Forward Modeling of the Geomagnetic Models of Hydrothermal Sulfide Deposit on Mid-Ocean Ridge

Polymetallic sulfides are regarded as one of the important potential deepsea mineral resources. The near-bottom magnetic survey provides an effective method to study the internal structures of sulfide deposit, which is involved with different geological processes. In our research, the study of forward modeling has been made, aimed to the sulfide deposits on mid-ocean ridges. Firstly, the 3-D geomagnetic models of the mafic and ultramafic-hosted hydrothermal sulfide deposits were established based on the previous research (Tivey and Dyment, 2010). Secondly, we used the method of ISDV (Intensity of the Spatial Differential Vector) (Seama, et al., 1993), to study the magnetic boundaries of the sulfide deposits. Finally, we discussed the effects of some factors, such as model geometry and survey system, on magnetic anomaly and boundary recognition of the sulfide deposits. It is validated that there is usually negative/lower magnetic anomaly on the top of mafic-hosted hydrothermal vent, while positive/higher anomaly for the ultramafic-hosted. It is revealed that ISDV is an effective approach to recognise the boundary of the hydrothermal mineralization of the sulfide deposits. 3-D Modeling results and edge recognition effects of geomagnetic models of hydrothermal sulfide deposit (The white solid and dotted lines represent the edge of model) (a) is magnetic field distribution of mafic-hosted hydrothermal deposit; (b) and (c) are respectively the edge recognition effects of E-W and S-N boundary by ISDV; (d) is magnetic field distribution of ultramafic-hosted; (e) and (f) are respectively the edge recognition effects of E-W and S-N