310 W. II. WEED — TWO MONTANA COAL FIELDS. 



coal occurs above tliis sandy belt, 1,479 feel above the mountain lime- 

 stone of the Carboniferous and 520 feet above the conglomerate carrying 

 Jurassic fossils. 



No plant remains whatever have been found in the shales resting upon 

 the coal. Careful search was made at every opening of the seam for 

 trace.- of plants, but with the same lack of success that attended the efforts 

 of previous investigators. Slabs containing indeterminate shells of Unio 

 were once sent to Professor Newberry as coming from the roof of the 

 seam, but I found no fossils of any kind, 



< >verlying the coal seam there is a prominent ledge of massive and dense 

 coarse sandstone capped by a series of rapidly alternating beds of lilac- 

 tinted or pink sandstones and red and purple shales. Like the same 

 beds at Great Falls, the sandstones form an excellent building stone. 

 This series is capped by an impure yellow limestone full of gasteropod 

 shells, which were forwarded to Dr. White for examination. His assist- 

 ant, Mr. T. W. Stanton, reports that these fossils consist of three forms of 

 fresh or brackish water types, viz, (1 ) Neritina, sp., resembling Neritina 

 (Neritella) nebrascensis, M. and H., from supposed Jurassic beds at the 

 head of Wind river, though the specimens (easts) are not well enough 

 preserved for positive identification; (2) Goniabasis {? . sp., some of the 

 more distinctly carinated forms very much resembling Goniabasis tenui- 

 carinatus, a Laramie species, though it is probable that all the elongate 

 gasteropods in this collection represent a single variable undescribed 

 species belonging to that section of Goniabasis which includes G. tenui- 

 carinata and 67. aultortuosa; and (3) some fragments of a small bivalve 

 that may belong to the genus ( 'orbula. 



The beds from which the plant remains determined by Professor New- 

 berry were obtained are similar to those lying above the coal seam and 

 between it and this limestone, and they form the northern extension of 

 the same horizon. 



The section above given represents the general characters of the Koo- 

 tanie formation throughout the field; briefly described, it is a series of 

 rapidly alternating sandstones and clay-shales, with few and thin beds of 

 impure limestone. Individual beds are inconstant, the heavy ledges of 

 firm sandstone passing laterally into arenaceous clays, and vice rrrsa. . 



The Dalvla. — No definite recognition of the Dakota has been made, 

 and therefore only an arbitrary upper limit of the Kootanie rocks can 

 be assigned to the section on Belt creek. The gasteropod-bearing lime- 

 stone just alluded to is capped by a massive and rather coarse sandstone 

 bed 25 feet thick, which forms the top of the table-land 200 feet above 

 Belt creek. This is covered by a series of shale beds, black, purple and 

 red, carrying thin beds of sandy limestones and passing upward into a 



