Sedimentology, dolomitization and diagenetic fluid evolution of the Middle Devonian Sulphur Point Formation, northwestern Alberta.

The Middle Devonian carbonates of the Sulphur Point Formation, Rainbow South Field, northwestern Alberta, are secondary gas-producing fractured and brecciated limestones and dolostones. These rocks have undergone complex diagenetic changes, represented mainly by multiple generations of calcite cementation and dolomitization. Calcite cements include isopachous (marine), drusy (shallow burial), equant (intermediate burial) and blocky (deep burial) varieties. Four types of dolomite have been identified: dolomicrite, matrix dolomite, saddle dolomite, and fracture-lining dolomite. Dolomicrite (2--20 mum) replaced both micrite and calcite cement in the mud-supported facies prior to early compaction. Matrix dolomite formed during intermediate burial. The precipitation of saddle dolomite (0.5--2.0 mm) is genetically related to fractures and breccia zones where it partially to completely occludes the fractures, breccias and vugs that were developed through the dissolution of the earlier matrix dolomites. Fracture-lining dolomite (0.2--1.0 mm) was the last dolomite phase to precipitate, and is intimately associated with blocky calcite, quartz, sulphide mineralization, and pyrobitumen. (Abstract shortened by UMI.)Dept. of Earth Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1999 .L66. Source: Masters Abstracts International, Volume: 39-02, page: 0461. Adviser: Ihsan S. Al-Aasm. Thesis (M.Sc.)--University of Windsor (Canada), 1999