As explained in the general introduction to this volume, the choice of two sites drilled in the Panama Basin during Leg 54 (Figure 1) resulted from a directive to the Leg 54 scientific party to conduct "drilling tests" in areas targeted for an extensive future drilling program (Legs 69 and 70). Nominally, the objectives were mainly technical-to find the answers to these questions : Could the Glomar Challenger locate small, supposed geothermal mounds south of the Galapagos Rift ? Could she then core them ? Finally, could she spud into basement beneath the mounds with a mere 25 to 30 meters of sediment cover, or anywhere else in the Panama Basin, given the problems encountered in drilling basalts elsewhere in the Pacific where spreading rates are high ? [NOT CONTROLLED OCR]