FLORA OF LAKOTA OF I'.LACK HILLS. 323 



30. LigliU-ciloieil cliiyrv sijrul v«ck ' ■' 



29. Lodge of grayi.sh to dark mini rock o 



28. Band of .shale. 



27. Light-eolored saiidstoiie •' 



20. Shale -" 



2.5. Light-colored elayey sand rock a little more imlii rated tluiii No. 2S i> 



24. A clayey layer ' ^ 



23. Fragile light-colored .sand rock '•' 



22. Dark shale ■■"' 



N'oTE. Nos. 22. 24, and 2ti .seem to Inive been due to .-.imilar condil ions nf di'eper uatei- allernalinj; 

 witli llio.M' forming the sandstone layers Xos. 23, 2.'i. and 27. 



21. A layer of rock nnich like Nos. 17 and 19, but forming a sharper ledge <> 



20. A shale tains 



19. Grayish .sand rock tending lo birm a ledge 



IS. Shaly .sandy material, yellowi-li iind more clayey above 



17. Mucii like No. 19 



10. Dark-colored .shales 



1."). Heavy ledge of drab sandstone 



'*) 



14. Soft rock or slude, followed above by a well-markiMl shale or c-lay ■ II 



13. Ledge of .sand rock '" 



12. Soft rock weathering out rather giay and shaly I'l 



11. Light-t'olored ledge of sand rock with ob.scnre plant impressions and frcc|ncril remain^ .if ihnnvaurs 



[Stegosaiirns and others] and .silicilied wimkI. .\s noted in the Held, No. 11 is .SO or !K) feet above 



No. 3 - ^ 



10. Shaly layer - ■* 



9. Soft flesh-colored sand rock ■'^ 



8. Shale ' 



7. Rather soft sand rock forming a ledgi' 12 



0. White sandstone, very soft, orcl.se in places splitting into small and irregular blocks 12 



.5. Soft sandstone or shales 1 •"> 



4. A layer of .sand rock sometimes forming a continuous ledge with No. 3 12 



3. Cross-bedded .sandstone with silicilied wood and frequent dinosaurian remains, especially in the lower 



part, somewhat conglomeratic. Forms a distinct ledge 12 



2. Light-colored to white .sandstone with .some banding, ochreous in places ."lO 



1. Highly colored sandstone of the t^alico Canyim quarry 00 



Total - ''13 



Note. — Nos. 1 and 2 constitute Darton's Unkpapa. They are very variable in thickness. No. 2 is some- 

 times followed by shale instead of sandstone. Whether or not this shale corresponds to that bearing din<isau- 

 rian remains, as at Piedmont, Sturgi.s, and other points, is a question, thcaigh such may he the fad. I am 

 unable to place the Piedmont and Minnekahta eyead horizon in this section, though it tnust be present some- 

 where above No. 1 1, the uppermost of the two dino.sanr horizons. 



With regard to the horizon of Ihe Minnekahta cycads much has 

 l)een said, Imt the following section includes some additional facts. In 

 it Nos. 3-() arc in the general position of the Reulali shales. 



Red Canijon Ciitk sit-linn (South litiKin), J, miles so\illtire''t of M innehililu. lokni <il n poiiil ahovl onc-foiirlh 



mile xontli of Muliif.i I'l'dk. 



Kcrl. 



13. A series of rocks nearlv repealing the cha racier of .Nos. li and 9 of i his --c.l ion, with sonic silicilied wood, 



though too much covered by talus to be readily divided SO 



12. Lioht flesh-colored sandstone, in places reddish, containing silicitied wood and jirobably some cycads. 20 



11. Characteristic, red lo yellowish sandstone, with cycads and large silicilied tree trunks, which may in 



part be Araucario.xylons, also fragments of saurian hones 20 



