STEVEXSOX— IXTERRELATIOXS OF FOSSIL FUELS. U9 



The presence of roots in the floor is apparently the ordinary 

 condition in much of Europe. Rzehak^'*^ says that the Wealden 

 coals of Hannover are distinctly autochthonous, there being root- 

 stocks in most of the underclays. Grand' Eury^*'' states that he 

 had found roots in the floor of Cretaceous coal at many places. At 

 la Liguisse and les Gardies in the Gausses there are many roots in 

 place under the seam mined there. The ^Middle Gretaceous at St. 

 Paulet shows roots in the marly mur of some coal seams ; these he 

 says are in place for some of them cross leaves of dicotyledons lying 

 flat in the rock. In his later paper, he reports that, at Sarladais, 

 roots in the mur give rise to stems. Similar conditions were seen 

 in the Upper Gretaceous at Valdonne. 



9. The Fauna.- — Fresh-water forms predominate in the Laramie, 

 the Judith River, the Bear River and occur occasionally in other 

 formations ; but for the most part the Gretaceous fauna is marine. 

 Discussion of the faunas as such has no place here, but reference 

 to some features is necessary. 



The Lower Colorado fauna is characteristic throughout the whole 

 region from western Utah to the eastern border ; it is present in the 

 limestone roof and floor of coal seams as well as in the occompany- 

 ing shales and in the coal-bearing sandstones of Utah. The Pierre 

 fauna abounds in the fine shales and occasional limestones, but it 

 abounds equally in the ^Middle Pierre (Mesaverde) sandstones of 

 New ]\Iexico, where it is found in profusion at several horizons. 

 The fauna is practically the same, be the rock sandstone or shale. 

 The depth of water in western Utah was not great, for coal beds are 

 numerous, one of them having a parting with fresh-water mollusks, 

 though the roof and floor are marine limestone. The character of 

 the rock and the numerous coal seams make the condition equally 

 clear for the IMesaverde of New^ INIexico. The marine faunas give 

 no support to the opinion that deep-sea conditions existed anywhere, 

 but they make probable that the body of water, covering at times 

 the greatest part of the Gretaceous area, was a very shallow sea. 

 Fineness of sediments, in general, may be taken as indicating dis- 

 tance from the source of supply. 



"8 A. Rzehak, Zeitsch. f. pr. Geologie, Vol. XXIL, 1914, p. 8. 

 "9C. Grand' Eury, Autun, 1902, p. 127; C R., t. CXXXVIIL, 1904, 

 669, 741. 



PROC. AMER. PHIL. SOC, VOL. LVI, K, MAY 29. IQIJ. 



