scholarly journals GAMMA-RAY SPECTROMETRY FOR DISTINGUISHING ACID AND BASIC ROCKS OF THE SERRA GERAL FORMATION, IN THE SERRA GAÚCHA WINE REGION, BRAZIL

2016 ◽  
Vol 34 (4) ◽  
Author(s):  
Rudi Cesar Comiotto Modena ◽  
Rosemary Hoff ◽  
André Rodrigo Farias ◽  
Jorge Antônio Viel ◽  
Osmar Gustavo Wohl Coelho
Keyword(s):  
Volcanic Rock ◽  
Gamma Ray ◽  
Rio Grande ◽  
Gamma Ray Spectrometry ◽  
Rio Grande Do Sul ◽  
Geophysical Method ◽  
Radioactive Elements ◽  
Rock Types ◽  
Wine Region ◽  
Basic Rocks

ABSTRACT. The gamma-ray spectrometric research has allowed for observation of the distribution of radioactive elements such as K, U and Th for recognizing the radioactive signatures of different rock types. The objective of this study was to evaluate the possibility to distinguish between acid and basic rocks of the Serra Geral Formation, in the Serra Gaúcha wine region in the state of Rio Grande do Sul (Brazil) through gamma-ray spectrometry techniques. This study contributed to geologically...Keywords: geophysical method, wine terroir, volcanic rock. RESUMO. A pesquisa por gamaespectrometria tem permitido observar a distribuição de elementos radioativos, tais como K, U e Th reconhecendo as assinaturas radioativas de diferentes tipos de rocha. O objetivo deste estudo foi avaliar a possibilidade de distinguir entre as rochas ácidas e básicas da Formação Serra Geral, na região vitivinícola Serra Gaúcha, no estado do Rio Grande do Sul (Brasil) por meio de técnicas de gamaespectrometriaPalavras-chave: m´étodos geofísicos, terroir vitivinícola, rocha vulcânica.

scholarly journals Análise Estatística da Concentração de Potássio Obtida por Aerolevantamentos Geofísicos em Diferentes Formações Geológicas na Região de Santa Maria (RS)

2007 ◽  
Vol 34 (2) ◽  
pp. 99 ◽  
Author(s):  
JOÃO EDUARDO DA SILVA PEREIRA ◽  
JOSÉ LUIZ SILVÉRIO DA SILVA ◽  
ADELIR JOSÉ STRIEDER ◽  
CARLOS ALBERTO DA FONSECA PIRES
Keyword(s):  
Linear Models ◽  
Gamma Ray ◽  
Volcanic Rocks ◽  
Rio Grande ◽  
Spatial Relation ◽  
Gamma Ray Spectrometry ◽  
Rio Grande Do Sul ◽  
Thematic Map ◽  
Mean Values ◽  
Santa Maria

The present work was developed in outcrops of Santa Maria region, southern Brazil, Rio Grande do Sul State. Statistic evaluations were applied in different rock types. The possibility to distinguish different geologic units, sedimentary and volcanic (acid and basic types) by means of the statistic analyses from the use of airborne gamma-ray spectrometry integrating potash radiation emissions data with geological and geochemistry data is discussed. This Project was carried out at 1973 by Geological Survey of Brazil/Companhia de Pesquisas de Recursos Minerais. The Camaquã Project evaluated the behavior of potash concentrations generating XYZ Geosof 1997 format, one grid, thematic map and digital thematic map files from this total area. Using these data base, the integration of statistics analyses in sedimentary formations which belong to the Depressão Central do Rio Grande do Sul and/or to volcanic rocks from Planalto da Serra Geral at the border of Paraná Basin was tested. Univariate statistics model was used: the media, the standard media error, and the trust limits were estimated. The Tukey’s Test was used in order to compare mean values. The results allowed to create criteria to distinguish geological formations based on their potash content. The back-calibration technique was employed to transform K radiation to percentage. Inside this context it was possible to define characteristic values from radioactive potash emissions and their trust ranges in relation to geologic formations. The potash variable when evaluated in relation to geographic Universal Transverse Mercator coordinates system showed a spatial relation following one polynomial model of second order, with one determination coefficient. The statística 7.1 software Generalist Linear Models produced by Statistics Department of Federal University of Santa Maria/Brazil was used.

scholarly journals Determination the Index of Radioactive Risk In The Batang Kuantan River

2018 ◽  
Vol 7 (2.13) ◽  
pp. 429
Author(s):  
Rindi Genesa Hatika ◽  
Indang Dewata ◽  
Alizar . ◽  
Purwo Subekti ◽  
Saiful Anwar
Keyword(s):  
Gold Mining ◽  
Gamma Ray ◽  
Background Radiation ◽  
Raw Materials ◽  
Environmental Damage ◽  
Gamma Ray Spectrometry ◽  
Mining Activities ◽  
Radioactive Elements ◽  
Limit Value ◽  
Decay Series

NORM is a material containing radioactive elements that exist naturally. All minerals and raw materials contain radionuclides from nature, most important for radiation protection purposes are the U-238, Th-232 and K-40 decay series. This element naturally grows and is considered a major contributor to the annual individual background radiation dose. Therefore, each individual can be exposed to NORM through various activities they do, one of which is gold mining activities. Gold mining in addition to causing exposure to NORM, is believed also can cause significant environmental damage. This study aims to determine the index of radioactive risks that resulted from gold mining activities in the batang kuantan river. The sample used for this research is soil from batang kuantan river which then analyzed using gamma ray spectrometry. The results show that the index of radioactive risk value indicated by all soil samples in the batang kuantan river is still below the predetermined maximum limit value.  

scholarly journals MAGNETIC SUSCEPTIBILITY AND GAMMA-RAY SPECTROMETRY ON DRILL CORE: LITHOTYPE CHARACTERIZATION AND 3D ORE MODELING OF THE MORRO DO PADRE NIOBIUM DEPOSIT, GOIÁS, BRAZIL

2015 ◽  
Vol 33 (2) ◽  
Author(s):  
Marta Henriques Jácomo ◽  
Tereza Cristina Junqueira Brod ◽  
Augusto Cesar Bittencourt Pires ◽  
José Affonso Brod ◽  
Matheus Palmieri ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Late Cretaceous ◽  
Gamma Ray ◽  
Gamma Ray Spectrometry ◽  
Drill Core ◽  
Carbonatite Complex ◽  
Central Brazil ◽  
Rock Types ◽  
Drill Holes ◽  
Fresh Rock

ABSTRACT. The Morro do Padre niobium Deposit, in the Late-Cretaceous Catal˜ao 2 alkaline-carbonatite complex, central Brazil, consists of stockworks of nelsonite and carbonatite dykes intruded into Precambrian phyllites, quartzites, and amphibolites. A gamma-ray spectrometry and magnetic susceptibility petrophysical survey was conducted on the cores of 73 drill holes in fresh-rock, producing a total of 1295 geophysical samples. Nelsonite, the host rock of the niobium mineralization in the Morro do Padre Deposit, has a characteristic geophysical signature, with higher gamma-ray spectrometry counting rates and magnetic susceptibility values, compared to other rock types. The studied nelsonites may be divided into N1 and N2 types. N2 nelsonite is richer in K, U and Th than N1. Carbonatites are divided into magnetic (C1) and nonmagnetic (C2) varieties. The nonmagnetic carbonatites can be subdivided into C2a and C2b. The C2a carbonatite is richer in K, U and Th than C2b, which is consistent with the presence of apatite and/or monazite in the former. The geophysical 3Dmodeling has shown that the main mineralized body is elongated in the E-W direction. It is about 100 m wide and 300 m long with a maximum depth of approximately 850 m reached by drilling.Keywords: 3D ore modeling, niobium ore, applied geophysics, alkaline rocks, nelsonite. RESUMO. O depósito de nióbio do Morro do Padre no complexo carbonatítico alcalino de Catalão 2 do Cretáceo Superior, região central do Brasil, consiste em stockworks de nelsonito e diques de carbonatito intrudidos em filitos pré-cambrianos, quartzitos e anfibolitos. A pesquisa petrofísica de gamaespectrometria e de susceptibilidade magnética foi realizada em testemunhos de 73 furos de sondagem em rocha fresca, produzindo um total de 1.295 amostras. Nelsonito, a rocha hospedeira da mineralização de nióbio no depósito Morro do Padre, tem uma assinatura geofisica característica, com maiores taxas de radiação gamaespectrométrica e maiores valores de susceptibilidade magnética em comparação com outros tipos de rochas. Os nelsonitos estudados podem ser divididos em N1 e N2. O nelsonito N2 é mais rico em K, U e Th do que o N1. Carbonatitos são divididos em magnéticos (C1) e não magnéticos (C2). Os carbonatitos não magnéticos podem ser subdivididos em C2a e C2b. O carbonatito C2a é mais rico em K, U e Th do que o C2b, o que é consistente com a presença de apatita e/ou monazita na composição minerológica. O modelamento 3D revela um corpo principal de nelsonito mineralizado, alongado segundo a direção E-W. Este é cerca de 100 m de largura e 300 m de comprimento, com uma profundidade máxima de 850 m.Palavras-chave: modelamento 3D de minério, minério de nióbio, geofísica aplicada, rochas alcalinas, nelsonito.

Gamma-ray spectrometry observations to monitor a presumed meteoritic signature at Maâdna crater (Talemzane, Algeria)

2020 ◽  
Author(s):  
Atmane Lamali ◽  
Lamine Hamai ◽  
Sid Ahmed Mokhtar ◽  
Abdelkrim Yelles-chaouche ◽  
Abdeslam Abtout ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Sedimentary Rocks ◽  
Clay Content ◽  
Gamma Ray Spectrometry ◽  
Gamma Spectrometer ◽  
Geophysical Method ◽  
Impact Cratering ◽  
High Level ◽  
The Impact

<p>By measuring changes in radioelement concentrations, gamma-ray spectrometry is increasingly emerging as an efficient geophysical method that allows such changes to be geologically mapped according to lithology and soil type. At Maâdna crater in southern Algeria, this method has been used to monitor any changes in the composition of the target rocks that may be associated with the impact cratering process. For this purpose, several measurements were carried out in situ using a portable field gamma spectrometer. As a result, most predominantly calcareous surface lithologies, exposed on the rim and flanks of the crater, showed a very low emitted radiometric response over the three channels (K, Th, U). However, no more than 90 Cps were counted both inside and outside the crater. Such a rate is indeed expected in sedimentary rocks with low clay content, and this remains valid, as long as other exogenous mineralogical enrichments are excluded. On the other hand, the contoured radioelement concentrations maps, have demonstrated an anomalous enhanced gamma radiation levels of potassium-dominated peaks over the central part of the crater and in the surrounding wadis. Nevertheless, the central potassium anomaly is well correlated with the shallower magnetic one that has been described in previous studies (see e.g. Lamali et al., 2016). Therefore, either near the surrounding wadis or in the central part of this crater, this anomalously high level of radioactivity may be linked to an accumulation of later altered deposits. Consequently, there are no objective criteria to link these results to an impact event occurring at the Maâdna structure, similar to what was done at the Serra da Cangalha crater (Vasconcelos et al., 2012).</p>

scholarly journals TERÉNNÍ GAMASPEKTROMETRICKÁ CHARAKTERISTIKA PSAMITŮ GODULSKÉHO SOUVRSTVÍ: VYUŽITÍ PRO INTERPRETACI JEJICH VZNIKU

2013 ◽  
Vol 20 (1-2) ◽  
Author(s):  
Daniel Šimíček ◽  
Ondřej Bábek
Keyword(s):  
Chemical Composition ◽  
Gamma Ray ◽  
Source Area ◽  
Heavy Minerals ◽  
Western Carpathians ◽  
Gamma Ray Spectrometry ◽  
Radioactive Elements ◽  
Modal Composition ◽  
Siliciclastic Sediments

Our study was focused on low to medium radioactive sandstones of the Godula Formation of the external fl ysch zone of the Western Carpathians. It is widely known that concentrations of radioactive elements (K, U and Th ) in siliciclastic sediments are primary controlled by facies and mineral and chemical composition, which is largely influenced by their provenance. In the Godula Formation, K was found to be predominantly incorporated in some framework and accessory detritic minerals (K-feldspars, albite, mica, glauconite, illite). Main sources of U and Th were identified in heavy minerals, such as monazite and zircon. Variations of K, U and Th concentrations correspond to changes in modal composition of sandstones and indicate uplift and subsequent erosion of structurally deeper crustal parts of source area (Silesian Ridge). Significant increase of K, U and Th concentrations was observed near the boundary between the Middle and Upper Godula beds. Gamma-ray spectrometry could be used as good supplementary technique for discrimination of sandstones of these lithostratigraphical parts of the Godula Formation.

scholarly journals Integration of remote sensing and airborne geophysical data applied to geological mapping: a case study of the Vieirópolis region (Paraíba), Rio Grande do Norte Subprovince, Borborema Province

2018 ◽  
Vol 18 (3) ◽  
pp. 89-103 ◽  
Author(s):  
José Ferreira de Araújo Neto ◽  
Glenda Lira Santos ◽  
Igor Manoel Belo de Albuquerque e Souza ◽  
Sandra De Brito Barreto ◽  
Lauro Cézar Montefalco de Lira Santos ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Shear Zone ◽  
Gamma Ray ◽  
Rio Grande ◽  
Shear Zones ◽  
Geological Mapping ◽  
Gamma Ray Spectrometry ◽  
Borborema Province ◽  
Geological Map

The integration of geological data obtained through fieldwork, remote sensing and airborne geophysics has been shown to be efficient in creation of precise geological maps. The Vieirópolis region, sited in the west of the Rio Grande do Norte Subprovince of the Borborema Province, is characteristically made up of rocks intensely deformed by transcurrent shear zones and late brittle structures which control the mineralization of gemmological and industrial minerals. ASTER GDEM and airborne geophysical images (magnetometry and gamma-ray spectrometry) were used in order to enhance the geological knowledge of this region and to facilitate the identification and delimitation of structures and lithologies mapped during stages of fieldwork. Thus, a geological map on a scale of 1:50,000 was achieved, made up of six main lithological units and three new shear zones (Vieirópolis, Lastro and São Pedro), as well as the NE-SW-trending Portalegre Shear Zone. Within the newly mapped structures, the Vieirópolis Shear Zone stands out due to its expressiveness. Aeromagnetometry data suggest that this zone originated on the edge of the Brejo das Freiras Subbasin, part of the Portalegre Shear Zone System. NW-SE, ESE-WNW and E-W lineaments were correlated to lesser extent brittle structures which sometimes transversely cut the regional foliation, allowing pegmatite fluids to rise. The RGB ternary composition map (K, eTh, eU) also corroborates the presence of these structures, besides helping to determine lithological units. In this case study, the integration of direct and indirect data showed to be essential for the understanding and producing of local geological map.

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