Note. Silty claysstones commonly- 1.) transitional upward into silicious claystons and thence to claystones and/or hard soft or lustrous clays. 2.) occur below fragmental claystones. Fragmental claystones evidence of periods of non-deposition + erosion? Why commonly & generally errony? What signif. of Fie at this stage cycle. What rel. of errony underlays to overlying coals? What is origin To? secundary? reconstituted primary? What's signif of fragmental clays in cycle of Fie underlays coal deposit? errony "" and orged U.S.