3D magnetotelluric imaging of the middle-upper crustal conduit system beneath the Lei-Hu-Ling volcanic area of northern Hainan Island, China

• Published in: Journal of volcanology and geothermal research Vol. 371; pp. 220 - 228
• Main Authors: Liu, Ying, Hu, Daogong, Xu, Yixian, Chen, Chao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2019
• Subjects: Conductor; Fluid; Magnetotelluric; Northern Hainan Island; Volcano; Volcano; Magnetotelluric; Conductor; Northern Hainan Island; Fluid
• ISSN: 0377-0273; 1872-6097
• DOI: 10.1016/j.jvolgeores.2019.01.013

We present a magnetotelluric study of the Lei-Hu-Ling volcanic system in the Haikou Volcanic Zone, Hainan, China. Data acquired from 111 broadband magnetotelluric sites was used to construct a 3D resistivity model of the magmatic system. The 3D inversion shows that a well-developed shallow low-resistivity zone in the southwest of the Changliu-Xiangou Fault corresponds to the Fushan depression, and a large conductor presents in the depths of 4–10 km underlying the Lei-Hu-Ling volcanic system. The deep conductor displays a N–S lineation oblique to the Changliu-Xiangou Fault, indicating that the fault does not control the deeper magmas path. We prefer to attribute the deep conductor to accumulation of high-salinity fluids in the storage zone with porosity of 1% to 1.6%, which was associated with the transportation of magmatic fluids and volatiles supplied by a partial melting zone at greater depths. •The Quaternary volcanic system in the Haikou Volcanic Zone, China is delineated by a 3D electrical image from new MT data.•The electrical model suggests a storage zone of saline fluids rather than magma beneath the volcanic system.•The Lei-Hu-Ling volcanic system is in a state of stability at present.