Serra Pelada is the newest Brazilian eucrite and the first recovered fall from Amazonia (State of Pará, Brazil, June 29 th 2017). In this paper, we report on its petrography, chemistry, mineralogy and its magnetic properties. Study of four thin sections reveals that the meteorite is brecciated, containing basaltic and gabbroic clasts, as well of recrystallized impact melt, embedded into a fine-medium grained matrix. Chemical analyses suggest that Serra Pelada is a monomict basaltic eucritic breccia, and that the meteorite is a normal member of the HED suite. Our results provide additional geological and compositional information on the lithological diversity of its parent body. The mineralogy of Serra Pelada consists basically of low-Ca pyroxene and high-Ca plagioclase with accessory minerals such as quartz, sulphide (troilite), chromite -ulvöspinel and ilmenite. These data are consistent with the meteorite being an eucrite, a basaltic achondrite and a member of the howardite-eucrite-diogenite (HED) clan of meteorites which most likely are from the crust asteroid 4 Vesta.Key words: Serra Pelada, meteorite, eucrite, Vesta, Brazilian Meteorite.

The scope of this work is to carry out a morphometric analysis of Pluto’s impact craters. A global Pluto digital elevation model (DEM) with a resolution of 300 m/px, created from stereoscopic pairs obtained by the New Horizons Mission, was used to extract the morphometric data of craters. Pluto’s surface was divided according to different morphometric characteristics in order to analyze possible differences in the impact dynamics and modification rate in each region. A Python code was developed, within the QGIS 3× software environment, to automate the process of crater outlining and collection of morphometric data: diameter (D), depth (d), depth variation, slope of the inner wall (Sw), diameter of the base (Db), and the width of the wall (Ww). Data have been successfully obtained for 237 impact craters on five distinct terrains over the west side of Sputnik Planitia on Pluto. With the collected data, it was possible to observe that craters near the equator (areas 3 and 4) are deeper than craters above 35°N (areas 1 and 2). Craters on the western regions (areas 2 and 3) contain the lowest depth values for a given diameter. The transition diameter from simple to complex crater morphology was found to change throughout the areas of study. Craters within areas 1 and 4 exhibit a transition diameter (Dt) of approximately 10 km, while Dt for craters within areas 3 and 5 the transitions occurs at 15 km approximately. The presence of volatile ices in the north and north-west regions may be the reason for the difference of morphometry between these two terrains of Pluto. Two hypotheses are presented to explain these differences: (1) The presence of volatile ices can affect the formation of craters by making the target surface weaker and more susceptible to major changes (e.g., mass waste and collapse of the walls) during the formation process until its final stage; (2) The high concentration of volatiles can affect the depth of the craters by atmospheric decantation, considering that these elements undergo seasonal decantation and sublimation cycles.

The Parauapebas meteorite, third official meteorite discovered in the Brazilian Amazon region, is a "hammer meteorite" which fell on December 9 th , 2013, in the city of Parauapebas, Pará State, Brazil. Mineralogy is dominated by forsterite, enstatite, iron, troilite, and tetrataenite. Albite, chromite, diopside, augite, pigeonite, taenite, and merrillite are minor components. Two main clasts are separated by black shock-induced melt veins. One clast exhibits an abundance of chondrules with well-defined margins set on a recrystallized matrix composed mostly of forsterite and enstatite, consistent with petrologic type 4 chondrites. The other clast displays chondrules with outlines blurring into the groundmass as evidence of increasing recrystallization, consistent with petrologic type 5 chondrites. The clasts of petrologic type 4 have a fine-grained texture compared to those of type 5. It is a genomict breccia (indicated by shock melt veins) with the clasts and matrix of the same compositional group, but different petrologic types, H4 and H5. The melted outer crust of the Parauapebas meteorite is comprised of forsterite with interstitial dendritic iron oxide, and is rich in irregular vesicles, which are evidence of the rapid formation of the crust. The type specimen is deposited in the Museum of Geosciences of the University of São Paulo, Brazil.

<p>Shallow landslides are geological phenomena that affect soil of small thickness originated from the weathering of the bedrock and downslope transportation. The goal of this work is to analyze the correlation between the conditioning factors and the triggering factor (rainfall) of shallow landslides in the continental area of Portugal. The understanding of the correlation between these factors can be of great help for the development of early warning systems, since it enables near real time updates of susceptibility maps relying on the rainfall forecast and the  specific physical characteristics of different regions. We used the DISASTER landslide historical database and analyzed the following conditioning factors: elevation, slope, aspect, lithology, land use, distance to rivers and faults. The historical rainfall data were obtained from the gridded NetCDF file provided by the Copernicus climate services. An automatic script was created to filter in the database the landslides that can be considered a shallow landslide and the ones that were probably triggered by rainfall events. Another automatic script was created to extract from the NetCDF file the intensity of the rainfall event that triggered the landslide. Then, we used the Boruta algorithm for feature selection. The Boruta algorithm helps to reduce the number of features in a dataset by identifying features that do not influence the study variable. In our case, the algorithm analyses which conditioning factor influences the rainfall intensity necessary to cause the respective landslide. It was found that only the lithology, slope, elevation and aspect had a significant contribution to the definition of the necessary rainfall intensity. In order to analyze how the changes in the conditioning factors affect the rain intensity necessary to cause the landslide, we grouped the events by lithology.  Two-mica granites were the lithology with the widest range of rainfall intensities that triggered landslides, reaching the lowest and higher values. This result possibly demonstrates that regions dominated by two-mica granites have higher susceptibility to landslides. Next, the Pearson correlation was used to determine whether the correlation between the relevant conditioning factors and the triggering factor were positive or negative. As a preliminary result, we found that all the Pearson correlations were low and positive, showing that the increase of value of conditioning factors result in a small increase in rain intensity necessary to cause landslides. This correlation can be probably explained by analyzing the scatter plot “rainfall intensity/slope”. The plot shows that the slopes lower than 10 degrees and higher than 20 degrees show a minimum rainfall intensity higher than the ones within slopes between 10 and 20 degrees. This could be explained by the fact that shallow slopes have low gravitational potential energy demanding high rainfall intensities to trigger a landslide and steep slopes could not have enough material accumulated to generate a landslide with low rainfall intensity. The next step will be to run a statistical model to completely correlate the conditioning factors with the respective rainfall intensities.</p>

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