EARLY DIAGENETIC CEMENTATION OF RECENT SANDS, FRASER RIVER DELTA, BRITISH COLUMBIA

Modern terrigenous sediments cemented by low‐magnesian calcite are found in distributary channels and adjacent shallow‐water marine localities at the front of the Fraser River delta. These permanently submerged areas are usually covered by sea water, including sea water intruded upstream along bottoms of river channels. The cemented sediments occur as irregular to platy nodular masses at or near to sediment‐water interface, where they are frequently encountered during dredging. The cement consists of small crystals arranged in fibrous rims and other aggregates around and between sand grains. Processes leading to cementation are not yet known, but may include dissolution of calcareous shells by pore waters in buried sediments, followed by precipitation of calcite at higher levels from these fluids as they are expelled upward during compaction. Copyright © 1969, Wiley Blackwell. All rights reserved