Arizona republican., 1916-12-15


 work F. A. Provot:
 General Description of Surface
 The Jerome district of which the town of Jerome is the center is situ- ated on the eastern slope of the Black Hills near their northern end These hills have a northwesterly and south easterly trend and lie between the Verde Valley on the east and Lonesome Val ley on the west.
 They rise west of Jerome to height of about 7.70O feet above sea level and 4500 feet above the Verde river. The postoffice at Jerome is at an elevation of 5153 feet If you will look at the top of these hills you will see that it con- sists of great thickness of lava and sedimentary rocks. which lie almost flat, except to the north of Jerome where they dip to the north.
 Cut from east to west by Mescal and Yaeger Canon the top has been di- vided into two tableland peaks known as Mingus and Woodshute mountains respectively The former lies little to the south of Jerome and the latter to the west. Both present on their eastern and western aspects great escarpment of lavas, limestones and sandstone having combined maxi mum thickness of 1700 feet and extend ing down to an elevation of 5000 feet above sea level. At this elevation thes' are underlaid by the very prominent bed of wine red Cambrian sandstone some 70 feet thick, which can be fol. lowed with but few interruptions around the whole mouEtain from Jerome south through the Copper Chief property and on, but not to the north where it is buried by the dip of tho strata.
 At this elevation of 5000 feet the hn- derlying schists and diorites are eX- posed in a wide belt extending south easterly from Jerome to and past the Copper Chief Mine and on into the Cherry Creek district.
 IL is at the contact of the sandstones and the schist and at an elevation of 5000 feet that all the springs of the district discharge their waters.
 The belt of schist and diorite pre- sents rugged surface of reddish brown hue in great contrast with the lime stones and lavas on either side. Its eastern border, at an altitude varying from 5000 feet at Jerome to 4400 feet just east of the Copper Chief mine. fol- lows approximately the strike of great fault. that has brought down the lavas and limestones some 1900 feet below their former positions. To the northeast of this fault lavas and lime stones again cover the schist 10 great depth and they in turn, as the Verde Valley itself is approached, are covered with thick deposits of modern con SlOmerates consisting of mountain wash. which has collected in old basins The whole eastern slope of the moun- tain is cut by guicbes running in an easterly direction and probably follow ing the course of minor east and west faults.
 At an altitude of about 3S00 feet and only two miles east of Jerome the foot hills fade into a plain or flat that sloDes gently to the Verde river.
 To the north of Jerome the schists disappear under the sedimentary rocks These latter dip down here at an angle of fifteen degrees or so to the north northeast and disappear in the distance under sedimentary rocks of young CT era
 Historical Sketch of Geological Events Leading Up To Present Conditions The oldest and underlying rock at Jerome is a schist which rorms the body of the mountain range. It extends south and westerly into the Bradshaw Mountains where the United States Geological Survey has examined 1t and giYen 1t the name of Yavapai schist To the north of Jerome it underies all the limestOnes, sandstones shades, etc.
 
 scape and 1t is found again in the bot tom of the Colorado Canyon. It under lies Mingus and WoOdshute mountains and again reappears on the west side of the range at Russell and farther south at the Yaeger Canon Copper Co. mines This schist is the folded and altered result of what at one time were flat lying lava beds and sediments. Sketch l.)
 In very ancient times these lava beds were folded in very tight and almost vertical folds whose general direction was northwest and southeast at Jerome Sketch 2.)
 They were then invaded from below by large diorite dil<es and stocks that forced their way up most easily along the planes of the folds and the cracks this folding had caused in the beds. tSketch 3.p As q consequencce of this condition these diorite intrusions have also a general northwest and south east trend.
 This mass of folded beds with it's diorite dikes was then subject to great pressure and chemical action probably through being buried and unburied one or more times under great masses of younger rocks. During this period many chemical changes took place and heavy shearing with a certain. though not very great amount of shattering, occurred which altered the beds to schist. Into the slips and minor faults caused by this shattering smaller dikes 0L more slliceOus materials such as