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Statistical analyses, a Piper diagram, the saturation index and the correlations of chemical parameters were used to reveal the hydrogeochemistry and hydrogeochemical evolution of shallow groundwater in the southern part of the Zhongwei section of the Yellow River alluvial plain. The water quality for agricultural and domestic uses was also assessed in the study. The results suggest that the shallow groundwater in the study area is fresh to moderately mineralized water. Higher Ca2+ and HCO3- are observed in the less mineralized water, whereas Na+ and SO42- are common ions in the highly mineralized water. The major hydrochemical facies for groundwater with total dissolved solids (TDS) <1 g/L are HCO3-Ca·Mg and HCO3-Ca·Na·Mg, and for groundwater with TDS > 1 g/L, SO4·Cl-Na and SO4·Cl-Na·Mg·Ca are the predominant hydrochemical types. The main reactions in the groundwater system are the dissolution/precipitation of gypsum, fluorite, halite, calcite and dolomite. Cation exchange is also important in controlling the groundwater chemistry. The water samples assessed in the paper are of acceptable quality for agricultural use, but most of them are not fit for direct human consumption (drinking). TDS, total hardness (TH), Cl- and SO42- are the main indices that result in the poor drinking water quality. [ABSTRACT FROM AUTHOR]

This paper evaluates the forecasting performance of two nonlinear models, k-nearest neighbor (kNN) and feed-forward neural networks (FFNN), using stream flow data of the Kızılırmak River, the longest river in Turkey. For the kNN model, the required parameters are delay time, number of nearest neighbors and embedding dimension. The optimal delay time was obtained with the mutual information function; the number of nearest neighbors was obtained with the optimization process that minimizes RMSE as a function of the neighbor number and the embedding dimension was obtained with the correlation dimension method. The correlation dimension of the Kızılırmak River was d = 2.702, which was used in forming the input structure of the FFNN. The nearest integer above the correlation dimension (i.e., 3) provided the minimal number of required variables to characterize the system, and the maximum number of required variables was obtained with the nearest integer above the value 21d +1 (Takens, 1981) (i.e., 7). Two FFNN models were developed that incorporate 3 and 7 lagged discharge values and the predicted performance compared to that of the kNN model. The results showed that the kNN model was superior to the FFNN model in stream flow forecasting. However, as a result from the kNN model structure, the model failed in the prediction of peak values. Additionally, it was found that the correlation dimension (if it existed) could successfully be used in time series where the determination of the input structure is difficult because of high inter-dependency, as in stream flow time series. [ABSTRACT FROM AUTHOR]

Seismologists working on the reflection of seismic data have been dealing with noise and trying to attenuate noise as much as possible without damaging a particular signal. Many methods have been used to remove noise types, each being partially effective. None of the transforms have been ideal and, even at the point of transform, noise becomes added to data. The double density dual tree (DDDT) discrete wavelet transform (DWT) method was used in this paper to attenuate noise in pre-stack and post-stack seismic data. Wavelet domain ground roll analysis (WDGA) was used for finding ground roll energy in the wavelet domain; it is a substitute method for thresholding in seismic data processing. The DDDTDWT method has four wavelets and two scaling functions. Using this method, shot gather data decomposes to sub-scales and each scale contains coefficients related to a particular signal. The procedure involved applying distinct wavelets and scaling functions to data and then eliminating the coefficient of noise from inverse DDDTDWT using the WDGA technique. The inverse transform provided a section without noise; double density DWT and dual tree DWT methods were combined (i.e. each method having its own characteristics and advantages). [ABSTRACT FROM AUTHOR]

Liquefaction is a phenomenon in which soils, typically sands, suddenly loose a substantial amount of their shear strength and stiffness, this often triggered by large-magnitude earthquakes. Most liquefaction research has focused on silicate-based sands and not on other sand types, such as calcareous biogenous sands. Calcareous sands are usually composed of skeletal or non-skeletal remains of marine organisms, with unique characteristics in terms of their mineralogy surface roughness, particle shape, crushability, and intraparticle porosity. The unique characteristics of calcareous sands suggest that their geotechnical engineering behaviour can be substantially different compared to that of terrigenous sands, including their behaviour under seismic loading, which have not been very well studied. This paper presents the results of an experimental programme aimed at studying the cyclic liquefaction resistance of uncemented calcareous biogenous sands retrieved from south-western Puerto Rico. Evaluation of liquefaction potential involved a comprehensive set of isotropically consolidated undrained cyclic triaxial tests on reconstituted samples of this calcareous sand. The programme also included tests on Ottawa terrigenous silica sand samples prepared and tested in similar conditions for comparison purposes. In general, the experimental results showed that Cabo Rojo calcareous sands had higher liquefaction resistance compared to Ottawa silica sands tested under similar conditions. Important differences between calcareous and silica sands regarding pore pressure generation characteristics and axial strain accumulation were also observed. [ABSTRACT FROM AUTHOR]

This paper describes the results of engineering geological investigations and rock mechanics studies carried out at the proposed Chamshir dam site. It is proposed that a 155 m high solid concrete gravity-arc dam be built across the Zuhreh River to the southeast of the city of Gachsaran in south-western Iran. The dam and its associated structures are mainly located on the Mishan formation. Analysis consisted of rock mass classification and a kinematic analysis of the dam foundation's rock masses. The studies were carried out in the field and the laboratory. The field studies included geological mapping, intensive discontinuity surveying, core drilling and sampling for laboratory testing. Rock mass classifications were made in line with RMR and DMR classification for the dam foundation. Dam foundation analysis regarding stability using DMR classification and kinematic analysis indicated that the left abutment's rock foundation (area 2) was unstable for planar, wedge and toppling failure modes. [ABSTRACT FROM AUTHOR]

This paper presents the results obtained from using electron paramagnetic resonance (EPR) to analyse tooth enamel found at the Aguazuque archaeological site (Cundinamarca, Colombia), located on the savannah near Bogota at 4° 37' North and 74°17' West. It was presumed that the tooth enamel came from a collective burial consisting of 23 people, involving men, women and children. The tooth enamel was irradiated with gamma rays and the resulting free radicals were measured using an electron spin resonance (ESR) X-band spectrometer to obtain a signal intensity compared to absorbed doses curve. Fitting this curve allowed the mean archaeological dose accumulated in the enamel during the period that it was buried to be estimated, giving a 2.10 ± 0.14 Gy value. ROSY software was used for estimating age, giving a mean 3,256 ± 190y before present (BP) age. These results highlight EPR's potential when using the quaternary ancient ruins dating technique in Colombia and its use with other kinds of samples like stalagmites, calcite, mollusc shells and reefs. [ABSTRACT FROM AUTHOR]

El Niño Southern Oscillation (ENSO) has been linked to climate and hydrologic anomalies throughout the world. This paper presents how ENSO modulates the basic statistical characteristics of streamflow time series that is assumed to be affected by ENSO. For this we first considered hypothetical series that can be obtained from the original series at each station by assuming non-occurrence of El Niño events in the past. Instead those data belonging to El Niño years were simulated by the Radial Based Artificial Neural Network (RBANN) method. Then we compared these data to the original series to see a significant difference with respect to their basic statistical characteristics (i.e., variance, mean and autocorrelation parameters). Various statistical hypothesis testing methods were used for four different scenarios. Consequently if there exist a significant difference, then it can be inferred that the ENSO events modulate the major statistical characteristics of streamflow series concerned. The results of this research were in good agreement with those of the previous studies. [ABSTRACT FROM AUTHOR]

Fine-grained and mainly reddish color, compact and slightly breccious and vesicular pyrometamorphic rocks (natural clinker) are associated to the spontaneous combustion of coal seams of the Cerrejón Formation exploited by Carbones del Cerrejón Limited in La Guajira Peninsula (Caribbean Region of Colombia). These rocks constitute remaining inorganic materials derived from claystones, mudstones and sandstones originally associated with the coal and are essentially a complex mixture of various amorphous and crystalline inorganic constituents. In this paper, a petrographic characterization of natural clinker, as well as the application of the X-ray diffraction (Rietveld method) by mean of quantitative analysis of its mineral phases were carried out. The RIQAS program was used for the refinement of X ray powder diffraction profiles, analyzing the importance of using the correct isostructural models for each of the existing phases, which were obtained from the Inorganic Crystal Structure Database (ICSD). The results obtained in this investigation show that the Rietveld method can be used as a powerful tool in the quantitative analysis of phases in polycrystalline samples, which has been a traditional problem in geology. [ABSTRACT FROM AUTHOR]

The seismic analyses integrated to interpretation techniques, processing, velocity model and geophysical data have permitted modeling different tectonic, stratigraphy or geomorphology features. This paper is the first approach to geomorphological features for a three dimensional depth model. The initial model comprises a seismic section grid with bidimensional configuration conversed to three dimensional subvolumes. These include a two and half dimensional model. Also, an attribute analyses in image section is necessary to determine the most relevant characteristics. The geomorphologic feature corresponds to the named Rio Grande Cone, which is characterized by principal tectonic and stratigraphic structures. That is why mapping and subsurface three dimensional modeling, with geology, geophysical and geomorphologic integration is necessary. The cone geomorphology is characterized by gravitational processes, bottom currents, tectonic structures and lithological compositions which are the principal factors that have been influencing it since Neogene. Then, the seismic interpretation could extract different tectonic, sedimentary structures and geoforms, for instance, faults, folds, channels, natural levee, contourites, etc. [ABSTRACT FROM AUTHOR]

Metamorphic pressure and temperature trajectories are generally used as tools to interpret the tectonic history of deformed belts of rocks that record past activity along active plate margins. The pre-Devonian metamorphic sequence of the Silgará Formation forms part of the ancient basement of the central Santander Massif, including pelitic schists, siliceous schists and intercalation of amphibolites accompanied by marble. This metasedimentary unit has been affected by Barrovian type metamorphism under middle-pressure/high-temperature conditions. This paper presents on the relationship of tectonic processes to pressure-temperature paths development. Detailed petrologic analysis of pelites and related rocks has been used to constrain the P-T history of this region in the eastern colombian cordillera. Mineral assemblages and Geothermobarometric calculations indicate metamorphic temperatures and pressures of 400-600 °C and 4.0-6.5 kbar, respectively. [ABSTRACT FROM AUTHOR]

Cluster analysis of gauged streamflow records into homogeneous and robust regions is an important tool for the characterization of hydrologic systems. In this paper we applied the hierarchical cluster analysis to the task of objectively classifying streamflow data into regions encompassing similar streamflow patterns over Turkey. The performance of three standardization techniques was also tested, and standardizing by range was found better than standardizing with zero mean and unit variance. Clustering was carried out using Ward's minimum variance method which became prominent in managing water resources with squared Euclidean dissimilarity measures on 80 streamflow stations. The stations have natural flow regimes where no intensive river regulation had occurred. A general conclusion drawn is that the zones having similar streamflow pattern were not be overlapped well with the conventional climate zones of Turkey; however, they are coherent with the climate zones of Turkey recently redefined by the cluster analysis to total precipitation data as well as homogenous streamflow zones of Turkey determined by the rotated principal component analysis. The regional streamflow information in this study can significantly improve the accuracy of flow predictions in ungauged watersheds. [ABSTRACT FROM AUTHOR]

Metacarbonate rocks (pure and impure marbles, carbonate-silicate rocks, calc-silicate rocks and carbonate-bearing silicate rocks) form a very complex group within the metamorphic sequence of the Silgará Formation at the central Santander Massif(CSM). These rocks are interpreted as derived from a sedimentary sequence (including limestones and dolostones, carbonate-bearing mudstones, sandstones, tuffaceous and evaporitic sediments and marlstones) overprinted by near-isochemical regional metamorphism. They usually appear as scarce intercalations from millimeter up to meter scale, within the high-grade pelitic rocks, in the lower part of the metamorphic section, although the proportion of metacarbonate rocks can be higher and different marble layers are exploited. We report for the first time the occurrence of a "reaction calcic exoskarn", which corresponds to such metacarbonate rocks, taking into account that a skarn can be developed during regional metamorphism and by different metasomatic processes, adjacent to intrusive bodies, along faults and shear zones, and what defines these rocks as a skarn is its mineralogy, which includes a variety of calc-silicate and associated minerals, usually dominated by garnet and pyroxene. Therefore, this paper focus attention to the occurrence of metacarbonate and related rocks, which occurs as small scale reactions zones that show a gradational contact from garnet-bearing pelitic rocks to marbles or carbonate-silicate rocks, giving particular interest to the calc-silicate rocks, which are characterized by the presence of elongated grains of banded clinopyroxene (diopside) and scapolite and massive or scattered garnet. Several reaction-zones occur in the contact between impure calcite marble and garnet-bearing metapelite and the sequence of mineral assemblages in these reaction zones is: biotite + plagioclase ± K-feldspar ± garnet (Zone I), biotite + plagioclase ± K-feldspar ± garnet ± staurolite ± epidote (Zone II), plagioclase + amphibole ± garnet + epidote (Zone III), amphibole + diopside + garnet + plagioclase (Zone IV), plagioclase + diopside ± scapolite (Zone V). epidote ± calcite (Zone VI), and calcite ± dolomite (Zone VII). [ABSTRACT FROM AUTHOR]

Wavelet transforms originated in geophysics in the early 1980s for the analysis of seismic signals. Since then, significant mathematical advances in wavelet theory have enabled a suite of applicalions in diverse fields. In geophysics, the power of wavelets for analysis of non stationary processes that contain multiscale features, detection of singularities, analysis of transient phenomena, fractal and multifractal processes, and signal compression is now being exploited for the study of several processes including resistivity surveys. The present paper deals with denoising Moroccan phosphate "disturbances" resistivity data? map using the Haar wavelet mother transform method. The results show a significant suppression of noise and a very good smoothing and recovery of resistivity anomalies. [ABSTRACT FROM AUTHOR]

Many treatments in geodesy and geophysics require regularly gridded gravity anomalies. The gridding of gravity data needs interpolation. For the predicted data to be accurate, the smoothest type of gravity anomaly should be used along with the most indicated prediction method. This paper presents the comparison of various prediction methods applied on different types of gravity anomalies and considering the relative geological complexity of the study area. Many algorithms are tested and the suitability of each type of anomaly and each prediction method discussed in a case-study in Cameroon (Central Africa), using a set of 43,000 gravity data points to determine the must accurate prediction technique. [ABSTRACT FROM AUTHOR]

The National Institute of Geology and Mining, INGEOMINAS -- Colombia, and the Federal Institute for Geosciences and Natural Resources, BGR -- Germany, perform since 1997 as a joint venture multi-parameter measurements at the Galeras volcano, in the southwest of Colombia. Since the end of 1998 the Multi-parameter Station at Galeras (Estación Multiparámetro del Galeras -- EMG) includes the continuous monitoring of electromagnetic variations. The electromagnetic (EM) station is located at the north-eastern foot walls of the central cone inside the caldera. During almost six years of electromagnetic monitoring, the data did not show significant variations of the electromagnetic field, which could be related to the volcanic activity. In July 2004 a new active period of Galeras began with two strong ash emissions. During both emissions strong self potential-(SP) signals were recorded lasting for several hours. The present paper will present the data which could give some indications on the movements of liquids during ash emissions. [ABSTRACT FROM AUTHOR]

Automatic classification of seismic signals has been typically carried out on feature-based representations. Recent research works have shown that constructing classifiers on dissimilarity representations is a more practical and, sometimes, a more accurate solution for some pattern recognition problems. In this paper, we consider Bayesian classifiers constructed on dissimilarity representations. We show that such classifiers are a feasible and reliable alternative for automatic classification of seismic signals. Our experiments were conducted on a dataset containing seismic signals recorded by two selected stations of the monitoring network at Nevado del Ruiz Volcano. Dissimilarity representations were constructed by calculating pairwise Euclidean distances and a non-Euclidean measure on the normalized spectra, which is based on the difference in area between spectral curves. Results show that even though Euclidean dissimilarities have advantageous properties, non-Euclidean measures can be beneficial for matching spectra of seismic signals. [ABSTRACT FROM AUTHOR]

In this paper, we propose a method to attenuate diffracted multiples with an apex-shifted tangent-squared Radon transform in angle domain common image gathers (ADCIG) . Usually, where diffracted multiples are a problem, the wave field propagation is complex and the moveout of primaries and multiples in data space is irregular. The method handles the complexity of the wave field propagation by wave-equation migration provided that migration velocities are reasonably accurate. As a result, the moveout of the multiples is well behaved in the ADCIGs. For 2D data, the apex-shifted tangent-squared Radon transform maps the 2D space image into a 3D space-cube model whose dimensions are depth, curvature and apex-shift distance. Well-corrected primaries map to or near the zero curvature plane and specularly-reflected multiples map to or near the zero apex-shift plane. Diffracted multiples map elsewhere in the cube according to their curvature and apex-shift distance. Thus, specularly reflected as well as diffracted multiples can be attenuated simultaneously. This approach is illustrated with a segment of a 2D seismic line over a large salt body in the Gulf of Mexico. It is shown that ignoring the apex shift compromises the attenuation of the diffracted multiples, whereas the approach proposed attenuates both the specularly-reflected and the diffracted multiples without compromising the primaries. [ABSTRACT FROM AUTHOR]

This paper describes the results from a study of the Florencia gold-telluride deposit in Central Cuba, including mineralogical, petrographical, microprobe and chemical analysis. Valuable information is provided for the exploration, mining and processing of gold ores from other nearby deposits with similar characteristics. Results highlight changes in the mineralogical composition of the ores between the north and south sectors of the deposit, as reflected in metallurgical concentrates after beneficiation and flotation of samples from these sectors. It is shown that gold deposits of the Cretaceous Volcanic Arc of Cuba largely consist of native gold, telluride and pyrite, where arsenopyrite is almost absent. Traces of lead, zinc and cadmium are present in the periphery of the main ore zones. [ABSTRACT FROM AUTHOR]

Understanding the climate change processes requires application of special methodologies for revealing a ground surface temperature history (GSTH). It was proved by different authors that the GSTH may be determined on the basis of analysis of the temperature field observed in short boreholes. In this paper, the authors analyze four mathematical models describing the GSTH: (1) sudden change, (2) linear increase, (3) square root of time increase and (4) exponential increase. Fifteen borehole temperature profiles from Europe, Asia and North America were selected in three groups based on their geographical proximity. After careful analysis of temperature-depth profiles in these boreholes it was found out that two models (linear increase and square root of time increase) provide the best fit with field data. The calculated warming rates in the 20th century were compared with those obtained by a few parameters estimation (FPE) technique. [ABSTRACT FROM AUTHOR]

This paper presents the results provided by the fine-scale thermohaline structure of near-surface layer (NSL) study done in the Colombian Pacific Ocean (CPO). Mathematical models for different regimes of the near-surface layer are formulated. Based on three stations, an hourly analysis of meteorological data, thickness change, temperature and salinity of this layer was done. The principles of formation of the thermohaline structure for NSL over CPO are related to night convection, wind-wave mixing, volume absorption of radiant energy and precipitation. [ABSTRACT FROM AUTHOR]

Usually, it is assumed in the continuous growth equation by coalescence, that mass and terminal velocity of the collected drops are negligible in comparison with the mass and velocity of the collector drop. These assumptions, which are reasonable in warm cloud modeling, appear to be not so adequate for mixed phase clouds, where interactions between different categories (cloud water, rain water, crystal ice, graupel, hail) have to be considered. When the above constraints are removed, new particular solutions of the continuous growth equation arise, which are presented in this paper. Two solutions are obtained by assuming a gamma droplet distribution. The first solution is obtained for a terminal velocity that is approximated by a power-law, while the second derives from a polynomial approximation. These solutions may be of interest for use with explicit microphysical parameterizations in mesoscale models. [ABSTRACT FROM AUTHOR]

This paper presents a deterministic two-step approach for the attenuation of ground-roll: modeling the ground-roll response and subtracting it from the recorded shot gather. The first step requires an elastic model of the shallow subsurface, which is created by estimating the p-wave velocity from the first arrivals or uphole times and the s-wave velocity from the ground-roll itself. A finite difference program simulates the elastic wave propagation in the model, providing both an acoustic seismogram and elastic one which contains the ground-roll and also the acoustic response. The provided seismograms are numerically subtracted trace by trace to furnish the isolated ground-roll. The method was applied to records from a Colombian foothill area. These records are contaminated with strong, dispersive, spatially aliased ground-roll that overwhelms the subsurface reflections. The results show that the method provides a better attenuation of ground-roll than those standard techniques such as low-cut frequency filters or f-k filtering, but it does so without sacrificing the low frequency component of data and without causing any distortion in seismic signal. [ABSTRACT FROM AUTHOR]

In hard rock masses, discontinuities control the slope stability, rather than block matrix breakage. The relative position of joints and slope face defines the most likely mechanisms of failure. Among these mechanisms, the wedge failure is one of the most common ways of failure in which joint sets dip and dip direction, slope geometry and direction, external forces (including water pressure and earthquake) and rock and joints mechanical properties control the stability. The determination of these input parameters is not straightforward, mainly due to their variability and the limited amount of information available. Besides, in most projects, input parameters come from different sources (e.g., expert opinion, back-calculation, laboratory tests, field test or different project stages). Therefore, this limited information from different sources should be appropriately incorporated into the stability analysis to assist the design and decision-making process. In this context, random sets arise as a powerful tool to combine different sources of information and to perform a reliability assessment under limited information. This feature makes it possible to update the probability of failure as new evidence is available. With this framework, this paper presents a reliability assessment of wedge stability in a rock slope of a sandstone quarry, located in Une Cundinamarca, where information on mechanical and geometrical parameters has been collected for 20 years.

Erzurum and its surroundings are one of the seismically active and hydrothermal areas in the Eastern part of Turkey. This study is the first approach to characterize the crust by seismic features by using the local earthquake tomography method. The earthquake source location and the three dimensional seismic velocity structures are solved simultaneously by an iterative tomographic algorithm, LOTOS-12. Data from a combined permanent network comprising comprises of 59 seismometers which was installed by Ataturk University-Earthquake Research Center and Earthquake Department of the Disaster and Emergency Management Authority to monitor the seismic activity in the Eastern Anatolia, In this paper, three-dimensional Vp and Vp/Vs characteristics of Erzurum geothermal area were investigated down to 30 km by using 1685 well-located earthquakes with 29.894 arrival times, consisting of 17.298 P- wave and 12.596 S- wave arrivals. We develop new high-resolution depth-cross sections through Erzurum and its surroundings to provide the subsurface geological structure of seismogenic layers and geothermal areas. We applied various size horizontal and vertical checkerboard resolution tests to determine the quality of our inversion process. The basin models are traceable down to 3 km depth, in terms of P-wave velocity models. The higher P-wave velocity areas in surface layers are related to the metamorphic and magmatic compact materials. We report that the low Vp and high Vp/Vs values are observed in Yedisu, Kaynarpinar, Askale, Cimenozu, Kaplica, Ovacik, Yigitler, E part of Icmeler, Koprukoy, Uzunahmet, Budakli, Soylemez, Koprukoy, Gunduzu, Karayazi, Icmesu, E part of Horasan and Kaynak regions indicated geothermal reservoir.

A natural phenomenon (hazard) may be characterized in terms of temporal, spatial and magnitude probabilities. The effects of the interaction between the hazard and the exposed element depend on the intensity of the hazard and on the resistance, sometimes called susceptibility, of the element at risk, which describes the propensity of a building or other infrastructure to suffer damage from a specific hazard impact. Consequently, a modern concept of vulnerability must consider the intensity of the hazard as well as the structural resistance of the exposed infrastructure. This concept is referred to as physical vulnerability, and the most accepted definition is a representation of the expected degree of loss quantified on a scale of 0 (no damage) to 1 (total destruction). Thus, this work presents a mathematical model for landslide physical vulnerability assessment, here named the T-Model, based on the “Principle of Natural Proportionality” and calibrated with field observations of the massive rainfall-triggered landslide event that occurred in Nova Friburgo, Brazil in November of 2011. The model was also calibrated for a flow-type movement that is based on field observations of the failure of a tailing dam that affected the district of Bento Rodrigues, Brazil in November of 2015. The results showed a good agreement between predictions and the observed level of damages. Thus, it is possible to conclude that from a mathematical point of view, the model may be qualified as universal. It is recognized that a real universal objective model for vulnerability to landslides is not practical at present. More important than the model itself is the methodology that is presented here, which leads the user to take qualitative damage information from the field and develop it into a quantitative mathematical framework. Potential users of the T-Model must be cautious regarding the values of parameters that are presented in this paper. The T-Model is just a modest proposal that requires further calibration and deep expert criticisms.

This paper investigates the capability of acoustic Full Waveform Inversion (FWI) in building Marmousi velocity model, in time and frequency domain. FWI is an iterative minimization of misfit between observed and calculated data which is generally solved in three segments: forward modeling, which numerically solves the wave equation with an initial model, gradient computation of the objective function, and updating the model parameters, with a valid optimization method. FWI codes developed in MATLAB herein FWISIMAT (Full Waveform Inversion in Seismic Imaging using MATLAB) are successfully implemented using the Marmousi velocity model as the true model. An initial model is obtained by smoothing the true model to initiate FWI procedure. Smoothing ensures an adequate starting model for FWI, as the FWI procedure is known to be sensitive on the starting model. The final model is compared with the true model to review the number of recovered velocities. FWI codes developed in MATLAB herein FWISIMAT (Full Waveform Inversion in Seismic Imaging using MATLAB) are successfully implemented usingMarmousi velocity model astrue model. An initial model is derived from smoothing the true model to initiate FWI procedure. Smoothing ensures an adequate starting model for FWI, as the FWI procedure is known to be sensitive onstarting model. The final model is compared with the true model to review theamount of recovered velocities.

The retardation factor (Rd) is one of the main important solute transport parameters. Its value can vary significantly depending on the method used for its determination. In this paper, the sodium Rd is experimentally determined using undisturbed sandy columns to compare four methods of Rd determination and assess the impact of the chosen method in the prediction of sodium movement. Column experiments in undisturbed soil columns and analytical analysis were performed. The results showed that the soil has dual-porosity and preferential pathways. The breakthrough curves were in accordance with the soil’s physical characteristics. The Rd values ranged from 1.7 to 7.77 depending on the initial concentration and on the method used. These differences arise from the conceptual model of each Rd determination method. The experimental and analytical analysis indicated that the higher the Rd, the slower the movement. The methods that best reproduced the laboratory sodium movement were Ogata and Banks’ (1961), and Langmuir and Freundlich’s isotherms. The prediction models presented smaller errors with the increase of the initial concentration. In these cases, the predicted concentrations can be overestimated up to 22.5 % when using a not suitable method. Hence these results suggest that the Rd determination method can strongly affect the prediction of the sodium movement. Because of that, it is of vital importance to evaluate each method and how they can be adequate to the soil under investigation when determining Rd.

Eco-environmental change prediction models are important decision tools for policy makers as they help to quantify environmental sensitivity and understand the relationship between human activities and environmental quality. Thus, this paper aims to analyze eco-environmental changes in Monteiro County, a semi-arid zone within northeastern Brazil. This study used means of satellite images, geographic information system and global position system techniques, topographic map, climatic data and soil maps, as well as field survey data. The result outputs were evaluated on their ability to accurately predict the most sensitive and least sensitive areas. The results showed that land cover changes have modified the environment in general, and two prominent environmental degradation processes were identified: land degradation, and low soil loss. The mean soil loss increased from 0.09 t ha−¹ yr−¹ in 1987 to 0.18 t ha−¹ yr−¹ in 2010, as an effect of vegetation gain and particularly the conversion of thousands of square kilometers of Tropophile forest middle slope and barren land into Tropophile forest plain and Tropophile forest high strand. Thus, this study provides insight on territorial ordering and management of environmental services with a regional perspective.

Continuously Operating Reference Station (CORS) networks consisting of multiple GNSS systems have been set up and operating in many developed countries. In Turkey, CORS-TR has been operating. The aim of CORS-TR is a fast, correct, and reliable collection of all kinds of geographic data, thus, speeding up the activities of cadastre, assuring organized urbanization, constituting the spatial infrastructure for relevant works of e-government, and monitoring plate tectonics. Therefore, in this paper, we investigated 788 days of linear and periodic of AKHR, BEYS, CIHA, KAMN, YUNA, AKSI and KNYA CORS-TR stations by linear trend analysis and Wavelet Transform in located in the Central Anatolia Region of Turkey. As a result of trend analyses of time series, it was determined that except a single station (KAMN), other stations were moving in the Southwest direction (17.78 mm/year). This finding is consistent with the region’s tectonic plate movements. In the periodical analyses, stations’ daily, monthly, seasonal, annual and even biennial movements resulting from atmospheric and hydrologic loading, climatic and other effects were revealed. Moreover, Detail (D) component, which protects the largest percentage of energy, was determined by calculating the energy spectrum. Energies of detail components are similar in horizontal, and especially D7-D8 have the highest energy. However, the components obtained the maximum energy was varied in Up coordinate time series. These results indicate that stations of CORS-TR network located in Central Anatolia were rather stable and able to be providing reliable, accurate and continuous data for national and international studies to be conducted in many fields.

This study estimates the regional environmental consequences of the impactor extraterrestrial body that could produce the probable Vichada impact crater structure on the Vichada Plain, in Colombia, South America. This paper details the parameter assumptions upon which the estimation is made. It describes an approach to quantifying the principal impact processes that could have affected the landscape in the vicinity of the probable Vichada impact event in the past. The key parameters are impactor diameter, impactor density, impact velocity before atmospheric entry, impact angle, and the distance from the impact at which the environmental effects are to be calculated, and the target type of sedimentary rock or crystalline rock. These parameters were chosen with support from The Vichada Structure dimensions obtained from remote sensing data interpretation, regional geologic mapping and interpreted satellite data and ground-based gravity and magnetic anomalies. The calculations are based on compiled novel algorithms for estimating the thermal radiation emitted by the impact-generated vapor plume or fireball, and the intensity of seismic shaking. Model validation is performed by obtaining the approximates various dimensions of the Vichada impact crater and ejecta deposit, as well as estimating the severity of the air blasting both crater-forming and air burst impacts. We illustrate the utility of the calculations by examining the predicted environmental consequences in seven localities of the Colombian territory, through hypothetical impact scenarios occurring in Cumaribo and Puerto Carreño (Vichada), Puerto Inirida (Guainía), Puerto Gaitán and Villavicencio (Meta), Mitú (Vaupes) and Bogotá, D.C. It is concluded that the most wide-reaching environmental consequence is seismic shaking. Both ejecta deposit thickness and air-blast pressure decay much more rapidly with distance than with seismic ground motion. Close to the impact site, the most devastating effect is from thermal radiation; however, the curvature of the Earth implies that distant localities are shielded from direct thermal radiation because the fireball is below the horizon. These results would guide further detailed fieldwork hunting for direct impact crater evidence and interpret high-resolution geophysical studies and borehole that could be carried out in the probable Vichada impact crater area shortly.

The study present the use of Geographic Information System (GIS) to assess the geotectonic regimen of the Sabinas Basin. Initially, the GIS database was designed using geological and geophysical information (total magnetic field reduced to the pole). Subsequently, 2D models of the basin were obtained along 4 profiles running on a north-south direction. The implementation of GIS enables a geological-geophysical interpretation generating various thematic maps that overlap the magnetic map during interpretation. The analysis of overlapping maps enables the identification of areas with different geotectonic regimes in the Sabinas Basin, as well as the relationship between these environments and mineralization. The qualitative and quantitative interpretation of the aeromagnetic data obtained for the total magnetic field reduced to the pole delineate uplifted basement areas as well as shallower blocks within them. This paper presents the location of both the basin´s deepest zones and its probable faults, which can be linked to the block boundaries. The faults zones and block boundaries correspond to the main mineral deposits found in the basin. Finally, the geotectonic regime of some sectors of the basin is detailed in order to reaffirm the results obtained by the interpretation of aeromagnetic data.

This paper investigates the potential of data mining techniques to predict daily soil temperatures at 5-100 cm depths for agricultural purposes. Climatic and soil temperature data from Isfahan province located in central Iran with a semi-arid climate was used for the modeling process. A subtractive clustering approach was used to identify the structure of the Adaptive Neuro-Fuzzy Inference System (ANFIS), and the result of the proposed approach was compared with artificial neural networks (ANNs) and an M5 tree model. Result suggests an improved performance using the ANFIS approach in predicting soil temperatures at various soil depths except at 100 cm. The performance of the ANNs and M5 tree models were found to be similar. However, the M5 tree model provides a simple linear relation to predicting the soil temperature for the data ranges used in this study. Error analyses of the predicted values at various depths show that the estimation error tends to increase with the depth.

This paper explores the applicability of a modified Q classification system and its component parameters for analysis and conclusion of site investigation data to estimate rock slope stability. Based on the literature, Q classification system has high applicable potential for evaluation of rock mass quality. Therefore, in this study, it was used with RMR and SMR rock mass classification systems to assess stability or instability of different rock slopes along the Hamedan-Ganjnameh-Tuyserkan road, Hamedan province west of Iran. Furthermore, a modified rock mass classification system namely Slope Quality Rating (SQR) was proposed based on the correction of the Q classification parameters and calculating some new parameters such as dip and strike of discontinuities and the method of rock excavation or blasting. For this purpose, the SMR and RMR rock mass classifications were also needed. By measuring SQR for different rock slopes, it will be possible to measure Slope Mass Rating (SMR). Evaluación del sistema Q modificado de clasificación del macizo rocoso para el análisis de estabilidad de pendiente de roca Resumen Este artículo explora la aplicabilidad del sistema de clasificación Q modificado y sus parámetros para analizar y determinar la información estimada de estabilidad de pendiente de roca en el sitio determinado de estudio. Según la literatura, el sistema de clasificación Q tiene un alto potencial de aplicabilidad paral a evaluación de la calidad del macizo rocoso. En este estudio además se utilizó el sistema Q junto con los sistemas Índice de Masa de Pendiente (SMR) y Clasificación Geomecánica de Bienawski (RMR) para evaluar la estabilidad e inestabilidad de diferentes pendientes rocosas en la carretera Hamedan-Ganjnameh-Tuyserkan, de la provincia de Hamedan, en el Oeste de Irán. Además, se propone el Índice de Calidad de Pendiente (SQR), un sistema de clasificación de macizo rocoso modificado, a partir de la corrección de los parámetros de clasificación Q y el cálculo de nuevos parámetros como pendiente y caída de las discontinuidades y el método de excavación o explosión de la roca. Para esta propuesta también se utilizaron las clasificaciones SMR y RMR. La medición SQR en diferentes pendientes hizo posible el cálculo del sistema SMR.

After the late 1990s, GNSS/GPS network RTK technology has become the preferred technique in the world, today widely used in various applications such as monitoring, early warning systems, and mapping and engineering applications. By the end of 2008, the CORS-TR network was being used for engineering applications to determine 3D positions across the whole of Turkey. On the other hand, single base RTK stations are being operated in Turkey. The YLDZ is one of these types of stations. It was established at the Yıldız Technical University by the Department of Geomatic Engineering in 2012. In this paper, the performance of the YLDZ station is examined by use of measurements in 5 Istanbul GPS Triangulation Network (IGNA) benchmark points, with five repeatability measurements up to 50 km from the station. The CORS-TR network RTK solution is used at the same points, and the results are compared. The measured coordinates produced by the two RTK solutions are compared with the IGNA point coordinates. Satellite geometry, initialisation time and the standard deviation of repeatability are also determined. The differences between measured and known coordinates are calculated as 1-2 cm horizontally and close to 3 cm vertically using the YLDZ single base RTK method. Desempeño de un Método de Navegación Cinética Satelital en Tiempo Real (RTK) de una Sola Base en Comparación de un Sistema RTK Resumen Después de la década de los 90, el Sistema Global de Navegación por satélite/Sistema de Posicionamiento Global (GNSS/GPS, en inglés), basado en tecnología de Navegación Cinética Satelital en Tiempo Real (RTK, del inglés Real Time Kinematic) se convirtió en la técnica preferida en el mundo y que todavía se utiliza en varias aplicaciones como el monitoreo, sistemas de alerta temprana y mapeo e ingeniería de aplicativos. Para finales de 2008, los aplicativos de ingeniería utilizan la red de Estaciones de Referencia de Funcionamiento Continuo (CORS-TR, un proyecto establecido en Turquía) para determinar posiciones en tres dimensiones a lo largo del territorio turco. Por otro lado, las estaciones RTK de una sola base han funcionado en Turquía. La YLDZ es una estación de este tipo que fue establecida en la Universidad Técnica de Yildiz por el departamento de Ingeniería Geomática en 2012. En este trabajo se examina el desempeño dela estación YLDZ a través de la medición de cinco puntos de referencia del Sistema de Triangulación GPS de Estambul (IGNA, en inglés) con cinco mediciones repetitivas a más de 50 km de la estación. Similares medidas RTK se hicieron con la red CORS-TR y se compararon los resultados. Las dos mediciones producidas por las soluciones RTK se compararon con los puntos de coordenadas IGNA. También se determinó la geometría satelital, el tiempo de inicialización y la desviación estándar de la repetibilidad. Las diferencias entre las coordenadas medidas y las coordenadas conocidas se calcularon en un rango de 1-2 centímetros horizontalmente y cerca de 3 centímetros verticalmente para la estación YLDZ con el método RTK.

The present paper contains longitudinal profile, hypsometric analysis of river basin and geomorphological studies for future planning of soil and water conservation in Anjani and Jhiri river basin, Jalgaon district, Maharashtra, India (20°45’ to 21°08’N Latitude and 75°09’ to 75°27’E Longitude). The main aim of the present study is to recommend a suitable site for soil and water conservation in Anjani and Jhiri river basin, Northern Maharashtra, India. The study area is geologically covered by Deccan trap basalts of the Cretaceous to the lower Eocene age, and some part is covered by thick alluvium of the Quaternary age. Drainage map of the study area reveals two drainage patterns including dendritic and sub dendritic patterns, indicating that the uniform lithology of the basaltic landforms has uniform resistance to erosion. This condition has caused the Anjani and Jhiri River get little recharge from the rainwater and the surface drainage flows during only monsoon season and latter becomes dry. Therefore, water conservation is a prime need for minimize water scarcity problems in the study area. In the present study, landscape information, such as longitudinal profile and hypsometric integral, has been analysed. The longitudinal profile reveals the presence of nick points at three locations in Anjani river and two locations in Jhiri river. The nick points indicate that the rapids are formed due to different erosion, relief and presence of lineament (Joint).The hypsometric integral values for the Anjani and Jhiri river are 0.52 and 0.51, respectively. The present research illustrates that both basins fall under equilibrium stage and are in a mature phase of development. Resumen El presente artículo contiene el perfil longitudinal, el análisis altimétrico de las cuencas ribereñas y los estudios geomorfológicos para la planeación a futuro de la conservación de suelos y aguas de los ríos Anjani y Jhiri, en el distrito Jalgaon, Maharashtra, India (20° 45' a 21° 08' N de latitud y 75° 09' a 75° 27' E de longitud). El objetivo principal de este estudio es la identificación de un lugar apropiado para la conservación de agua y de suelos en las cuencas de los Anjani y Jhiri, al norte de Maharashtra. El área de estudio está geológicamente cubierta por basalto de las Traps del Decán, en la era del Cretáceo al bajo Eoceno, y por aluvión espeso de la era Cuaternaria. El mapa hidrográfico de la zona de estudio muestra dos modelos de drenaje, el dendrítico y el subdendítrico, lo que indica que la litología uniforme de los accidentes geográficos basálticos tiene una resistencia uniforme a la erosión. Esta condición ha causado que los ríos Anjani y Jhiri tengan una pequeña recarga proveniente de las aguas lluvias y de los drenajes superficiales durante la única estación monsónica del año y que luego se secan. Es por esto que la conservación del agua es una necesidad primaria para minimizar los problemas de escasez en el área de estudio. En el presente trabajo se analizó la información del paisaje, como el perfil longitudinal y la altimetría integral. El perfil longitudinal revela la presencia de cambios de gradiente en tres puntos del río Anjani y en dos puntos del Jhiri. Los cambios de gradiente indican que los rápidos se formaron debido a la erosión diferente, al relieve y presencia de lineamiento (convergencias). Los valores de altimetría integral para los ríos Anjani y Jhiri son de 0.52 y 0.51, respectivamente. La presente investigación muestra que ambas cuencas se encuentran en un escenario de equilibrio y en una fase madura de desarrollo.

The estimation of caving depth is of particular interest in the oil industry. During the drilling process, the rock classification problem is studied to analyze the concentration of cuttings at the vibrating shale shakers through the classification of caving images. To date, depth estimation based on caving rock images has not been treated in the literature. This paper presents a new depth caving estimation system based on the classification of caving images through feature extraction. To extract the texture descriptors, the cutting images are first mapped on a common space where they can be easily compared. Then, textural features are obtained by applying a multi-scale and multi-orientation approach through the use of Gabor transformations. Two different depth classifiers are developed; the first separates the textural features by using a soft decision based on the Euclidean distance, and the second performs a hard decision classification by applying a thresholding procedure. A detailed mathematical formulation of the developed classifiers is presented. The developed estimation system is verified using real data from rock cutting images in petroleum wells. Several simulations illustrate the performance of the proposed model using real images from a wellbore in a Colombian basin. The correct classification rate of a database containing 17 depth estimates is 91.2%. Resumen La estimación de la profundidad de la que provienen los derrumbes que usualmente se presentan en las caras del pozo o también llamados cavings es de gran interés en la industria petrolera. Durante el proceso de perforación de un pozo, el problema de clasificación de rocas ha sido estudiado con el fin de analizar la concentración de recortes o ripios de perforación en las zarandas vibratorias a través de la clasificación de imágenes de cavings. Sin embargo, la estimación de la profundidad de los derrumbes basada en la utilización de imágenes de los mismos no ha sido tratada en la literatura. Este artículo presenta un nuevo modelo para la estimación de la profundidad de derrumbes a través de extracción de características. Para la extracción de estas características o descriptores de textura, imágenes de recortes son transformadas en un espacio común, el cual permite su comparación. Luego, las características se obtienen aplicando la transformación de Gabor, un enfoque que se caracteriza por proporcionar un análisis multi-escala y multi-orientación. Se desarrollaron dos clasificadores, el primero separa las características de textura usando un enfoque basado en la norma Euclideana y el segundo basado en decisiones por umbral. La formulación matemática detallada de los clasificadores desarrollados se presenta en este artículo. El sistema de estimación desarrollado se evalúa usando datos reales de imágenes de derrumbes pertenecientes a un pozo petrolero. Simulaciones muestran el rendimiento del modelo propuesto usando imágenes reales de un pozo perteneciente a una cuenca Colombiana. La correcta clasificación para una base de datos de imágenes que contiene 17 clases o profundidades es de 91.2%.

In recent years, due to the increase in providers of orbit and clock corrections of satellites for data evaluation in real-time and post-processing the method of Precise Point Positioning (PPP) using measurements of Global Navigation Satellite System (GNSS) and Web-based online positioning services have become widespread. Owing to some advantages, such as work-duration and cost-effectiveness, many of users have implemented PPP method instead of the traditional relative positioning method for several applications. On GNSS applications the quality of satellite ephemerides products used for data evaluation is a significant factor that affects the results in post-processing solutions either applying relative or PPP methods on analyses. These products, classified as ultra-rapid, rapid and final orbits, are regularly provided by several national and international organizations to the users. In this paper, the accuracy of PPP method has been studied comparing the outcomes from various online Web services using different software and satellite ephemerides products. For this purpose, three test points were established in a place with completely free satellite visibility (AC01) and on the other two places with partially (YC01) and vastly (KC01) prevention of satellite signals near and within a forest area at Campus of Davutpaşa of the Yildiz Technical University in Istanbul. At these stations, static observations have been conducted with a time span of 6 hours on 4th May 2015. The dataset collected using Topcon HiperPro receiver, a receiver for GPS and GLONASS data, was evaluated manually by means of the Bernese v5.2 (BSW) and GIPSY-OASIS v6.3 (Gipsy) scientific software. Moreover, the GNSS data were also proceeded using six different Web-based online services (AUSPOS, OPUS, CSRS-PPP, APPS, GAPS, Trimble-RTX) with ultra-rapid, rapid and final satellite ephemerides products. For the station with free satellite visibility (AC01), the analyses of outcomes indicate a coordinate accuracy of 1 cm for Web-based and manual data processing. That suggests relative good quality of orbit and clock corrections of satellites used by online data processing services for PPP. Furthermore, for station with partially (YC01) prevention of satellite signals, manual solutions have approximately 1 cm coordinate accuracies for n, e and u components. Moreover, when we compare the results among Web-based services, AUSPOS in relative solution and TrimbleRTX in PPP solution provides the best results. Here, one must emphasize that Trimble-RTX is a Web-based processing service for GNSS data (GPS, GLONASS, BeiDou, and QZSS) and operates an own global network of approximately 100 stations around the world for this purpose. For station with vastly (KC01) prevention of satellite signals, the best solutions were provided by APPS and CSRS-PPP using PPP approach among the Web-based services. Here, Trimble-RTX could not produce any solution. These results could demonstrate the benefit of multi-constellation of GNSS in the areas with limited satellite visibility because of increasing of the number of measurements. Comparación de precisión del método de Posicionamiento Preciso frente al posicionamiento relativo a través de diferentes productos de efemérides satelitales cerca y bajo un ambiente boscoso Resumen En los años recientes, debido al incremento de operadores satelitales de corrección de órbita y tiempo para la evaluación de información en tiempo real y de postproceso, se ha generalizado el método de posicionamiento preciso (PPP, del inglés Precise Point Positioning) que utiliza medidas del Sistema Global de Navegación por Satélite (GNSS, del inglés Global Navigation Satellite System) y servicios web de posicionamiento en línea. Debido a ventajas como el tiempo de ejecución y la relación costo-efectividad, muchos de los usuarios han implementado el método PPP en varias aplicaciones antes que el método tradicional de posicionamiento relativo. En las aplicaciones GNSS, la calidad de los productos de efemérides satelitales utilizados para la evaluación de información es un factor significante que afecta los resultados en las soluciones postproceso sea con la aplicación de métodos relativos o PPP en los análisis. Estos productos, clasificados como ultrarrápidos, rápidos y de órbita final, los proveen a los usuarios diferentes organizaciones nacionales e internacionales. En este artículo se estudia la exactitud del método PPP en comparación con los resultados de varios servicios web que utilizan diferentes productos de software y de efemérides satelitales. Con este objetivo se establecieron tres puntos de evaluación: el primero en un lugar con completa visibilidad satelital (AC01) y los otros dos con parcial (YC01) y reducida (KC01) señal satelital, en los alrededores y al interior de una zona boscosa del campus de Davutpaşa , en la Universidad Técnica Yildiz de Estambul. En las estaciones se llevaron a cabo observaciones estáticas con intervalos de seis horas el 4 de mayo de 2015. La información se recolectó con el programa Topcon HiperPro, un receptor de GPS y GLONASS (sistema GNSS desarrollado por la Unión Soviética), y se evaluó manualmente con el software científico Bernese v5.2 (BSW) y GIPSY-OASIS v6.3 (GIPSY). Además, la información también se procesón con seis servicios web en línea (AUSPOS, OPUS, CSRS-PPP, APPS, GAPS, Trimble-RTX) con productos de efemérides ultrarrápidas, rápidas y finales. Para la estación con completa visibilidad satelital (AC01), el análisis de los resultados indican una precisión coordinada de 1 cm en los procesamientos web y manual. Esto sugiere una buena calidad de las correcciones satelitales de órbita y tiempo usadas por los servicios de procesamiento de información en línea con el método PPP. Además, para la estación con señal parcial (YC01), las soluciones manuales tienen aproximadamente 1cm de coordinación en la precisión para los componentes Norte y Este. Luego, cuando se comparan los resultados entre los servicios web, los mejores resultados fueron de AUSPOS en soluciones relativas y Trimble RTX en el método PPP. Es importante recalcar que Trimble RTX es un servicio de procesamiento web para información GNSS (GPS, GLONASS, BeiDou y QZSS) y opera una red global propia de unas 100 estaciones en el mundo para este fin. Para la estación con una reducida señal satelital (KC01), las mejores soluciones fueron ofrecidas por APPS y CSRS-PPP con el método PPP entre los servicios web. En este caso, Trimble-RTX no puede producir ninguna solución. Estos resultados demuestran los beneficios de la multiconstelación GNSS en las áreas con visibilidad satelital limitada gracias al incremento del número de medidas.

Beryl crystals are found within stream sediments transecting schists in the northeast of Eskişehir, western Anatolia. This paper studied the Eskişehir beryl crystals with optical microscopy, scanning electron microscopy (SEM-EDX), infrared spectroscopy (IR) and geochemical analyses. Beryl is accompanied by garnet, glaucophane, quartz, epidote, muscovite and chlorite in the stream sediments. The crystals are euhedral emerald (green gem beryl) and light bluishgreen aquamarine, with ideal sharp IR bands. Wet chemical analysis of Eskişehir beryl yielded 61.28% SiO2, 15.13% Al2O3, 12.34% BeO, 0.18% Cr2O3, 1.49% MgO, 1.69% Na2O, 0.98% Fe2O3, and 0.008% V2O3, resulting in the formula (Al1.75Cr0.01Mg0.22Fe0.08)(Be2.90Si6.00)(Na0.32)O18. Large Ion Lithophile Elements (LILE) (barium, strontium), some transition metals (cobalt, except nickel) and High Field Strength Elements (HFSE) (niobium, zirconium, and yttrium) in stream sediments that are associated with beryl exhibited low content about metamorphic rocks. Beryl formation appears to be controlled by upthrust faults and fractures that juxtaposed them with Cr-bearing ophiolitic units and a regime of metasomatic reactions. Such beryl crystals have also been found in detrital sediments that are derived from the schists. Presencia de berilios relacionados con Cromo en corrientes sedimentarias de Eskisehir, noroeste de Turquía Resumen Cristales de berilo fueron encontrados en sedimentos de corrientes que atraviesan en esquistos en el noreste de Eskisehir, al oeste de Anatolia. En este artículo se presentan resultados sobre el estudio de los cristales de berilio de Eskisehir con microscopio electrónico de barrido (SEM-EDX, del inglés Scanning Electron Microscopy), espectroscopia infrarroja y análisis geoquímicos. El berilio estaba acompañado de granate, glaucofana, cuarzo, epidota, moscovita, y clorito en las corrientes sedmientarias. Los cristales son esmeraldas de formas definidas (gema verde de berilio) y aguamarinas color verde celeste, con bandas de espectroscopia infrarroja de buena nitidez. El análisis químico húmedo del berilio de Eskisehir mostró 61.28 % de SiO2, 15.13 % de Al2O3, 12.34 % de BeO, 0.18 % de Cr2O3, 1.49 % de MgO, 1.69 % de Na2O, 0.98 % de Fe2O3, y 0.008% de V2O3, lo que resulta en la formula (Al1.75Cr0.01Mg0.22Fe0.08)(Be2.90Si6.00)(Na0.32)O18. Los elementos litófilos de ion grande (bario, estroncio), algunos metales de transición (cobalto, excepto níquel) y los elementos de gran campo de fuerza (niobio, circonio e itrio) en las corrientes de sedimentos que están con berilio mostraron un bajo contenido sobre las rocas metamórficas. Las formaciones de berilio aparecen controladas por fallas de cabalgamiento y fracturas que se yuxtaponen con las unidades ofiolíticas relacionadas con cromo y un régimen de reacciones metasomáticas. Estos cristales de berilio se han encontrado también en sedimentos detríticos que se derivan de los esquistos.

Lake water temperature is one of the key parameters in determining the ecological conditions within a lake, as it influences both chemical and biological processes. Therefore, accurate prediction of water temperature is crucially important for lake management. In this paper, the performance of soft computing techniques including gene expression programming (GEP), which is a variant of genetic programming (GP), adaptive neuro fuzzy inference system (ANFIS) and artificial neural networks (ANNs) to predict hourly water temperature at a buoy station in the Yuan-Yang Lake (YYL) in north-central Taiwan at various measured depths was evaluated. To evaluate the performance of the soft computing techniques, three different statistical indicators were used, including the root mean squared error (RMSE), the mean absolute error (MAE), and the coefficient of correlation (R). Results showed that the GEP had the best performances among other studied methods in the prediction of hourly water temperature at 0, 2 and 3 meter depths below water surface, but there was a different trend in the 1 meter depth below water surface. In this depth, the ANN had better accuracy than the GEP and ANFIS. Despite the error (RMSE value) is smaller in ANN than GEP, there is an upper bound in scatter plot of ANN that imposes a constant value, which is not suitable for predictive purposes. As a conclusion, results from the current study demonstrated that GEP provided moderately reasonable trends for the prediction of hourly water temperature in different depths. Resumen La temperatura del agua es uno de los parámetros básicos para determinar las condiciones ecológicas de un lago, ya que está influenciada por procesos químicos y biológicos. Además, la exactitud en la predicción de la temperatura del agua es esencial para el manejo del lago. En este artículo se evalúa el desempeño de técnicas de soft computing como la Programación de Expresiones de Genes (PEG), que es una variante de la Programación Genética (PG), el Sistema Neuro-fuzzy de Inferencia Adaptativa (Anfis, en inglés) y las Redes Neuronales Artificiales (RNA) para predecir la temperatura del agua en diferentes niveles de una estación flotante del lago Yuan-Yang (YYL), en el centro-norte de Taiwán. Se utilizaron tres indicadores estadísticos, el Error Cuadrático Medio (ECM), el Error Absoluto Medio (MAE, en inglés) y el Coeficiente de Correlación (R) para evaluar el desempeño de las técnicas de computación. Los resultados muestran que la PEG es más exacta en la predicción de la temperatura del agua entre 0,2 y 3 metros de profundidad. Sin embargo, se evidencia una tendencia diferente a partir del metro de profundidad. A esta distancia de la superficie, las RNA son más exactas que la PEG y el Anfis. Los resultados de este estudio probaron claramente la usabilidad del PEG y las RNA en la predicción de la temperatura del agua a diferentes profundidades.

The late Permian thermal events related to Emeishan Basalt has made a great impact on the underlying carbonate rock properties in the western margin of the Yangtze Platform. In this paper, we investigate the carbon and oxygen isotopic composition of the Qixia Formation carbonates from two sections: the Qiaoting Section in the northeastern part of the Sichuan Basin and the Changjianggou Section at the northwestern edge of the Basin. The data reveal that: (i) Samples from Qiaoting section show a relatively narrow range of δ13C and δ18O, varying from 2.7‰ to 5.2‰ with an average of 4.2‰, and -3.8‰ to -7.8‰ with an average of -5.4‰, respectively. In contrast, Samples from Changjianggou section exhibit larger magnitude of variation in δ13C and δ18O, ranging from -1‰ to 3.8‰ with an average of 1.5‰, and -2.1 to -9.2‰, with an average of -6.0‰ respectively; (ii) δ13C and δ18O records in carbonates from Qiaoting section are similar to those of Middle Permian seawater whereas carbonates from the Changjianggou section are depleted in 13C and 18O compared to contemporary seawater; (iii) On the basis of combined petrographic and paleo-heat flow evidence, the lower carbon and oxygen isotopic composition of the carbonates from the Changjianggou section are interpreted to be the results of thermal effects of Emeishan Basalt because of its proximity to the eruption center of the basalt. The high temperature reduced the δ18O values of the carbonates and forced the organic matter to mature at an early stage, thus producing 13C-enriched carbon dioxide to participate in the formation of carbonates. Composición Isotópica de Oxígeno y Carbón en Rocas de Carbonato de la Formación de Edad Pérmica Qixia, en la Cuenca de Sichuan: Efectos Térmicos del Basalto Emeishan Resumen Los eventos térmicos del Pérmico tardío relacionados con el Basalto Emeishan han tenido un gran impacto en las propiedades de las rocas de carbonato subyacentes en el margen occidental de la plataforma Yangtze. En este artículo se investiga la composición isotópica de carbonatos de la formación Qixia en dos secciones: la sección de Qiaoting en la parte nororiental de la cuenca Sichuan y la sección Changjianggou, en el noroccidente de la cuenca. La información evidencia que, (i) las muestras de la sección Qiaoting tienen un espectro más angosto que va de δ13C a δ18O, con variación de 2.7 ‰ a 5,2 ‰, con un promedio de 4.2 ‰, y -3.8 ‰ a -7.8 ‰, con una media de -5.4 ‰, respectivamente. En contraste, las muestras de la sección Changjianggou tienen una variación de mayor magnitud en δ13C a δ18O que va desde -1 ‰ hasta 3.8 ‰, con un promedio de 1.5 ‰, y de -2.1 a -9.2 ‰, con una media de -6.0 ‰, respectivamente; (ii) los registros de δ13C y δ18O en carbonatos son similares a los de agua marina del pérmico medio, mientras que los carbonatos de la sección Changjianggou se ven empobrecidos en 13C y 18O comparados al agua marina de esta edad; con base en la petrografía combinada y la evidencia del flujo paleotérmico, la baja composición isotópica de oxígeno y carbón de los carbonatos en la sección de Changjianggou se interpretó como resultado de los efectos térmicos del Basalto Emeishan debido a la proximidad con el centro de erupción. La alta temperatura redujo los valores de δ18O de los carbonatos y llevó a la maduración temprana de la materia orgánica, lo que produjo dióxido de carbono enriquecido en 13C durante la formación de los carbonatos.

This paper describes the results of engineering geological investigations and rock mechanics studies carried out at the proposed Chamshir dam site. It is proposed that a 155 m high solid concrete gravity-arc dam be built across the Zuhreh River to the southeast of the city of Gachsaran in south-western Iran. The dam and its associated structures are mainly located on the Mishan formation. Analysis consisted of rock mass classification and a kinematicanalysis of the dam foundation's rock masses. The studies were carried out in the field and the laboratory. The field studies included geological mapping, intensive discontinuity surveying, core drilling and sampling for laboratory testing. Rock mass classifications were made in line with RMR and DMR classification for the dam foundation. Dam foundation analysis regarding stability using DMR classification and kinematic analysis indicated that the left abutment's rock foundation (area 2) was unstable for planar, wedge and toppling failure modes.

Fine-grained and mainly reddish color, compact and slightly breccious and vesicular pyrometamorphic rocks (natural clinker) are associated to the spontaneous combustion of coal seams of the Cerrejón Formation exploited by Carbones del Cerrejón Limited in La Guajira Peninsula (Caribbean Region of Colombia). These rocks constitute remaining inorganic materials derived from claystones, mudstones and sandstones originally associated with the coal and are essentially a complex mixture of various amorphous and crystalline inorganic constituents. In this paper, a petrographic characterization of natural clinker, aswell as the application of the X-ray diffraction (Rietveld method) by mean of quantitative analysis of its mineral phases were carried out. The RIQAS program was used for the refinement of X ray powder diffraction profiles, analyzing the importance of using the correct isostructural models for each of the existing phases, which were obtained from the Inorganic Crystal Structure Database (ICSD). The results obtained in this investigation show that the Rietveld method can be used as a powerful tool in the quantitative analysis of phases in polycrystalline samples, which has been a traditional problem in geology.

Metamorphic pressure and temperature trajectories are generally used as tools to interpret the tectonic history ofdeformed belts of rocks that record past activity along active plate margins. The pre-Devonian metamorphic sequenceof the Silgará Formation forms part of the ancient basement of the central Santander Massif, including pelitic schists, siliceous schists and intercalation of amphibolites accompanied by marble. This metasedimentary unit has been affected by Barrovian type metamorphism under middle-pressure/high-temperature conditions. This paper presents on the relationship of tectonic processes to pressure-temperature paths development.Detailed petrologic analysis of pelites and related rocks has been used to constrain the P-T history of this region in the eastern colombian cordillera. Mineral assemblages and Geothermobarometric calculations indicate metamorphic temperatures and pressures of 400-600 °C and 4.0-6.5 kbar, respectively.

Cluster analysis of gauged streamflow records into homogeneous and robust regions is an important tool for the characterization of hydrologic systems. In this paper we applied the hierarchical cluster analysis to the task of objectively classifying streamflow data into regions encompassing similar streamflow patterns over Turkey.The performance of three standardization techniques was also tested, and standardizing by range was found better than standardizing with zero mean and unit variance. Clustering was carried out using Ward's minimum variance method which became prominent in managing water resources with squared Euclidean dissimilarity measures on 80 streamflow stations. The stations have natural flow regimes where no intensive river regulation had occurred. A general conclusion drawn is that the zones having similar streamflow pattern were not be overlapped well with the conventional climate zones of Turkey; however, they are coherent with the climate zones of Turkey recently redefined by the cluster analysis to total precipitation data as well as homogenous streamflow zones of Turkey determined by the rotated principal component analysis. The regional streamflow informationin this study can significantly improve the accuracy of flow predictions in ungauged watersheds.

Metacarbonate rocks (pure and impure marbles, carbonate-silicate rocks, calc-silicate rocks and carbonate-bearing silicate rocks) form a very complex group within the metamorphic sequence of the Silgará Formation at the central Santander Massif (CSM). These rocks are interpreted as derived from a sedimentary sequence (including limestones and dolostones, carbonate-bearing mudstones, sandstones, tuffaceous and evaporitic sediments and marlstones) overprinted by near-isochemical regional metamorphism. They usually appear as scarce intercalations from millimeter up to meter scale, within the high-grade pelitic rocks, in the lower part of the metamorphic section, although the proportion of metacarbonate rocks can be higher and different marble layers are exploited. We report for the first time the occurrence of a "reaction calcic exoskarn", which corresponds tosuch metacarbonate rocks, taking into account that a skarn can be developed during regional metamorphism and by different metasomatic processes, adjacent to intrusive bodies, along faults and shear zones, and what defines these rocks as a skarn is its mineralogy, which includes a variety of calc-silicate and associated minerals, usually dominated by garnet and pyroxene. Therefore, this paper focus attention to the occurrence of metacarbonate andrelated rocks, which occurs as small scale reactions zones that show a gradational contact from garnet-bearing pelitic rocks to marbles or carbonate-silicate rocks, giving particular interest to the calc-silicate rocks, which are characterized by the presence of elongated grains of banded clinopyroxene (diopside) and scapolite and massiveor scattered garnet. Several reaction-zones occur in the contact between impure calcite marble and garnet-bearing metapelite and the sequence of mineral assemblages in these reaction zones is: biotite + plagioclase K-feldspar garnet (Zone I), biotite + plagioclase K-feldspar garnet staurolite epidote (Zone II),plagioclase + amphibole garnet epidote (Zone III), amphibole + diopside + garnet + plagioclase (Zone IV), plagioclase + diopside scapolite (Zone V), epidote calcite (Zone VI), and calcite dolomite (Zone VII).

Many treatments in geodesy and geophysics require regularly gridded gravity anomalies. The gridding of gravity data needs interpolation. For the predicted data to be accurate, the smoothest type ofgravity anomaly should be used along with the most indicated prediction method. This paper presents the comparison of various prediction methods applied on different types of gravity anomalies andconsidering the relative geological complexity of the study area. Many algorithms are tested and the suitability of each type of anomaly and each prediction method discussed in a case-study in Cameroon (Central Africa), using a set of 43,000 gravity data points to determine the must accurate prediction technique.

Automatic classification of seismic signals has been typically carried out on feature-based representations. Recent research works have shown that constructing classifiers on dissimilarity representations is a more practical and, sometimes, a more accurate solution for some patternrecognition problems. In this paper, we consider Bayesian classifiers constructed on dissimilarity representations. We show that such classifiers are a feasible and reliable alternative for automaticclassification of seismic signals. Our experiments were conducted on a dataset containing seismic signals recorded by two selected stations of the monitoring network at Nevado del Ruiz Volcano. Dissimilarity representations were constructed by calculating pairwise Euclidean distances and a non-Euclidean measure on the normalized spectra, which is based on the difference in area between spectral curves. Results show that even though Euclidean dissimilarities have advantageous properties, non-Euclidean measures can be beneficial for matching spectra of seismic signals.

The city of Sampacho, situated in Rio IV department, center of Argentina, it is located in an intraplate region with proved historical and current seismic activity, where the level of seismicity, which is important, makes a low constant seismic geoamenace to the all region. It is worth mentioning that it was epicenter of two historical earthquakes (year 1934), considerated two of the most destructive ones within of the zone of reduced seismicity.In this paper characterizes preliminarily the Seismic Susceptibility in the sourrounding areas of Sampacho City, as a base for future studios of seismic microzoning and evaluation of Seismic-Risk. The following methodology emphatized the local Iithologic, geomorphologic and hydrologic factors, which may have an important incidence in the displacement of elastic wave front.It also defines five classes of susceptibility from superimpose of information levels (lithology and depth oflevel freatic), from wich the moderately low prevails. The areal distribution of them is presented in a preliminary Map of Seismic Susceptibility in digital support, being this one the first document developed on this theme for the region. La localidad de Sampacho, situada en el Departamento Rio Cuarto, Provincia de Córdoba, centro de la Republica Argentina, se encuentra emplazada en una región de intraplaca con probada actividad sísmica histórica y actual, donde el nivel de sismicidad, que es importante, pone en una constante geoamenaza sísmica a toda la región. Es de destacar que esta fue epicentro de dos terremotos históricos (año 1934), considerados dos de los mas destructores ocurridos dentro de la zona de sismicidad reducida.En el presente trabajo se caracterizo de manera preliminar la susceptibilidad sísmica en el entorno de la localidad de Sampacho, como base para futuros estudios de microzonificación sísmica y evaluación del riesgo sísmico. La metodología seguida hizo énfasis en el estudio de los factores litológicos, geomorfológicos e hidrológicos locales, los cuales pueden tener una importante incidencia en el desplazamiento del frente de ondas elásticas.Se definieron cinco clases de susceptibilidad a partir de la superposición de niveles de información litología y profundidad del nivel freático, de las cuales predomina la moderadamente baja. La distribución areal de las mismas se presenta en una carta de susceptibilidad sísmica preliminar en soporte digital, siendo este el primer documento sobre esta temática generado para la región.

Elastic waves provide characteristics of earth interior, which are necessary in Hydrocarbon and mineral prospect ions. This information is affected by shallow layers distorting the data coming from deep layers. In the colombian geology are fragment shallow layer with high velocity. In this case waves travel by anomalous paths being difficult to identity them, because these events contaminate and alternate the information considerated usefull. The effects associated to this phenomena are unknown with details. In this paper, one of these case is presented througen seismic modeling and vial data with an interpretation about its characteristics.Las ondas elásticas son una importante fuente de información de las características del interior de la tierra, necesarios en la búsqueda de hidrocarburos y otros recursos minerales. Esta información es afectada generalmente por las capas someras, cuyas características distorsionan los datos provenientes de las capas de interés, usual mente más profundas. Un caso, frecuente en la geología colombiana es el de las capas someras de alta velocidad. En este caso las ondas siguen direcciones anómalas, y con frecuencia la información es muy difícil de identificar, ya que se generan eventos que la contaminan y probablemente la atenúan, Aunque se sabe que existe este efecto, muchos de sus detalles son desconocidos. Aquí se presenta uno de estos casos, se ilustra con modelamiento sísmico con datos reales y se presenta una interpretación de sus características.

This paper presents the results of the Geophysical exploration of the emerald deposits in the town of Chivor and interesting areas in the town of Macanal, located in the Department of' Boyaca (Colombia), using a combination of radiometric, emanometric, magnetometric, geoelectric and electromagnetic methods. The geophysical exploration was made in the areas selected by the geochemical exploration done by Cardozo and Leal (2000) in their research (Cardozo et al., 2000).The field work was divided in two steps. In the first, radiometric and magnetometric methods allowing fost field data acquisition. In the second, electromagnetic and resistivity methods were applied. These methods are slower but have higher resolution than the first one. The two steps were applied both in the active mines areas and in the probably productive zones were the mineralization are covered by colluvial deposits defined by geochemical anomalies. The obtained results with the geophysical exploration were compared with the geochemical and geological models with a high correlation between all them.A direct exploration zones were recommended, based on the results of phase 2, by direct drilling, tunnels and open pit works in order to determine if the geophysical anomalies are productive or not. This jobs has to be make in the future as part of mining prospects develop.Se realizó la caracterización geofísica de los depósitos esmeraldíferos en el municipio de Chivor y zonas de interés en el municipio de Macanal, ubicados en el departamento de Boyaca-Colombia, mediante los métodos de radiometría, emanometría, magnetometría, geoeléctrica y electromagnetismo. Se desarrollo la exploración geofísica de las áreas preseleccionadas en la exploración geoquímica llevada a cabo por Cardozo y Leal (2000) en el trabajo de grado "Evaluación geológica y geoquímica de nuevas áreas potencialmente esmeraldíferas en el sector de Macanal (departamento de Boyaca)", Se dividió el trabajo en dos fases. En la primera fase se utilizaron métodos radiométricos y magnetométricos que ofrecen mayor rendimiento en campo, y por tanto, logran un mayor cubrimiento en el menor tiempo posible.En la segunda fase se emplearon métodos de electromagnetismo y resistividad eléctrica en zonas de interés preseleccionadas en la fase 1. Estos últimos métodos son más lentos pero permiten una mejor resolución. En ambas fases se recorrieron tanto las zonas de minería activa como las de presencia de anomalías geoquímicas sin explotación minera actual.Los resultados obtenidos mediante la exploración geofísica fueron comparados con las anomalías geoquímicas y con el modelo geológico de la zona, encontrando una muy buena coincidencia entre todos los modelos. Con base en los resultados obtenidos en la Fase II, se recomendaron los sitios de interés para la exploración directa mediante apiques, perforaciones o túneles, con el fin de determinar si las anomalías encontradas son productivas o no, las cuales hacen parte de las recomendaciones de actividades futuras por realizar en el área de estudio.