Porosity Development Controlled by Deep-Burial Diagenetic Process in Lacustrine Sandstones Deposited in a Back-Arc Basin (Makó Trough, Pannonian Basin, Hungary)

Figure 10

Photomicrographs showing petrographic features of the bituminous organic matter in samples of the Algyő Formation. (a) Brown streaks of organic matter occur along concavo-convex grain contacts. Along secondary pores (blue resin), dark dots include pyrite and organic matter (open arrows), well K1, 3051 m, Algyő Fm. (b) Pyrite together with organic matter (open arrows) occurs along secondary pores and among kaolinite crystals, well B1, 2702 m, Algyő Fm. Abbreviations: Cal: calcite; Kln: kaolinite; Kfs: K-feldspar; L: carbonate rock fragment; Qz: quartz. (a, b) plane polarized light.

(a)

(b)