_Table of the Specific Gravities of the Henry Mountain Sedimentary series in the Order of Superposition._ ───────────────────────────────────┬───────────────── Bed. │Specific gravity. ───────────────────────────────────┼───────────────── Masuk Sandstone │ 2.16 Masuk Shale estimated│ 2.40 Blue Gate Sandstone │ 2.14 Blue Gate Shale │ 2.45 Tununk Sandstone │ 2.15 Tununk Shale estimated│ 2.45 Henry’s Fork Conglomerate │ 2.25 Flaming Gorge Shale │ 2.42 Gray Cliff Sandstone │ 2.13 Vermilion Cliff Sandstone estimated│ 2.15 Shinarump Shale estimated│ 2.40 Aubrey Sandstone estimated│ 2.15 ───────────────────────────────────┴───────────────── Taking into account the thicknesses of the several beds enumerated in the foregoing table, it is easy to obtain the mean specific gravity of all which lie above a given horizon; and by making this determination for the horizon of the base of each of the indicated beds, the following table has been derived. The figures are based on the assumption that the rock series included nothing above the Masuk sandstone. If (as is probable) there were Tertiary beds also, the estimates are too low, for the Tertiaries of the vicinity are calcareous and argillaceous and consequently dense. _Table showing the Mean Specific Gravities of the Rock Series contained between certain horizons and the summit of the Masuk Sandstone._ ─────────────────────────────────┬───────────────── Horizons. │ Specific │ gravities. ─────────────────────────────────┼───────────────── Base of Masuk Sandstone │ 2.16 Base of Masuk Shale │ 2.28 Base of Blue Gate Sandstone │ 2.23 Base of Blue Gate Shale │ 2.32 Base of Tununk Sandstone │ 2.31 Base of Tununk Shale │ 2.34 Base of Henry’s Fork Conglomerate│ 2.33 Base of Flaming Gorge Shale │ 2.36 Base of Gray Cliff Sandstone │ 2.33 Base of Vermilion Cliff Sandstone│ 2.32 Base of Shinarump Shale │ 2.33 ─────────────────────────────────┴─────────────────