Laserfiche WebLink
20(16 Subsidonce and Geologic Freld Obsarvabons <br />Botc Canyon. Wast Flatiron, Apacho Rocks, and South of Divldo Mlning Aroas <br />Thr prorctis oFdesiccution involves the shrinking of previously wrttrJ ~9ays and silts during thr <br />(Irving process. <br />,.. , <br /> • l <br />~ <br />r <br />~ 3e <br />, r ~ `~. <br /> • <br />, <br /> <br />- r <br />t ~ Ott i <br />l'~ <br />~ <br />n' +~~ip..~ ~~`'.~r. t ~ <br />~4 I ~ ~ ,~. , <br />. <br />~' ~~ <br />~ ly , <br />} r,~ ~ ~\ <br />~ <br />- <br />•.' r <br />t <br />{. ~.~~ <br />I t <br />r_ t <br />^~'~~1 Y' <br />Pigute 3 Contbut.nu+n de.recuuonert.k:utJ Frnttc-mdu:ed ~rark, I,~;.nrd itt acadtercd <br />ela~.ame of the \1'as:deh ti~mrwon aM~~c un•nnnal cool I ht. irrc}~ular rratk. ahteh is <br />as mwh a< I i mehes utdc anJ is roughly parallel to the .rest :hIT of 1Vc<t Planner. rs <br />most likely ebncc n gracuy-ut.luccd crack m lhr undcrlymg tna..a~c sandsranc (lhtn <br />Creek the crack also nppean to be enhanced ba the shnnkmg .,I the acnthered <br />clan stone. <br />Desiccation cracks can alien he recognized by their irregular, hr:lnrhing, an(I dicrrging pattern <br />less regular than typical soh<idence cracks. tiome 11f the largest desiecauon cracks in thr \1'rst <br />F:Ik ~linc area rvrrc observed ut clays of the Eiarren ~trmher uI~ the 's9rsarrrdr Fumtatiun in the <br />floor (iulrh-Minnesota Rrsrr~uir area attar there had hrrn no mining. The larger, nture <br />regular desiccation crack, and construction cracks may he confused with subsidence rra.ks in <br />areas where Honing has occurred. I loa•cr rr. transcrrse and lungnudin:d trn.ion crlcks c:ulsed by <br />subsidence hJ1'l' a dctinilc spatial relationship kt Ihr g¢tinnrtn of the longaall nunutg panel <br />causing the cracks. <br />831-032 750 N/right Water Engmeors. Inc. Page 6 <br />Decombor 7.006 <br />