DOI: 10.1007/s00531-014-1001-1
Scopus记录号: 2-s2.0-84908566966
论文题名: Volatile (H2O, CO2, Cl, S) budget of the Central American subduction zone
作者: Freundt A. ; Grevemeyer I. ; Rabbel W. ; Hansteen T.H. ; Hensen C. ; Wehrmann H. ; Kutterolf S. ; Halama R. ; Frische M.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2014
卷: 103, 期: 7 起始页码: 2101
结束页码: 2127
语种: 英语
英文关键词: Arc magmatism
; Forearc dewatering
; Subduction fluids
; Subduction input
Scopus关键词: carbon monoxide
; chloride
; convergent margin
; island arc
; magmatism
; serpentinization
; slab
; subduction zone
; sulfur
; volatile element
; Central America
英文摘要: After more than a decade of multidisciplinary studies of the Central American subduction zone mainly in the framework of two large research programmes, the US MARGINS program and the German Collaborative Research Center SFB 574, we here review and interpret the data pertinent to quantify the cycling of mineral-bound volatiles (H2O, CO2, Cl, S) through this subduction system. For input-flux calculations, we divide the Middle America Trench into four segments differing in convergence rate and slab lithological profiles, use the latest evidence for mantle serpentinization of the Cocos slab approaching the trench, and for the first time explicitly include subduction erosion of forearc basement. Resulting input fluxes are 40–62 (53) Tg/Ma/m H2O, 7.8–11.4 (9.3) Tg/Ma/m CO2, 1.3–1.9 (1.6) Tg/Ma/m Cl, and 1.3–2.1 (1.6) Tg/Ma/m S (bracketed are mean values for entire trench length). Output by cold seeps on the forearc amounts to 0.625–1.25 Tg/Ma/m H2O partly derived from the slab sediments as determined by geochemical analyses of fluids and carbonates. The major volatile output occurs at the Central American volcanic arc that is divided into ten arc segments by dextral strike-slip tectonics. Based on volcanic edifice and widespread tephra volumes as well as calculated parental magma masses needed to form observed evolved compositions, we determine long-term (105 years) average magma and K2O fluxes for each of the ten segments as 32–242 (106) Tg/Ma/m magma and 0.28–2.91 (1.38) Tg/Ma/m K2O (bracketed are mean values for entire Central American volcanic arc length). Volatile/K2O concentration ratios derived from melt inclusion analyses and petrologic modelling then allow to calculate volatile fluxes as 1.02–14.3 (6.2) Tg/Ma/m H2O, 0.02–0.45 (0.17) Tg/Ma/m CO2, and 0.07–0.34 (0.22) Tg/Ma/m Cl. The same approach yields long-term sulfur fluxes of 0.12–1.08 (0.54) Tg/Ma/m while present-day open-vent SO2-flux monitoring yields 0.06–2.37 (0.83) Tg/Ma/m S. Input–output comparisons show that the arc water fluxes only account for up to 40 % of the input even if we include an “invisible” plutonic component constrained by crustal growth. With 20–30 % of the H2O input transferred into the deeper mantle as suggested by petrologic modeling, there remains a deficiency of, say, 30–40 % in the water budget. At least some of this water is transferred into two upper-plate regions of low seismic velocity and electrical resistivity whose sizes vary along arc: one region widely envelopes the melt ascent paths from slab top to arc and the other extends obliquely from the slab below the forearc to below the arc. Whether these reservoirs are transient or steady remains unknown. © 2014, Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908566966&doi=10.1007%2fs00531-014-1001-1&partnerID=40&md5=c5ebe85038957c1cbeea6ac690cf8d24
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70349
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
There are no files associated with this item.
作者单位: SFB 574, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; SFB 574, Institute for Geosciences, Christian Albrechts University, Kiel, Germany; Institute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany
Recommended Citation:
Freundt A.,Grevemeyer I.,Rabbel W.,et al. Volatile (H2O, CO2, Cl, S) budget of the Central American subduction zone[J]. International Journal of Earth Sciences,2014-01-01,103(7)