Abstract
To delineate the mantle flow fields in the vicinity of a previously proposed slab window and the possible roles that they may play in the formation of potassic volcanism in Central Java, we conduct shear wave splitting analyses using both local S and teleseismic XKS waves (including SKS, SKKS, and PKS) recorded by 121 onshore stations and two ocean bottom seismometers (OBSs). The XKS fast orientations from the OBSs are trench normal and in accord with previous subslab anisotropy measurements. In the eastern part of Central Java, the XKS and local S fast orientations from the onshore stations are mostly trench-parallel; in contrast, in the western part of Central Java, the XKS fast orientations are trench-normal while the local S measurements are spatially varying. The observations can be attributed to four flow systems including (a) subslab trench normal mantle flow in areas away from the trench which is entrained by the Australian Plate, (b) trench normal flow that goes into the mantle wedge from the subslab area through a slab window beneath the western part of the study area, (c) trench-parallel subslab flow near the trench beneath the eastern part of the study area which is driven by slab-rollback, and (d) dominantly trench-parallel flow system in the mantle wedge reflecting the horizontal component of the escaped flow system through the slab window. We propose that the vertical component of the escaped flow is responsible for the formation of the potassic volcanoes in the adjacent oceanic area.
Recommended Citation
F. Kong et al., "Potassic Volcanism Induced by Mantle Upwelling through a Slab Window: Evidence from Shear Wave Splitting Analyses in Central Java," Journal of Geophysical Research: Solid Earth, vol. 127, no. 3, article no. e2021JB023719, Wiley, Mar 2022.
The definitive version is available at https://doi.org/10.1029/2021JB023719
Department(s)
Geosciences and Geological and Petroleum Engineering
International Standard Serial Number (ISSN)
2169-9356; 2169-9313
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2022 American Geophysical Union (AGU), All rights reserved.
Publication Date
17 Mar 2022
Comments
The study was supported by the Natural Science Foundation of China (41890811, 41976071, 42025601), Zhejiang Qianjiang Plan (QJD1902026), Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) (No.311021003), and the U.S. National Science Foundation (No. 1830644 and 1919789 to S. S. Gao and K. H. Liu).