Near Surface Seismic Reflection Studies to Delineate Depth to Bedrock, Salbukh, Saudi Arabia

G. Al-Anezi¹

Abstract

In order to evaluate the use of shallow seismic technique to delineate the bedrock up to the depth of 20-25 m, three high-resolution seismic reflection profiles were carried out in April, 2012. The data were acquired using a Strata Visor with 48-channel, 40 Hz geophones and a weight drop system as a seismic source. Seismic reflection data were recorded using a CMP (common mid-point) acquisition method. The sediment layer is composed of alluvial sediments and gravel, which underneath by a sequence of limestone and dolomite layers. The results show that the bedrock lies at about 18-25 m depth. The bedrock related horizon observed here is of low frequency, its depth is almost similar in all three seismic lines and thus giving us the enough confidence in results and also following the subsurface structure. Reflection line 3 is being crossed by reflection line 1 and reflection line 2. A good structural image of the subsurface is visible from the seismic sections and for interpreter it’s easy to mark structure and integrate it with other methods. With the proper equipment, field parameters and particularly great care in data collection and processing, we can image reflections from layers as shallow as 20 m.

AAPG Search and Discovery Article #90188 ©GEO-2014, 11th Middle East Geosciences Conference and Exhibition, 10-12 March 2014, Manama, Bahrain