4 



beds, usually massive, are separated by layers of grey argillo-arenaceoas 

 shale, which, as well as the sandstc^es, sometimes contain nodules of 

 argillaceous iron ore. In the middle and lower part, there are interstra- 

 tified two conspicuous beds of claret-red, green, and dark grey argillo- 

 arenaceous shale ; in the upper one of which are two, and in the lower, 

 eight bands of a grey tough rock, much like fire-clay, penetrated verti- 

 cally by the rootlets of Fsilophyton 428 



4. Drab sandstones, inclining to green ; some of which contain quartz and 



jasper pebbles ; many parts have large hard spheroidal masses, as 

 before. The beds are in general very thick, and they are separated by 

 layers of grey argillaceous shale, from which large argillaceous masses 

 occasionally protrude into the superincumbent sandstone, some of these 

 being as much as three feet high and as broad. Comminuted carbon- 

 ized plants, similar to those already named, occur on the surfaces of the 

 lower beds 2052 



5. Drab sandstone ; in massive beds, in only a few of which there are scat- 



tered quartz and jasper pebbles. The sandstones are interstratified with 

 five conspicuous bands of claret-red, green, and grey argillo-arenaceous 

 shale, of an aggregate thickness of 140 feet 442'. 



6. Drab strong and coarse conglomerates, in massive beds, one of them 158 



feet thick. The pebbles of these consist of white quartz, black chert, 

 yejlow, green, and blood-red jaspers, and jasper porphyry ; with which 

 are sometimes found others of feldspar and of limestone, the whole 

 enclosed in a matrix of drab-colored sandstone. In some portions of 

 the deposit, the pebbles diminish in quantity so that the rock becomes a 

 rather fine-grained sandstone, with only occasional pebbles. The car- 

 bonized comminuted remains of plants occur on the surfaces of the 

 beds, and in their oblique elementary layers or false bedding. Among 

 the organic remains of this division, fishspines or ichthyodorulites occur, 

 of the genera Onchus and Machseracanthus : one of them, the J/. Sulca- 

 tus of Newberry 856 ' 



7. Red sandstones, sometimes slightly calcareous, with green stripes and 



spots, many of the beds massive ; associated with occasional drab 

 sandstones, and with two thin bands of conglomerate, holding pebbles 

 of quartz, jasper and limestone. All of these are interstratified with 

 red argillaceous and arenaceous shales, spotted and striped with green. 

 In many cases, the sandstones exhibit on their under surfaces, highly 

 relieved casts of shrinkage cracks and of rain drops, and on the upper 

 surfaces ripple-marks. The shales are sometimes penetrated by branch- 

 ing plants, in vertical, oblique, and prostrate attitudes ; while one or 

 two beds have fibrous root-like impressions, probably of Fsilophyton, 

 running across them at right angles 1151 



8. Drab massive sandstones, which in the lower part are clouded or mottled 



with a reddish tinge, and at the bottom exhibit an interstratification 

 with red shales ; at the summit the beds are inclined to grey. In many 

 parts, they hold scattered pebbles of white and greenish quartz, and 

 blood-red jasper, with some of limestone ; but the pebbles never become 

 so numerous as to constitute a conglomerate. On the surfaces of many 

 of the strata, and in the oblique elementary layers or false bedding of 

 some of them,'^there occur carbonized comminute remains of plants ; 

 which are too imperfect to be determined 663 



703S- 



