asscciation for mexican cave studies box 7672 ut station austin ...

11First Exploration of NogalThursday afternoon Alex Cochrane, Don Broussard, Roy Jamison, andAndy Grubbs returned from a scout trip to San Jose two miles north ofConchas. The locals showed them a rather deep hole named Sotano de Nogalnear town. One entrance is a 260' free drop in very large passage. A5X5 foot hole led off the bottom to a 30 foot climbdown and a 30 foot dropwhere they ran out of rope. (They had to tie a knot 60 feet off the floorjust to do the entrance drop!) They reported air blowing strong enough toput out a carbide li~ht!So the next day, with great difficulty, we managed to rouse 5 people'from the 37 at camp to hike out again with roughly 750 feet of rope. Wearrived around noon at the double entrance (60 feet from the 250 foot dropis another 200+ foot drop which surely connects but has yet to be descended.)Steve Zeeman did most of the rigging while Steve Ward and I shot thesurvey in behind him. Roy kept book and Alex did a bio collection. Thepassage was so pleasant, dry, and spacious that Ward and I had no problemkeeping the survey right on Zeeman's heels as he rigged each virgin drop.Beyond the 30 foot drop was a 60 foot pitch, followed by a 140 foot dropwith a knot 30 feet off the floor. The room above this drop was the moststriking example of bedding exposure in a cave I've ever seen. Dippingalmost vertical, huge scabs just stuck out of the walls and floor. Slickensidesand an obvious fault wall were quite impressive. Beyond the 140 footdrop was a steep climbdown for 50-60 feet then another 100 foot drop intothe "Greccian Column Room." A 60 foot drop off here led across a crystallake, through more sinuous passage and finally another 50 foot drop wherewe ran out of rope. This was unfortunate as just 50 feet away was anotherl50-foot-plus drop. Que Lastima! The cave was still pushing a lot of air,even at that depth. The survey showed that the top of the 150'+ drop was800 feet below the entrance. The most significant differences in Sotanode Nogal are what will undoubtedly make it deeper than Conchas. One, Nogalis a "Paleo-Floodwater" cave, apparently taking huge amounts of drainagelong before San Jose was established. This circumvents the main cork injust about all of the San Juan plateau caves. The advent of farming allowedtons of silt to be sloughed off by arroyos everytime it rained. Since alldraina~e on the central plateau is internal, that silt only had one placeto go -- right down the tubes. Jamison reports a usable limestone depthof about 2700 feet from the plateau to the Rio Jalpan (altimeter readings).Almost all the San Juan systems consequently silt up at constriction pointsfar above the usable limit of limestone. Hence, since Nogal has none ofthe silt problems the other caves do, it is quite expectedly a clean, crycave as far as we pushed. Secondly, the evidence of a strong air flow asdeep as -800 feet indicates considerably more passage -- or a lower entrance-- something none of the other caves show -- almost all the others havebad air and organic debris near the bottom.Without stepping too far beyond reason, I would say that some May whenwe return, San Juan will have its second SOOm+ system!Bill Stone