284 BULLETIN UNITED STATES GEOLOGICAL SURVEY. [Vol. YJ. 



ing as they grew, whicli are reported to liave been five or six meters 

 high at the advent of the present residents of the region. Piecemeal 

 they have been destroyed by vandal tourists, until now not one of them 

 rises more than a meter above the surface of the ground, and many of 

 them are entirely leveled ; but their huge size is attested by the relics, 

 the largest of which can be seen to have been three or four meters in 

 diameter. These gigantic trees appear to be sequoias, as far as can be 

 told from thin sections of the wood submitted to Dr. George L. Goodale. 

 As is well known, remains of more than one species of sequoia have been 

 found in the shales at their base. 



At the opposite sloping end of the mesa a trench was dug from top 

 to bottom to determine the character of the different layers, and the 

 section exposed was carefully measured and studied. In the work of 

 digging this trench we received the very ready and welcome assistance 

 of our companion, Mr. Bowditch, and of Mr. Hill, the owner of the 

 grounds. 



From what information we could- gain about the weUs in this neigh- 

 borhood it would appear that the present bed of the ancient Florissant 

 lake is entirely similar in composition for at least ten meters below the 

 surface, consisting of heavily bedded non-fossiliferous shales, having a 

 conchoidal fracture. Mr. Peale does not say whether the well seen by 

 Mr. Taggart passed below the trachyte which he says it first entered. 

 Above these basal deposits, on the slope of the hill, we found the fol- 

 lowing series, from above downward, commencing with the evenly bed- 

 ded strata : 



Section in southern lake. 



[By S. H. ScuDDEB and A. Lakes.] 



Centimeters. 



1. Finely laminated, evenly l»edded, light-gray shale ; plants and insects scarce 



and poorly preserved 3. 2 



2. Light-browu, soft and pliable, fine-grained sandstone ; unfossiliferous 5 



3. Coarser, ferruginous sandstone ; unfossiliferous 3. 8 



4. Resembling No. 1 ; leaves and insect remains 21 



5. Hard, compact, grayish-black shale, breaking with a conchoidal fracture, 



seamed in the middle with a narrow strip of drab shale ; fragments of 

 plants 28 



6. Ferruginous shale; unfossiliferous 1.5 



7. Resembling No. 5, but having no conchoidal fracture ; stems of plants, in- 



sects, and a small bivalve moUusk 9 



8. Very fine gray ochreous shale ; non-fossiliferous 0. 5 



9. Drab shales, interlaminated with finely-divided paper shales of a light- 



gray color ; stems of plants, reeds, and insects 46 



10. Crumbling ochreous shale ; leaves abundant, insects rare 7.5 



11. Drab shales ; no fossils 7.5 



12. Coarse, ferruginous sandstone ; no fossils 3. 8 



13. Very hard drab shales, having a conchoidal firacture and filled with no- 



dules; unfossiliferous 63 



14. Finely laminated yellowish or drab shales ; leaves and fragments of plants, 



with a few insects 30 



15. Alternating layers of darker and lighter gray and brown ferruginous sand- 



stone ; no fossils 10 



