| Show geology of the park the geological gut voy of the yellowstone pink was begun by the national government in seven n yours years of field m ork and as aa wany more of of flee alid laboratory study hap been devoted to fro this subject by specialists of the united states geological sil sinev rev and now the publications ai me e approach ing completion and the first work nork the geological I 1 ollo olio of thel th lark lim hn just juht ben been issued the lollo folio consists of bix pages of do de text three pages of ll lustia eions four topographic sheets scale 1125 and four sheets delineating 9 the areal geology of the region ahe general descriptive text giving A succinct narrative of the geological history and development of the pa park C country from the time of the easiest eallie t continental land surfaces up to an 1111 and including ImI the hydrothermal hydro thermal phenol cna as sen epen today to day wan mas willan by ar nold hague geologist in charge it la Is fol follow ed by an account of the sedimentary rocks bioni the cail eail lest cambrian deposits to the tertian con by falter harvey nied aed and a detailed besci dis pili p aloa of tho the igneous looks locks by joseph id dings hie of country covered by the alie ocllo tc floii stone national anric I 1 ollo olio ali il s between 44 and 45 41 north latitude and meridians and it Is tod la ili the ext ionie northwest corner of wyoming fal fai the grenter pait of the park Is iq include od ed within the aie ahei of the four atlas alias sheets but a narrow strip lira ilos to tile the in montana ani a still ani rower strip extends hegt cst mard but both into idimo and montana in ili the organic act the declai declared ed that the leser antion nas ab dedica dedicated td and set bet as it a public pa park r k and pleasure plon mure ground for the benefit and enjo enjoyment vinent of ill ohp peo pie to the maiv ulous of geysers and hot springs and such physical foa features tures as the grand orn nd canon and yellowstone iche tills this folio possesses mole moie than ordinal interest to every studious man the oldest rocks of this region are goranites granites gra gneiss and reg regarded aided ded na fl of aichman age they occur cecur in ili all the mountain uplifts that encircle the park but ale aie unknown in the central portion astound these theme couil dental land masses there NA as aa deposit ed a conf 01 rouble setler of and bioni aiom the time of the middle Cambi Inn the lowest beds exposed through the cambrian ani brinn devonian carbon irlas 1 ains lp and Creta cretaceous including the laralle Larau ile Band genrl nil fill aliese greit divi of and an times anre char chap by a typical fossil fauna mth etli the clow of the deposit mitlon inn of the sandstone tile conformable hails of canie came to an end iho 11 lie entire was elevated above tile the spa and folding of lails uplift out the toalii ranks of the jini thern ling inis been as the post rion lorai nt laid rocks occupy only small arens in the pirk ali ohp antti art of the region being covered by bensle tens le e flows of I 1 liva ian A inagh of coarse conglomerate ling has been reft frred to tile the rocene anti an obscure exposure of pliocene Il locene alid aad W Y ff PR 4 y jbf r arfi r coarse sands are well exposed in th taft escarpments of the grand canon volcanic energy which has played so great a part in the geological development of the country was waa connected with n alth the pout post laramie laralle movement and fol followed loed closely upon the elevation of the mountains and the accompanying dislocation and compres compre aalon ll 11 ion 0 of f strata the eruptive masses in fu forcing their way upwards sought bought egress along the lines of least resistance or wherever strain had been greatest in the crump led sediments volcanic outly rats con tinned on a grand scale throughout I 1 tertiary time |
