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Geoexploraciones Inc. - Services

Geophysics Geoexploraciones S. A. offers an integral management service to the potential miner investor that includes activities like Mine Claims, Geophysical Studies, Deposit Evaluation, Geology, Exploitation Projects Evaluation, Underground Water Prospections, Geothermal, Geotechnics, etc.
Our enterprise uses the following tools, techniques and available services for our customers:





Geophysics

Geophysics is a science that studies the physical phenomena that are developed inside the earth in order to obtain information of the upper terrestrial crust. Its studies are based on measurements of the effects produced by the different physical fields, such as gravitational, magnetic, seismic, electromagnetic and others. The contrasts or anomalies of physical properties of the investigated terrain will be the key to obtain the required information and, instead of other sciences, geophysics often uses non invasive methods to obtain data, which usually are aerial, terrestrial, satellite and marine techniques.



Seismic studies

The seismic studies investigate the geophysical behavior of a terrain or structure from the point of view of the seismic wave propagation velocities. Through these techniques it is possible to obtain important geophysical parameters, such as compressional anerrain or structure from the point of view of the seismic wave propagation velocities. Through these techniques it is possible to obtain important geophysical parameters, such as compressional and share wave propagation velocity, Poisson modulus, elastic modulus, maximum acceleration, acceleration spectrum, etc. The fields of application are the evaluation of the quality of soils, terrain and structure stability, studies of mechanical stress, fault detection, blasting adverse effects, cavity and tunnel detection, stratigraphic and rock basement determination or delineation, etc.



Aerial and Terrestrial Magnetic and Radiometic Studies

The magnetic field of the earth may be altered by the presence of magnetic materials that are found near the surface of the crust, like magnetite, that is normally associated with the presence of iron or other deposits. This survey can be done from aerial orof magnetic materials that are found near the surface of the crust, like magnetite, that is normally associated with the presence of iron or other deposits. This survey can be done from aerial or terrestrial platforms. Nevertheless, this field is also affected by other factors like lunar and solar tides, solar storms and meteorological phenomena. For this reason, aside from field measurements it is also required a simultaneous measurement of the magnetic field in a fixed base station, that registers the variations of the terrestrial magnetism while surveying is performed. After these compensations are done, a magnetic map of the sector will be obtained, whose variations or anomalies will be associated with the zones of interest.



Gravimetrics

The gravimetrical method is a set of measurements that has a myriad of practical applications in engineering and environmental studies, whose importance can be seen in:

  • subterranean cavities mapping
  • rock basement mapping
  • mapping of regions with potential stress (irregularities in fault zones)
  • mapping of regions with potential weakness ( paleo-cracks, sutures and faults)
  • fills mapping
  • density determination (water saturation, porosity) from the topographic characteristics.

These investigations are only possible when mass variation (density) and anomaly volumes are big enough to make the measurement of these anomaly fields possible. Nevertheless, the density variations in the zones of interest are usually minor and confined to limited volumes. For this reason, the resultant gravitational anomalies are much smaller compared to the external components (noises) generated by non geological sources.



Geoelectrical studies

The geoelectrical studies are performed to investigate the electromagnetic behavior of a terrain from the point of view of the magnetic and/or electric fields in it. Through these techniques, it is possible to obtain important geophysical parameters, such asctromagnetic behavior of a terrain from the point of view of the magnetic and/or electric fields in it. Through these techniques, it is possible to obtain important geophysical parameters, such as spontaneous potential, electric resistivity, resistive tomography, impedances, induced polarization, electromagnetic transient, etc. The application fields are often the evaluation of mining deposits, water detection, ground mesh design, buried bodies detection, stratigraphical determination and rock basements.



Well Logging

In view of the final objective of an exploration, there will be many different techniques to perform a geophysical well logging. But in general terms, it can be said that it involves the application, inside of a borehole or drilling well, of most of the traditional superficial methods in order to the study subsurface formations. The objective of a geophysical well -or a series of wells- logging is to extend drilling mapping data using in situ formations geophysical parameters measurements and permits a better correlation between drilling wells inside a particular zone of interest.

The geophysical well logging means an important saving in drilling costs, because it allows that many of these being drilled with trepans or tri-cones, making unnecessary the expensive drilling with diamond crowns and core sample recovering. In those places where the geological features don?t permit core sample recovering, this method performs a valuable contribution for the stratigraphic description of the crust, allowing -in many cases- to clearly define the interfaces and physical features of the crossed formations. At the same time, these characteristics can give indirect and quantitative information about specific aspects of interest in prospecting, such as porosity, water contents, water salinity, presence of hydrocarbons or radioactive elements, etc.



Thermal conductivity of the soil

Basically there are two methods to determine thermal properties of soil: the linear source method and the cylindrical source method, both of them are based on approximated solutions in permanent regime to the problem of heat conduction from an infinitely lon of soil: the linear source method and the cylindrical source method, both of them are based on approximated solutions in permanent regime to the problem of heat conduction from an infinitely long source through an infinitely homogeneous medium. There are some minor differences in the implementation of both methods. The basic difference is that one of these is considered a linear thermal source and the other cylindrical. In this case the initial data must be discarded, because the approximations done to obtain the solution make the model very inaccurate in regard to the original behaviour. Also, both require that the heat transfer to the terrain must be kept constant at all times while the sampling process is performed, which can last 60 hours.



Topography

In engineering at the basic, conceptual and constructive phases, the topographic information requirements have a variety of solutions that include, Lidar flights, aerophotogrametry and detail terrestrial surveys. In every project the best solution to this important issue is, for sure, to obtain digital images and coordinated points of the surface using Lidar and simultaneous digital photographs with a point density adjusted to the project requirements.



Mine Claims and Mine Cadastral Studies

A mine land cadastral shows the state of claims or miner franchises that are constituted or under processing inside the area of study, which is an extremely dynamic issue. This concept is applicable to the claims that are at a state of processing a manifest, measurements inquiries and exploration claims whose deadlines are fixed by the Chilean Mining Code. These claims can expire for various reasons: an auction, neglect, voluntary resignations and process abandonment.



Mining property

Whatever the objective of the mining project may be, it will be necessary to generate mine claims of exploration and exploitation. The complete process until the registration of the mine claims is a complex legal and technical process, which involves activities in legal courts, publications in the official bulletins, exploitation mine property alignment, special reports or mine topographic measurements. The process requires a constant surveillance and checking of the publications and claim overlapping and collision detection that requires geographical information that must be constantly updated.



Aero transported laser topography (Lidar)

The laser survey is based on Lidar system, i.e. consists of using a laser transmitter-receiver pair to make a surface scan of the terrain in order to obtain a digital representation of the topography of the area of study. It is also possible to obtain geo-referenced digital pictures, called orthophotos , using a digital camera of high resolution attached to the system. The Lidar system is mounted on a specially conditioned airplane, whose trajectory will be determined by a high precision GPS control located at known coordinates. The high point density that can be measured using this system and the high resolution that can be obtained, turn it into a powerful tool for basic and detailed engineering studies over important civil projects, roadworks, infrastructure, mines, etc. A main difference with the traditional methods is the fact that the information does not depend only on the photographs, and so it is not affected by terrain variations, light or shadow conditions, etc. Data processing allows generating maps at different scales and georeferenced in different coordinates systems. It also allows to get plannimetry, contour lines, data models (DMT), structure and buildings outline, etc. The main advantages of this technology compared to the terrestrial methods are the capacity of covering great extensions of terrain in small amounts of time, to reach high risk places without danger for the workers, complement the acquired information with high quality photos and finally craft a map in any scale with the data of the same flight.









Galvarino Gallardo st 1841, Providencia - Santiago de Chile

Phones: +56-2-2236-0551 +56-2-2235-3892 Fax: +56-2-2225-6099
E-mail: info-geo@geoexploraciones.cl Website: http://www.geoexploraciones.cl/