KARST AT THE WIPP SITE

                          PHOTOGRAPHS FROM DOCTORAL DISSERTATION OF RICHARD HAYES PHILLIPS:
                      "PROSPECTS FOR REGIONAL GROUNDWATER CONTAMINATION DUE TO KARST LANDFORMS
                          IN MESCALERO CALICHE AT THE WIPP SITE NEAR CARLSBAD, NEW MEXICO"

          LEFT:  Weakly consolidated caliche remnants underneath the WIPP-14 sinkhole.  Two distinct caliche
          horizons in the trench walls indicate multiple episodes of carbonate accumulation.  Caliche is now
          soft, sandy and chalky.  Bluish-gray gleyed sediments in the trench walls indicate past ponding of
          the depression, during which time the caliche was leached and degraded under reducing conditions.
          All other trench exposures showed red to brown sand, indicating oxidizing conditions.

          RIGHT:  Solution features in remnants of Mescalero caliche underneath the WIPP-14 sinkhole.

               For a full discussion of the geologic context of these photographs see "Direct Testimony"
                                        http://www.cardnm.org/techsecfrm_a.html