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' ~ de Cristo fault, vet also dispLavs recent fault scarps with <br />low historical seismicity. Figure 2 does not represent an analysis <br />for the Sangre de Cristo fault, but it does show the ,~enerai <br />idea and form such an analysis will take. To generate Figure <br />2 I have used the same curve produced by C1ufF et a1.;1980) <br />For the llobble Creek portion of the Wasatch fault (deformation <br />t rate 1 mm/yr) and Lengthened the horizontal Cime scald to <br />correspond to deformation rates more typical of the S<<ngre <br />de Cristo fault. <br />From Figure 2, and depending on the deformation mate (0.4 <br />mm/yr, or 0.1 mm/yr) and the time since the Last fault rupture <br />(2,000 years to 5,000 years), one obtains a probability of a <br />' similar event in the next 50 years to be from 1 percent to <br />5 percent. These probabilities are higher than the 1/4 per- <br />cent to 1.5 percent calculated in Table III, but not remakably <br />i ~ higher. <br />Earthquake design should anticipate strong ground shaking <br />I during such an event, but confinement of facilities to areas <br />within the Sangre de Cristo mountain block (upthrown portion <br />of the Sangre de Cristo fault) should provide protectipn from <br />fault displacement, ground tilting and ground failure (graben <br />' and fissure development) common to the docanthrown portion of <br />normal fault events. <br />I icECOMME[JDATIONS <br />The calculations and estimates provided above are presented <br />to provide a benchmark idea of the earthquake hazard at: the <br />Battle Mountain Gold Co. property near Rito Seco Greek. The <br />sparse data suoport for these calculations necessitated nu;aeroL~s <br />assunptions. :+.lthou2h i beli.eve the ass~.~.mptior.s are reasonable <br />ones, I a1~'o believe more informatio; will significantly improve <br />confidence in the results. B~+sed on tha geomorphology of the <br />t mountain front and the 1o•a historical seismicity, howzver, I <br />do not believe the probabilities will change significantly( from <br />I Z percent, for example, to 0.2 or 20 percent). <br /> <br />1 9 <br />