Taylor, Kevin G.1, Rob L.
Extensive diagenetic carbonate cementation of marine sandstones is a commonly documented process, as an internal supply of marine carbonate shell material is often available. Such cementation of fluvial sandstone successions is generally considered to be minimal. Here we document an example where carbonate cementation of fluvial successions is intensive (cement bodies over 100 m) and extensive (occurring over distances of 10s of kms) with implications for modelling of sub-surface reservoirs.
Carbonate cement bodies up to 100m long
and 20m thick are present within the lowstand fluvial strata of the Desert
Member and Castlegate Sandstones, Book Cliffs,
The source for cements was detrital dolomite remobilised from updip whitecap units, as has also been shown for cements in marine shoreface sandstones in the Book Cliffs. δ18O data suggests that cements precipitated from meteoric fluid, although recrystallisation cannot be ruled out. The shape and distribution of the cement bodies, and their relationship to whitecaps and stratigraphy, supports an interpretation of detrital dolomite remobilisation by meteoric fluids from up-dip whitecaps, leading to extensive dolomite cementation in down-dip portions of the fluvial succession.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California