328 /Scientific Intelligence. 



II. Geology and Natural History. 



1. United States Geological Survey. — The following folios 

 have recently been published : 



No. 91. Parker folio, South Dakota ; by J. E. Todd. 



No. 99. Mitchell folio, South Dakota ; by J. E. Todd. 



No. 100. Alexandria Folio, South Dakota; by J. E. Todd and 

 C. M. Hall. 



Four connecting folios dealing with the James River region 

 have thus far been published and they show clearly the unity of 

 this geologic province. Sioux quartzite (Algonkian) underlies 

 the region and constitutes the " bed rock " of the well drillers. 

 The Paleozoic, Triassic and Jurassic are absent, and the Creta- 

 ceous is represented by the Colorado Group (Benton and Nio- 

 brara). Rock outcrops are exceedingly rare and the distribution 

 and characters of the pre-glacial formations is determined in large 

 measure from the numerous artesian well records. 



The whole area is practically a plain of till diversified by a 

 series of moraines left by the retreating glacial lobe. The till is 

 from 10 to 350 ft. deep and appears to belong entirely to the 

 Wisconsin epoch. No complicated drainage modifications are 

 apparent, and, in fact, the area exhibits simple geologic structure 

 in every respect. These three folios together with the Olivet 

 (No. 96), are particularly valuable for their descriptions of glaci- 

 ation and artesian water conditions. 



No. 98. Tishomingo folio, Indian Territory; by Joseph A. Taff. 

 The Tishomingo quadrangle exhibits two types of topography ; 

 a Cretaoeous peneplain composed of Paleozoic formations, and a 

 dissected plain of Cretaceous strata. In addition to the Creta- 

 ceous, Cambrian, Silurian, Devonian, and Carboniferous strata 

 are represented. A pre-Cambrian granite occupies a considerable 

 area and with it are associated a quartz-monzonite and numerous 

 dikes of diabase, diorite and aplite intruded at different times. 

 A commendable feature of the folio is the publication of lists of 

 fossils with each formation and the attention given to correla- 

 tion. The Arbuckle uplift, occupying the northern half of the 

 quadrangle, is composed of a number of folds, constituting a 

 broad arch. The synclines are faulted to an extraordinary degree, 

 the main faults being approximately parallel with the folds. 

 "The folds are open and never overturned" . . . " and the fault- 

 ing, in most cases at least, is of the normal type or drop faulting." 

 Asphaltic deposits of economic importance occur in the Ordo- 

 vician sandstone and limestone, and to less extent in the Carbo- 

 niferous limestone conglomerate. 



2. Glacial Geology of Tasmania • by J. Walter Gregory. 

 Quart. Jour. Geol. Soc, Ix, 37. — The existence of Carboniferous 

 glacial beds in Tasmania has long been known, and in 1894 E. J. 

 Dunn furnished the first conclusive evidence of Pleistocene gla- 

 cial action, after an examination of the summits of the Western 

 Highlands. Prof. Gregory now shows that, contrary to the view 



