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Copyright 2004 - All photos by J. Pint unless otherwise indicated    Updated September, 2013



Pico Volcano on Pico Island


Sixty-seven cavers from fifteen countries came together on Portugal’s Pico Island, in the Azores, for the Eleventh International Symposium on Vulcanospeleology, May 14-17, 2004. Presentations and discussions on volcanic caves and pits were held every other day and, of course, in between there were visits to caves, calderas and other attractions of these volcanic islands of the Atlantic.

These meetings are held every two years under the auspices of the International Union of Speleology (UIS) Commission on Volcanic Caves. The last gathering was in Iceland  and this year’s event was organized by cavers in the Azores (GESPEA) and the Environmental Department of the Regional Government.

Most of the opening talks were in Portuguese with simultaneous translation into English via headsets. Geologist Antonio M. Galopim de Carvalho led off with slides of natural wonders in Portugal which, despite many obstacles, are now being recognized as geomonuments by the government. He also stated that “Vulcanospeleology is no longer a punishment from God,” in reference to olden times when tremors, boiling seas and other “mysterious” volcanic phenomena were much feared on these islands.


 An outdoor dinner followed, with folk dances for entertainment. We were surprised and pleased to see that the dancers really were “just folks” from the neighborhood...




...The dances were held near a beautifully illuminated Dragon’s Blood tree (Dracaena draco)...




...The next day, we took the ferry boat to Faial Island, about a half an hour from Pico. We visited a museum dedicated to the 1957 and ’58 volcanic eruptions and then drove to Ponta dos Capelinhos where it all happened....



...Dr. Stephan Kempe and John Pint put their noses to the grit, looking for semi-precious stones at Capelinhos...



Photo courtesy of Susy Pint


After sampling the world’s most delicious “Churrasgo” chicken, we visited a two-km-wide caldera surrounded by all sorts of wildflowers, and then headed for our first cave...

....Capelo Cave on Faial Island. Unfortunately, when you put 30 people into a 30-meter-long cave, all you can see are bodies!





The next day featured presentations. The most important one for Saudi Arabia was Paolo Forti’s description of nineteen minerals, many of them quite rare, which his team discovered in samples we gathered from Hibashi Cave. The most unusual of these minerals were formed due to the effect of heat from a guano fire on the components of bat-urine “stalactites” and unburnt guano.

After showing surprisingly sharp pictures of these tiny crystals, Paolo announced that Saudi Arabia’s Hibashi Cave had been added to the list of the ten most important volcanic caves in the world in terms of the mineral contents of its speleothems. He further pointed out that the Hibashi results confirmed his theory that lava caves are likely to house more rare minerals than limestone caves.

It should be observed that inclusion among the ten most important volcanic caves of the world implies that Hibashi cave is eligible for world-scale recognition as one of the most important geological sites on the planet.

Below is a picture of one of the samples and a few of the minerals found. For more information, see "Ghar Al Hibashi Lava Tube: the richest site in Saudi Arabia for cave minerals" by P. Forti and others, available from GESPEA.

Photo courtesy of Paolo FortiPhoto courtesy of Paolo FortiLeft: One of the most important samples, a fragment of a jaw with external vitreous saccaroid crusts. Right: Opal-C  (SiO2×nH2O – tetragonal), distinguishable by its flat, lenticular shape.



Photo courtesy of Paolo FortiPhoto courtesy of Paolo FortiLeft: Chlorapatite [Ca5(PO4)3Cl - monoclinic] Right: "A still not determined material which may be an intermediate phase between pyrocoproite and  arnhemite.” Could it be a new mineral?.



In other presentations, Azores cavers brought us up to date on the many different projects and studies they are involved in. Teófilo Braga discussed their environmental education program and told us that, in the last few years, 1,441 school children have gone on guided visits to the Gruta Do Carvao on Sao Miguel Island...


...Ines Vieira da Silva and Miguel Vieira showed plans for an unconventional visitors’ center for Gruta das Torres Cave on Pico Island. The shape, material and color would suggest lava and fit in with the environment around the mouth of the cave. An equally harmonious wall would protect the cave entrance from intruders while still leaving it open to the sky.  Stairs made of local pahoehoe slabs have already been built...

Visitors to Torres Cave. will be issued helmets and lights in order to preserve the cave's natural state.




...Dr. Stephan Kempe reported studies carried out in Jordan by himself, Dr. Ahmad Al-Malabeh, Dr. Horst-Volker Henschel, and others. They found five lava tunnels and two pressure ridge caves in the Harrat Al-Jabban volcanics, part of the Harrat Al Sham volcanic field which covers territory both in Jordan and in Saudi Arabia...

Dr. Al-Malabeh, Abdulrahman Al-Jouid and Mahmoud Al-Shanti in Abu Al Kursi East

Photo courtesy of Stephan Kempe


Note: Dr. Kempe uses the term “lava tunnel” in preference to lava tube because his studies in Hawaii reveal that lava does not flow through channels which are later crusted over, but by repeated underflowing and inflating of initial lava deltas.

...All of the Jordanian caves were surveyed and mapped, the longest being Beer Al-Hammam (445 meters). As in Saudi Arabia, sediments cover the floors, stone walls and cairns are seen and pigeon (probably rock dove) droppings are found, as well as bones carried in by hyenas. Indeed, a naturally mummified hyena was found in Dabié Cave. Unlike in Saudi Arabia, digs have been carried out in some of the Jordanian caves and numerous flint tools, possibly Neolithic, have been found....

Entrance to Beer Al-Hammam

Photo courtesy of Stephan Kempe




...John Pint gave two presentations.  One was on the Caves of Shuwaymis reporting the mapping of Kahf Al Shuwaymis (513 m) and of Dahl Romahah (202 m long). The latter is well decorated with flowstone and speleothems composed of secondary minerals which have leaked through the ceiling and walls...

Saeed Al-Amoudi setting up a survey station beneath the sort of flowstone  typically found throughout Dahl Romahah.



...The second presentation was on surveys and studies conducted in Hibashi Cave (565 m long). OSL age-dating of the fine silt or loess on the floor has shown that it is 4500 years old at a depth of 1.5m and, farther inside the cave it is 5800 years old at the bottom of a hole 40cm deep. Carbon dating of a human skull found in the cave reveals it is 425 years old...


...Speculation was made that much could be learned about the plant life of ancient Saudi Arabia from phytoliths, or tiny, uniquely shaped bits of opal which have been found in plant material contained in hyena scat commonly seen in Saudi caves.

Left: broken coprolite with plant material. Rightphytolith photo courtesy of C. Mulder

The Hibashi presentation concluded with a report that Researchers working with the Field and Space Robotics Lab at MIT to develop microrobots for cave exploration on Mars, recently requested permission to use photos of Hibashi Cave to illustrate the possible interior conditions of lava tubes on Mars. They had been using Arizona caves as models, but they now think that the thick layer of loess on the floors of Saudi caves is closer to conditions that will be found on Mars.



At this session, Chris Wood described the study of a lava cave in Iceland which no one has ever entered! These studies began in 2000 with a magnetometer and ground penetrating radar (GPR) survey which indicated that Stefánshellir Cave, (see Saudicaves in Iceland [[link]] ) continues on the other side of a 20m long lava seal at its upflow end. Three hundred and fifty meters of cave passage were “discovered” (but not seen!) and more recent studies indicated that the concealed cave (given the Icelandic name Hulduhellir, Hidden Cave) may be 1.2 kms long.



Next day, May 15, we visited some of the most interesting caves on Pico. First we went to Torres Cave, 5214m long. This is the one the Azores cavers would like to build a tourist center for.



A pahoehoe-block stairway leads down into Gruta das Torres.



Paolo Forti ducks under the lovely ceiling of the cave. The steam in this picture may look like "hot air" but Paolo is exploring, not giving a lecture!





Ropy-lava floor of the cave, something we never see in Saudi Arabia due to thick layers of sediment or loess, up to 1.5m deep.






As everywhere, there’s a graffiti problem.  However, these words are written in the slime on the cave walls and can be erased in an instant.






To get everyone in and out of Montanheiros Cave quickly and easily, a ten-meter aluminum ladder was set up.





Marieke Meuller examines lava stalactites on a fallen piece of the cave’s ceiling.






Bill Halliday inspecting delightful dribbles on the walls of Gruta dos Montanheiros.






Stephan Kempe explained that what we see here was once a lava ball which was carried along in the lava stream until it got stuck (forever) at this tight spot.





Gruta do Soldao was a fascinating cave, as you'll see from the pictures below...


Ken Ingham's cheerful smile tells us that the cave entrance may be tight, but it's well worth it.




...Ahem, well, beside the tight entrance, there is this tricky little climb-down, but it's still worth the effort!






...For example, I finally got to see a lava bench...which not only looks like a bench, but can actually be used for one, as Paolino Costa demonstrates here.

And guess what? Soldao Cave also has a lava gutter... which looks just like... yes, you got it: a real gutter!





...Moreover, the ceiling of this cave is covered with curious formations, such as the brightly colored coating on the left and the amazing OPAL stalactites on the right...




...But most wonderful of all is the stunning view of the sea from a small "window" in the cave wall.  That's Paolo Borges admiring the waves.






The next day there was a power outage at the school where the presentations were being held and the entire day’s sessions were all jammed into one very long afternoon. The morning was dedicated to the official meeting of the UIS Commission on Lava Caves.  Paolo Borges and Jan Paul van der Pas chaired the meeting. Inquiries were made into the publication of the Proceedings from the Iceland Symposium and it came to light that some contributions may have vanished into Cyberspace instead of reaching the hands of Siggy Jonsson....


...The venue for the 2006 Symposium was then discussed. Saudi Arabia was a contender, but, in the end, the honor of holding the next Symposium was given to Korea. This was accepted by Mr. Kyung Sik Woo, who suggested holding the event on Cheju Island, whose lava tubes are candidates for World Heritage status....

Kyung Sik Woo describing the extraordinary features of Korean lava tubes...




In the afternoon, oral presentations began with Biospeleology of Volcanic Caves. Paulo Borges, Rosalina Gabriel and Elvio Nunes, among others, spoke of ground beetles, hoppers, liverworts and mosses while Diana Northup focused on “bacterial mats” meaning the “slime” we often find on the walls of humid caves. ...

Yuck. Here is yet another feature from Soldao Cave. On the wall we found what seems to be cave slime mixed with muck that has leaked in from outside. Will Diana discover strange new creatures growing in it?..




Later in the afternoon, Stephan Kempe presented two Hawaiian lava caves that have been eroded and greatly modified by water. Arni Stefansson of Iceland then speculated on ways to permit public viewing of Thrihnukagigur Cave, a giant bottle-shaped volcanic chimney. He proposed a balcony 60 m below the entrance, accessible through a 200 m man-made tunnel angling down from the surface. “The sight downward into the widening chamber is as if one were standing on the top of a 20-story building inside a mountain.” If one Euro could be collected from all persons who can't pronounce the name of this cave, Arni's project would be guaranteed success!

At the closing session of the Symposium, the Azorean cavers proudly announced the discovery -- made during the Pre-Symposium field trip to Algar do Montoso at S. Jorge Island -- of yet another new species of troglobitic insect (Trechus n.sp.). It was obvious from these presentations that studies of the flora and fauna in caves are likely to result in important discoveries and we look forward to the day when such research will begin in Saudi caves.

On this optimistic note, we end this report on the XI Symposium on Lava Caves and look forward to the next one on Cheju Island in Korea: MANSEI!



See you in Korea!



John J. Pint


UIS Commission on Lava Caves