Estimation of air-overpressure produced by blasting operation through a neuro-genetic technique     

Edy?Tonnizam Mohamad  Danial?Jahed ArmaghaniEmail author  Mahdi?Hasanipanah  Bhatawdekar?Ramesh?Murlidhar  Mohd?Nur?Asmawisham?Alel 《Environmental Earth Sciences》2016,75(2):174

Blasting operations usually produce significant environmental problems which may cause severe damage to the nearby areas. Air-overpressure (AOp) is one of the most important environmental impacts of blasting operations which needs to be predicted and subsequently controlled to minimize the potential risk of damage. In order to solve AOp problem in Hulu Langat granite quarry site, Malaysia, three non-linear methods namely empirical, artificial neural network (ANN) and a hybrid model of genetic algorithm (GA)–ANN were developed in this study. To do this, 76 blasting operations were investigated and relevant blasting parameters were measured in the site. The most influential parameters on AOp namely maximum charge per delay and the distance from the blast-face were considered as model inputs or predictors. Using the five randomly selected datasets and considering the modeling procedure of each method, 15 models were constructed for all predictive techniques. Several performance indices including coefficient of determination (R ²), root mean square error and variance account for were utilized to check the performance capacity of the predictive methods. Considering these performance indices and using simple ranking method, the best models for AOp prediction were selected. It was found that the GA–ANN technique can provide higher performance capacity in predicting AOp compared to other predictive methods. This is due to the fact that the GA–ANN model can optimize the weights and biases of the network connection for training by ANN. In this study, GA–ANN is introduced as superior model for solving AOp problem in Hulu Langat site.  相似文献   

Sedimentology and Sequence Stratigraphy of Marine to Lacustrine Deltaic Deposits in a Craton Basin and Their Controlling Factors: Shan 2 Member–He 8 Member (Guadalupian–Lopingian, Permian), Southeast Ordos Basin, North China     

SHAN Xin  YU Xinghe  Peter ?CLIFT  LI Yalong  JIN Lin  SU Dongxu  DU Yonghui  ZHOU Jinsong  HAN Xiaoqin 《《地质学报》英文版》2018,92(1):268-285

  相似文献   

The Juchatengo complex: an upper-level ophiolite assemblage of late Paleozoic age in Oaxaca,southern Mexico     

Grajales-Nishimura  José Manuel  Ramos-Arias  Mario Alfredo  Solari  Luigi  Murillo-Muñetón  Gustavo  Centeno-García  Elena  Schaaf  Peter  Torres-Vargas  Ricardo 《International Journal of Earth Sciences》2018,107(3):1005-1031

International Journal of Earth Sciences - The Juchatengo complex (JC) suite is located between the Proterozoic Oaxacan complex to the north and the Xolapa complex to the south, and was amalgamated...  相似文献   

Precursory slope distress prior to the 2010 Mount Meager landslide,British Columbia   总被引：1，自引：1，他引：0  

Gioachino Roberti  Brent Ward  Benjamin van Wyk de Vries  Pierre Friele  Luigi Perotti  John J. Clague  Marco Giardino 《Landslides》2018,15(4):637-647

In 2010, the south flank of Mount Meager failed catastrophically, generating the largest (53 ± 3.8 × 10⁶ m³) landslide in Canadian history. We document the slow deformation of the edifice prior to failure using archival historic aerial photographs spanning the period 1948–2006. All photos were processed using Structure from Motion (SfM) photogrammetry. We used the SfM products to produce pre-and post-failure geomorphic maps that document changes in the volcanic edifice and Capricorn Glacier at its base. The photographic dataset shows that the Capricorn Glacier re-advanced from a retracted position in the 1980s then rapidly retreated in the lead-up to the 2010 failure. The dataset also documents 60 years of progressive development of faults, toe bulging, and precursory failures in 1998 and 2009. The 2010 collapse was conditioned by glacial retreat and triggered by hot summer weather that caused ice and snow to melt. Meltwater increased pore water pressures in colluvium and fractured rocks at the base of the slope, causing those materials to mobilize, which in turn triggered several secondary failures structurally controlled by lithology and faults. The landslide retrogressed from the base of the slope to near the peak of Mount Meager involving basement rock and the overlying volcanic sequence. Elsewhere on the flanks of Mount Meager, large fractures have developed in recently deglaciated areas, conditioning these slopes for future collapse. Potential failures in these areas have larger volumes than the 2010 landslide. Anticipated atmospheric warming over the next several decades will cause further loss of snow and glacier ice, likely producing additional slope instability. Satellite- and ground-based monitoring of these slopes can provide advanced warning of future landslides to help reduce risk in populated regions downstream.  相似文献   

Effects of tilling methods on soil penetration resistance,organic carbon and water stable aggregates in a vineyard of semiarid Mediterranean environment   总被引：3，自引：0，他引：3  

Pietro Catania  Luigi Badalucco  Vito Armando Laudicina  Mariangela Vallone 《Environmental Earth Sciences》2018,77(9):348

Tillage, especially in semiarid Mediterranean environment, enhances the mineralization process of soil organic matter (SOM) and, in turn, decreases aggregate stability. Furthermore, continuous tillage leads to the formation of plough pan beneath the tilled layer. In the present study, we investigated the effect of an innovative self-propelled machine (spading machine, SM) for shallow tillage on SOM, water stable aggregates (WSA) and soil penetration resistance (PR). Such effects were compared to those of chisel plough (CP), rotary tiller (RT) and no tillage (NT). Each tilling method was applied up to a depth of 15 cm, whereas in NT only a brush cutter was used for weed control. Soil analyses were performed at the start of the experiment (March 2009, T0), in April 2010 (T1), May 2012 (T3), and June 2014 (T5) at both 0–15 and 15–30 cm. Compared to T0, soil PR increased with time in all the treatments and generally followed the order SM?<?RT?<?CP?<?NT. In soil tilled with the SM, soil PR never exceeded 2.5 MPa that was demonstrated to be a critical value for root elongation, and no evidence of the formation of plough pan beneath the tilled layer was observed. SOC as well as water content and WSA were higher in SM compared with CP and RT. In conclusion, the spading machine was proved to be more efficient in lowering the soil PR and in avoiding the formation of the plough pan. Furthermore, SM increased SOC and WSA.  相似文献   

Formation by silicate–fluoride + phosphate melt immiscibility of REE-rich globular segregations within aplite dikes     

Charles?R.?SternEmail author  Julien?M.?Allaz  Markus?B.?Raschke  G.?Lang?Farmer  M.?Alexandra?Skewes  Jeremy?T.?Ross 《Contributions to Mineralogy and Petrology》2018,173(8):65

Aplite dikes intruding the Proterozoic 1.42(±?3) Ga Longs Peak-St. Vrain Silver Plume-type peraluminous granite near Jamestown, Colorado, contain F, P, and rare earth element (REE)-rich globular segregations, with 40–46% REE, 3.7–4.8 wt% P₂O₅, and 5–8 wt% F. A combination of textural features and geochemical data suggest that the aplite and REE-rich globular segregations co-existed as two co-genetic liquids prior to their crystallization, and we propose that they are formed by silicate–fluoride?+?phosphate (+?S?+?CO₂) melt immiscibility following ascent, cooling, and decompression of what was initially a single homogeneous magma that intruded the granite. The REE distribution coefficients between the silica-rich aplites and REE-rich segregations are in good agreement with experimentally determined distribution coefficients for immiscible silicate–fluoride?+?phosphate melts. Although monazite-(Ce) and uraninite U–Th–Pb microprobe ages for the segregations yield 1.420(±?25) and 1.442(±?8) Ga, respectively, thus suggesting a co-genetic relationship with their host granite, ε_Nd1.42Ga values for the granites and related granitic pegmatites range from ??3.3 to ??4.7 (average ??3.9), and differ from the values for both the aplites and REE-rich segregations, which range from ??1.0 to ??2.2 (average ??1.6). Furthermore, the granites and pegmatites have (La/Yb)_N <50 with significant negative Eu anomalies, which contrast with higher (La/Yb)_N >100 and absence of an Eu anomaly in both the aplites and segregations. These data are consistent with the aplite dikes and the REE-rich segregations they contain being co-genetic, but derived from a source different from that of the granite. The higher ε_Nd1.42Ga values for the aplites and REE-rich segregations suggest that the magma from which they separated had a more mafic and deeper, dryer and hotter source in the lower crust or upper mantle compared to the quartzo-feldspathic upper crustal source proposed for the Longs Peak-St. Vrain granite.  相似文献   

Carbon and nitrogen isotope,and mineral inclusion studies on the diamonds from the Pozanti–Karsanti chromitite,Turkey     

Dongyang?LianEmail authorView author&#;s OrcID profile  Jingsui?Yang  Michael?Wiedenbeck  Yildirim?Dilek  Alexander?Rocholl  Weiwei?Wu 《Contributions to Mineralogy and Petrology》2018,173(9):72

The Pozanti–Karsanti ophiolite (PKO) is one of the largest oceanic remnants in the Tauride belt, Turkey. Micro-diamonds were recovered from the podiform chromitites, and these diamonds were investigated based on morphology, color, cathodoluminescence, nitrogen content, carbon and nitrogen isotopes, internal structure and inclusions. The diamonds recovered from the PKO are mainly mixed-habit diamonds with sectors of different brightness under the cathodoluminescence images. The total δ¹³C range of the PKO diamonds varies between ??18.8 and ??28.4‰, with a principle δ¹³C mode at ??25‰. Nitrogen contents of the diamonds range from 7 to 541 ppm with a mean value of 171 ppm, and the δ¹⁵N values range from ??19.1 to 16.6‰, with a δ¹⁵N mode of ??9‰. Stacking faults and partial dislocations are commonly observed in the Transmission Electron Microscopy foils whereas inclusions are rather rare. Combinations of (Ca_0.81Mn_0.19)SiO₃, NiMnCo-alloy and nano-sized, quenched fluid phases were observed as inclusions in the PKO diamonds. We believe that the ¹³C-depleted carbon signature of the PKO diamonds derived from previously subducted crustal matter. These diamonds may have crystallized from C-saturated fluids in the asthenospheric mantle at depth below 250 km which were subsequently carried rapidly upward by asthenospheric melts.  相似文献   

Experimental study of quartz inclusions in garnet at pressures up to 3.0 GPa: evaluating validity of the quartz-in-garnet inclusion elastic thermobarometer     

Jay?B.?ThomasEmail authorView author&#;s OrcID profile  Frank?S.?Spear 《Contributions to Mineralogy and Petrology》2018,173(5):42

Garnet crystals with quartz inclusions were hydrothermally crystallized from oxide starting materials in piston–cylinder apparatuses at pressures from 0.5 to 3 GPa and temperatures ranging from 700 to 800 °C to study how entrapment conditions affect remnant pressures of quartz inclusions used for quartz-in-garnet (QuiG) elastic thermobarometry. Systematic changes of the 128, 206 and 464 cm^?1 Raman band frequencies of quartz were used to determine pressures of quartz inclusions in garnet using Raman spectroscopy calibrations that describe the P–T dependencies of Raman band shifts for quartz under hydrostatic pressure. Within analytical uncertainties, inclusion pressures calculated for each of the three Raman band frequencies are equivalent, which suggests that non-hydrostatic stress effects caused by elastic anisotropy in quartz are smaller than measurement errors. The experimental quartz inclusions have pressures ranging from ??0.351 to 1.247 GPa that span the range of values observed for quartz inclusions in garnets from natural rocks. Quartz inclusion pressures were used to model P–T conditions at which the inclusions could have been trapped. The accuracy of QuiG thermobarometry was evaluated by considering the differences between pressures measured during experiments and pressures calculated using published equation of state parameters for quartz and garnet. Our experimental results demonstrate that Raman measurements performed at room temperature can be used without corrections to estimate garnet crystallization pressures. Calculated entrapment pressures for quartz inclusions in garnet are less than ~?10% different from pressures measured during the experiments. Because the method is simple to apply with reasonable accuracy, we expect widespread usage of QuiG thermobarometry to estimate crystallization conditions for garnet-bearing silicic rocks.  相似文献   

Electrical conductivity of the plagioclase–NaCl–water system and its implication for the high conductivity anomalies in the mid-lower crust of Tibet Plateau     

Ping?Li  Xinzhuan?GuoEmail author  Sibo?Chen  Chao?Wang  Junlong?Yang  Xingfan?Zhou 《Contributions to Mineralogy and Petrology》2018,173(2):16

In order to investigate the origin of the high conductivity anomalies geophysically observed in the mid-lower crust of Tibet Plateau, the electrical conductivity of plagioclase–NaCl–water system was measured at 1.2 GPa and 400–900 K. The relationship between electrical conductivity and temperature follows the Arrhenius law. The bulk conductivity increases with the fluid fraction and salinity, but is almost independent of temperature (activation enthalpy less than 0.1 eV). The conductivity of plagioclase–NaCl–water system is much lower than that of albite–NaCl–water system with similar fluid fraction and salinity, indicating a strong effect of the major mineral phase on the bulk conductivity of the brine-bearing system. The high conductivity anomalies of 10^?1 and 10⁰ S/m observed in the mid-lower crust of Tibet Plateau can be explained by the aqueous fluid with a volume fraction of 1 and 9%, respectively, if the fluid salinity is 25%. The anomaly value of 10^?1 S/m can be explained by the aqueous fluid with a volume fraction of 6% if the salinity is 10%. In case of Southern Tibet where the heat flow is high, the model of a thin layer of brine-bearing aqueous fluid with a high salinity overlying a thick layer of partial melt is most likely to prevail.  相似文献   

An experimental study of Fe–Ni exchange between sulfide melt and olivine at upper mantle conditions: implications for mantle sulfide compositions and phase equilibria     

Zhou?ZhangEmail authorView author&#;s OrcID profile  Anette?von der Handt  Marc?M.?Hirschmann 《Contributions to Mineralogy and Petrology》2018,173(3):19

The behavior of nickel in the Earth’s mantle is controlled by sulfide melt–olivine reaction. Prior to this study, experiments were carried out at low pressures with narrow range of Ni/Fe in sulfide melt. As the mantle becomes more reduced with depth, experiments at comparable conditions provide an assessment of the effect of pressure at low-oxygen fugacity conditions. In this study, we constrain the Fe–Ni composition of molten sulfide in the Earth’s upper mantle via sulfide melt–olivine reaction experiments at 2 GPa, 1200 and 1400 °C, with sulfide melt \(X_{{{\text{Ni}}}}^{{{\text{Sulfide}}}}=\frac{{{\text{Ni}}}}{{{\text{Ni}}+{\text{Fe}}}}\) (atomic ratio) ranging from 0 to 0.94. To verify the approach to equilibrium and to explore the effect of \({f_{{{\text{O}}_{\text{2}}}}}\) on Fe–Ni exchange between phases, four different suites of experiments were conducted, varying in their experimental geometry and initial composition. Effects of Ni secondary fluorescence on olivine analyses were corrected using the PENELOPE algorithm (Baró et al., Nucl Instrum Methods Phys Res B 100:31–46, 1995), “zero time” experiments, and measurements before and after dissolution of surrounding sulfides. Oxygen fugacities in the experiments, estimated from the measured O contents of sulfide melts and from the compositions of coexisting olivines, were 3.0?±?1.0 log units more reduced than the fayalite–magnetite-quartz (FMQ) buffer (suite 1, 2 and 3), and FMQ ??1 or more oxidized (suite 4). For the reduced (suites 1–3) experiments, Fe–Ni distribution coefficients \(K_{{\text{D}}}^{{}}=\frac{{(X_{{{\text{Ni}}}}^{{{\text{sulfide}}}}/X_{{{\text{Fe}}}}^{{{\text{sulfide}}}})}}{{(X_{{{\text{Ni}}}}^{{{\text{olivine}}}}/X_{{{\text{Fe}}}}^{{{\text{olivine}}}})}}\) are small, averaging 10.0?±?5.7, with little variation as a function of total Ni content. More oxidized experiments (suite 4) give larger values of K_D (21.1–25.2). Compared to previous determinations at 100 kPa, values of K_D from this study are chiefly lower, in large part owing to the more reduced conditions of the experiments. The observed difference does not seem attributable to differences in temperature and pressure between experimental studies. It may be related in part to the effects of metal/sulfur ratio in sulfide melt. Application of these results to the composition of molten sulfide in peridotite indicates that compositions are intermediate in composition (\(X_{{{\text{Ni}}}}^{{{\text{sulfide}}}}\)?~?0.4–0.6) in the shallow mantle at 50 km, becomes more Ni rich with depth as the O content of the melt diminishes, reaching a maximum (0.6–0.7) at depths near 80–120 km, and then becomes more Fe rich in the deeper mantle where conditions are more reduced, approaching (\(X_{{{\text{Ni}}}}^{{{\text{sulfide}}}}\)?~?0.28)?>?140 km depth. Because Ni-rich sulfide in the shallow upper mantle melts at lower temperature than more Fe-rich compositions, mantle sulfide is likely molten in much of the deep continental lithosphere, including regions of diamond formation.  相似文献