An Experimental Seismic Imaging Study On Blind Orebodies Structure Of Lala Copper Mine

A blind copper mine in the Hongni Slope-Lushui area of the Lala Copper Mine region was firstly discovered by drilling. Later magnetic and electromagnetic survey data were obtained, which provide the first understanding of the rough shape of the underground geological structure in which the ore bodies were embedded. However, due to the limitation of conventional geophysical exploration methods for metal ore mines, further understanding of more detailed information of the geological structure is difficult. Therefore we carried out a high precision seismic exploration in the research area to image the stratum structure and ore reserves.This study involves seismic exploration, multi-scale geophysical data interpretation, 3D seismic forward modeling algorithm development, forward modeling and inversion analysis, etc. It is a comprehensive research project covering a large research range from theory study to practical exploration. Furthermore, as the seismic experiment for metal ore exploration is different from conventional work for petroleum exploration, seismic source experiment was required for the purpose, and it needed to solve a variety of special problems of data acquisition, processing and interpretation. Thus it was also a relatively strong exploratory experimental work.The experiment has achieved satisfactory results, including:(1) The high-density control of underground stratum structure of the exploration area and the spatial distribution of the ore body using regular grid with 10 seismic profiles.(2) Integrated the shallow information of refraction seismic data and the deep information of reflection seismic data, we obtained a model with seismic wave velocity parameters of our research area.(3) In the entire work area, a strong seismic reflection event of the reflection data, which is found from depth of 50 ms to 100 ms, reveals the depth of the bottom interface of the loose regolith.(4) A widespread scattering body with strong energy and high seismic velocity appears in the lower portion of all reflection seismic profiles. It is not only in line with the depth scope information of the anomaly of induced polarization method, and also consistent with drilling, in which high-grade copper was found in a depth of 160 m. It revealed the spatial distribution of ore-containing structure in our research area.(5) In addition, a seismic structure model of the region was built for three-dimensional seismic wave equation forward modeling. The synthetic results are in good agreement with the exploration data. It verifies the feasibility of the seismic structure model of the region.The goals of the experiment are fully satisfactorily achieved.