12MB PDF - Association for Mexican Cave Studies

oulders mixed with silt.Chichicasapan apparently drainsinto Atepolihuit and this, at itsbottom, continues in a terrible canyontaking a "Yochib-like" quantityof water. Where does this resurge,and at what elevation? The rumorwas that it continued to the northto Canon Zempoala which reportedlyis so wild and difficult of accessthat even local Indians questionedknew nothing of its bottom. What achallenge! Accordingly, one restday I drove down to the ferry northwestof Tetcilla (above Reyes deVallarta) at the mouth of the canyon,at an elevation of about 100 meters.The river was low, at a guess about10 CFS or less; perhaps enough tobe described as Yochib-like if confinedin a cave passage. The canyonwas not cliffs down to the watersedge, so I made my way upstream withlittle difficulty, crossing almostat will and never getting more thancrotch deep. About 800-1000 metersupstream there was obvious water enteringfrom the south and pokingaround I found a cave entrance ofwalk-in size with cold air flowingout. My flashlight refused to workso I didn't go far in, but it seemedto go. The water flow out didn'tseem more than 1-2 CFS. About 2kilometers upstream from where Istarted I came to another ferry crossing(these ferrys are just boatsfor foot travelers poled back andforth at a quiet place in the river).The second ferry is a trail crossingbelow Tuzamapan, a town on the roadI had driven down. Here I turnedback after examining a collapsedspring opeping on the north side ofthe river right at the crossing. A­bout 2-3 CFS was the flow. At notime was lout of sight of a personor corn field on the way upstream.So much for the terrible canyon.The trend of Sistema Cuetzalan(and Atepolihuit) makes it seem unlikelythat its resurgence would befurther upstream. If it were, mostof the river's flow would have to bethe flow described for Atepolihuit.Another possibility is that the systemresurges in a lesser canyon ofthe R10 Toxan just to the south. Accordingto the maps we had, this wastoo high in the area where the cavesshould cross, but after that it loseselevation and enters the Zempoala belowReyes de Vallarta.So another day, LaForge and Idrove down the road below Cuetzalanthat skirts the south rim of the R10Toxan canyon. I dropped Dick offabout 3 kilometers down - he took atrail into the canyon at a point a­bove where the cave system shouldcross. I continued on to where theroad was blocked by a slide. ThereI continued on, hiking along theroad and checked the Toxan and anothercanyon coming in from the south.I came to where these two joined, a­bove their confluence with the R10Zempoala. Both were quite dry. Interestingsince Dick found the Toxanto have several CFS of flow higherup. I continued on, out onto thecoastal plain which presented astrange appearance. As far as youcould see was a landscape of rolling,steep-sided hillocks 20 to 30 metershigh, covered with green grass andoccasional trees and cows. Betweenthe hills were no stream channels -it was karst. But where the road Iwas following cut into these hills,they were shown to be sand. Apparentlythe ocean once lapped against thebase of the mountains.So we still don't know where theresurgence is, but my guess would beeither the R10 Zempoala near Reyes deVallarta or the edge of the dune karstsomewhere. If so, the depth potentialof the system is something like 1200meters. If the resurgence is furtherup the Zempoala than the crossing belowTuzamapan, then the potential is1000 to 1100 meters.69