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Isotopic constraints of vein carbonates on fluid sources and processes associated with the ongoing brittle deformation within the accretionary wedge of Taiwan
Author(s) -
Wang PeiLing,
Wu JiaJing,
Yeh EnChao,
Song ShengRong,
Chen YueGau,
Lin LiHung
Publication year - 2010
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2010.00940.x
Subject(s) - geology , accretionary wedge , meteoric water , isotopes of oxygen , diagenesis , δ18o , geochemistry , vein , wedge (geometry) , stable isotope ratio , mineralogy , petrology , seismology , subduction , tectonics , hydrothermal circulation , psychology , physics , optics , quantum mechanics , psychiatry
Terra Nova, 22, 251–256, 2010 Abstract The continuously distributed, well‐preserved fracture‐filling carbonates were collected from the cores retrieved from the Taiwan Chelungpu‐fault Drilling Program between 400 and 2000 m depth for carbon and oxygen isotope analyses to constrain the fluid compositions and processes associated with brittle deformation within the accretionary wedge. The isotope analyses of fracture‐filling carbonates yielded δ 18 O values steadily increasing with depth. The δ 13 C values exhibited a pattern similar to that of δ 18 O values at shallower depths, but an opposite trend at greater depths. Such variations in the isotopic compositions could be best explained by a mixing of shallow, meteoric water and deeply rooted fluid carrying isotopic signatures of various microbial processes. The notable excursion of δ 18 O values might infer a conduit for the lateral fluid transport along the high vein density zone. Overall, the isotopic patterns preclude the substantial influence of early diagenesis and suggest pervasive fluid percolation through the fracture network.