| Queen City sandstones in Mestena Grande Field are predominantly very fine-grained subarkose. The present relative abundances of the three major framework components are 73 percent quartz, 22 percent feldspar, and 5 percent rock fragments. Allowing for dissolution of some framework grains, the original proportions are estimated to have been 69 percent quartz, 24 percent feldspar, and 7 percent rock fragments.;Assuming that the original porosity of the sand was 40 percent, then 45 percent of the original porosity has been destroyed by compaction, whereas 39 percent has been filled by cement. Ferroan dolomite, kaolinite, dolomite, and quartz overgrowths are the major cements.;The sequence of diagenetic events is: siderite, grain-coating chlorite, quartz overgrowths, albite, dolomite, early-stage dissolution, kaolinite, chlorite, ferroan dolomite, pyrite, and late-stage dissolution. Diagenetic processes reduced porosity to an average of 10.5 percent. |
