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SUNDAY MINE COMPLEX-HYDROGEOLOGIC REPORT <br /> The five individual mine portals have been constructed near the contact between the Salt Wash <br /> and Brushy Basin members of the Morrison Formation. CDM (2009) prepared geologic cross <br /> sections that trend subparallel to each of the mine areas at SMC. These cross sections have <br /> been reproduced in this report and are shown in Appendix D. <br /> 4.3 Geologic Structure <br /> Geologic structure in the vicinity of the SMC consists of local, more complicated zones of <br /> subparallel normal faulting associated within broader regional anticlinal and synclinal structures. <br /> Cater(1955) has mapped the northwest-trending Gypsum Valley salt anticline and <br /> Disappointment syncline axes short distances to the northeast and southwest of the SMC, <br /> respectively. The Gypsum Valley anticline is one of several anticlinal structures in the region <br /> that are the result of large salt intrusions from salt and gypsum originating in the Hermosa <br /> Paradox member and possibly deeper deposits. The anticline's axis falls along the axes of Big <br /> Gypsum Valley and extends some distance to the north. The salts intruded into the overlying <br /> Paleozoic and Mesozoic strata; these strata are upturned on the flanks of the anticline, forming <br /> the ridges bounding Big Gypsum Valley. <br /> The anticline is breached and eroded and Cater's (1955) geologic map shows related collapse <br /> features bound by numerous northwest-trending normal faults. These faulted blocks of strata <br /> show a variety of attitudes or rotational orientations. Faults on both sides of the anticline <br /> generally show downward movement on the valley sides of the faults. In the vicinity of the SMC, <br /> it is probable that much of the Paleozoic and Mesozoic strata have been repeatedly truncated <br /> and offset by the Gypsum Valley salt anticline and subsequent collapse and erosion. This is <br /> illustrated in cross section A-A' of the geologic map of Hamm Canyon quadrangle (Cater, 1955). <br /> Cater(1955) remarks that pre-Morrison formations thin or wedge out against the salt-gypsum <br /> core of the Gypsum Valley anticline and are not present at all over the top of the core. At the <br /> beginning of the deposition of the Morrison Formation, sediments covered the salt intrusive <br /> anticlines. In addition, older post-Morrison formations dip more steeply than the younger <br /> formations. <br /> Cater(1955) also mapped the presence of a syncline in the region whose axis trends northwest <br /> parallel to and through Disappointment Valley. The syncline is illustrated by structural contours <br /> of the top of the Entrada Sandstone. Disappointment syncline is a broad fold that plunges gently <br /> to the southeast. <br /> Western Water& Land, Inc. 11 <br />