The AAPG/Datapages Combined Publications Database
AAPG Bulletin
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AAPG Bulletin; Year: 2025; Issue: April DOI: 10.1306/03182524012
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Figure 6. Sequence of brittle deformation events in well A based on crosscutting relationships. (A) Fractured silica layers and small displacement faults showing cataclastic texture and clasts of host rock within a dark matrix. (B) Opening-mode fracture filled with microcrystalline infill that is dolomitized. (C) Chalcedony and megaquartz veins showing irregular walls and quartz geodes, with preserved porosity. Fragments of host rock wall are cemented within chalcedony cement. Megaquartz cement can be found filling some fractures without the earlier chalcedony phase. Solid bitumen is commonly the final filling in fractures. Pore is commonly preserved where fracture widths are large.
Figure 6. Sequence of brittle deformation events in well A based on crosscutting relationships. (A) Fractured silica layers and small displacement faults showing cataclastic texture and clasts of host rock within a dark matrix. (B) Opening-mode fracture filled with microcrystalline infill that is dolomitized. (C) Chalcedony and megaquartz veins showing irregular walls and quartz geodes, with preserved porosity. Fragments of host rock wall are cemented within chalcedony cement. Megaquartz cement can be found filling some fractures without the earlier chalcedony phase. Solid bitumen is commonly the final filling in fractures. Pore is commonly preserved where fracture widths are large.