Spatial Prediction of Lateral Variability of a Laterite-Type Bauxite Horizon Using Ancillary Ground-Penetrating Radar Data     

Oktay Erten  Mehmet Siddik Kizil  Erkan Topal  Lachlan McAndrew 《Natural Resources Research》2013,22(3):207-227

Tropical laterite-type bauxite deposits often pose a unique challenge for resource modelling and mine planning due to the extreme lateral variability at the base of the bauxite ore unit within the regolith profile. An economically viable drilling grid is often rather sparse for traditional prediction techniques to precisely account for the lateral variability in the lower contact of a bauxite ore unit. However, ground-penetrating radar (GPR) offers an inexpensive and rapid method for delineating laterite profiles by acquiring fine-scale data from the ground. These numerous data (secondary variable) can be merged with sparsely spaced borehole data (primary variable) through various statistical and geostatistical techniques, provided that there is a linear relation between the primary and secondary variables. Four prediction techniques, including standard linear regression, simple kriging with varying local means, co-located cokriging and kriging with an external drift, were used in this study to incorporate exhaustive GPR data in predictive estimation the base of a bauxite ore unit within a lateritic bauxite deposit in Australia. Cross-validation was used to assess the performance of each technique. The most robust estimates are produced using ordinary co-located cokriging in accordance with the cross-validation analysis. Comparison of the estimates against the actual mine floor indicates that the inclusion of ancillary GPR data substantially improves the quality of the estimates representing the bauxite base surface.  相似文献   

Morpho-tectonic evolution of the ?anakkale Basin (NW Anatolia): evidence for a recent tectonic inversion from transpression to transtension     

Erkan G?ka?an  Tolga G?rüm  Hüseyin Tur  Fatmagül Batuk 《Geo-Marine Letters》2012,32(3):227-239

Onshore and offshore seismic and geologic-morphologic evidence from the wider region of the ?anakkale Basin indicates that this area has been widely exposed to transpressional tectonism, which already commenced in the Pliocene. During this transpressional tectonism, the Gelibolu Fault and the Anafartalar Shear Zone on the Gelibolu Peninsula, as well as the Bozcaada-Biga Shear Zone on the Biga Peninsula were activated. As a consequence, the northern part of the Gelibolu Peninsula, and a broad zone between Bozcaada Island and the Karaburun Peninsula were uplifted to form the northern and southern boundaries of the ?anakkale Basin, respectively. This remained a low-elevation intermontane basin between these two highlands. The original morphology of the ?anakkale Basin may have developed as a coastal and shelf section of the large extensional Marmara Sea Basin at the end of the Late Miocene. This tectonic phase was followed in the Pliocene by the transpressional tectonism of the North Anatolian Fault Zone, which destroyed the initial morphology and formed the present V-shaped basin. The activity of the Gelibolu Fault and the Anafartalar Shear Zone along the northern boundary of the ?anakkale Basin ended in the late Pleistocene with the initiation of the northern segment of the North Anatolian Fault Zone. The tectonism along the northern boundary of the ?anakkale Basin thus shifted from a transpressional to a transtensional regime. Seismic data indicate that the Bozcaada-Biga Shear Zone continues to be active to the present day.  相似文献   

Heat Flow and Geothermal Potential in the South-Central United States     

Petru T. Negraru  David D. Blackwell  Kamil Erkan 《Natural Resources Research》2008,17(4):227-243

Geothermal exploration is typically limited to high-grade hydrothermal reservoirs that are usually found in the western United States, yet large areas with subsurface temperatures above 150°C at economic drilling depths can be found east of the Rocky Mountains. The object of this paper is to present new heat flow data and to evaluate the geothermal potential of Texas and adjacent areas. The new data show that, west of the Ouachita Thrust Belt, the heat flow values are lower than east of the fault zone. Basement heat flow values for the Palo Duro and Fort Worth Basins are below 50 mW/m² while, in the frontal zone of the belt, they can exceed 60 mW/m². Further east, along the Balcones fault system the heat flow is in general higher than 55 mW/m². The eastern most heat flow sites are in Louisiana and they show very high heat flow (over 80 mW/m²), which is associated with the apparently highly radioactive basement of the Sabine uplift. The geothermal resource in this area is large and diverse, and can be divided in high grade (temperature above 150°C) convective systems, conductive based enhanced geothermal systems and geothermal/geopressured systems. One of the most attractive areas east of the cordillera extends from eastern Texas across Louisiana and Arkansas to western Mississippi. Here temperatures reach exploitation range at depths below 4 km, and tapping such a resource from shut in hydrocarbon fields is relatively easy. The initial costs of the development can be greatly reduced if existing hydrocarbon infrastructure is used, and therefore using shut-in hydrocarbon fields for geothermal purposes should not be neglected.  相似文献   

Morphologic and seismic features of the Gulf of Gökova, SW Anatolia: evidence of strike-slip faulting with compression in the Aegean extensional regime   总被引：1，自引：1，他引：0  

Yeliz İşcan  Hüseyin Tur  Erkan Gökaşan 《Geo-Marine Letters》2013,33(1):31-48

Recently acquired (2005) multi-beam bathymetric and high-resolution seismic reflection data from the E–W-oriented Gulf of Gökova off SW Anatolia were evaluated in order to assess the uneven seafloor morphology and its evolution in terms of present-day active regional tectonics. Stratigraphically, the three identified seismic units, i.e., the basement, deltaic sediments deposited during Quaternary glacial periods, and modern gulf deposits, are consistent with those observed in previous studies. Structurally, the folds and faults with strike-slip and reverse components have been regionally mapped for the first time. Of these, NE–SW-oriented left-lateral strike-slip faults with compressional components forming the so-called Gökova Fault Zone intersect and displace two WNW–ESE-oriented submarine ridges and deep submarine plains. Thus, strike-slip faults are the youngest major structures in the gulf, and control present-day active tectonism. E–W-oriented folds on the inner and outer shelf, which are generally accompanied by reverse faults, delimit the margins of these submarine ridges, and deform the young basin deposits. These features also reveal the concomitant existence of a compressional tectonic regime. The compressional structures probably represent pressure ridges along left-lateral strike-slip fault segments. However, some E–W-oriented normal faults occur on the northwestern and partly also southern shelf, and along the borders of the adjacent deep submarine plains. They are intersected and displaced by the strike-slip faults. The lower seismicity along the normal faults relative to the NE–SW-oriented strike-slip faults suggests that the former are at present inactive or at least less active.  相似文献   

Zum Einfluß einiger Gefügeparameter auf die Würfeldruckfestigkeit der Granite     

Y. Erkan 《Rock Mechanics and Rock Engineering》1971,3(2):113-120

ZusammenfassungZum Einfluß einiger Gefügeparameter auf die Würfeldruckfestigkeit der Granite Die Möglichkeit, die physikalischen Eigenschaften des Festkörpers durch einige Gefügeparameter zu erfassen, wird in der vorliegenden Arbeit erörtert.Anhand der Bestimmung der Druckfestigkeitswerte der Granitproben und der Oberflächen-und Volumendichte zwischen deren Mineralen wird gezeigt, daß die Druckfestigkeit des Gesteins mit steigender Oberflächendichte der Minerale zunimmt und daß die Volumendichte der einzelnen Minerale für die Druckfestigkeit keine Bedeutung hat.Die Ergebnisse können ferner die Bedeutung einiger metrischer und stereologischer Methoden für quantitative Erfassung von physikalischen Eigenschaften, von Gesteinsgefügen und vom modalen Mineralbestand zeigen.

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SummaryInfluence of Some Structural Parameters on the Compressive Strength of Granite The present paper discusses and illustrates the possibility of characterizing strength properties of rock by structural parameters.Tests including the determination of the compressive strength of granites and the surface and volume densities of their minerals indicated that the compressive strength increases with increasing surface density of the minerals, whereas no significant influence of the volume density of the individual minerals was found.

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RésuméL'influence de quelques paramètres structuraux sur la résistance à la compression de granite Dans cet article l'auteur montre les relations entre les propriétés physiques des corps solides et certains paramètres de texture.Par l'étude de la resistance à la compression des granites et de la densité superficielle et volumétrique des minéraux on montre que la résistance à la compression des roches croît avec l'augmentation de la densité superficielle des minéraux, alors que la densité volumétrique des minéraux individuels, à cet égard, n'est pas significative.Par conséquent ces résultats démontrent l'importance que peuvent avoir les méthodes métriques et stéréologiques pour décrire d'une manière quantitative les propriétés physiques, les propriétés de textures et d'analyse modale des roches.

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Für wertvolle Anregungen, Hinweise und Korrekturen bin ich Herrn Prof. Dr. G. C. Amstutz und Herrn Dr. H. Giger sehr dankbar.

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Mit 5 Abbildungen  相似文献   

Palynology, geochemistry, and thermal history of the shales associated with the Küre massive sulfide deposits (northern Turkey)     

Volkan . Ediger  Ayhan Erler 《Ore Geology Reviews》1990,5(5-6)

The relationship between the palynology and geochemistry of the shales associated with the Küre massive sulfide deposits in the Kastamonu Province, northern Turkey, has been studied. SEM seems to be the most effective method to study the palynology of fusinitic particulate organic matter in these thermally-altered sedimentary rocks. Major thermal maturation indicators obtained from the organic and inorganic fractions of the shales and mineral geothermometers of the orebodies suggest that the shales indicate much lower temperatures that the ore and therefore were deposited after the formation of the massive sulfide ores in the area of study.  相似文献   

A comparative assessment of indirect methods for estimating the uniaxial compressive and tensile strength of rocks     

Karaman  Kadir  Kesimal  Ayhan  Ersoy  Hakan 《Arabian Journal of Geosciences》2015,8(4):2393-2403

Arabian Journal of Geosciences - The uniaxial compressive and tensile strength of rocks are crucial parameters in the design stage of geotechnical structures. However, direct determination of these...  相似文献   

Multi-criteria optimal structural design under uncertainty     

James L. Beck  Eduardo Chan  Ayhan Irfanoglu  Costas Papadimitriou 《地震工程与结构动力学》1999,28(7):741-761

A general framework for multi-criteria optimal design is presented which is well suited for performance-based design of structural systems operating in an uncertain dynamic environment. A decision theoretic approach is used which is based on aggregation of preference functions for the multiple, possibly conflicting, design criteria. This allows the designer to trade off these criteria in a controlled manner during the optimization. Reliability-based design criteria are used to maintain user-specified levels of structural safety by properly taking into account the uncertainties in the modelling and seismic loads that a structure may experience during its lifetime. Code-based requirements are also easily incorporated into this optimal design process. The methodology is demonstrated with a simple example involving the design of a three-storey steel-frame building for which the ground motion uncertainty is characterized by a probabilistic response spectrum which is developed from available attenuation formulas and seismic hazard models. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

Real Option Identification Framework for Mine Operational Decision-Making     

Ajak  Ajak Duany  Lilford  Eric  Topal  Erkan 《Natural Resources Research》2019,28(2):409-430

Natural Resources Research - Identification of opportunities for applying real options (RO) in mining operations is a major challenge to decision-makers. In order to make optimal decisions in...  相似文献   

Evaluation of Indirect Tensile Strength of Rocks Using Different Types of Jaws     

Eren Komurlu  Ayhan Kesimal 《Rock Mechanics and Rock Engineering》2015,48(4):1723-1730

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