The AAPG/Datapages Combined Publications Database
AAPG Bulletin
Figure
AAPG Bulletin; Year: 2025; Issue: July DOI: 10.1306/06132522006
Return to Full Text
Figure 7. Typical carbonate cementation in the third interval of the Paleogene Shahejie (Es3) sandstone reservoirs of the Bonan oil field. (A) Blocky calciteI (yellow color) and poikilotopic calcite II (dark red color) cementation (cathodoluminescence). (B) Pervasive poikilotopic calcite II cementation, quartz (Q) grain corroded by calcite II and mold pore (plane-polarized light). (C) Blocky calciteI (red color) surrounded by blocky ankerite (Ank; orthogonal-polarized light). (D) The same image zone as (C), blocky calciteI (red color) surrounded by blocky Ank (nonluminescent) (CL). (E) Blocky calcite II surrounded or emplaced by blocky Ank; dissolved feldspar (F) replaced by calcite II (orthogonal-polarized light). (F) Ank crystal stained by bitumen (plane-polarized light). Cal I = first-phase calcite; Cal II = second-phase calcite; Es3l = lower part of Es3; Es3m = middle part of Es3; Es3u = upper part of Es3; Qc = quartz overgrowth; R = lithic fragment.
Figure 7. Typical carbonate cementation in the third interval of the Paleogene Shahejie (Es3) sandstone reservoirs of the Bonan oil field. (A) Blocky calciteI (yellow color) and poikilotopic calcite II (dark red color) cementation (cathodoluminescence). (B) Pervasive poikilotopic calcite II cementation, quartz (Q) grain corroded by calcite II and mold pore (plane-polarized light). (C) Blocky calciteI (red color) surrounded by blocky ankerite (Ank; orthogonal-polarized light). (D) The same image zone as (C), blocky calciteI (red color) surrounded by blocky Ank (nonluminescent) (CL). (E) Blocky calcite II surrounded or emplaced by blocky Ank; dissolved feldspar (F) replaced by calcite II (orthogonal-polarized light). (F) Ank crystal stained by bitumen (plane-polarized light). Cal I = first-phase calcite; Cal II = second-phase calcite; Es3l = lower part of Es3; Es3m = middle part of Es3; Es3u = upper part of Es3; Qc = quartz overgrowth; R = lithic fragment.