Ward — Geology of the Little Colorado Valley. 4-09 



The reason why these conditions are not earlier met with in 

 the valley of the river is simply that the river does not follow 

 the line of strike, and these beds, being common to the entire 

 formation, must always occupy the same horizon. Above the 

 point mentioned, therefore, they must be looked for farther in 

 the interior. We found them in fact five miles east of Black 

 Falls, or 25 miles southeast of Tanner's Crossing. The great 

 bend in the river culminating at Winslow keeps these beds 

 constantly so far to the northeast, and in a region where it is 

 so difficult to penetrate x that their exact condition for a distance 

 of over 50 miles is little known. But farther up the river, 

 where they approach somewhat to the region of settlement, 

 they again admit of access, and as already remarked, they appear 

 in great force in the valley of Le Roux Wash. Here they 

 cover an area of nearly 100 square miles and form two great 

 amphitheaters of veritable bad lands, but in which the great 

 variety and symmetry in the form of these buttes and ridges, 

 as well as the variegated and iridescent colors that prevail, ren- 

 der them a magnificent spectacle. They can be seen from the 

 southeast for a distance of 20 miles as a white line. Yiewed 

 from the top of the mesa out of which they have been carved, 

 the denudation having been arrested at a particular point, they 

 reveal more completely than at any other place the true char- 

 acter of this formation. In the Petrified Forest the Le Roux 

 beds are also well developed and the variegated marls are found 

 only half a mile east of the Lower Forest. The buttes here are 

 quite large and well developed and bones of theBelodont occur 

 in them. In the northern part of the Petrified Forest region 

 the variegated marls lie somewhat farther to the eastward. 

 What is called the Middle Forest lies in the midst of them, and 

 the petrified wood, as everybody has observed, differs here con- 

 siderably in its constitution and coloration from that of the 

 upper and lower forests, which lie in the horizon of the con- 

 glomerate series. 



As was remarked when treating of the conglomerates, these 

 variegated marls are actually found stratified'between the sand- 

 stones by the transformation of certain shales into marls. If 

 these beds are carefully traced a short distance in the direction 

 of the dip, they will be seen to thicken very rapidly and soon 

 to take on the character of the true variegated marls. As they 

 start from underneath a bed of sandstone which caps the con- 

 glomerates, and which does not so readily pass into marl, 

 the buttes that are first formed are usually topped out by 

 a block of this sandstone, and it is necessary to proceed some 

 distance farther in the direction of the dip to reach a point 

 where the sandstones disappear. This however ultimately 

 takes place and the marl beds thicken to such an extent 



