scholarly journals Location of agate geodes in Permian deposits of Simota gully using the GPR

2021 ◽  
Author(s):  
Michał Mierczak ◽  
Jerzy Karczewski

AbstractThe article describes the establishment of the location of agate geodes using the GPR method in the area of the Simota gully (Lesser Poland Voivodeship). Agates (a multicolored variety of gemstone of chalcedony group) have multifaceted values that informed their study. Traditional methods of geode location are less reliable, hence the attempt to use the GPR method. Measurements were taken at two study test sites with subsurface geology of weathered melaphyre and pyroclastic deposits using a GPR system (ProEx). A high-frequency antenna (1.6 GHz) was used along with the pre-established profiles of lengths of 6-m and 10-cm intervals. Furthermore, simple soil tests using the soil sampler tool were made prior to the GPR measurement. The GPR results show significant high attenuation of the electromagnetic energy interpreted to be due to clay components of the regolith. Advanced signal processing procedures (such as the attribute of the signal) were used on the data for better enhancement that aided interpretation. Other anomalies depicted on the radargrams were thought to be the presence of roots, pieces of melaphyres-targeted agates. Furtherance to ascertain the reflection coefficients as recorded on the GPR data, in situ samples (root pieces, melaphyres, agates) taken were tested in the laboratory for electric permittivity property. Based on the interpretation results, several agate geodes were dug out from the ground.

Geophysics ◽  
1991 ◽  
Vol 56 (1) ◽  
pp. 50-58 ◽  
Author(s):  
K. Hsu ◽  
R. Burridge

The reflection coefficients derived from sonic and density logs are frequently used in seismic exploration. Even though they measure the in‐situ formation slowness and density, sonic and density tools do not measure the exact, continuous formation properties but locally averaged properties sampled at discrete depth points. Furthermore, the logs are frequently reinterpolated to form a Goupillaud medium for many applications such as synthetic seismogram computation. Both the logging tools and the Goupillaud interpolation introduce averaging and sampling effects into the reflection coefficients and significantly alter the autocorrelation of the reflection coefficient sequence. Analytical formulas are derived to show how the autocorrelation is altered and to calculate how the autocorrelation depends on the averaging and sampling intervals. Essentially, these effects impose sincsquared envelopes on the power spectrum of the reflection coefficient sequence and alias high‐frequency components to low‐frequency components in the spectral domain. These findings are verified using synthetic and real examples.


2018 ◽  
Vol 60 (7-8) ◽  
pp. 727-732
Author(s):  
Uğur Çavdar ◽  
İ. Murat Kusoglu ◽  
Ayberk Altintas

2009 ◽  
Author(s):  
Robert A. Buhrman ◽  
Daniel C. Ralph ◽  
Bill Rippard ◽  
Tom Silva ◽  
Stephen Russek ◽  
...  

1998 ◽  
Vol 76 ◽  
pp. 149
Author(s):  
Gousei Lee ◽  
Hisayuki Qhata ◽  
Yosuke Ujike ◽  
Chieko Yanagi ◽  
Kazutaka Momose

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Brian Helmuth ◽  
Francis Choi ◽  
Allison Matzelle ◽  
Jessica L. Torossian ◽  
Scott L. Morello ◽  
...  

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