Naturwerksteine Thailands: Lagerstättenerkundung und Bewertung
Dimension stones in Thailand: exploration and assessment of their deposits
by Andreas Hoffmann
Date of Examination:2006-10-31
Date of issue:2007-05-02
Advisor:Prof. Dr. Siegfried Siegesmund
Referee:Prof. Dr. Siegfried Siegesmund
Referee:Prof. Dr. Bernhard Stribrny
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Description:Dissertation
Abstract
English
The last three decades were characterised by a continuous growth with respect to the demand of dimension stones. At the present time it is already obvious that the large quantities that are needed in the future cannot be quarried from the existing deposits. This implies that either new resources must be found or existing deposits must be developed. Problems concerning the availability of dimension stone moreover arise from the fact that in some deposits stones are quarried without any knowledge of the geological background and quality of the resource. Due to this lack of information, many quarry owners chose mining strategies which are inadequate with respect to the geological conditions and which harm the sound and high quality material. It becomes clear that the problems related with the production of dimension stones demand for a profound resource characterisation on the basis of geoscientific investigations and evaluations. Within the present work, dimension stones from Thailand that consist of granitoid rocks and gneisses, a hornblendite, various marbles as well as carbonate and clastic sediments underwent detailed studies and assessments concerning their depositional environment and stone properties. These assessments were conducted mainly by lithological, structural and geotechnical analyses. The lithological studies were carried out by different petrographic, texture-oriented and X-ray methods, which were used to quantify the décor, the micro fabric and the mineralogical composition of the varieties. The mineralogy and the fabric must be regarded as a basic element for the assessment of dimension stones, since both parameters significantly control the technical properties of the material under the influence of weathering. The structural investigations mainly concentrated on the deposits of the stones, here in particular the fracture spacing as well as tectonic and depositional aspects. Thereby it was possible to record, how far and to what extend the exploitation of a resource is influenced by the geological history of the mining area. Together with the documentation of block sizes and waste quantities, conclusions for the block prospectivity were derived. The characterisation of the lithologies was supported by geotechnical investigations, which cover among others the index parameters of a stone such as density and porosity as well as the mechanical and thermal properties. The results of the geotechnical characterisation were used to quantify the suitability of the stones for construction purposes, so that in furthers steps an evaluation of the economic potential of the deposit might be possible. Lithological and structural investigations together with information from the regional geology finally allowed to create models for the stone deposits, from which precise conclusions concerning the genesis and post-genetic evolution of the mining area were derived. The models enabled to receive a more detailed picture of all influencing geological factors on the quarrying and led to the development of exploitation and exploration strategies.Abstract (GER)Niedersächsische Staats- und Universitätsbibliothek Göttingen 37070 GöttingenUrheberrechtCopyright
Keywords: Dimension stones; Thailand; exploration of deposits; assessment; geotechnical properties
Schlagwörter: Naturwerksteine; Thailand; Lagerstättenerkundung; Bewertung; gesteinstechnische Eigenschaften