GPR profiling line
GPR profiling was performed strictly along the profiles made earlier by the topography and geophysics team of the Pomorskaya geological survey expedition of CJSC Severalmaz, Fig. 9.
Fig. 9. Map of GPR profiles in the Kepinsky site
The results of the survey gave a more precise picture of the structure and lithologic and stratigraphic properties of the stratified deposits in the upper part of the geological section up to 180 m deep. Radargrams were generated to a depth of 180 m reflecting physical and lithologic inhomogeneities possibly related to the presence of kimberlite pipes. The location of verification wells are also indicated (Fig. 10-a,b).
Fig. 10 – a,b. Loza GPR vertical sections of profiles surveyed in the Arkhangelsk region (Kepinskaya section).
Fig. 11 shows horizontal sections of the area of profiles 41-55 using 3D algorithm, for the depths of 40, 60, 80 and 100 m. Two closed ring-shaped objects – objects No.1 and No.2 – are clearly outlined in the horizontal sections of this area.
Fig. 12 provides the legend for Figs 9, 10 and 11.
Processing – derivative function Processing – 2 min/max
Fig. 11 Horizontal sections produced during the processing using 3D algorithm in profiles 41-55 for the depths of 40, 60, 80, 100 m (Kepinsk field). Results of two processing filters are shown.
Fig.12. Legend for figures 9, 10, 11
If the results from the same site are processed using PSEUDO-RELIEF algorithm, the identified object No.1 appears even more distinct, Fig. 13
Horizontal section 1600 NS at 80 m depth
Fig. 13. Results of processing the area of profiles 41-55 with 3D algorithm using PSEUDO-RELIEF option.