Geological Investigation of Greenland: Past and Present

1961 ◽  
pp. 1185-1187
Author(s):  
K. Ellitsgaard-Rasmussen
1977 ◽  
Author(s):  
Edward W. Wolfe ◽  
N.G. Bailey ◽  
B.K. Lucchitta ◽  
W.R. Muehlberger ◽  
D.H. Scott ◽  
...  

Author(s):  
A. J. Cooper

AbstractThick and predictable deposits of fine grained Quaternary materials have been used for the siting of waste management facilities in Ontario. The search for such sites is founded on the application of techniques in Quaternary geology and hydrogeology. Two examples are presented. Oxford County is located southwest of Toronto in an area of parallel morainic ridges separated by flat till plains. Conventional wisdom would focus on the till plains for thick, consistent fine grained Quaternary Sediments. However, the careful analysis of the Quaternary stratigraphy and glacial history revealed that better sites are located along the moraines. A site on the Ingersoll Moraine was studied in detail and defended at a public hearing. Concerns about the geology of the materials were allayed by the confirmation of homogeneous clayey silt materials exposed when the site opened in late 1986. A much wider ranging search was undertaken for a major hazardous and liquid industrial waste treatment and disposal facility for the Province of Ontario. Progressively more detailed investigations of the Quaternary geology were used to assist a multi-disciplinary site selection team. Initial interpretations covered an area of 75 000 km2 at a scale of 1:250 000. Eight candidate sites were then selected for further investigation with five continuously sampled stratigraphic boreholes. The chosen site is located in a depression in the bedrock filled with 40 m of glaciolacustrine clayey silt. Site specific hydrogeological and geotechnical studies were integrated with a detailed geological investigation.


2011 ◽  
Vol 08 (02) ◽  
pp. 229-245 ◽  
Author(s):  
AIQING WU ◽  
QIGUI YANG ◽  
GUISHENG MA ◽  
BO LU ◽  
XIAOJUN LI

Wenchuan earthquake, Ms 8.0 in magnitude and occurred on May 12, 2008 in Sichuan Province, China, triggered a lot of landslides, rock collapses, debris flow, etc. The Tangjiashan landslide, with its total volume 20.37 million m3, was the biggest and the most notable one for its effects. Based on the field geological investigation and the typical acceleration records of the main shock obtained in the period of the earthquake, numerical simulation of the whole sliding process of Tangjiashan landslide has been carried out by DDA method. It is shown that the Tangjiashan landslide was a high-speed landslide, behaved with nonlinear features in the whole sliding process. The total duration of the landslide was about 30 s while nearly all of their slipping displacements were carried out in the beginning 25 s, with the maximum sliding velocity about 30 m/s, and the average 15–17 m/s in the beginning 25 s. The crash of rock blocks induced a much higher stresses near the middle and lower parts of the landslide, with the maximum value of 6–7 MPa. The dynamic earthquake load caused an incessant deformation of the landslide, resulting in the reduction of mechanical parameters, especially the shear strength on the sliding surface and the ratio of friction coefficient on sliding surface in kinematical and static conditions are no more than 0.35. DDA simulation considering the displacement-based parameter reduction has been developed in the original DDA code, and its results primarily reflect the evolvement process of a landslide under strong seismic loads.


2014 ◽  
Vol 2 ◽  
pp. 24-35
Author(s):  
Kabiraj Paudyal

A detailed geological investigation was carried out to assess the distribution of minerals and their geological control in Bandipur-Gondrang area of Tanahu district, a part of Lesser Himalaya in central Nepal. The area is found rich in both metallic and non-metallic mineral deposits. The main metallic minerals found are iron in Phalamdada and Labdi Khola, copper in Bhut Khola and poly-metallic deposits including suspected gold in Bhangeri Khola and Jaubari Khola-Bar Khola sections. A large deposit of inorganic carbon is found around the Gondrang-Watak area. Similarly, a good quality of green marble (metabasite) is found as decorative stone in Bagar Khola area and good quality of roofing stone in Bandipur area. In addition to these economic deposits other several sub economic to non-economic mineral are also located in the geological map of the area. Categorization of these mineral deposits is based on the probable reserve and laboratory analysis of related samples. Geological control of mineral deposits is considered to be the stratigraphic, structural, metamorphic and hydrothermal. Iron mineralization of the area is found stratigraphical control, copper deposits by magmatism of basic rocks (amphibolites), and poly-metallic deposits are related to the hydrothermal processes.


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