Recent work at Pan de Azucar

 

Since the last WSG visit to Pan de Azucar in April last year, a number of trips to the area have been undertaken by Evelio and myself and a visit made by a Spanish group consisting of cavers from Pays Vasco together with a small team of divers from Madrid. This short article is an update on our understanding of the area and includes a few pointers as to what to do next.

 

Firstly, the Spanish visit resulted in the making of a film for Spanish TV. This film should be ready this summer and Im told includes footage from both Cueva Grande, Cueva Chiquita, Hoyo de los Cimarrones and diving at Cueva Jaiba. I understand that the film also includes an interview with Evelio who assures me that past work done by WSG is fully credited. Well see. During the visit the Pays Vasco team disgraced themselves in a number of ways, the result of which is that they will not be allowed back to the area.

 

On the other hand Im told that the diving team from Madrid were very professional and their activities very worthwhile. The team dived the following sites:

 

 

 

 

In between times Evelio, Coco and I have been scrambling about the surface of the mogote above Cueva Chiquita with a GPS unit. Although the accuracy of GPS under the canopy of the rain forest and within the canyons leaves a lot to be desired we now have a pretty good idea of where Cueva Alfredo lies together with a number of other surface features that are gradually revealing the geology of the area. The streams which feed Cueva China and Cueva Titanic were surveyed during the last WSG visit and a further two streams have been followed:

 

 

 

So what does all this tell us? Well, the geology of this particular section of the mogote presents itself as four distinct bands extending from south-west to north-east. To the south-east is an area of igneous and metamorphic rocks which acts as the collector for the various streams. So far weve only explored what appears to be a small part of this area and have no idea as to the extent of these rocks.

 

The remaining three bands are all limestone. Progressing from the south-east the second band is characterised by gently descending streambeds where, unfortunately, no-one has seen fit to record the dip of the limestone. When they reach the third band of steeply bedded limestone (60-700) the streams abruptly descend cascades into steeply descending canyon-like hoyos. The streams sink into caves at the lower end of these canyons where the fourth band of horizontally bedded limestone is reached. This final band extends to the edge of the mogote.

 

Interestingly the end of Cueva Titanic, the only extensive upland cave weve found so far, seems to lie very close to the boundary between the second and third bands. In addition Cueva Chiquita appears to be formed totally within the horizontally bedded fourth band. Not surprisingly perhaps, the immediate geological structure of the mogote plays an important role in cave development.

 

So what next? Well, one of the most immediate things that needs doing is to explore Cueva Alfredo and hopefully connect it with the China-Chiquita system, presumably somewhere in the region between The Classroom and 100 Acre Wood. The overland route to Cueva Alfredo is pretty arduous and takes around an hour and a half from the farm, having a direct underground route will hopefully ease this and allow an accurate survey of the canyon above to be undertaken.

 

To the northeast of the Cueva Alfredo canyon is the Hoyo de los Platanos. Ive only passed through this once whilst returning to the farm but have the distinct impression that there is a sink, possibly a cave, at the lowest point of this hoyo. Exploration further to the east, above the end of Cueva Chiquita is also required as somewhere in this area is the stream that flows at the end of the cave even at the end of the dry season.

 

The extent of the non-limestone rocks also needs to be ascertained. No doubt further surface streams exist to the north-east of the currently explored area which are likely to lead to further caves. The terrain on the non-limestone rocks is very much easier to traverse than the limestone itself so this should hopefully be relatively easy. We dont know whether the igneous and metamorphic rocks form a cap overlying the limestone, or are an intrusion of some form, or maybe a relic of some previous landscape that existed prior to the limestone being deposited. Hopefully fuller investigation of the feature will shed some light on this.

 

Another area of the surface that might prove interesting to explore is that above the end of Cueva Grande. Maybe examination of the mogote here will yield some clues as to the sudden end of the cave. Cueva Susanna should hopefully provide access to this area. In 1992 a line of three small hoyos were explored from this point though in what direction nobody knows.

 

Locating the Hoyo de los Cimarrones would be useful. GPS is good enough for positional data but we do need some accurate means of assessing altitude since GPS is hopeless for this, suggestions please.

 

Finally, more diving is required. The sumps in Cueva Campamento would be worth investigating though no doubt two of them will prove to connect. Investigation of the upstream sump might indicate where this water comes from. Whilst poking around near the Pan de Azucar main resurgence we noticed that there appears to be a point where the volume of water suddenly increases. In the opposite bank is what appears to be a rising that might be worth investigating. Numerous other sumps exist in small caves around the base of the mogote. The end of Cueva Hoyo de los Cimarrones is wide open, though donkeys would be needed for the carry in.

 

Bob Wilkins - May 2000