May 1, 1896.] 



SCIENCE. 



659 



microscopic examination. The basin forma- 

 tion is considered by Mr. Hill to be of 

 Pleistocene age, but somewhat more recent 

 than the Llano Estacado. 



In regard to the origin of the Texas sul- 

 phur beds, the most significant of the asso- 

 ciated materials are the beds of gj'psum 

 which a few miles to the northeast are of 

 commercial importance because of their 

 greatthickness and purity; thesprings of sul- 

 phur water which are abundant along all the 

 deeper drainage ways; and the ancient lake 

 deposits which practically make the coun- 

 try. These deposits contain much organic 

 matter along with calcareous and siliceous 

 sediments. 



The sulphur deposits of Sicily have prob- 

 ably received more careful study than any 

 others, and they are generally thought to 

 be derived from springs charged with cal- 

 cium sulphide or sulphuretted hydrogen 

 and carbonate of lime, resulting from the 

 decomposition of gypsum in presence of or- 

 ganic matter. The decomposition products 

 of the sulphur, in turn, acting upon calca- 

 reous matters, yield gypsum, thus comple- 

 ting the cycle. 



Without enquiring into the origin of the 

 great gypsum deposits of this section, I 

 think we must consider the sulphur as one 

 of its products, though due more immedi- 

 ately to the oxidation of sulphuretted hy- 

 drogen. 



If these deposits were more accessible 

 there could be no question as to their com- 

 mercial importance. They are twenty miles 

 from railroad lines, and in a country desti- 

 tute of fuel and with scanty supply of sur- 

 face waters. On the other hand, there would 

 be no difficulty in the way of constructing a 

 railroad or tramroad, which could be built 

 out to the sulphur beds almost without 

 grading, and that a supply of water could 

 be had by artesian borings is as good as cer- 

 tain, for further down the basin near Pecos 

 City abundance of water is obtained from 



borings of 200 to 300 feet. The nearest 

 source of fuel would probably be the Texas 

 coal fields. Eugene A. Smith. 



University of Alabama. 



I CURRENT NOTES ON PHYSIOGRAPHY. 

 THE ADIRONDACK MOUNTAINS AND VALLEYS. 



A FEW pages in the account of Essex 

 county, N. Y., by Kemp (Eept. State 

 Geol., N". Y., 1893, 438-441) describe the 

 .Adirondack ridges thereabouts as trending 

 to the northeast, Lake Champlain round- 

 ing their ends in a series of bays. The 

 longitudinal valleys are said to be chiefiy 

 due to faults, and the mountains are re- 

 garded as of the tilted-block type ; the evi- 

 dence of the faults being found in breccias 

 and shear zones (as of Avalanche lake, 

 Amer. Journ. Sci., Aug., 1892), and in the 

 narrow ' passes ' which are said to be evi- 

 dently produced by fault scarps. More- 

 over, the ridges are commonly abrupt on 

 one side and slope more gradually on the 

 other, as in Knob mountain. A later re- 

 port by the same author states that the re- 

 lief of the region is not caused entirely by 

 erosion, but that it is ' in a large part due 

 to block faulting ' (Bull. N. Y. State Mu- 

 seum, III., 1895, 328). It is further con- 

 cluded that many of the valleys must have 

 been outlined in pre-Cambrian times ; for 

 small areas of Potsdam sandstone occur in 

 the depressions far within the mountains. 



TOPOGRAPHIC FORMS PRODUCED BY 

 FAULTING. 



The context of the above extracts seems 

 to indicate that their author infers an an- 

 cient date for the faults mentioned, and a 

 considerable amount of erosion subse- 

 quently in the excavation of the valleys ; 

 yet the hasty reader might gather the idea 

 that the forms now visible were directly 

 initiated by faulting of comparatively . re- 

 cent date. It is not decidedlj' stated 

 whether the faults lately produced the ex- 



