Fábio Ramos Dias de Andrade

Physical properties of palm fruits processed with tools by wild bearded capuchins (Cebus libidinosus).

Habitually, capuchin monkeys access encased hard foods by using their canines and premolars and/or by pounding the food on hard surfaces. Instead, the wild bearded capuchins (Cebus libidinosus) of Boa Vista (Brazil) routinely crack palm fruits with tools. We measured size, weight, structure, and peak‐force‐at‐failure of the four palm fruit species most frequently processed with tools by wild capuchin monkeys living in Boa Vista. Moreover, for each nut species we identify whether peak‐force‐at‐failure was consistently associated with greater weight/volume, endocarp thickness, and structural complexity. The goals of this study were (a) to investigate whether these palm fruits are difficult, or impossible, to access other than with tools and (b) to collect data on the physical properties of palm fruits that are comparable to those available for the nuts cracked open with tools by wild chimpanzees. Results showed that the four nut species differ in terms of peak‐force‐at‐failure and that peak‐force‐at‐failure is positively associated with greater weight (and consequently volume) and apparently with structural complexity (i.e. more kernels and thus more partitions); finally for three out of four nut species shell thickness is also positively associated with greater volume. The finding that the nuts exploited by capuchins with tools have very high resistance values support the idea that tool use is indeed mandatory to crack them open. Finally, the peak‐force‐at‐failure of the piassava nuts is similar to that reported for the very tough panda nuts cracked open by wild chimpanzees; this highlights the ecological importance of tool use for exploiting high resistance foods in this capuchin species. Am. J. Primatol. 70:884–891, 2008.

Distribution of potential suitable hammers and transport of hammer tools and nuts by wild capuchin monkeys

Selection and transport of objects to use as tools at a distant site are considered to reflect planning. Ancestral humans transported tools and tool-making materials as well as food items. Wild chimpanzees also transport selected hammer tools and nuts to anvil sites. To date, we had no other examples of selection and transport of stone tools among wild nonhuman primates. Wild bearded capuchins (Cebus libidinosus) in Boa Vista (Piauí, Brazil) routinely crack open palm nuts and other physically well-protected foods on level surfaces (anvils) using stones (hammers) as percussive tools. Here we present indirect evidence, obtained by a transect census, that stones suitable for use as hammers are rare (study 1) and behavioral evidence of hammer transport by twelve capuchins (study 2). To crack palm nuts, adults transported heavier and harder stones than to crack other less resistant food items. These findings show that wild capuchin monkeys selectively transport stones of appropriate size and hardness to use as hammers, thus exhibiting, like chimpanzees and humans, planning in tool-use activities.

Metadolomitos Talcificados do Grupo Itaiacoca, Paraná: Regime de Fluidos e Implicações Genéticas

Brazils largest talc deposits occur in the Itaiacoca Group, which is a low-grade metasedimentary belt composed mainly of dolomitic rocks. Fluid inclusions from three geological settings in which talc was formed differently were analysed. Talc schist ore occur along transcurrent shear zones. These talc schists are host to quartz veins, which indicates prolonged circulation of hydrothermal fluids at high water:rock ratios. The fluid inclusions in the quartz veins contain predominantly low-salinity (< 5 wt % NaCl equiv.) and CO2-free aqueous inclusions. The wide range of Thtot values in the primary fluid inclusions in the veins, mainly from 110 to 230oC, is related to several episodes of fluid percolation during the shear zone evolution. As a contrast, outward of the shear zones, fractured metadolomites with lower concentrations of talc contain quartz veins with CO2-rich fluid inclusions (X CO2 from 0.17 to 0.81) and Thtot ranging mainly from 250 to 300oC, which indicates restricted fluid circulation during the trapping of these inclusions, shortly after the peak of talcification, in a later brittle stage. Density-salinity relationships for these inclusions suggest supersolvus mixing in variable proportions of aqueous-carbonic fluids. In the contact aureole between the metadolomites and the Cunhaporanga granite complex, where talc was formed in minor amounts by retrometamorphism of high temperature magnesium silicates, fluid inclusions are mainly carbonic to aqueous-carbonic, suggesting restricted fluid circulation. Fluid inclusions in this setting show a wide range of measured and calculated parameters, such as salinity (0 to 20 wt % NaCl equiv.), dCO2 (0.13 to 1.0 g/cm³), dtot (0.2 to 1.0 g/cm³), and Thtot (between 130 and 574oC). Results obtained in this study did not allow precise determination of the talc-ore forming conditions, considering that the inclusions contain fluids which were trapped after the peak of talcification. Conditions similar to those of talcification are suggested by the Thtot values obtained for the inclusions in quartz-veins from fractured metadolomites, although from a later, brittle stage.

As Jazidas de Talco no Contexto da História Metamórfica dos Metadolomitos do Grupo Itaiacoca, PR

Four main types of talc occurrences have been recognized in the Proterozoic metadolomites of the Itaiacoca Group, Parana State, southern Brazil: a) talc schists along transcurrent shear zones; b) incipient talc formation along fractures and bedding planes; c) irregular pockets of fine-grained, massive talc; d) retrometamorphic talc associated with lenses of olivine, diopside, tremolite, calcite and quartz in the contact zone with the neighbouring granites. Of these, only types (a) and (c) form ore deposits. The Itaiacoca Group underwent four metamorphic episodes: 1) greenschist facies regional metamorphism during the Neoproterozoic Brasiliano orogeny; 2) thermal metamorphism along the contact with the Neoproterozoic Cunhaporanga granite batholith; 3) hydrothermalism related to transcurrent shear zones, that formed large volumes of talc schists and irregular pockets of fine-grained massive talc; 4) small-scale thermal metamorphism related to Mesozoic diabase dikes. The Itapirapua transcurrent shear zone marks the contact between the Itaiacoca Group and the Proterozoic Tres Corregos granite batholith, and the main talc deposits are aligned along its branches. Enhanced permeability due to shearing provided channels for percolation of the silica-rich aqueous solutions that reacted with the metadolomite to form the talc deposits. Minor amounts of talc occur along fractures and sedimentary layering. The massive pockets of talc (type c) that replaced the metadolomite probably formed statically at lower temperatures by the activity of hydrothermal fluids introduced through a network of microfractures.

Study of mural paintings by Fulvio Pennacchi in São Paulo City by mineralogical techniques

The present research deals with two mural paintings made in 1947 with the fresco technique by Fulvio Pennacchi in the Catholic Chapel of the Hospital das Clinicas (Sao Paulo City, Brazil), namely the Virgin Annunciation and the Supper at Emmaus. This study regards the materials and painting techniques used by the artist, based on historical research, on in situ observations and laboratory analytical techniques (stereomicroscopy, scanning electron microscopy with an energy dispersive spectrometer, X-ray diffractometry, electron microprobe, images obtained with UV-light), aiming to improve the methods of characterization of objects of our cultural heritage, and to enhance its preservation accordingly. Theresultsleadtotheidentificationoftheplastercomponentsandofdistinctlayersinthefrescoes, besides further information on grain size, impurities and textures, composition of pigments, and features of deterioration, such as efflorescences. The degree of degradation of the murals painting was assessed by this way. Our data suggest that a single layer of plaster was used by Pennacchi, as a common mortar with fine- and medium-grained aggregates. Differences in texture were obtained by adding gypsum to the plaster.