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.

scholarly journals Characterization of Ar-Rassafeh Badyieh area (Area-2), Syria by using the airborne gamma-ray spectrometric and fractal modelling techniques

2019 ◽  
Vol 49 (4) ◽  
pp. 459-478
Author(s):  
Jamal Asfahani
Keyword(s):  
Gamma Ray ◽  
Geological Mapping ◽  
Modelling Technique ◽  
Study Region ◽  
Spectrometric Data ◽  
Modelling Techniques ◽  
Geological Map

Abstract The available aerial gamma-ray spectrometric data of Ar-Rassafeh Badyieh area (Area-2) are used herein for geological interpretations and mapping purposes. Those data are interpreted by the concentration-number (C-N) fractal modelling technique, with the use of log-log graphs. According to C-N model, different radioactive ranges of TC, eU, eTh, and K have been isolated. Those ranges are thereafter used to characterize the lithological outcrops in the study area. The radioactive signatures of all the outcrops in Area-2 have been discussed and documented through establishing the C-N maps of TC, eU, eTh, and K, and benefiting of the available geological map. The C-N fractal modelling technique proves its efficacy, where radioactive and lithological boundaries of outcrops are in concordance. The case study presented in this paper shows the importance and the role of airborne gamma-ray spectrometric and fractal modelling techniques to support the geological mapping and the interpretations in geological context, particularly when the study region is rugged and difficult to be accessed.

scholarly journals Análise multiespacial para mapeamento geológico: estudo de caso no corpo gabróico-granítico, Faixa de Dobramentos Sergipana / Multispacial analytics to geological mapping: case study at gabroic-granitic body, Sergipano Fold Belt

2018 ◽  
Vol 28 (53) ◽  
pp. 337-361
Author(s):  
Lauro Roberto De Jesus Rosa ◽  
Adriane Machado ◽  
Cristine Lenz ◽  
Luciana Oliveira dos Santos ◽  
Lucas Santana Menezes
Keyword(s):  
Remote Sensing ◽  
Satellite Images ◽  
Geological Mapping ◽  
Igneous Rocks ◽  
Landsat 8 ◽  
Fold Belt ◽  
Mixing Processes ◽  
Geological Map ◽  
Gis Software

Novos dados geológicos foram obtidos em um corpo gabróico-granítico na Faixa de Dobramentos Sergipana (Capela, SE), utilizando as técnicas de sensoriamento remoto e geoprocessamento integradas, em uma escala de semi-detalhe (1: 30.000). Esse corpo é constituído de um conjunto de rochas ígneas, compostas principalmente por gabros, ocorrendo ainda quartzo-dioritos e granodioritos. Nesse estudo, foram utilizados dados de magnetometria, de imagens de satélite Landsat 8 e dados TOPODATA, geoprocessados no software Quantum Gis. As informações obtidas, associadas a dados de trabalhos de campo, permitiram a identificação de novas litologias e estruturas, o que levou a uma melhor delimitação desse pluton no campo e a obtenção de um novo mapa geológico da região estudada. Com essas informações, foi possível concluir que o corpo estudado é resultado de vários pulsos magmáticos, associados a processos de mistura de magmas, que originaram uma grande variedade de rochas ígneas na área. Palavras-Chave: Sensoriamento Remoto, Geoprocessamento, Corpo Gabróico-Granítico.AbstractNew lithological data were obtained of a gabbroic-granitic body in Sergipano Fold Belt (Capela, SE), using remote sensing and geoprocessing as integrated techniques in a semi-detail scale (1:30,000). This body is composed of a number of igneous rocks, mainly gabbros, besides quartz-diorites and granodiorites. In this study, it was used magnetometry data, satellite images of Landsat 8 and TOPODATA data, geoprocessed in Quantum Gis software. With these data, coupled with information obtained in fieldworks, it was possible to identify new lithologies and structures, and as a consequence, to obtain a better field limits for this igneous pluton and a new geological map of the studied area. It is possible to conclude that these rocks are the result of many magmatic pulses, with several mixing processes, which originated a great variety of igneous rocks in the area.Keyword:. Remote sensing, Geoprocessing, Gabbroic-Granitic body.

scholarly journals Application of Gamma-ray Spectrometry in Discovering the Granitic Monument of King Pepi I: A Case Study from Hierakonpolis, Aswan, Egypt

2018 ◽  
Vol 176 (4) ◽  
pp. 1639-1647 ◽  
Author(s):  
Akram Aziz ◽  
Tamer Attia ◽  
Liam McNamara ◽  
Renee Friedman
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Spectrometry

scholarly journals Engineering Geological and Geotechnical Approaches for the Construction of Powerhouse Cavern of Tehri Pumped Storage Plant (1000 MW) - A Case Study

2019 ◽  
Vol 24 ◽  
pp. 35-44
Author(s):  
Rajeev Prasad ◽  
Nishith Sharma
Keyword(s):  
Underground Structure ◽  
Shear Zones ◽  
Structural Features ◽  
Geological Mapping ◽  
Left Bank ◽  
Rock Composition ◽  
Northern India ◽  
Set Up ◽  
Pumped Storage

Construction of underground Cavern in the Himalayan region is full of challenges and uncertainties. Experience has shown that construction in Himalayan regions requires good understanding of geology, adequate site investigations, proper design and selection of suitable construction methodology and technology. The most commonly encountered geological problems during excavation of underground structure in Hydroelectric Projects are, Fault/Thrust/Shear Zones squeezing and swelling, wedge block failure etc. Tehri Pumped Storage Plant (PSP) is located at the left bank of river Bhagirathi in the state of Uttarakhand in Northern India. This case study indicates about the geological challenges faced and their remedial measures during the construction of Tehri PSP Powerhouse Cavern having dimension of 203m x 24m x 58m.3D-geological mapping with 1:100 scales was carried out in excavated central drift of powerhouse to evaluate the rock composition, behavior of rock mass, structural features and further investigation to finalize the layout and orientation. During the investigation Sheared Phyllite with bands of thinly Phyllite Quartzite rock were encountered in the end portion of central drift of powerhouse which had posed a mammoth challenge in designing the powerhouse cavern. Keeping in view the recommendations of geotechnical experts and the design consultants, decision were made to shift the cavern further by 50 m to avoid Sheared Phyllite bands. The shifting of cavern led to the reorientation of structures like control room, service bay and location of units etc. This paper briefly describes the Engineering Geological and Geotechnical set up of powerhouse with proper investigation approaches and excavation sequences highlighting the importance of orientation and Sheared Phyllite Zone.

scholarly journals Integrating Landsat 7 and 8 data to improve basalt formation classification: A case study at Buon Ma Thuot region, Central Highland, Vietnam

2019 ◽  
Vol 11 (1) ◽  
pp. 901-917
Author(s):  
Ngo Van Liem ◽  
Dang Van Bao ◽  
Dang Kinh Bac ◽  
Nguyen Hieu ◽  
Do Trung Hieu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Spectral Band ◽  
Landsat 8 ◽  
Central Highland ◽  
Band Ratios ◽  
Landsat 7 ◽  
Cenozoic Basalt ◽  
Geological Map ◽  
Geological Formations

Abstract Cenozoic basalt regions contain various natural resources that can be used for socio-economic development. Different quantitative and qualitative methods have been applied to understand the geological and geomorphological characteristics of basalt formations. Nowadays the integration of remote sensing and geographic information systems (GIS) has become a powerful method to distinguish geological formations. In this paper, authors combined satellite and fieldwork data to analyze the structure and morphology of highland geological formations in order to distinguish two main volcanic eruption episodes. Based on remote sensing analysis in this study, different spectral band ratios were generated to select the best one for basalt classification. Lastly, two spectral combinations (including band ratios 4/3, 6/2, 7/4 in Landsat 8 and 3/2, 5/1, 7/3 in Landsat 7) were chosen for the Maximum Likelihood classification. The final geological map based on the integration of Landsat 7 and 8 outcomes shows precisely the boundary of the basalt formations with the accuracy up to 93.7%. This outcome contributed significantly to the correction of geological maps. In further studies, authors suggest the integration of Landsat 7 and 8 data in geological studies and natural resource and environmental management at both local and regional scales.

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