The AAPG/Datapages Combined Publications Database
AAPG Bulletin
Figure
AAPG Bulletin; Year: 2025; Issue: April DOI: 10.1306/03182524012
Return to Full Text
Figure 9. Photomicrographs from well B thin sections. (A) Host rock clasts (HRC) with radiaxial-fibrous calcite rims (SR). Breccia pores are filled by micritic infill (MI) forming a geopetal feature and megaquartz cement (BQ). (B) Vuggy pores and fractures cemented by quartz. Several pores have MI deposited at the bottom of the pore, followed by BQ. Quartz veins (QV) link vug networks and are cemented by the same quartz phase. Some vugs are rimmed by radiaxial-fibrous calcite (SR) and show clasts of radiaxial-fibrous calcite rim (SRC) floating in the MI. (C) Spherulitestone with a vuggy fracture filled with SR and barite (B). Spherulites were originally formed in a Mg-silicate clay matrix now substituted by quartz. The SR, dendritic calcite (DS), and spherulites show different growth directions (GD), marked by arrows. (D) Fracture filled by SR and showing preserved open aperture. (E) The SR showing dissolution features (DSR). Pore is filled by quartz (QTZ) and B. Radiaxial-fibrous calcite rim relicts (SRR) are preserved within QTZ cement. (F) The QTZ with solid bitumen (SB). Microbrecciation (MB) visible on the left wall. (G) Energy-dispersive x-ray spectroscopy map showing the presence of a calcitic host rock protolith (Cal), commonly substituted by dolomite (Dol) and cemented with QTZ and B.
Figure 9. Photomicrographs from well B thin sections. (A) Host rock clasts (HRC) with radiaxial-fibrous calcite rims (SR). Breccia pores are filled by micritic infill (MI) forming a geopetal feature and megaquartz cement (BQ). (B) Vuggy pores and fractures cemented by quartz. Several pores have MI deposited at the bottom of the pore, followed by BQ. Quartz veins (QV) link vug networks and are cemented by the same quartz phase. Some vugs are rimmed by radiaxial-fibrous calcite (SR) and show clasts of radiaxial-fibrous calcite rim (SRC) floating in the MI. (C) Spherulitestone with a vuggy fracture filled with SR and barite (B). Spherulites were originally formed in a Mg-silicate clay matrix now substituted by quartz. The SR, dendritic calcite (DS), and spherulites show different growth directions (GD), marked by arrows. (D) Fracture filled by SR and showing preserved open aperture. (E) The SR showing dissolution features (DSR). Pore is filled by quartz (QTZ) and B. Radiaxial-fibrous calcite rim relicts (SRR) are preserved within QTZ cement. (F) The QTZ with solid bitumen (SB). Microbrecciation (MB) visible on the left wall. (G) Energy-dispersive x-ray spectroscopy map showing the presence of a calcitic host rock protolith (Cal), commonly substituted by dolomite (Dol) and cemented with QTZ and B.