The oft repeated alternation of gypseous beds with shales or limestone is illustrated by the section at Buffalo[1], where five to six repetitions of gypsum and shale are exposed. A like repetition of gypsum beds, the gypsum mostly in thin seams and nodular layers, is shown in the section of the Livonia salt shaft,[2] Livingston county, N. Y. This alternation of the gypseous beds with the dolomites and shales indicates a constant change of conditions which is difficult of explanation in a slowly and regularly desiccating basin, but denotes a periodic interruption of the drying process, either by inflow over the bar, or, perhaps, by seasonal freshets.
Another feature of the Salina beds favoring the bar theory is the great thickness of the salt beds. In the Retsof salt shaft at York, Livingston co., [Luther, op. cit. p. 118] the drill passed successively through 22 feet of salt, 30 feet of shale and limestone and again through 58 feet of
- ↑ Section by Julius Pohlman [Buffalo Soc. Nat. Sci. Bul. 5:97] from the base of the Eurypterus beds (Bertie waterlime) of Buffalo down to near the base of the Salina formation
Feet 1–25 Shale and cement rock in thin streaks 25–30 Tolerably pure cement rock 30–43 Shale and cement rock in thin streaks 43–47 Pure white gypsum 47–49 Shale 49–61 White gypsum 61–62 Shale 62–66 White gypsum 66–73 Shale and gypsum, mottled 73–131 Drab colored shale with several layers of white gypsum, measuring 18 feet in all 131–133 Dark colored limestone 133–137 Shale and limestone 137–140 Dark colored compact shale 140–720 Gypsum and shale, mottled and in streaks 720–725 Limestone 725–760 Soft red shale 760–785 White solid quartzose sandstone, very hard 785–1305 Soft red shale - ↑ Luther. N. Y. State Geol. Rep't, 1893, 1: 90 et seq.
