256 
STRATIGRAPHICAL GEOLOGY 
collected specimens show there an important outcropping of the 
Late Cretacic beds with this chalky facies, extending along the 
axis of the Channel; and prove that the opening of La Mauche 
Channel already existed at that epoch, which allowed communica¬ 
tion between the Cretacic seas of the Paris Basin and those of 
the Pyrenees and the Mediterranean regions. 
This is the first time that the geologic study of the bottom of 
the sea off the French coast has been undertaken systematically 
with the aid of a new contrivance used by the Commander.^ The 
same apparatus was used again last year (1921) during the second 
cruise of the Pourquoi Pas? 
Charcot. 
Dakotan Sandstone in Missouri. There was recently obtained 
by members of the Missouri Geological Survey, and sent to me 
by Director Buehler, a large sample of dark brown, or chocolate- 
colored, coarse-grained sandrock which had been collected in 
Mercer County, a few miles west of Anderson, near the northern 
boundary of the State. It was at once recognized that this sample 
was a piece of the typical Nishnabotona, or Dakotan, sandstone. 
Although the possible presence of Cretacic strata in north 
Missouri had been long suspected this is the first real indication 
that rocks of this age actually exist there. Judging for the sub¬ 
mitted sample alone there was no information showing that it 
might not be merely a fragment of a Drift boulder. However, 
in later inspection of the locality, a mass of similar sandstone was 
disclosed in such position and of such size as to preclude recent 
transportation. 
By singular coincidence the locality is such that a very con¬ 
siderable outlier of the Dakotan sandstone should be preserved. 
It is very close to the line of the great Cap-au-Gres fault, which 
here has a displacement of about 100 feet. Being on the down- 
throv/ side and thus depressed below the general plains-level, the 
Cretacic beds, which undoubtedly once widely covered this region, 
are preserved from regional planation. Thus on the same level, 
flat-lying Cretacic strata but flat lying Carbonic beds. 
1 Doctor Charcot was the commander of the Pourquoi Pas? during the dredging 
operatoins of both the first cruise and the second cruise last year, 1921. — Ed. 
