The volcano-plutonic rocks of the Siner area of the Malani Igneous Suite (MIS) are characterized by high content of radioactive elements (U, Th, K) and are classified as high heat producing felsic volcano-plutonic rocks of A-type grani- toid. Microgranite shows highly comparable heat production (26.07 HP) and total heat generation value (62.06 HGU in average) as compared to other granite (HP = 12.73; HGU = 26.57), rhyolite (HP = 4.98; HGU = 11.85) and trachyte (HP = 5.00; HGU = 11.91). The volcano-plutonic rocks of the present show higher average value of total HGU than the average value of 3.8 HGU for the continental crust, which suggests a possible linear relationship among the crustal heat generation of the MIS.
Abstract. Recent developments in the application of micro- energy-dispersive X-ray fluorescence spectrometry mapping (µ-EDXRF) have opened up new opportunities for fast geo- scientific analyses. Acquiring spatially resolved spectral and chemical information non-destructively for large samples of up to 20 cm length provides valuable information for geosci- entific interpretation. Using supervised classification of the spectral information, mineral distribution maps can be ob- tained. In this work, thin sections of plutonic rocks are ana- lyzed by µ-EDXRF and classified using the supervised clas- sification algorithm spectral angle mapper (SAM). Based on the mineral distribution maps, it is possible to obtain quanti- tative mineral information, i.e., to calculate the modal min- eralogy, search and locate minerals of interest, and perform image analysis. The results are compared to automated min- eralogy obtained from the mineral liberation analyzer (MLA) of a scanning electron microscope (SEM) and show good ac- cordance, revealing variation resulting mostly from the limit of spatial resolution of the µ-EDXRF instrument. Taking into account the little time needed for sample preparation and measurement, this method seems suitable for fast sample overviews with valuable chemical, mineralogical and textural information. Additionally, it enables the researcher to make better and more targeted decisions for subsequent analyses.
The XIV iron-oxide prospect in the northern part of the Bafq mining district is hosted by intrusive rocks and demonstrates similar characteristics with Kiruna mi- neralization. The plutonic complex of the XIV prospect is composed of two major types of intrusive rocks, including: 1) a granitic intrusive body which is itself com- posed of two types; a pale-pink leucogranite and a white-gray aplite, as well as 2) a gabbrodiorite intrusive body. Geochemically, these rocks are tholeitic-calcalkaline and metaluminous in nature. Geochemical characteristics of the plutonic rocks of the study area support a non-orogenic continental setting.
The alteration assemblages associated with the iron ore deposits are evidence of an im- portant metasomatic component in the ore-forming process, where the alteration mi- neralogy is controlled by the bulk chemistry of rock, the composition of the mineraliz- ing fluids, and P-T conditions of formation. However, alteration at the XIV iron pros- pect shows a general transition from sodic alteration (albite-rich) at deeper levels espe- cially in the plutonic rocks or their adjacent volcanics, to potassic alteration (potassium feldspar + sericite) at intermediate levels (in the plutonic), to sericitic and silicic altera- tion (sericite + quartz) in the uppermost portion of the system. Actinolite (sodic-calcic
The Askaoun Pluton with N-S trend occurs as an elon- gated body exposed in the Ouzellarh-Sirwa promontory, Anti-Atlas, Morocco (Figure 1). This pluton is intrusive within the volcano-detritic rocks of Saghro Group, and is crosscut by important mafic dyke swarm mostly NE-SW oriented. The main rock types of the pluton are quartz diorite and granodiorite. These plutonic rocks comprise abundant microgranular mafic enclaves (MMEs). These MMEs were studied in detail by , ( in reviews) who recorded monzodioritic, quartz dioritic and dioritic com- position.
Coal is one of the important minerals in the family of hard rock which can be burned as solid fossil fuel. The coal has many advantages in worldwide. The most vital uses of coal are in electricity generation, steel production, cement manufacturing industry and as a liquid fuel. Thus, the proper and efficient extraction of coal is becoming very necessary. The knowledge of compressive strength of coal helps in efficient extraction of coal. In this paper a laboratory investigation on the compressive strength of field collected coal was carried out. The compressive strength of coal is a most difficult property to examine by experimental means. The maximum compressive strength of 0.24 MPa and minimum of 0.12 MPa was recorded for the number of blows of 25 and 5 in the Protodyaknov Strength Index test. REFERENCES
Published By not completely understood. Because of the great risk to workers safety and the extensive damage to equipment, rock bursts are indeed considered by many as the biggest unresolved problem in deep underground excavations. Rock bursts are defined as ‘‘a sudden displacement of rock that occurs in the boundary of an excavation, and cause substantial damage to the excavation (Brady and Brown, 2006)’’. A rock burst is the most dangerous event that can occur during excavation works. Surrounding rock is extruded into an underground open space by a severe force during a rock burst. This event may cause an accident or even the death of mining workers, and it may destroy the excavation space. For this reason, studies of this problem are very important theoretically and for practical applications. Rock burst is a mining induced seismic event which causes destruction of rock excavations (Jiang et al.,2016). Rock burst in coal mine is a dynamic phenomenon with sudden severe damage, throw-out of large quantity of rock or coal body, and loud sound in the surrounding rock of roadway or working face, which is induced by instantaneous release of elastic deformed energy of the surrounding rock and occurs during the mining process. It usually leads to severe supporting device damage and large deformation in the roadway and working face, casualties and coal mine collapse in the worse situation, and even ground collapse that induces local earthquake. It is one of major hazards in coal mine (Tsirel’ et al.,2001; azka,2004). The phenomenon of sudden and violent failure of rock mass in and around mine openings releasing a tremendous amount of energy is termed as rock burst (Adhikari, 2001). Rock burst a catastrophic phenomenon in underground engineering, are characterized by sudden, explosion or ejection of cracked rocks. In underground coal mines this phenomenon is also known as coal burst and causes destruction of supporting equipment in mining stope; distortion and destruction of stope and drifts; casualties among the mine personnel; and even collapse of ground surface accompanied by local seismicity. Although the definition of rock burst differs from author to another, the common ground of these definitions is the instantaneous/sudden release of energy in the form of violent explosion of rock, due to seismic event.
The development of a country is directly related to the energy production. Un- fortunately, Pakistan is facing worst energy crisis at present time. The basic and cheapest source of power production is hydropower in Pakistan due to the presence of natural topography which creates natural hydraulic heads along streams especially in hilly areas. Rock bursting is a common and serious form of disasters that can happen in deep underground excavations. The underground excavation passes through variable rock cover, this variation can induce instabil- ities like spalling, raveling, squeezing and rock bursting. In weak strata squeezing of rocks can take place and rock bursting can occur in un-jointed massive strata where rock mass strength is less than induced stresses . The estimation of rock squeezing, bursting and deformation modulus of rock mass before excava- tion is one of the most important parameters of the rock mass to mitigate the chances of rock bursting in the excavation i . e . tunnel by applying safest and economical support with both empirical and numerical approaches. In China, during the construction phase of Jinping-II Hydropower project, hundreds of rock bursts occurred which caused damage to the structure, causalities and se- rious economic loss . In the Sunjiawan Coal mine in 2005, a rock burst caused 215 dead and 30 people injured. Many deep tunnels in China, Canada, Switzer- land, and Peru have experienced rock bursting of various degrees. Therefore, the assessment of rock bursting at pre-feasibility and feasibility stage is highly ne- cessary to minimize the casualties. Zhang et al .  described the intense rock- bursts in tunnels of Jingping II hydropower station by surveying the geological conditions and failure of the affected sections. Gong et al .  discussed the problems encountered due to in situ stresses etc. during TBM tunneling and suggested measures to overcome the problems. Kaya et al . [5
Rock blasting is the most commonly used method for rock breakage in mining. Controling the blast fragmentation after blasting is always an important subject for the mining industry. Blasting has a significant impact on downstream processes of mining such as the mucking productivity through the rock diggability, the excavator efficiency, the oversize problems and secondary blasting, the crusher throughput and the energy consumption, the plant efficiency, yield, and recovery. Moreover, many investigations has indicated that blasting influences the overall cost of a mining operation. Blasting has been proven to be the most energy-efficient stage in the comminution process. Optimizing the fragmentation by blasting can achieve an energy efficiency between 15% and 30%, in contrast to grinding in which the efficiency is approximately 2%. Over the past decades, the optimization of the whole mining system has been taken into account from drilling to grinding or even the subsequent steps. The so called “mine to mill optimization” concept defines the system and its subsystems, determines the objective(s) of the system, searches the different solutions and alternatives to reach the objective(s), and finally, evaluates and chooses the best existing alternative. Therefore, prediction of rock fragmentation in open-pit mines is one of the important keys in the mine to mill optimization [1, 2, 3, 4, 5, 6, 7, 8, 9]. Several studies have been conducted on blastability and prediction of fragmentation. The parameters that determine fragmentation by blasting is divided into four groups: (a) Blast design parameters; (b) explosive parameters; (c) rock mass structure parameters; and (d) intact rock and discontinuity physical and
Values of the SL index over the study area, determined from digital elevation models and geographic information system (GIS), are shown on Fig. 3. In order to discriminate values at the index related to rock resistance, different levels of average rock strength were defined (by rock type and field observation) from very low strength (silt, sand and marl), low strength (older alluvial fan deposits and fairly well-consolidated conglomerate), moderate strength (fillite and schist), high strength (calcareous sandstone, travertine, and conglomerate), and very high strength (marble). Based upon the quantitative SL indices linked to relative rock resistance described above with field observations suggest that: 1- Along the southern part of the Maroon River, values of the SL index show a variable distribution. The highest and perhaps most anomalous values of the index are along the Maroon River on its pass from Khayiz anticline. These high indices are not associated with particularly resistant rocks, so is interpreted to be a tectonic signal. Several locations along the western flank of the Khayiz anticline also have anomalously high SL index values on relatively soft rocks.
This work shows the Kédougou-Kéniéba inlier (eastern Senegal) pillow lavas behavior from laboratory to field. Some uniaxial tests are carried out on five types of specimens of pillow lavas. These types of speci- mens are: microscopically healthy rock, fractured rock without filling, fractured rock filled with epidote, chlorite and calcite and rocks with tension crack filled with quartz. The Young moduli and the uniaxial com- pression strength are good for the healthy rock. The Young moduli fall slightly for facies with horizontal cracks while uniaxial compression strength (R c ) varies slightly. For filled fractured specimens, R c and Young
These four aspects relate to the second line of reasoning for the three-highest occupant ternary approach, the relationship of eudialyte group chemistry to host rock. Although the eudialyte group minerals collect several elements in varying quantities in M(3), the fact that nearly 70% of the analyses plot on two related ternary diagrams (Si-Nb-Ta & Si-Nb-Zr) is indicative of the overarching chemical theme, that the crystal chemistry of eudialyte group minerals is fundamentally governed by the bulk chemistry of their host system, the mineralogy of which, in this study, is heavily influenced by niobium and zirconium. To further reinforce the point, using a Si-Nb-Zr ternary collects 51% of the analyses from the East Hill Suite.
Rock abrasion plays a significant role in geotechnical design, tunneling opera- tions and the safety of foundations from scour. It is imperative to determine such properties of uniaxial compression strength (UCS), rock quality designa- tion (RQD) and hardness for rock engineering to help determine the amount of scour at foundation locations in order to prevent structural collapse, wear on drilling tools and help predict unstable rock conditions. Current practice for estimating maximum rock abrasion is based on the Los Angeles abrasion test; however, more research is needed to provide a more accurate and com- patible method for all subsurface materials used in mining and civil engineer- ing projects. This report will provide simple correlations relating abrasion re- sistance to RQD, UCS, Geological Strength Index (GSI) and Rock Mass Rating (RMR) and shear strength of metamorphic rock (Quartzite). Methods, results, recommendations and conclusions are presented. The paper also introduces recommendations for future rock abrasion techniques and discusses the use of these correlations exhibiting strong relationships between the mentioned rock properties.