PETRIFIED FORESTS OF ARIZONA. 295 



if holesjiredugin this gravel to a depth of 4 or 5 feet water will accu- 

 mulate and stand in them. 



The valley of this creek is narrow in the northern and central parts 

 of the area, and there are several short branches or affluents, tmt at 

 the southern end it broadens out, and its rugged, spurred, and can^^oned 

 slopes are highly picturesque. Here is located its principal petrified 

 forest, and this is the region that has been characterized by some as 

 Chalcedony Park. The petrified logs are countless at all horizons 

 and lie in the greatest profusion on the knolls, buttes, and spurs, and 

 in the ravines and gulches, while the ground seems to be everywhere 

 studded with gems, consisting of broken fragments of all shapes and 

 sizes and exhibiting all the colors of the rainbow. When we remem- 

 ber that this special area is several square miles in extent some idea 

 can be formed of the enormous quantity of this material that it 

 contains. 



Although much fossil wood occurs throughout the whole region, as 

 above delimited, still for several miles to the north of this Chalcedony 

 Park it is less abundant, and it is not until the northern end of the 

 area is reached that another center of accumulation occurs. This lies 

 between two mesas in a valley that opens out upon the general plain 

 which stretches north to the Rio Puerco. It is much smaller in extent 

 than the southern park, but substantially the same general features are 

 presented. 



There is still a third center of accumulation, called the "middle 

 forest," which lies some 2 miles southeast of this last, and extends to 

 the eastern margin of the general region. It occupies the western 

 slope of the table-laud on the east, and is very extensive, stretching a 

 mile or more in a north and south direction and having a width of 

 half a mile in places. It presents many interesting novelties. 



GEOLOGICAL CONSIDERATIONS. 



All the petrified forests thus described are, geologically speaking, 

 entirely out of place, and the trunks bear every evidence of having 

 dropped down to their present position from a higher horizon in which 

 they were originally entombed and from which they have been subse- 

 quently washed out. Nor is their original position to be discovered 

 by ascending the several mesas included in the area, although some of 

 these rise 400 feet above the bed of the above-mentioned creek. It is not 

 until the still higher plateau is reached which bounds the whole region 

 and lies more than 700 feet above the valley that the stratum is at last 

 found which actually holds the fossil wood. A geologist might there- 

 fore traverse the entire area from north to south, visit all three of the 

 principal forests, and go out with the impression that everything was 

 out of place and with no correct idea of the true source of the fossil 



