154 



SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1921. 



t^ucalyptus geinitzi ^lleer) Hecr. 



Ficus ilaiilinoircnoidfs (Ilpor^ Berry. 



Laurophyllum mimis Nowborry. 



Laurus plutonia lli-cr. 



Liriodendron qucrcifolium Xewlierry. 



Magnolia si)ocio8a Ilecr. 



Malapocnna falcifolia (I^osquorouxt Knowlton? 



Myrica oinarsrinata Ilcor. 



Orocxlaphiicala Iiamensis Horry. 



Palaoocassia laurinea Lcsiiucrciix. 



PodozamiU's lanceolatus ^Lindley and llutlon) 



Braun. 

 Populus harkoriana I^esquereux. 

 Rhamnus tenax lA's<|Uoreux. 

 Rhus redditiformis Berry. 

 Sapindus morrisoni Heer. 

 Sterculia lugubris I.esquereux? 

 Tricalycitos papyracous Xcwberry. 

 Viburnum robustum I>^8(|ueroui? 

 Zizyphus lamaronsis Berry. 



It was deemed desirable, in connection witli 

 the problem of the age of the Dakota sandstone 

 and the rehition between the Upper Cretaceous 

 formations of the Coastal Plain and those of 

 the Western Interior, that the flora of the 

 Woodbine sand should be critically reviewetl. 



Consequently all the material in the United 

 States Xational Museum from Arthurs Bluff 

 was sent to me anil constitutes the basis of the 

 present report. I have never visited the region, 

 nor have I seen the collections from Cooko and 

 Grayson counties, hence recorded forms from 

 these locahties are ignored imless they are 

 present in the collections studied. The total 

 numVjer of species in the -Vrthurs Bluff mate- 

 rial amounts to 43, and it is probable that de- 

 tailed explorations would double or treble the 

 number of known forms. Hence the present 

 report must be regarded entirely as a prelim- 

 inary contribution. 



Fortunately the conclusions to be derived 

 from a study of this small flora are so complete 

 and decisive as regards the age and relatioiisliip 

 of the deposits that no subsequent additions 

 to the flora can change the general conclusions, 

 and this fact must be the excuse for calling an 

 account of but 43 species from a single locality 

 the flora of the Woodbine formation. 



THK WOODBINK SAND. 



NAME. 



The name Woodbine formation was pro- 

 posed by Hill" in 1001 from the town of Wood- 

 bine, in the northeastern ])art of Cooke Cotmty, 



• Hill, R. T., op. dt., p. SM. 



Tex. On account of the predoimnanceof tuicon- 

 soliilated sand the formation is now called the 

 Woodbine sand. These beds have a somewhat 

 complicated nomenclatorial history. Ilill some 

 years earlier" called them the '"Timber Creek 

 group" or "Lower Cross Timbers formation." 

 In still earlier years they had usually been con- 

 sidered of Tertiary age. They were originally 

 described by G. G. Shumard as the "arenaceous 

 and marly clay or Red River group'' and re- 

 ferred to the Tertiary. His brother, who was 

 the first to record fossil plants from thi^se 

 strata, placed them in various positions in the 

 sections of Texas formations whicii lie pub- 

 lisheil at different times. 



Hill clearh- recognized their equivalence 

 with the Dakota sandstone but quite rightly 

 objected to the indiscriminate use of that term 

 and fortunately decided to apply the local 

 name. 



CHARACTER OF MATERIALS. 



The Woodbine materials are largely cur- 

 rent-bedded sands, generally white and friable 

 where nonfcnuginous, in places browniish and 

 consolidated b}"^ iron oxide, containing exten- 

 sive to small lenses of more or less carbona- 

 ceous laminated clays with some interbedded 

 layers of lignite or lignitic clay. They give 

 rise to sandy soils strewn M'ith fragments of 

 ferruginous sandstone and siliceous ironstone. 



The limits of the Woodbine are uncertain. 

 It is said to be unconformable with the under- 

 l3'ing Denison formation of the Washita group 

 and to pass without a break into the overlying 

 Eagle Ford formation. TafT " described the 

 formation under the name Dakota sand and 

 divided it into Timber Creek beds. Dexter 

 sand, an<l basal day. Hill conibinetl tiie lower 

 two divisions under the name Dexter sands 

 and renamed the upper division the Lewisville 

 beds because Timber C^'ci-k was preoccupied. 

 The fossil plants described in the present rejjort 

 are said to come from Hill's Dext(>r sand mem- 

 ber, th<' overlying Lewisville member, which 

 makes up from oO to 100 feel of the several 

 hundred feet of total thickness of the Wood- 

 bine, Ix'itig marine and so far as known lacking 

 determinable fossil plants. 



The Woodbine sediments from a niaxinuim 

 thickness of 300 to 500 foot in the Rod liivor 



• Am. Jour. 8H., 3d .lor., vol. 33, pp. MI-JMW, 1S87. 



' Tail, J. A., Texan Oool. Sun-oy Kourlh Ann. Ropl., p.Z«, IWi. 



