAREOUS PLANKTON BIOSTRATIGRAPHIC SCHEME AND BIOCHRONOLOGY FOR THE MEDITERRANEAN MIDDLE MIOCENE

The relative position of 30 main bioevents  pertaining to calcareous nannofossils and planktonic foraminifera was identified in the time interval between 13.75 Ma and 10.50 Ma, based on the quantitative study of the those microfossils in three Mediterranean sections spanning the late Langhian – lower Tortonian stratigraphic interval. The events were correlated  to the astronomic target curve using a cyclostratigraphic approach, resulting in a very detailed biostratigraphic and biochronologic subdivision of the interval. The zonal scheme proposed by Fornaciari et al. (1996) was adopted for the calcareous nannofossils, but three subzones were identified in the MMN7 Zone. For the planktonic foraminifera reference is made to the zonal scheme recently proposed by Foresi et al. (1998), slightly modified in order to increase its biostratigraphic resolution. The age of all the zonal boundaries is reported.&nbsp

Climate fluctuations and human impact during the late Holocene in a multi-proxy marine record from the Gulf of Gaeta (Tyrrhenian Sea, central Italy)

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