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Imported quartz cement in aeolian sandstone grew from water of uniform composition but has complex zonation
Author(s) -
Sullivan M. D.,
Macaulay C. I.,
Fallick A. E.,
Haszeldine R. S.
Publication year - 1997
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.1365-3121.1997.tb00020.x
Subject(s) - geology , quartz , petrography , sedimentary rock , sedimentary depositional environment , aeolian processes , cement , meteoric water , mineralogy , geochemistry , geomorphology , structural basin , paleontology , hydrothermal circulation , composite material , materials science
The origins and volumes of waters which mass‐transport silica in sedimentary basins remain obscure. Many previous analytical studies have illustrated cases where quartz cements in sandstones originate from complex and variable fluids. By contrast we show, by using a combination of separation and analytical techniques, that in Lower Permian sandstones of the southern North Sea the cementing fluid was isotopically uniform during growth of quartz cement with a δ 1B O of 19.6 + 1.0%‰ V‐SMOW. In this relatively uniform fluid quartz cements grew and developed complex cathodoluminescence (CL) zonations. Petrographic data show that 8–10% quartz cement (locally 30%) was imported into this 380 km 2 × 180 m thick aeolian sandstone, and cement distribution controlled by depositional permeabilities. We infer a large‐scale, high volume, flux of evolved meteoric fluid during 2 km deep burial, and show that complex CL zonation may arise from relatively subtle changes in water composition.