On May 28th, 1989, a group of geologists traveled to Los Iros to examine the ‘Mud Island’ that had gained attention in the news media some weeks earlier. The field trip was led by J. Frampton (Trinmar) and J. Keens-Dumas (Trintopec). At Los Iros, John Frampton pointed out the old cliff line, now some 100 meters inland, and explained that the area now being eroded by the sea was an ancient wave-cut platform and/or deposits associated with the past sealevel. Towards the west along the beach fossiI beach-rock and back-beach lagoonal deposits with abundant plant remains were observed. It was also

noted that these deposits were overlain by fossil mud flows which had probably erupted from the Los lros mud volcanoes.

The mud island itself exhibited several thrusts (Plate 4), which ramped towards the south. Beach sand could be seen covering much of the 'island'. There were no signs of active mud volcanism or gassing. From here the party moved inland through the bushes to view the large faults which developed contemporaneously with the mud island. In summary, the 'mud island' was interpreted as a massive slump of fossil mud flow with the mud island representing the toe of the slump upthrusted along faults (Plate 5).

The group departed Los lros beach and traveled east to stop 2, Loronsette, Palo Seco, to examine sedimentary structures in the Pliocene sands and silts of the Lower Morne L' Enfer Formation. These sedimentary structures consist of ripped-up clay clasts (Plate 6) convolute laminations, fluid escape structures and symmetrical water-ripples (Plate 7). Low angle cross stratification, probably hummocky cross-stratification was also discernible in the sequence. Keens-Dumas interpreted the sequence as inner shelf deposits under storm wave surges. He further stressed that although the exposure was not as extensive as most geologists would like, however, a great deal of sedimentologic information could be retrieved and inferences could be made on the depositional processes involved.

The mud volcanoes at Palo Seco and Anglais Point were also visited under the guidance of John Keens Dumas. Activity was normal at both mud volcanoes but heavy rains had eroded a deep valley in the lower part of the mud flow at Anglais Point exposing the almost vertical beds of the Cruse Formation. Several interesting sedimentary structures were visible.