Deep Targeting an Iron-Oxide Ore Body Using a Seismic Landstreamer and a 500-Kg Drop Hammer Source
A. Malehmir, G. Maries, E. Bäckström, M. Schon and P. Marsden
Event name: 79th EAGE Conference and Exhibition 2017
Session: Near Surface - Seismic, Mining
Publication date: 12 June 2017
Info: Extended abstract, PDF ( 2.15Mb )
Price: € 20
In a pilot study, a known down to ca. 850 m deep mineralized iron-oxide zone was targeted in the historical Blötberget-Ludvika mining area of central Sweden using a MEMS-based, 240 m long, comprising of 100 sensors landstreamer (2-4 m spacing) and combined with 74 wireless recorders (mixed 10 Hz and MEMs, 10 m spacing). A Bobcat-mounted drop hammer, 500 kg, was used to generate the seismic signal. Within 4 days, about 3.5 km of seismic data using 2-10 m source and receiver spacing were acquired. At each source location 3 records were made and stacked vertically to improve the signal-to-noise ratio. The streamer moved 9 times, each time 200 m forward, and wireless recorders were kept at both ends of the profile, moved once, to provide long offsets in the data. While in a swampy and challenging near-surface environment, reflection data processing results clearly image the mineralization as a set of strong high-amplitude reflections and likely slightly extending beyond the known depth. This is encouraging and suggests such a cost-effective exploration method can be used in the area to delineate deep deposits and their depth and lateral extents.