Diagenesis of arc-derived sandstones of Cretaceous formations in the Queen Charlotte Islands, British Columbia, Canada(MEMORIAL VOLUME TO THE LATE PROFESSOR TERUHIKO SAMESHIMA)
- Publisher: Shizuoka University. Institute of Geosciences
Geoscience reports of Shizuoka University,
diagenesis | porosity | pseudomatrix | authigenic cements | arc-derived sandstones | Queen Charlotte Islands | Cretaceous
Diagenesis of sediments derived from a magmatic arc provenance may greatly differ from that of sediments derived from an intracratonic- or foreland-type provenance. Sediments from the magmatic arc are compositionally immature and rich in volcanic and sedimentary rock fragments. Sandstone samples of mid- to Upper Cretaceous formations in the Queen Charlotte Islands, British Columbia, Canada, contain either large amounts of pseudomatrix or authigenic cements. An inverse relationship between the content of pseudomatrix and that of authigenic cements suggests that ductile deformation of soft rock fragments has reduced much of the original porosity and has preceded the formation of authigenic cement. The described inverse relationship clearly contradicts the recent report of diagenesis of sandstones rich in volcanic rock fragments (Hawlader 1990 ).