Kinds Of Rocks Research Articles

The Elastic Wave Velocities of the Granitoids from Eastern Junggar of Xinjiang at High Temperature and High Pressure and Their Geological Constraints on the Crustal Structure

AbstractThe compressional (VP) and shear wave velocities (VS) of typical granitoids (alkali‐feldspar granite, alkaline granite, granodiorite, monzogranite and quartz diorite) from Kalamaili granite belt and Yemaquan body in Eastern Junggar, Xinjiang were experimentally measured at pressures up to 1.0 GPa (room temperature) and temperatures up to 700°C (1.0 GPa) by ultrasonic reflection‐transmission method. The results show that both VP and VS of the granitoids present a linear velocity increase with the pressure at room temperature from 0.4∼1.0 GPa, which is interpreted in terms of closure of the microcracks in rocks under this pressure range. The VP and VS of the granitoids are 5.79∼6.84 km·s−1 and 3.26∼3.85 km·s−1 respectively at room temperature and 1.0 GPa. On the basis of the linear relationship between pressure with VP and VS, we derived the pressure derivatives of VP and VS as 0.1568∼0.4078 km/(s·GPa) and 0.0722∼0.3271 km/(s·GPa) respectively, and the reference velocities VP0 and VS0 are 5.62∼6.47 km·s−1 and 3.15∼3.75 km·s−1 respectively. At 1.0 GPa, VP and VS of the granitoids show a linear decrease with temperature from room temperature to 700°C, and temperature derivatives of velocities are (−3.41∼−4.96) × 10−4 km/(s · °C) and (−0.88∼−3.22) × 10−4 km/(s · °C), respectively. Taking advantage of derivatives of velocities and reference velocities of the granitoids obtained from our experiments, and combining regional geothermal resources of East Junggar area, VP and VS‐depth profiles were calculated. From the comparison of velocity‐depth profiles with geophysical exploring results, we infer that the VP and VS of the alkali‐feldspar granite, alkaline granite, monzogranite and part of granodiorite in Eastern Junggar of Xinjiang are coherent well with the velocity of the upper crust, and the average Poisson's ratio of several rocks are also consistent with the Poisson's ratio of the upper crust. Therefore, we suggest that these kinds of rocks are important parts of the upper crust in this region. In addition, the VP and VS of the quartz diorite are both in accord with the middle crust, suggesting that it may be one kind of rocks in the middle crust of this region.

Impact compressive and bending behaviour of rocks accompanied by electromagnetic phenomena.

It is well known that electromagnetic phenomena are often observed preceding earthquakes. However, the mechanism by which these electromagnetic waves are generated during the fracture and deformation of rocks has not been fully identified. Therefore, in order to examine the relationship between the electromagnetic phenomena and the mechanical properties of rocks, uniaxial compression and three-point bending tests for two kinds of rocks with different quartz content, granite and gabbro, have been carried out at quasi-static and dynamic rates. Especially, in the bending tests, pre-cracked specimens of granite were also tested. Using a split Hopkinson pressure bar and a ferrite-core antenna in close proximity to the specimens, both the stress-strain (load-displacement) curve and simultaneous electromagnetic wave magnitude were measured. It was found that the dynamic compressive and bending strengths and the stress increase slope of both rocks were higher than those observed in static tests; therefore, there is a strain-rate dependence in their strength and stress increase rate. It was found from the tests using the pre-cracked bending specimens that the intensity of electromagnetic waves measured during crack extension increased almost proportionally to the increase of the maximum stress intensity factor of specimens. This tendency was observed in both the dynamic and quasi-static three-point bending tests for granite.

Kinematical analysis of highway tunnel collapse using nonlinear failure criterion

For different kinds of rocks, the collapse range of tunnel was studied in the previously published literature. However, some tunnels were buried in soils, and test data showed that the strength envelopes of the soils followed power-law failure criterion. In this work, deep buried highway tunnel with large section was taken as objective, and the basic expressions of collapse shape and region were deduced for the highway tunnels in soils, based on kinematical approach and power-law failure criterion. In order to see the effectiveness of the proposed expressions, the solutions presented in this work agree well with previous results if the nonlinear failure criterion is reduced to a linear Mohr-Coulomb failure criterion. The present results are compared with practical projects and tunnel design code. The numerical results show that the height and width of tunnel collapse are greatly affected by the nonlinear criterion for the tunnel in soil.

Non-linear Behavior of Normal Contact Stiffness of Tunnel Surface and Supporting System of Tunnel Boring Machines

The interfacial contact stiffness between the supporting system of tunnel boring machines(TBM) and the tunnel surfaces is closely related to the mechanical behavior of rocks and the morphology of tunnel surfaces. The mathematical model based on the fractal theory is employed to study the relation between the roughness and fractal parameters of three dimensional tunnel surfaces. The coarse surfaces are established by using the projecting method according to the characteristics of tunnel surfaces. Many parameters such as the roughness of the tunnel surfaces, the mechanical behavior of rocks, the number of the supporting boots and composite geologic structures are taken into consideration to obtain the correlation between the normal contact stiffness and the loads. The results show that the increases of the fractal dimension, the elastic modulus, the normal loads and the number of support boots cause the increase of the interfacial contact stiffness. The contact stiffness of the double supporting systems is twice of that of the single one subjected to the same load. The normal stiffness is minimal when the ratios of the soft and hard rocks in the composite geologic structures are approximately identical. The increasing of the ratio of soft rocks in the contacting area causes the increase of the contact stiffness. However, the variation of the contact stiffness is not obvious when the proportions of two kinds of rocks on the contacting area are changed.

Physical, mechanical and petrographic properties of Lesser Himalayan rocks from Kavre area: An assessment of quality for concrete aggregate

With rapidly growing population, development of human civilization and increasing construction of infrastructures, the demand of aggregate is increasing day by day. The quarries of naturally occurring sand and gravel are not sufficient to fulfill the demand, and are disturbing the river environments. Therefore, the crushed-rock aggregates should be used to meet the requirements. The accessible resources, quality and quantity for aggregates play an important role in the durability of roads, buildings, projects, many other infrastructures and sustainable development. Negligence of quality of aggregates would lead to rapid degradation of concrete structures. Therefore, being aware of these things, quality of aggregates should be prioritized. The exploration of outcrops from which suitable aggregates can be exploited is essential. This study aims to explore and evaluate the resources and quality of crushed-rock aggregates from the Lesser Himalayan rocks in the Kavre area.
 Different kinds of rocks were identified from the outcrop in the study area: quartzite, psammitic schist, calc­quartzite, metasandstone and metasiltstone. Thirteen representative samples were taken from different lithological formations. The water absorption value (WAY) of samples ranges from 0.302 to 2.393%. Dry density varies from2.308 to 2.743gm/cm3 and the uniaxial compressive strength value ranges from 23.62 to 217.92 MPa. In general, these values indicate that the aggregates are compact and strong. The aggregate crushing value (ACY) ranges from 19.56 to 35.4% and the aggregate impact value (AIV) ranges from 11.02 to 23.84%showing that the aggregates are resistant against compressive load and strong against impact load. The sodium sulphate soundness value (SSSV) lies between 5.95 to 16.66% and methylene blue absorption values (MBAV) in all samples are <1% indicating that the samples are durable and chemically sound. The alkali silica reactive features, swelling and expanding clay minerals like chert, opal, high-quartz, extremely deformed fractured quartz, smectite, and kaolinite are absent. Though some quartz grains are undulosed and fractured, they are mega and low-quartz. Only the clay mineral illite, IM type is present in very small proportion. All these parameters show that the samples of the Lesser Himalayan rocks from the Kavre area are suitable and acceptable for concrete aggregates of general.

Fragments of the Western Alpine Chain as Historic Ornamental Stones in Turin (Italy): Enhancement of Urban Geological Heritage through Geotourism

In Piemonte, stone has always been the most widely used raw material for buildings, characterizing the architectural identity of the city of Turin. All kinds of rocks, metamorphic, igneous, and sedimentary, are represented, including gneisses, marbles, granitoids, and, less commonly, limestones. The great variety of ornamental stones is clearly due to the highly composite geological nature of the Piemonte region related to the presence of the orogenic Alpine chain and the sedimentary Tertiary Piemonte Basin. This paper provides a representative list of the most historic ornamental stones of Piemonte, which have been used over the centuries in buildings and architecture. The main stones occurring in Turin have been identified and described from a petrographic and mineralogical point of view in order to find out the corresponding geological units and quarry sites, from which they were exploited. This allows the associated cultural and scientific interest of stones to be emphasized in the architecture of a town which lies between a mountain chain and a hilly region.

Study of the effect of moisture content and bending rate on the fracture toughness of rocks

Generally, rock material failure is controlled by cracks under specific conditions. The study of rock fracture toughness belongs to the current frequent directions of research in the area of rock failure. The present paper describes the effects of parameters influencing the resultant properties of rock materials (bending rate, rock moisture) during fracture toughness measurement of different kinds of rocks (sandstone, marble, granite). The highest fracture toughness values were found in the marble samples. This is probably due to the inner structure of analysed marble, which is composed of only one mineral (calcite) and also has a lower porosity than the used granite. The lowest fracture toughness values were found in the sandstone sample, and reached c. 17–30 % of the measured fracture toughness values of the analysed granite and marble samples. As in the case of the other mechanical properties of rocks (e.g. uniaxial compressive strength) also in the case of higher sandstone (carboniferous) moisture the fracture toughness values decrease and its deformation ability increases. Preparation of samples for fracture toughness tests and performance of these tests are more complicated than in the case of tensile tests (e.g. the Brazilian test) and therefore this contribution presents a comparison between fracture toughness of analysed rocks and tensile strength values. The measured data in this study considering the fracture toughness tests and Brazilian tests were compared with results published by Zhang (2002).

Some Aspects of Economic Geographic Views at the Geological Makeup: The Case Northeastern Montenegro

This paper discusses some aspects of the economic and geographic look at the geological structure of northeastern Montenegro. The geological structure of part all three groups of rocks metamorphic, igneous and sedimentary. When viewing certain kinds of rock and emphasized their economic importance. The considered area has excellent possibilities for development of mining, particularly as Berane basin contains significant reserves of brown coal and lignite (176.231.197 tons). Since metallic materials have be discovered bearing the following metals: lead, zinc, copper, iron and pyrite. A deposit of non-metallic building materials: gravel, sand and decorative stone. Northeastern Montenegro has exceptional opportunities for the development of industry, whose focus should be about n Berane coal production in the basin, which would cause intense regrouping and integration of industrial enterprises, which would undoubtedly affect the entire economic life of the considered geographic space.

The discovery adakitic rock along the Phan Si Pan zone in northwestern Vietnam and Cu-Au-Mo mineralization

Recent work shows that there is a close relationship between adakite and Cu-Cu-Mo epithermal deposit and porphyry copper deposits. We discovered that adakiticss exist in the northwest of VN. Previous studies indicated that its belonged to A type or I type granite. The laser-plasma mass spectrometry (LA-ICP-MS) was used for the zircon U-Pb dating of adakitic in Phan Si Pan zone and the isotope age was obtained to be 38-35 Ma, indicating an Eocene related to the stage of the India-Asia collision. This kind of rocks is represented by granite, and similar in chemical composition to the adakitics rock. In this study we introduce the basic rock types adakitics as well as discuss the existence of this type of research. The discovery may provide a theoretical basis for the prospecting and exploration of the above-mentioned mineral resources in the Phan Si Pan zone in northwestern Vietnam.

Mineralogical and chemical composition of petrologic end members of Alberta oil sands

The Alberta oil sands ores are a combination of four petrologically different kinds of rocks, called “end members”, deposited in marine and estuarine sedimentary environments. The combination of the different end members affects the properties of the oil sands. Applying organic solvents for bitumen extraction from the oil sands is an alternative to the current commercial hot water extraction process. Certain minerals (mainly clay minerals) in the oil sands may affect processability of the ore during non-aqueous extraction.The aim of the present study was to perform mineral and chemical characterization of the four end members in order to better understand the mineralogical and geochemical factors affecting bitumen extraction and subsequent solvent recovery from the extraction tailings.The as-received end members and their different size fractions were examined using XRD, QXRD, FTIR, ICP-MS and C, H, N and S content analysis. The results revealed variable amounts of toluene insoluble organic carbon in the samples after bitumen removal. The amount was higher in the finer size fractions, indicating its association mainly with the clay minerals. Bitumen removal was the most effective in the coarse grained quartz-rich samples containing a minimal amount of the clay minerals. The four end members consisted of quartz, clay minerals (kaolinite, illite, mixed layer illite–smectite and chlorite), carbonates (calcite, dolomite and siderite), K-feldspar, TiO2 minerals (anatase and rutile) and pyrite. The highest relative amount of mixed layer illite–smectite was found in the finest fractions (<0.2μm). The expandability (SXRD) of illite–smectite was 10±2%. The quantitative mineralogical analysis correlated well with chemical composition analysis of the petrologic end members of the oil sands.

Thermal ecology of two sympatric saxicolous lizards of the genus Phymaturus from the Payunia region (Argentina)

We evaluated the thermal biology of two sympatric saxicolous species of the genus Phymaturus, endemic from the Argentine Payunia region. Taking into account that the distributional range of Phymaturus roigorum (the largest species) is greater than the range of P. payuniae, we evaluated the habitat (type of rocks) used by these species. We recorded body temperature and operative temperatures in different habitats, and we determined the preferred body temperature in the laboratory. We compared the thermal quality of habitats occupied and not occupied by Phymaturus payuniae, and the accuracy and effectiveness of thermoregulation between species.P. roigorum was found on many different kinds of rocks, but P. payuniae was found mainly on two types or rocks and not found on dark basalts. No differences were found in habitat thermal quality or in preferred temperatures when comparing among populations or between species. Although both species are thermoregulators, P. payuniae demonstrated better accuracy and effectiveness. This is the first study to assess thermal biology in coexisting species of the genus Phymaturus and provides the first data on effectiveness of thermoregulation for the genus. The results obtained have importance from a conservation perspective, since both endemic species are vulnerable and no data on habitat or thermal requirements were available up till now.

Research on the Rock Breaking by Double Disc Cutter Test-Bed

Rock tunnel boring machine is one of the main machineries and equipments for underground engineering, and the failure of tool systems is its main failure form. Rock hob test-bed is the only testing equipment for tool failure and wear. In this paper, the breaking rock by the double disc cutter is simulated and four kinds of rocks are selected to test the influece of rock characteristics and spacing between two disc cutters on the rock breaking by the double disc cutter test-bed. The results show that there is different optimal spacing between two disc cutters for different rock; the optimal spacing is inversely proportional to the hardness of the rocks; the maximum stress appears the boundary between the disc cutter and rock.

Permeability Evolution Laws and Equations during the Course of Deformation and Failure of Brittle Rock

AbstractPermeability tests on limestone and sandstone during the course of deformation and failure are carried out with a servocontrolled testing machine. The permeability evolution of the two kinds of rocks with axial, lateral, and volumetric strains are investigated. The test results show that the permeability has an obvious correlation with the strain. The permeability mechanisms during the course of deformation and failure are discussed. According to the feature variations of permeability and strain of rock specimens, a conceptual model for the permeability evolution with the strain is proposed. The test results of sandstone are used to validate this model, and the relevant permeability-strain equation in the process of deformation and failure is fitted by using the mathematical method. The fitting precision is good. The proposed equation may provide another important control equation for the stress-seepage coupling analysis.

Experimental study of infrasonic signal generation during rock fracture under uniaxial compression

The low frequency infrasonic signals generated during micro fracture process of six types of rocks (including granite, mudstone, sandstone, phyllite, limestone and red sandstone) under uniaxial compression were detected. A specialized data collection system was developed for infrasonic signals sensing and analog-to-digital conversion. The wavelet-based de-noising method, Short-Time Fourier Transform (STFT) time-frequency analysis and accumulative ring-down count (ARC) of events were used to process and analyze digital infrasonic signals in order to investigate the characteristics of infrasonic emission (IE) event during rock micro fracture process. The experimental results indicate obvious infrasonic emission events before rock failure. The characteristic frequency typically ranges from about 2.0 to 8.0Hz for the six kinds of rocks and it has no necessary relationship with structure or lithology. According to the ARC estimate, hard rocks (such as granite, limestone) can generate much more infrasonic emission events than soft ones (mudstone, phyllite), in other words, the brittle fracture is more prone to generate infrasonic signals. In addition, infrasound is an inaudible and low-attenuate signal that cannot be absorbed easily by water or air, and can propagate avoiding huge obstacles due to its long wavelength. The research results and the advantages of the infrasound will provide a beneficial supplement for our further studies on rock instability or rocky landslide in field combined with other advanced methods.

Potential Indonesia Ores as Raw Material for Producing Iron Nugget

Indonesia due its archipelago has so many kinds of rocks which contain ores. With the finding in technology iron source is not iron ore alone like it use to be in the past. This research is conducted to see availability of mineral rocks in Indonesia as iron source. Four different kinds of mineral rocks are used. They are: limonite, saprolite, malachite, and chalcopyrite. Separation of limonite is done by magnetic separation process while saprolite, malachite, and chalcopyrite are done by washing separation methods. Analysis on Fe content is done at origin and roasting condition for all rocks. The results show that other mineral rocks can become iron source, separation will enhance Fe content, and lateritic nickel rocks especially limonite can be new other iron source.

Hydrocarbon Behavior at Nanoscale Interfaces

Throughout Earth’s crust and upper mantle, fluids play the dominant role in transporting and concentrating Earth’s energy and mineral resources (Liebscher and Heinrich 2007). Furthermore, the flux of fluids, which act as both reaction media and reactants, strongly influences the genesis and evolution of many different kinds of rocks. Among many different types of fluids, those containing volatile carbon, hydrogen and oxygen (C-H-O) species tend to dominate in the lithosphere along with various electrolytes and silica. These fluids commonly contain methane as both a major constituent and an important energy source. Conventional natural gas deposits reside in sedimentary basins where fluid overpressure often results in brittle failure of the confining rocks. Industry exploration and exploitation of shale gas (e.g., the Marcellus, Utica, and Barnett formations) has refocused attention on understanding the fundamental behavior of volatile hydrocarbon—rock interactions. Recent observations of hydrocarbons emanating from non-sedimentary systems (abiogenic), such as mid-ocean ridge hydrothermal systems or occurring within some crystalline rock-dominated Precambrian shield environments have challenged the view that organic rich sediments provide the only significant source of crustal hydrocarbons (Potter and Konnerup-Madsen 2003; Sleep et al. 2004; Sherwood Lollar et al. 2006; McCollom 2013; Sephton and Hazen 2013). Geopressured-geothermal regimes contain C-H-O fluids with vast energy potential in the form of methane and hot water at high pressure. Even fluid inclusions from both metamorphic and igneous terrains record the presence of methane-bearing fluids reflecting reduced redox state conditions of formation. The consequences of coupled reactive-transport processes common to most geological environments depend on the properties and reactivity of these crustal fluids over broad ranges of temperature, pressure and fluid composition. The relative strengths of complex molecular-scale interactions in geologic fluids, and the changes in those interactions with temperature, pressure, and fluid composition, are the fundamental basis for observed …

The Geochemistry Research on Eocene Volcanic Rocks in Sanshui Basin

Guangdong Sanshui Basin evoluted with extreme volcanic activities. Eruptions between Paleocene to Eocene were concentrated on Xinzhuang, Buxin, Baoyue and Huayong formations. For realized the relationship between various kind of rocks, Geochemistry analysis such as multi-element and rare-earth element determination were launched on Basalt, Trachyte and Rhyolite samples from the research area. Geochemistry diagram suggest that: REE distribution of Basalt followed as mid-plate alkali Basalt mode, while their trace element spider diagrams act as continental alkali Basalt with Nb, Ti rich and Sr loss. REE distribution of Trachyte and Rhyolite are similar, which indicate the same crystalization separation process. S-B diagram and Pearce diagram show that: Granite were partial melted from source region, while Trachyte in ZMY and Rhyolite in LBS originated from the same source region, and occur with the process of crystallization separation with plagioclase adventage.

SCB試験による水蒸気圧下での種類の異なる岩石の破壊靭性の評価

SCB試験による水蒸気圧下での種類の異なる岩石の破壊靭性の評価

Experimental Study on Engineering Geological Properties of Sandstone

Based on field survey sampling and indoor test of four big quarry rock in Wulumuqi, rock's engineering geological properties is system analyzed. Investigation and test results show that there is mainly sedimentary sandstone in the area, the composition of the substance is mainly debris, feldspar and quartz.Debris content of 60% or more, feldspar and quartz content of about 30%, cementing material is mainly made up of argillaceous and carbonate class whose ratio is about 10%. The compressive strength is higher in the natural state, the general in between 30 MPa-90MPa. In different moisture content state the compression strength are very different.Compared saturated state to dry state, the compressive strength reduced by about 40%. Tensile strength, flexural strength, shear strength and elastic modulus increase with increase of compressive strength. The same kind of rock in the same moisture content which tensile strength is only the 1/15-1/25 of the compressive strength, the flexural strength is the 1/4-1/7 of the compressive strength. Sandstone frost resistance is better, after 25 times the freeze-thaw cycle test, its strength is lower slightly and quality is not damaged.

Tidal triggering of earthquakes in Longmen Shan region: the relation to the fold belt and basin structures

We found a distinctive pattern of tidal triggering of earthquakes related to the fold belt and basin structures. We studied the correlation between tidal variations and seismic events in the Longmen Shan region. We divided this region into two subregions: one is located in the Songpan-Garze Fold Belt which has a soft and weakened crust; the other is located in the Sichuan Basin which has a relatively rigid and strong crust. The results of Schuster’s test show that there is a higher correlation in the subregion of the Songpan-Garze Fold Belt than in the subregion of the Sichuan Basin. The reason for this distinctive triggering pattern is that the rock failure mechanism is related to the mechanical properties of the rocks: under conditions of high stress, different kinds of rocks have a different nonlinear behavior of rock deformation and fracture patterns. The nonlinear behavior of rock deformation, which is the prerequisite for a critical stress state in which the tidal stress could trigger an earthquake, increases as the rigidity and the strength of rocks decrease. Therefore, this triggering pattern is closely related to the properties of the crustal rocks of the Songpan-Garze Fold Belt and the Sichuan Basin.