







B. 



EEVIEW OF FIELD-NOTES OF 1871, AND DISCUSSION OF GENEEAL TOPICS 



CONNECTED WITH THE GRAVEL QUESTION. 



By W. A. GOODYEAR. 



Section I — Review of Field-Notes. 



In the following pages I propose to write first a sort of running review of the mass of my field- 

 notes for 1871, herewith presented, making such additional remarks as may be applicable to special 

 localities, with references, so far as needful, to the pages where these localities are more particularly 

 described ; and afterwards to discuss to some extent a variety of more general topics connected 

 with the gravel question. 



It is necessary to premise in the first place that, in the section of country to which these notes 



relate, although a considerable number of instances may be found of distinct and unmistakable 



channels worn in the solid bed-rock, and marking for certain distances the exact location and course 



of the ancient streams which accumulated the gravel that now fills their beds, and though in a few 



cases these channels have been actually traced and proved continuous for distances of from one 



to two miles ; yet, when compared with the vast aggregate of the surface over which the ancient 



auriferous gravel was spread, the channels which can be thus definitely and certainly traced, even 



for the shortest distances, are few and far between. It will also appear more fully, I think, in the 



sequel, that this state of things is not only a natural, but a necessary result of the mode in which 



the gravel was accumulated, and the situation in which it has been left since the excavation of the 

 modern canons. 



Furthermore, wherever mention is made hereafter of the course of any of these ancient channels, 

 or of the direction of flow of the water in them, unless otherwise distinctly specified, it must be under- 

 stood as referring to the direction of its flow at that time only, while the water was running upon 

 the naked surface of the rock, or when the lowest stratum of gravel was beginning to gather in the 

 channels ; for there is plenty of evidence that the period during which the gravel accumulated was 

 long, and that during this period the streams were constantly shifting their beds. Thus it is often 

 the case that the water has flowed successively in very different directions over the same ground, 

 and the direction of its flow at first upon the surface of the rock is frequently no indication what- 

 ever of the subsequent courses which it may have followed over the same spot while the upper 

 portions of the banks were accumulating. 



The estimate on page 119 would give in round numbers about 26,000,000 cubic yards of aurif- 

 erous gravel in the Iowa Hill ridge between the first Sugar Loaf and Independence Hill. Of this 

 quantity I should estimate that about 20,000,000 yards were concentrated in the deep channel 

 which crosses the crest at Iowa Hill itself, and the balance scattered along the sides of the rid«e 



