17MB PDF - Association for Mexican Cave Studies

the trip and the long hours mapping, we returned to camp about2 AM, egerly awaiting the next day when we would push on deeperinto Tinaja.After a leisurely breakfast the next morning, we walkeddown the entrance ~assage (it drops 62 feet in a horizontal distanceof 1826 feet), climbed down the cable ladder drop (27 feet),and turned left to the Sandy-floored Passage. This day we plannedto check all the leads off this passage except the downstreampassage. After walking about 2000 feet, we carne to Collins' Passagehigh on the right .wall. This passage turned out to be aseries of small rooms almost blocked by formations for severalhundred feet, then a mud-floored room a couple of hundred feetlong, and after more squeezeways finally a long room running diagonalto the passage. This last room contained two massivecolumns on the order of 40 feet in diameter and a deep mud fill,and was several hundred feet long. Two other short passages offthe Sandy-floored Passage were mapped along with the 550 footconnecting loop to the downstream passage. Once again we returnedto camp for the evening after having mapped more than 2000 feetof passage.The next morning we returned to the Sandy-floored Passageto map the downstream passage which begins about 400 feet fromthe cable ladder drop. After a series of short drops and steep31SOTANO DE LA TINAJALine Map from Brunton and Tape SurveyIIIIIIIIIIf: Water PassageIIIIIIIII , \Arroyo '"~r-------:-~-_~~........... tEntrance Cable ~Ladder./DropSandy-flooredPassageNmScale in Feeto 800Passage