Paolo Forti

University of Bologna | UNIBO · Department of Biological, Geological and Environmental Sciences BiGeA

Tra i minerali di grotta i fosfati, gene-ralmente correlati alla presenza di gua-no e/o ossa rappresentano il secondo composti (Audra et al., 2019). Nono-di tutto il mondo, solo di rado formano concrezionamenti ben sviluppati, costi-tuiti essenzialmente da un solo mine-rale: l'idrossiapatite (Ca 5 (PO 4) 3 OH). Lo studio dei processi che sovrintend...

New biogenic forms were recently observed inside the caves of Palawan. They consist of perfectly rounded holes, developed over any kind of limestone surface interested by bat droppings. Their genesis is controlled by the peculiar Palawan climate, which is characterized by short but strong rainfalls followed by rather long dry periods.

Since the early 20 th century, monocrystalline calcite soda straws and helictites have been described in the literature. Recent observations have also shown that subaerial macrocrystalline speleothems are much more frequent than earlier thought, often occurring in very stable cave environments where slow epitaxial growth can be favored over long ti...

San Giovanni cave, a natural gateway connecting the Sa Duchessa valley to the Cixerri Plain (Southwest Sardinia), has been known since prehistoric times. Cyclopic remains of walls are still visible at both majestic entrance halls. The presence of a perennial important karst spring at its southern entrance, the fact that it is crossed by a temporary...

Caves are places where palaeontological and archaeological discoveries are common. Sometimes these remains/artefacts may be of fundamental importance for understanding the evolution of life or the human history. Some examples are the rock art paintings in Lascaux cave in France or the Altamura Neanderthal skeleton in Italy, just to mention a few of...

Circa un quinto del territorio italiano è caratterizzato dalla presenza di rocce so-lubili, costituite soprattutto da calcari e dolomie, ma anche da marmi e rocce evaporiti-che (gessi). Attualmente sono conosciute più di 50.000 grotte naturali, un numero in co-stante aumento grazie alle esplorazioni speleologiche. Meno dell'1% di queste grotte sono...

The Puerto Princesa Underground River (PPUR) is one of the most extraordinary coastal karst systems in the world. Its hydrodynamics heavily depends on the complex interactions between the flow-rate fluctuations of the river that flows through it and the internal dynamics of the tides. In fact, tides affect the whole cave, making their effects felt...

The network of lava tubes is one of the most unexploited natural wonders of the Galapagos Islands. Here, we provide the first morphological, mineralogical, and biogeochemical assessment of speleothems from volcanic caves of the Galapagos to understand their structure, composition, and origin, as well as to identify organic molecules preserved in sp...

Speleothems show an array of shapes. Flowstones are commonly tabular sheet-like deposits, which cover cave floors and walls. They can procure detailed information about past hydrogeological conditions through their morphology, geochemical composition and stratigraphic properties, which in turn are related to the climate conditions at the surface. T...

Brazil’s caves, home to diverse species and minerals, were stripped of protections by a recent presidential decree.

The Galapagos Islands (Ecuador) have a unique ecosystem on Earth due to their outstanding biodiversity and geological features. This also extends to their subterranean heritage, such as volcanic caves, with plenty of secondary mineral deposits, including coralloid-type speleothems and moonmilk deposits. In this study, the bacterial communities asso...

Geomorphological studies have been carried out in rapidly evolving salt caves related to small watersheds in the San Pedro de Atacama area, Chile. Radiocarbon ages of bones and wood from cave deposits, combined with the presence of large salt caves, geomorphological and sedimentological observations, and the results of micrometer measurements outsi...

Fascinating and fragile environments as are the underground estuaries, need to be studied, understood and protected for present and future generations. Even if wide and abundant bibliography related to tides and their behaviour with respect to the external estuaries is available, none dealed with the estuary caves and the related hydrogeology. This...

A popular book on Puerto Princesa Underground River and its physical and biological features

The Puerto Princesa Underground River, amongst the largest caves of the Philippine Islands, is the most visited show cave in the country, even though it has undergone no tourism adaptation at all. Its scientific importance primarily relies on the fact that it is one of the largest known underground estuaries in the world, and the effect of tides is...

The mine caves of Naica (Chihuahua, Mexico) are famous because they host large gypsum crystals. Mine works intersected new caves hosting the largest crystals in the world in the year 2000. From 2006 these caves became the object of a multidisciplinary research project with the goal of inferring their ages, the boundary conditions for their formatio...

Three-dimensional X-ray micro-computed tomography permits to investigate the internal structure of objects at a high resolution without altering its original form. It also facilitates the rendering and visualization of a virtual replica, which can be subjected to rigorous and complex analyses. In the present study, micro-computed tomography was use...

The caves of Naica (Chihuahua, Mexico) have been known since the beginning of the nineteenth century, when they were intersected by mines. They became world famous in 2000 when the mining activities intersected three small caves, which hosted gigantic gypsum crystals. Their genesis and evolution is strictly related to rising thermal fluids induced...

In Sardinia, no active hypogenic caves have yet been discovered or described. Although there are a few thermal springs, mostly correlated to Quaternary volcanic activity, none of these thermal waters have interacted with carbonate rocks. Nevertheless, in the SW of the Island many metal ore deposits hosted in Cambrian limestones have been exploited...

In the past 15 years several expeditions by French, American and especially Italian cavers have surveyed over 15 km of salt cave passages in the Cordillera de la Sal, close to San Pedro de Atacama village (Atacama Desert, Northern Chile). Over 50 caves have been explored up to now at an elevation around 2,500 m asl. These karst systems are characte...

More than 600 caves have been surveyed in the Triassic and Messinian gypsum beds of the Northern Apennines (Emilia-Romagna region, N Italy). Despite the fact that these caves have been studied for a very long time, their age was inaccurately believed to be Late Glacial. In fact, the fast dissolution of gypsum and the regional uplift of the mountain...

The Association La Venta was founded in 1991 with the aim of organizing and running geographical exploration projects with particular attention to the underground world. In 25 years of activity, La Venta has undertaken explorations in several countries, involving over hundred speleologists and researchers. Such projects are carried out using a mult...

During a speleological expedition to the Puerto Princesa Underground River (Palawan, Philippines) a drapery characterized by several close-to-horizontal ribs has been noticed. Its study allowed to present an hypothesis on the evolutionary mechanism leading to its development which may fit also for other complex speleothems, like the stepped flowsto...

Although outcropping rarely in Italy, evaporite (gypsum and anhydrite) karst has been described in detail since the early 20 th century. Gypsum caves are now known from almost all Italian regions, but are mainly localised along the northern border of the Apennine chain (Emilia Romagna and Marche), Calabria, and Sicily, where the major outcrops occu...

Chemical deposits inside evaporite (gypsum, anhydrite and halite) caves are far less common than those developed within limestone or volcanic cavities. Moreover they exhibit a lower scarce mineralogical variability due to several reasons, the most important of which are: 1) calcium sulfate and sodium chloride are by far less reactive than calcium c...

The area around Ragusa in Sicily is well known for the exploration of petroleum deposits hosted in Mesozoic carbonate rocks. These reservoirs are overlain by less permeable rocks, whereas the surface geology is characterized by outcrops of Oligo-Miocene carbonate units hosting important aquifers. Some of the karst springs of the area are used as dr...

Over the past 15 years several expeditions by French, American and especially Italian cavers have unveiled over 50 caves in the Cordillera de la Sal (Atacama Desert, Northern Chile). Many of these caves contain a variety of speleothems and minerals, some of which have rarely been observed within karst systems. Most of the secondary deposits in thes...

During the 2011 speleological expedition to the Puerto Princesa Underground River (Palawan, Philippines) a drapery characterized by several close-to-horizontal ribs has been noticed. Even without sampling and analyzing its internal growth layers, a detailed morphological study allowed to present a possible genetic model. The presented model helps t...

Gypsum beds host the majority of the caves in the north-eastern flank of the Apennines, in the Emilia Romagna region (Italy). More than six hundred of these caves have been surveyed, including the longest known epigenic gypsum cave systems in the world (Spipola-Acquafredda, ~11 km). Although this area has been intensively studied from a geological...

The area around Ragusa in Sicily is well known for the exploration of petroleum deposits hosted in Mesozoic carbonate rocks. These reservoirs are overlain by less permeable rocks, whereas the surface geology is characterized by outcrops of Oligo-Miocene carbonate units hosting important aquifers. Some of the karst springs of the area are used as dr...

Hydrogeological mapof seaward side of Apuan Alps (in italian), scale 1:50.000

Carbonate speleothems record a series of environmental and climatic information (McDermott, 2004). Their mere presence in a cave signifies that water was present in the karst system and conditions were adequate to stimulate supersaturation with respect CaCO3. The most exploited geochemical proxies are oxygen (δ18O) and carbon (δ13C) stable isotopes...

Caves are among Earth's most important minerogenetic environments and they host over 350 minerals, some of them new for science. The presence of such an unexpected richness is a direct consequence of the variety of rocks traversed by water or other fluids before entering a cave and the sediments therein. In the last 50 years, systematic studies def...

V Savdski Arabiji je bilo raziskanih in izmerjenih več velikih vulkanskih jam v različnih poljih lave. Ena največjih je Ghar Al Hibashi na polju lave Harrat Buqum-Nawasif. To je v glavnem raven rov (400 m dolg in 15 m širok), dostopen skozi majhno brezno, ki se odpira v stranskem rovu. Jama je dolgo služila za skrivališče netopirjem, hijenam, volko...

The caves of the Naica Mine have been the subject of study by scientists from up to seven counties over the past decade. Up to fifty research works have published to date, most relating to the origin of the giant selenite crystals of the Cueva de los Cristales. Nevertheless, a great deal of knowledge has been generated about other relevant aspects...

Triassic and Messinian gypsum beds host the majority of the caves in the eastern flank of the northern Apennines. To date, more than six hundreds voids have been mapped, including the longest known epigenic gypsum cave system in the world (Spipola-Acquafredda, ~11 km of tunnels) (De Waele et al., 2013). Superimposed caves are typically sub-horizont...

Different types of hard and soft speleothems (stalactites, stalagmites, columns, crusts, flowstones, micro-gours and botryoidal coralloids) have been observed throughout lava tubes in the Galapagos archipelago, Ecuador. Three lava tubes were studied in this work: Gallardo and Royal Palm volcanic caves (Santa Cruz Island) and Sucre Cave (Isabela Isl...

Ana Heva lava tube (Easter Island, Chile): Preliminary characterization of the internal layers of coralloid-type speleothems - Volume 21 Issue S6 - A.Z. Miller, M.F.C Pereira, J.M. Calaforra, P. Forti, A. Dionísio, C. Saiz-Jimenez

Detailed mineralogical and geochemical analysis of exceptional speleothems of hemimorphite found in Iglesiente mine caves.

Detailed geomorphological analysis has revealed that subhorizontal gypsum caves in the Northern Apennines (Italy) cut across bedding planes. These cave levels formed during cold periods with stable river beds, and are coeval with fluvial terraces of rivers that flow perpendicular to the strike of bedding in gypsum monoclines. When rivers entrench,...

Most caves in Emilia-Romagna are developed in Triassic and Messinian gypsum outcrops. These evaporite rocks, although representing only around 1% of the surface outcrops, host over 600 caves, among which the longest epigenic cave in the world (the system Spipola-Acquafredda close to Bologna, with over 11 km of surveyed passages) and the deepest one...

It is well known that artificial cavities sometimes host speleothems very different from those growing in caves. This is the case of the old aqueduct of Sassari (Sardinia, Italy), an about 4 km-long tunnel dug in 1880 within Miocene carbonate in order to supply drinking water from the Bunnari dam to the town. At 2 km from the entrance, it intercept...

The present work deals with the results of long-term micro-erosion measurements in the most important gypsum cave of Spain, the Cueva del Agua (Sorbas, Almeria, SE Spain). Nineteen MEM stations were positioned in 1992 in a wide range of morphological and environmental settings (gypsum floors and walls, carbonate speleothems, dry conduits and vadose...

Ngamiland in northwestern Botswana hosts the Gcwihaba Caves which present unique subterranean environments and host speleothems never before recorded. Cave atmospheric conditions can be extreme with temperatures as high as 28°C and relative humidity nearing 99.9%. Within Dimapo and Diviner’s Caves peculiar root speleothems that we named ‘Hairy Stal...

Las investigaciones que han abordado el estudio de cristales de yeso gigantes descubiertos en algunas cavidades se han centrado principalmente en los mecanismos genéticos que dieron lugar a estas anomalías mineralógicas. Sin embargo, poco se sabe acerca de los problemas de conservación que podría conllevar la habilitación de estas cuevas como recur...

The paleoclimate significance of gypsum karst is still poorly explored in comparison with limestone karst, mainly because of the worldwide less extent of gypsum bedrock. However, the central Italian Spipola-Acquafredda (12 km tunnels) and Monte Tondo (11 km tunnels) karst systems, among the world’s largest epigenic gypsum caves, give the possibilit...

RESUMEN El reciente descubrimiento de minerales hidratados sobre la superficie de Marte sugiere la presencia de importan-tes cantidades de agua líquida durante algunas etapas de su historia geológica. A raíz de este hallazgo, los estudios sobre minerales hidratados en ambientes terrestres como potenciales análogos marcianos han adquirido gran rele-...

RESUMEN El reciente descubrimiento de minerales hidratados sobre la superficie de Marte sugiere la presencia de importan-tes cantidades de agua líquida durante algunas etapas de su historia geológica. A raíz de este hallazgo, los estudios sobre minerales hidratados en ambientes terrestres como potenciales análogos marcianos han adquirido gran rele-...

Speleothems are usually composed of thin layers of calcite (or aragonite). However, cemented detrital materials interlayered between laminae of speleothemic carbonate have been also observed in many caves. Flowstones comprising discontinuous carbonate layers form due to flowing water films, whilst flood events introduce fluviokarstic sediments in c...

The karst of Sorbas (SE Spain) is one of the most important gypsum areas worldwide. Its underground karst network comprises over 100 km of cave passages. Rounded smooth forms, condensation cupola and pendant-like features appear on the ceiling of the shallower passages as a result of gypsum dissolution by condensation water. Meanwhile, gypsum spele...

Coralloid-type speleothems were recorded on the ceiling of the Ana Heva lava tube in Easter Island (Chile). These speleothems were morphologically, geochemically and mineralogically characterized using a wide variety of microscopy and analytical techniques. They consist dominantly of amorphous Mg silicate and opal-A. Field emission scanning electro...

In the past few years the systematic study of caves intercepted by mine workings in southwest Sardinia has permitted us to observe morphologies due to rare speleogenetic and minerogenetic processes related to ancient hydrothermal activity. These relic morphologies are slowly being overprinted by recent speleogenetic processes that tend to obscure t...

We examined the isotopic composition of gypsum hydration water (18 O and D) in several selenite speleothems from the caves of the Naica Mine (Chihuahua, Mexico). The gypsum samples were collected from depths of-120 m (" Sword Cave ") and-290 m below the surface (" Crystales Cave " and " Ojo de la Reina Cave "). 18 O ranged between-4.66 and-3.26‰, w...

Although the exploration of the deep karst systems in Mt. Tondo (Gypsum outcrop of the “Vena del Gesso romagnola”) can be considered almost closed, only little is known about the speleogenesis and the evolution of these caves. The presence of some very well developed horizontal cave levels, not only in the Re Tiberio Cave but also in many other min...

Despite the fact that the exploration in the Re Tiberio karst system can be considered as almost concluded, not much is known on its formation and speleogenesis, and especially on the origin of some of the strange sediments and morphologies encountered locally. The detailed analysis of the erosion and dissolution forms and of the chemical and physi...

Short introduction on the importance of mine caves

The caves of the Naica Mine (Chihuahua, Mexico) contain some of the World’s most impressive secondary hypogene speleologenetic processes actually mainly known for their gypsum crystals that in the last ten years have attracted attention of scientific community. In fact, the Naica cave patterns are not interpreted as strictly hypogene, but could ha...

The "espada" speleothems of Cueva de las Espadas (Naica Mine, Chihuahua, Mexico) comprise a high-purity selenite core overlain by successive deposits of calcite, gypsum and aragonite. Gypsum precipitated under water from a hydrothermal solution (~58°C) when the water table was above the cave level ca. 57 ka, during the last glaciation, and some int...

in march 2009 the Guacamaya cave was discovered on the auyan Tepui by the helicopter pilot Raul arias. it rep-resents one of the longest caves explored on this table mountain, the only one known today with a complete hori-zontal development, comparable with those of the Brewer Cave System, in the Chimantha Tepui (the world largest sandstone cave)....

Strontianite is a very rare cave mineral, up to now found in only two caves respectively in Spain and in the USA. The discovery of dissolution pockets and fractures filled with almost pure strontianite in a small cave in Iran has allowed us to investigate in detail the minerogenetic mechanisms that have brought to its formation in a carbonate karst...