Hydrochemistry and Geology in the Brazilian Amazon Region

In the Brazilian Amazon Region the relations between chemistry of waters (groundand running waters) and the geology of their catchment areas are qtrite obvious. The archean massifs in the north and south of Amazonia produce chemically very poor and pure waters, with low pH. Still poorer and more acid are the waters in the pliocene-pleistocene "Series of the Barreiras" ancl "Formation Parâ" areas, while in the west, in the zone of the "Formation Pebas", of same geological age, also richer and less acicl waters occur. In all these geological zones, there are spots of bleached sands (podsols), covered with a special vegetation type, which produce "black" waters, while from the yellowish brown-loams (latosols), with high forest cover, clear waters come. The "black" waters contain huge amounts of colouring humus substances while their content in inorganic ions and their pH values are the lowest in all Amazonia. Quite different from the waters in the mentioned geological zones are those in the carboniferous strips, where there are limestone and gypsum layers ancl diabase outcrops, and in the'miocene "Formation Pebas" with also limestone deposits. These waters are generally richer in incirganic ions and have higher pH values. The importance of the chemistry of the Arnazonian waters for an estimation of soil fertility and for human health is mentioned

Pesquisas limnológicas na região da estrada de ferro de Bragança, Estado do Pará, Brasil.

Geografia, geologia e solos da Zona Bragantina. As águas da Zona Bragantina. Tentativa de uma delimitação da região da Formação Pirabas, baseada nos valores de pH das águas. O Rio Guamá com o Rio Capim. Observações biológicas. Resultados práticos e propostas para a agricultura

Time variations in the deep underground muon flux measured by MACRO

More than 30 million of high-energy muons collected with the MACRO detector at the underground Gran Sasso Laboratory have been used to search for flux variations of different natures. Two kinds of studies were carried out: search for periodic variations and for the occurrence of clusters of events. Different analysis methods, including Lomb-Scargle spectral analysis and Scan Test statistics have been applied to the data.Comment: 6 pages, 4 EPS figures. Talk given at the 29th ICRC, Pune, India, 3-10 August 200

Time variations in the deep underground muon flux

More than 35 million high-energy muons collected with the MACRO detector at the underground Gran Sasso Laboratory have been used to search for flux variations of different nature. Two kinds of studies were carried out: a search for the occurrence of clusters of events and a search for periodic variations. Different analysis methods, including the Scan Statistics test and the Lomb-Scargle spectral analysis have been applied to the data.Comment: 7 pages, 5 figures, accepted by EP