Publication Date:
2024-05-02
Description:
The plumbing systems of subduction-zone volcanoes consist of magma reservoirs with different degrees of
evolution at multiple depths. The geometries of plumbing system of intraplate monogenetic volcanic fields are
generally characterized by basaltic magma ascending from the mantle and/or a shallower reservoir along dikes.
However, the shape and vertical extent of these plumbing systems are largely unknown due to the rareness of
robust geophysical data. The possible role of faults and mountain chains in controlling the geometry of magma
reservoirs is also poorly understood. To address these limitations, we present a three-dimensional resistivity
structure beneath the Holocene Jingpohu Monogenetic Volcanic Field (JMVF) in the Zhangguangcai Range
(ZGC), northeastern China. The resistivity model was derived from the magnetotelluric data in a dense net-like
array. We identified an inverted cone-shaped high-resistivity (~10,000 Ω m) anomaly below the ZGC. This
anomaly traverses almost the entire crust. We interpret this high-resistivity anomaly to be the stiff basement of
the ZGC. At the base of the resistive volume, we resolved a sill-like, low-resistivity anomaly that occurs at the top
of the lithospheric mantle. Sheet-like low-resistivity anomalies surrounding the high-resistivity body depart from
the lithospheric mantle. We interpret these sill- and sheet-like anomalies as a trans-crustal saucer-shaped magma
plumbing system beneath the JMVF. This system involves multi-level magma reservoirs, including basaltic
magma at its base, basaltic dikes/sills swarms in the middle and sill intrusions in the upper crust. We propose
that the stiff crustal root and the topographic loading of the ZGC work together to deflect the upward magma
propagation towards the edges of the ZGC. The magma ascent to the surface is probably controlled by preexisting,
lithospheric faults. Our data show how mountain chains, together with the crustal structure, play a
key role in controlling the geometry of multi-level plumbing systems of intraplate monogenetic volcanic fields.
Description:
Published
Description:
118523
Description:
OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
Description:
JCR Journal
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
