Show 1 v OR TALK ON AST r filial I 1 UM george holman eldridge discusses Oc occurrence currance of that element throughout this section of country countr Y tho the following blittle 1 j george 1101 mans eldridge ou oil the tile for formation abot of asphalt veins mid and the of that element cannot but in be OL of general interest throughout utah whore where the greatest deposits in the west are boand nud and mined asphalt veins eua as he be lire are be beartel atteL ed through most of the territory of the etli e nod and are of far wider than inet veins the wider occurrence of 0 its ahalt veins la to due to the fact that petroleum tr the mineral from i aich the asphalt hae has been derived has nu an ex tensho I 1 distribution in tha the strati stratified fled rocks from the oldest to the youngest in the crumpling to which the cruet crust of the eurth earth line has been subjected euch such etrata strata have frequently been folded and then exposed by ero erosion gion there Is no marked difference in vein phenomena whether the fissures be filled tilled with bituminous matter or ores and gangue the character of an asphalt vein depends largely on the nature ot of the country rock the tile purer varieties vurl otles of asphalt occur in fissures the formation of which has been brought about by folding or contraction when frao frac atutes are due to folding a displace jentof ment of the originally adjacent walla walls lias hug often taken place while in the ils produced hv iv contraction this title doca not necessarily occur to assign the origin of a fissure to 1 the causo cause IP Is however often attended with considerable uncertainty because lack of displacement may nc tie company phenomena of the llast class the greatest asphalt tilled filled in the world Is ono in which there Is no displacement the vein having a amax anax icum width of eighteen ft et nail and a length of po lia less than ten measured in dullea ilea athers occurring nearby are ure only t h kittle smaller Blun ller and IQ in addition display iho tho phenomenon of forking in both instances the eins trend in the tile direction of the dip of the duclus ing strata ahey are therefore more probably tho the result of contraction than of folding thu the axes of the flex turea tures trending at right angles to tho vein veins the itle lineal extent of filled r 11 varies from a n few foet to bristly miles in width the fissures when single und and uninterrupted by horses and inclusions that havu have fallen in froin from tho the walls runge from at m F if of eighteen feet down to ex tr ti mely minely fine threadlike thread like chelcea whose length Is always tlona tiona tely great A clean flexure frequently Illen tl attains a width of eee gereral rul feet 4 in most cases instead of a elipio fissure a zono zone of fissures has been in which it large num berot ee parate fracture fractures occur the einhell r ones oties interlacing with one another and the he whole network together ofTon Ung it large aggregate space far for tho the pas sage of the material with which the haruro Is alls mode of occur ie Is the more interesting as it affords forda a cloen parallel to characters inon more common commonly ly found among veins which carry minerals min enild particularly ticul arly those in areas of cryltal file oc hister or in the matar elates slates tit of moro wont recent geologic epochs simple ore filled flaaen fla a on the other hand are usually illy con conquer to heavy bedded rocks such as limestone and aund stone or tu masslon roke amona asp asphalt halt vone veins are found IV somo remarkable remark ablo examples of ten city lo 10 the cris where the tile wonderful velna veins of utah are found the ma writer baa has observed bonfa u instance of t tilled fissure hn uninterrupted asphalt of a wid h not exceeding one half tin an jact a lineal extent of full four liun hun re L it a appears at tile surface a a jet let black line and when view viewed ed from a distance resembles a carbon crayon i mark drawn on the eroded of light colored yellowish gray sandstone san detone ehe downa downward aird extent of the re ie is more of deep workings working remain un however th the certa certain in in general vertical rang range of the more mor a persistent velna veins ot clear material lal la greatest in mag ive beda of andexl it practically cowen sive with the i enal rook it Is thick nest of 0 the thought that th the a great kr aboy vein ea JA er in eastern utah had tind before erosion effected the strata a vertical range of at least two thou feet which la Is tho tile thickness oi 01 the massive sund sandstone in which ic occurs in addition to tho the long straight veins another type may often he be noted in which tle veins show a closer relation to tho the folded structure of the enclosing rocks und exhibit a li it gher degree of complexity an excellent illustration of thia this type may ic to 8 seen in to ono one of the asphalt di district tracts of butia tho the velna veins are located on thi th i I 1 nose or easterly ca etorly end of an anticline od ori the sides or limbs of the fold at some little distance dis tunco from its downward pIt pitching cIni extremity are one of 0 two normal closures flo As u CC C C approaches the end of the told fold the rocks become relatively broken broka brok a and crushed and the regularity of the strike fissures la to lost in the complexity of the interlocking fractures the general trend el of fracturing however continues ai as a whole to follow the strike of the beds curving around the pitching end of aba fold and connecting the strike lasures en an the ona one limb these on the other the strata in this case comprise a succession of thin bedded lime stones and calcareous clays the tile lime stones predominate but the clays are in sufficient abundance to give to the measures it thinly laminated character rendering them in a sense between eu a typical heavy beddla and it series the belus therefore are likewise transitional neither as regular as those usually found la in heavy havy bedded roc kanor nor its irregular na as those in hales |