\n<\/strong>Cave geology
\nInstitution
\n<\/strong>Institute of Geosciences at the University of S\u00e3o Paulo (IGc-USP)
\nEducational background
\n<\/strong>Bachelor\u2019s degree in geology (1982), master\u2019s (1987) and PhD (1994) in geosciences, at USP<\/div>\n
When was the first time you ever entered a cave? When did you decide to study geology? Did you manage to study caves during your undergraduate course? Why six? We see how caves are formed, with dissolution and corrosion at depth, opening up voids in the soluble rock<\/p><\/blockquote>\n What did you all want to see at the Ecos cave? Can we use cave as a synonym of Karst? Who were your companions at this time? It seems your time as an undergraduate was very busy. Valdir Felipe Novello\u2009\/\u2009USP<\/span>In the Diabo cave, 2012: Veronica Ruiz, Bruna Cordeiro, Paul Williams, Bruno Lenhare, Karmann, and William Sallun FilhoValdir Felipe Novello\u2009\/\u2009USP<\/span><\/p><\/div>\n How was this mapping received? What was Operation Tatus? Over time, I started saying that I am a geologist of nothing. I have to explain the absence of rock, not the rock itself<\/p><\/blockquote>\n And how was the discipline? How did the idea that caves may provide the history of past climates come into being? How did you resolve this? You also researched the role of microbial activity in the formation of caves, did you not? How many caves have you discovered? Do you remember any moments of elation? Aziz Ab’Saber always recommended: \u201cYou want to understand a cave? Go outside it, look at what surrounds it, understand the system\u201d<\/p><\/blockquote>\n Have you ever gotten lost? You must be a zero for claustrophobia, right? What are the basic rules for exploring these kinds of places? Do you still go into caves? The story above was published with the title “Ivo Karmann: <\/strong>Geologist of the void<\/strong>” in issue in issue 349 of march\/2025.<\/p>\n","protected":false},"excerpt":{"rendered":"In good humor and with a strong team spirit, researcher tells of the beginnings and evolution of scientific investigations into caves in Brazil","protected":false},"author":17,"featured_media":562843,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[161],"tags":[5900,240],"coauthors":[5968,1601],"class_list":["post-562842","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-interview","tag-geography-en","tag-geology"],"acf":[],"_links":{"self":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/562842","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/users\/17"}],"replies":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/comments?post=562842"}],"version-history":[{"count":2,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/562842\/revisions"}],"predecessor-version":[{"id":565412,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/562842\/revisions\/565412"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media\/562843"}],"wp:attachment":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media?parent=562842"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/categories?post=562842"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/tags?post=562842"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/coauthors?post=562842"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n<\/strong>I was a teenager when I read a newspaper article about some French scientists exploring caves in the Vale do Ribeira region; the group included Guy Collet [1929\u20132004], Pierre Martin [1932\u20131986], Yugoslav Peter Slavec, and a group from the Brazilian Speleology Society (SBE), which these Europeans practically founded. I went to the headquarters in downtown S\u00e3o Paulo and told them I wanted to go with them. They asked me: \u201cBut have you ever been in a cave?\u201d I answered: \u201cNo, never, I\u2019ve only seen photos in magazines.\u201d My family had a subscription to National Geographic<\/em>, which ran a lot of articles on caves. At the time, Mammoth Cave in the US, one of the world\u2019s biggest, was being explored. I was fifteen or sixteen years old, and they allowed me to go\u2014Guy Collet practically adopted me. The first trip was to Itaoca, in Vale do Ribeira, more focused on archaeology. It was and still is an extremely important archaeological site, with proven signs of human occupation some 10,000 years ago, and we found several tombs. My first actual cave was the Sumidouro, in Ribeir\u00e3o Grande, S\u00e3o Paulo. Another expedition with the SBE personnel took us to Iporanga, also in Vale do Ribeira, one of the Brazilian municipalities with most caves in Brazil: there are more than 300. During these trips I met people from the speleology group of the University Excursion Center (UEC), still operating today, including Geraldo Gusso [1953\u20131993], more commonly known by his nickname Peninha, and Mauro Stavale; these two really were cavers. The first cave I visited with them was the Gurutuva, also in the south of S\u00e3o Paulo State; it\u2019s amazing, with waterfalls up to 10 meters (m) high. That was when I realized what exploration really is, because with Collet it was a lot gentler.<\/p>\n
\n<\/strong>During those days in the seventies, the caves Ouro Grosso, \u00c1gua Suja, and others in Alto Ribeira State Tourist Park (PETAR) were being discovered; geology students were visiting as well, and I was attracted to this field. I started the course and continued on the UEC expeditions. On one trip we practically spent a month camping north of Bras\u00edlia, in the region of Posse and S\u00e3o Domingos, studying the S\u00e3o Mateus-Imbira system, which has 20 kilometers [km] of galleries. We produced the first map of this cave system, which was featured in several articles. We had no money, but we did receive a lot of donations. Volkswagen and GM loaned us cars, which we pretty much destroyed on those roads full of stones and potholes.<\/p>\n
\n<\/strong>There wasn\u2019t yet any course on cave geology. In the beginning it was difficult to find someone interested in doing scientific research into the theme of Karst [type of relief] and caves. We were inspired by Aziz Ab\u2019Saber [1924\u20132012], a geographer. We spent hours talking in his classroom, and to this day I remember his recommendation: \u201cYou want to understand a cave? Go outside it, look at what surrounds it, understand the system.\u201d This approach was very important; these days we talk about the Karst system, which includes the movement of water and materials, because part of what enters leaves, but the rest is retained. The geology people were more traditional; they said: \u201cYou\u2019re into caves, so go to geography, you\u2019re not a geologist.\u201d But I was always somewhat single-minded and stubborn. I put together a research plan to apply for a scientific initiation grant from FAPESP, and presented it to geology professor Thomas Fairchild, who was always very open to new ideas. He read it and said: \u201cLook, I\u2019ve never been inside a cave, but I found your proposal very interesting, and I will advise you on it.\u201d The project was totally new, a group scientific initiation with one advisor and six students, all covered by a grant.<\/p>\n
\n<\/strong>Because you don\u2019t do cave work alone\u2014you need a minimum of three to do the map. One has the tip of the tape measure, another holds its base, and the third does the sketch in the notebook. One is from the field of geology, the other looks more at the relief. We also have to understand the outside of the cave, through photointerpretation. That\u2019s how we conducted a geological research project on the Ecos Cave in Corumb\u00e1, Goi\u00e1s State, 60 km west of Bras\u00edlia. The limestone does not show at the surface\u2014it doesn\u2019t outcrop\u2014and there\u2019s a large underground lake. We formulated a geological map showing these aspects, which were a novelty. At that time there were no other research groups of explorers dedicated solely to speleology. The Speleological Excursion Society of Ouro Preto, one of the oldest, operated more in Minas Gerais State, a paradise of limestones and caves. There was a professor there embarking upon a more scientific project: Victor Dequech [1916\u20132011], of the Federal University of Ouro Preto.<\/p>\n
\n<\/strong>We had already explored enormous limestone caves in the region of Posse and S\u00e3o Domingos, north of Bras\u00edlia. I was starting the work at the Ecos cave. It\u2019s enormous, not just in terms of kilometers, but in dimensions and volume, and it\u2019s not just a limestone development. We saw that there was something different. To enter you have to negotiate a level difference of some 60 meters, and at the bottom next to the lake, we discovered noncarbonate rock (mica schists and quartzites) overlaid on the carbonate. We saw how caves are formed, with dissolution and corrosion acting at depth, opening voids in the soluble rock, and thereby connecting to the surface. Very few occurrences of this type had been described at that time. Years later we published this discovery in the Journal of Cave and Karst Studies<\/em>, and it became a reference in interstratal Karst, where insoluble rocks overlap underground Karst, which, by processes of slump and erosion, connects the porosity to the surface and opens an access way.<\/p>\n
\n<\/strong>No. Karst is a type of relief predominated by soluble rocks. The surface is shaped by chemical dissolution, generating the cavities; in other words, Karst is where caves emerge. The Karst system includes underground water circulation structures with inlets, springs, sinks, and outlets. The water that feeds the system originates from rainfall, and primarily from the river system catchment. Therefore we also need to map the flow routes, the conduits, as if it were plumbing within the rock.<\/p>\n
\n<\/strong>Lu\u00eds S\u00e1nchez, known as \u201cLuiz\u00e3o,\u201d who\u2019s now at Poly [Polytechnic School of the University of S\u00e3o Paulo], Peter Milko, Ant\u00f4nio Montanheiro, who no longer practices geology, having moved to Pernambuco (northeastern Brazil) and decided to do medicine, and Spaniard Juan Carlos, a diver, because there was a lake in the Ecos Cave and no one knew how to explore it.<\/p>\n
\n<\/strong>It was. And on top of that we gave talks at geology schools in Rio Claro [S\u00e3o Paulo], Ouro Preto [Minas Gerais], and Bras\u00edlia, making the most of our exploration trips. We wanted to encourage future geologists to visit the caves and put geological maps together, which we still didn\u2019t have. People got very interested\u2014they asked why caves are important, they suggested that they were just voids, that there was nothing there. That\u2019s why, over time, I started saying that I am a geologist of nothing. I have to explain the absence of rock, not the rock itself. Once, at the University of Bras\u00edlia (UnB), Myl\u00e8ne Berbert, now a speleologist at the Brazilian Geological Service, asked: \u201cHow are we going to study caves? Where are the caves in Brazil? What are they like?\u201d Luiz\u00e3o and I approached Aziz, and the proposal came from him: \u201cWhy don\u2019t you do a survey where there are favorable rocks for the development of caves and Karst?\u201d We got the maps from DNPM [National Mineral Production Department] and the SBE; everything was done by hand at the time, and we made the first map on areas of occurrence of carbonates and cave regions. We finished in 1979, still undergraduates, and published a piece in the journal Espeleotema<\/em>, of the SBE. We mapped some 500 caves, and today we have 23,000 registered with the National Center for Cave Research and Conservation of the Chico Mendes Biodiversity Conservation Institute (ICMBio). The number has grown considerably with the inclusion of caves in the iron formation, of which there are many, albeit small.<\/p>\n![\"\"](\"https:\/\/revistapesquisa.fapesp.br\/wp-content\/uploads\/2025\/09\/RPF-entrevista-ivo-karmann-caverna-grupo-2025-03-800.jpg\")
\n<\/strong>This work in the speleological provinces had a significant impact, primarily in terms of regionalizing the type and size of caves associated to different rock types. We started to produce results, gaining credibility and the support of other Institute of Geosciences (IGc) professors, such as Aldo Rebou\u00e7as [1937\u20132011], Oscar R\u00f6sler, and Roland Trompette, who was my advisor and frequently visited the institute. During my master\u2019s degree I submitted a proposal for a speleology discipline. I tried several times until the department\u2019s council gave it the green light as an optional study area, and mindful that speleology is not just geology but also includes the environment, biology, and archaeology, I invited Eleonora Trajano, of the Institute of Biosciences, who also worked with caves. I had known her since before I graduated, as she also frequented the CEU. In January and February 1975, we participated together in Operation Tatus.<\/p>\n
\n<\/strong>It was an experience of living in a cave; I was part of the outside support team. We wanted to know what it would be like to live in an underground environment; it was a novelty at the time, to understand how sunlight influences the cycle of wakefulness and sleep. Experiments were being run in France, and the UEC personnel decided to do it here as well, with eleven people in the Santana cave, Iporanga, at the state park (PETAR), for fifteen days. They stayed in the very sizeable S\u00e3o Paulo cavern, with only artificial light, primarily carbide, some gas lamps, and a cooker to prepare food, along with a system for waste collection. Telephone communication was only possible from the inside out, to ensure that nobody inside knew what was happening outside. While they slept, we made notes of what was happening down there. Some slept more, some less. We saw that sleep and wakefulness periods lasted for 73 hours, with almost 30 hours of sleep or rest, and 30-plus hours of activity. After fifteen days had passed, those inside thought that they were still on their seventh or eighth day. They had lost all sense of time.<\/p>\n
\n<\/strong>It began as a novelty, with geology, biology, and geography students, because it offered vacancies to other units and even to the general public. There were also the field activities, so Eleonora, as a biologist, showed us things we often overlooked, such as the blind catfish (Pimelodella kronei<\/em>) and other animals adapted to life in the caves (see <\/em>Pesquisa FAPESP issue n\u00ba 224<\/em><\/a>). I later changed the focus and the name to Karstland Geology, with a geological emphasis, but also with vacancies for students from other units. The course continues to run, it\u2019s very sought-after, and I participate in it to this day, now as a senior professor. Every October we go to the Iporanga caves.<\/p>\n
\n<\/strong>In 1982, in a German journal to which I then subscribed, Bild der Wissenschaft<\/em> [Image of science], I read an article by Wolfgang Dreybrodt, of the University of Bremen. This was one of the first studies into paleoclimate [climates of the past] in speleothems [structures formed by water circulation among cave rocks, for example stalactites and stalagmites]. It was such a novelty, but it was difficult to date the material\u2014the method we use today, with uranium-thorium, had not yet been developed. Dreybrodt tried dating with carbon-14, which went wrong several times, but put the idea out there. You see a stalagmite growing gradually, you look at the dripping, and you think: why does it stop dripping? It\u2019s because when it doesn\u2019t rain, there is no recharge. You look at the internal structure of a stalagmite, it\u2019s a sedimentary basin, with various layers, colors, and thicknesses. The composition also varies: it could be calcite, aragonite, or whatever. Why so? What controls the formation and growth of speleothems is the environment surrounding the cave. They record sedimentation processes\u2014the chemical precipitation of minerals, such as calcite. In the Taqueupa cavern of the Santana cave, there are drinking straw-like formations two or three meters long, with very different stratigraphies [distribution of layers].<\/p>\n
\n<\/strong>We only really took off when geologist Chico Bill [Francisco Cruz] arrived from Rio Grande do Norte [in northeastern Brazil], came into my office, and declared: \u201cI want to work with large caves.\u201d Yay, I hooked one more. Well-known large caves during this time were in the region of Iraquara, Chapada Diamantina, Bahia State. I had done part of my PhD in Canada with Derek Ford, a reference in geospeleology, and I learned to use isotopes [variations of the same chemical element] for dating. I proposed to Chico Bill: \u201cLet\u2019s deep-dive into climate histories in speleothems. This area is going to really take off.\u201d We put together a research plan and went in search of a speleothem that might have climate records. It\u2019s important to make the point that you cannot just take anything from caves, because they are protected by law; we always carry ICMBio authorization for research and sample collection. We had a lot of help from a colleague at the institute, Marly Babinski, who knew the rock geochronology people. She spoke to Warren Sharp, then at the University of Minnesota [currently at the University of California, Berkeley], who used uranium-thorium dating: exactly what we wanted. We made contact, Chico Bill took a trip out there, and then we were able to do our dating. We measured the proportions of oxygen and carbon isotopes in liaison with the people from USP\u2019s Center for Nuclear Energy in Agriculture (CENA) in Piracicaba. We ran our first isotope variation curve, indicating climate variation, on speleothems in the Botuver\u00e1 cave in eastern Santa Catarina, and the Santana cave in southeastern S\u00e3o Paulo. A beautiful curve, also showing the solar cycle and insolation variation (see <\/em>Pesquisa FAPESP issue n\u00ba<\/em>\u00a0111<\/em><\/a>). It was one of the most important projects I have participated in. I very much liked seeing how the rain modifies drip activity within caves, and how the Karst system functions. For me, fieldwork is the most exciting part of research.<\/p>\n
\n<\/strong>At the time of the Ecos Cave, we already had this question in mind: what dissolves rocks at depth, if carbonic acid doesn\u2019t get down there? There must be another corrosive agent, or other mechanism for producing some kind of acid, that doesn\u2019t seep in with water. People were considering the possibility of it being bacterial action, which could transform sulfide into a type of acid. Limestone rock has no sulfur, which is found in sulfide. We decided to go looking for these bacteria and made advances, partly with chemistry PhD Murilo Andrade Valle, in 2010. I reached out to the microbiology people, and with Vivian Pellizari, currently at the USP Oceanographic Institute (IO), we looked into the microbiology of groundwater; in 2024, as part of master\u2019s research by geologist Tom Dias Morita, we managed to partly trace the genome of the bacteria that acts deep in the caves of the Una group, Chapada Diamantina region, in Iraquara, Bahia State. These are anaerobic bacteria [they do not use oxygen as an energy source] that we call sulfur oxidizers and sulfur reducers. They obtain energy from digesting minerals containing sulfur, such as pyrite and galena, which are iron and lead sulfides, whose decomposition produces the sulfuric acid corroding the rock.<\/p>\n
\n<\/strong>We don\u2019t talk about it that way, because it is always a group effort. The most relevant discoveries I have participated in were with the UEC at the caves in Goi\u00e1s, north of Bras\u00edlia, the region of Posse, S\u00e3o Mateus, Imbira, and Terra Ronca. The people in the region already knew of these. S\u00e3o Mateus had a doline\u2014a depression in the ground\u2014and they took us there. They said: \u201cThere\u2019s a hole this side and another one over there.\u201d The doline was in the middle. Down we went; it was a big space. Giant pearls [rounded limestone formations at ground level in caves], and stalagmites eight, ten meters high. We explored Vale do Ribeira, and saw new features such as caves with more vertical development, known as abysses. We descended using ropes and steel wire ladders. I participated in the discovery of the Ponta de Flecha abyss, also in Iporanga, which had bone remains of Pleistocene megafauna. We did a paleontological dig around 1980, with the support of Oscar R\u00f6sler. The team was made up of Clayton Lino [speleologist and architect], Eleonora Trajano, a student of zoologist Paulo Vanzolini [1924\u20132013], another of our sponsors, and archaeologists Erika Robrahn and Paulo de Blasis, of USP\u2019s Museum of Archaeology and Ethnology (MAE). We found the tip of a flint arrow in a very small conduit beside a large tooth from a toxodon, in its time a very large megafauna animal. We had already seen animal bones with cut marks, indicating that people took meat off the bones.<\/p>\n
\n<\/strong>The craziest to date was in S\u00e3o Mateus de Imbira, state of Goi\u00e1s, a long time ago. It was pretty overwhelming, a place so full of things that you didn\u2019t know where to look first; a show of speleothems, with mineral aragonite formations of all sizes, helictites [speleothems in the form of a fan, either protruding from the ceiling or the walls] growing, that floor of stars, and the underground river, a natural dam of giant travertines [barriers of calcite or other minerals]. It was like something from another world. Then, at the Torrinha Cave, Lapa Doce, in the Chapada Diamantina area, I saw things I\u2019d never have imagined. You get a bit dizzy at such beauty.<\/p>\n
\n<\/strong>Not lost, but I did have several moments when I asked myself: \u2018Okay, where am I? How do I get back?\u2019 One time, our lights went out. We were using helmets with a flame and flashlights with incandescent bulbs. Each team member carried a two-compartment cylinder on their belts: one with carbide stones, and the other with water that dripped upon them. When the carbide reacted with the water, acetylene was released, passing up through a small pipe to the helmet to fuel the flame. This was in the days before the superpowerful LED bulbs we have today, where you only need one to light a huge cavern very easily. The flame went out in the Santana cave and my lighter was soaked. We waited an hour or two, then someone turned up to light our flame. Another time, in 1990 or 1991, during research into the chemistry of quartzite dissolution in the Lap\u00e3o cave in Len\u00e7\u00f3is, Bahia State, a block of rock dislodged and trapped my leg. I was with a colleague, who ran for help. After an hour or two, some people came, wanting to roll the rock back. I said: \u201cNo, stop, don\u2019t roll the rock, or you\u2019ll crush my leg! Get my hammer and chisel and cut it to free me.\u201d I managed to come out of that with just a few deep scratches.<\/p>\n
\n<\/strong>It\u2019s almost zero, because very narrow passages make me nervous, so I tend to avoid them. Some cavers are like worms\u2014if they pass through and tell me it\u2019s okay, then I go. I\u2019ve said many times: \u201cI can\u2019t get through there, I\u2019m not going.\u201d We did a lot of crazy things, without equipment, or good ropes. We descended and ascended the F\u00f3ssil abyss, 40 meters vertical\u2014the height of a 12-storey building\u2014with a steel wire ladder, and we trained with it in the well of one of the CRUSP [USP halls of residence] buildings. At the F\u00f3ssil abyss I would descend using the ladder, but Peninha would rappel down, jumping onto the rope, then later ascend. Once he was entering to jump, and I looked over and warned him: \u201cThe rope is corroded halfway through. Stop, and go back real slow.\u201d It would have been a vertical drop of 40 meters. Safety is a lot better these days.<\/p>\n
\n<\/strong>The first rule is never to enter alone\u2014working in a group of three, including more experienced cavers, is ideal. The second is to know the region. People going into caves are very afraid of snakes. I\u2019m not, but I am scared of bees. Rocky entrances, such as those in the state of Piau\u00ed, normally have bee clusters, so it\u2019s good to be supported by local people who will tell you of any hazards. Another one is to always take reserve lighting. Beginners get excited, in they go, and if they only have one flashlight, it may be difficult to get back. You also need to let those outside know that you\u2019re going in. As for the rest, it\u2019s always good to have a bit of courage, enter with caution, be careful with fragile speleothems, respect the space, and relish the wonders you find.<\/p>\n
\n<\/strong>Yes. We\u2019re planning a water monitoring project in the Tapagem cave [official name of the Diabo cave in Eldorado, Vale do Ribeira], with colleagues from the IGc: Nicolas Stricks, Chico Bill, and students. Scenically and geologically speaking, this cave is sensational. And there are some interesting scientific questions yet to be well explained.<\/p>\n