922 General Notes. [November, 



level strata appear well exposed. The strata consist of heavy 

 bedded, grayish and creamy sandstone, separated by thin layers 

 of shale. The sandstones in many places, especially in the eastern 

 cliff, are strongly affected with cross laminations, indicating de- 

 posit by rapid shifting, overloaded currents — in other words, river 

 flood deposits. We have, therefore, the mouth of an ancient 

 stream. There appear to have been two shale floors about two 

 feet apart, on which layer tracks are found. The whole area un- 

 covered is literally strewn with these tracks. Parts of the area 

 cleared have been trampled over by men and horses for eight or 

 ten years, without attracting scientific attention. Their impor- 

 tance was first recognized by the intelligent Warden, Major 

 Garrard, and their hardness has been the means of preserving 

 them. Besides the tracks, a considerable number of fossils have 

 been found which may assist in determining their age. Among 

 these are fragments of tusks and molars of an elephant, and 

 molars and fragments of jaws containing molar teeth of two species 

 of horse. These were but imperfectly petrified. Two species of 

 fresh-water shells have been found, an Anodonta and Sphaerium, 

 also one Gastropod, Physa. Vegetable remains are also abundant, 

 occuring mostly as matted masses of silicified herbaceous plants. 

 The age of the strata seems difficult to determine, but judging 

 from the mammalian remains alone, there can be no doubt that 

 the deposit is either Quaternary or the Upper Pliocene. 1 The 

 molars discovered at Carson, above the tracks, indicate the Elephas 

 primigeniits rather than the americanus. The teeth of the horse 

 indicate the Equus major, which although similar to modern 

 horses, was somewhat larger. The lithification of the strata and 

 fossilization of plants and organic remains, and the slight tilting 

 of the strata, may be adduced as evidence of an earlier age than 

 the Quaternary. The strata somewhat resemble a lake terrace 

 deposit. Although Miocene lake deposits are here not far off, 

 Professor Le Conte thought the presence of horse and elephant 

 a bar to that age. The ancient Pliocene lake was the most ex- 

 tensive, covering the whole basin region from the Sierra Nevada 

 to the Wahsatch. Its extensive deposits have been largely 

 covered up by the later deposits of the two great Quaternary 

 lakes in the same region. Carson plains was about 240 feet 

 above the level of these latter lakes; hence, a smaller and very 

 shallow contemporaneous lake must have existed at a higher 

 level, probably emptying into the greater lake. 



The tracks supposed to be human naturally excite the greatest 

 interest, being several hundred in number. No one who studies 

 them can fail to observe their remarkable general resemblance to 

 human tracks, both in their form and in the apparent singleness 

 of each impression. Their size calls for explanation; although 



1 The age was indicated as Pliocene from specimens sent one of the Editors, 1 



