Correlative microscopy of the constituents of a dinosaur rib fossil and hosting mudstone: Implications on diagenesis and fossil preservation
(A) Main optical thin section (noise background removed). Major phases were calcite, quartz, albite, and fluorapatite. Vermiculite and illite were distinctly identified clay phases. (B) Hosting mudstone powder and rib bone powder focused on identifying clay phases. Clay phases besides illite were not detected from the rib bone sample. The prominent illite peaks at 20° range and the peaks in 24° range in the mudstone sample indicate that both 1M and 2M1 illite polytypes are present. A = albite, C = calcite, F = fluorapatite, I = illite, K = kaolinite, Q = quartz, S = sanidine, V = vermiculite.