Earth features and their meaning; an introduction to geology for the student and the general reader

Hobbs, William Herbert

doi:10.5962/bhl.title.18732

Cited by 39 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The SPOT 5 sensor provides imagery with a higher resolution (5m) than the NigeriaSat-X sensor (22m) which was used to extract lineaments in areas where cloud cover made it impossible to extract lineaments. Linear features on the earth surface have been a theme of study for geologists for many years, from the early years of the last century (Hobbs, 1904(Hobbs, , 1912 (Richards, 2000). In order to map structurally significant lineaments, it is necessary to, by careful and critical analysis of the image, to differentiate between geological and man-made structures.…”

Section: Introductionmentioning

confidence: 99%

Lineament Extraction from SPOT 5 and NigeriaSat-X Imagery of the Upper Benue Trough, Nigeria

Ogunmola

Ayolabi

Olobaniyi

2014

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

View full text Add to dashboard Cite

ABSTRACT:The Upper Benue Trough is part of the Benue Trough of Nigeria and is comprised of three basins: the east-west trending Yola Basin (Yola Arm), the north-south trending Gongola Basin (Gongola Arm) and the northeast-southwest trending Lau Basin (Main Arm). This research is an ongoing research at understanding the structural framework of the Upper Benue Trough using several techniques including the use of Remote Sensing and GIS. Several digital image enhancement techniques such as general contrast stretching and edge enhancement were applied to the NigeriaSat-X and SPOT 5 image in ERDAS IMAGINE 9.2 after which structures were mapped out on-screen using ArcMap 10. The Digital Elevation Model (DEM) of the Trough was also used to enhance geomorphic features. The analysis carried out on the images revealed that lineaments are abundant in the Upper Benue Trough and they can be subdivided into four major trends, NE-SW, NW-SE, W-E and N-S in order of abundance and range in length from about 300m to 26km. Several faults were also mapped out within the Basin such as a sinistral fault around Bakoreji village in Bauchi, a dextral fault close to Kalmai town in Gombe and a dextral fault close to Wong in Taraba. It was discovered that some of the sites where minerals such as lead and zinc ores are being mined occur in the zones of high lineament density. This study shows the capability of the DEM, SPOT 5 and NigeriaSat-X images for lineament/structural interpretations.

show abstract

Section: Introductionmentioning

confidence: 99%

Lineament Extraction from SPOT 5 and NigeriaSat-X Imagery of the Upper Benue Trough, Nigeria

Ogunmola

Ayolabi

Olobaniyi

2014

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

View full text Add to dashboard Cite

show abstract

“…Those lineaments are materialized by the limits formed by the dark and clear zones lines [74][75] more or less regularized and the hydrographic network disturbances [76].Their signature in the field is very diverse, they may correspond to contacts between formations of different lithology, outcrop limits or to fractures or faults lines [77][78]. The figure 7 shows a map of lineaments extracted from the Sentinel-1A image processing of the study area.…”

Section: Fig6 Flowchart Of Adopted Methodology For Lineaments Extramentioning

confidence: 99%

Contribution of gravity data and Sentinel-1 image for structural mapping. Case of Beni Mellal Atlas and Beni Moussa plain (Morocco).

et al. 2018

View full text Add to dashboard Cite

Abstract. The present work is a combined study of gravity and Sentine-1 data for fracture mapping in the karstic massif of Beni Mellal Atlas and the adjacent plain of Beni Moussa. In order to locate the various faults that contribute to the study area structuring, the gravimetric contacts analysis method, based on the joint use of the horizontal gradient and the upward continuation at different altitudes, has been applied to the gravity data. To optimize the structural mapping in the study area, the gravimetric lineaments obtained were completed and correlated with the lineaments got from Sentinel-1 image. Four faults families of NE-SW; E-O; N-S and NW-SE directions have been highlighted. There fault families are perfectly combined with the studied area's surface water network, moreover, they corroborate with the previous geological and structural studies.

show abstract

“…Precipitation of these materials would form a surface crust, creating a hardened surface (Garner, 1974;Twidale, 1982;Watson and Pye, 1985). Under these circumstances, the water in the rock may carry salts toward the surface where they precipitate and weakening the core (Hobbs, 1919).…”

Section: Polygonal Cracking and Case Hardeningmentioning

confidence: 99%

Polygonal cracking in granite and considerations for a morphological classification (La Pedriza de Manzanares, Spain)

García–Rodríguez

Heras

Buergo

et al. 2016

Journal of Iberian Geology

View full text Add to dashboard Cite

The area known as Pedriza de Manzanares forms part of the Upper Manzanares River Basin and of the recently (June 2013) listed Sierra de Guardarrama National Park, located in the Spanish province of Madrid. The region is home to Late Palaeozoic granites characteristic of the Spanish Central Systam, which were intruded during the Variscan Orogeny and uplifted to their present position during the Alpine Orogeny.Previous studies of polygonal cracking in granite suggest several possible control mechanisms. Some authors contend that weathering patterns are governed by internal geodynamic factors, such as the final stages of magmatic consolidation or differential movements in fault planes as a result of their structural position. Others claim that climate-related external factors, specifically insolation rates and thermal differences, can explain the predominance of a given orientation in such patterns.The present paper is a study of the effect of case hardening on polygonal cracking, and the role of variables such as temperature and rock surface hardness in granite weathering. It also aims to establish a general systematic classification for polygonal cracking, focusing particularly on the cracking associated with the sub-vertical planes of fracture at Pedriza de Manzanares. The morphometric parameters associated with cracks and fractures, including strike and dip, are analysed, along with the height of occurrence and shape of polygonal cracks.Keywords: Polygonal cracking, case hardening, granite weathering, Sierra de Guardarrama National Park La Pedriza de Manzanares forma parte de la cuenca alta del río Manzanares en la provincia de Madrid, y desde junio de 2013 forma parte del Parque Nacional de la Sierra de Guadarrama. La zona está formada por granitos característicos del Sistema Central Español que intruyeron a finales del Paleozoico durante la orogenia Varisca y sufrieron un levantamiento hasta su posición actual durante la orogenia Alpina.Trabajos previos sobre agrietamientos poligonales en granitos sugieren diversos posibles mecanismos de control. Algunos autores mantienen que los patrones de meteorización están controlados por factores geodinámicos internos relacionados con estados tardíos de consolidación magmática, o por movimientos diferenciales de planos de fractura, como consecuencia de su posición estructural. Otros autores apuntan que los factores externos tales como el clima, específicamente por diferencias térmicas debido a la insolación, pueden explicar la abunadancia de estas formas de acuerdo con un patrón de la orientación del afloramiento.En este trabajo se estudia la influencia de los endurecimientos superficiales en la evolución de los agrietamientos poligonales, y se analizan variables como la temperatura y la dureza de la superficie rocosa en el proceso de meteorización del granito. Además, el trabajo trata de presentar una clasificación general de los agietamientos poligonales, incidiendo en los agrietamientos asociados a planos de fractura subverticales identificados en La Pedriza ...

show abstract

Earth features and their meaning; an introduction to geology for the student and the general reader

Cited by 39 publications

References 0 publications

Lineament Extraction from SPOT 5 and NigeriaSat-X Imagery of the Upper Benue Trough, Nigeria

Lineament Extraction from SPOT 5 and NigeriaSat-X Imagery of the Upper Benue Trough, Nigeria

Contribution of gravity data and Sentinel-1 image for structural mapping. Case of Beni Mellal Atlas and Beni Moussa plain (Morocco).

Polygonal cracking in granite and considerations for a morphological classification (La Pedriza de Manzanares, Spain)

Contact Info

Product

Resources

About