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Journal & Proceedings of the Royal Society of , Vol. 137, p. 123–149, 2004 ISSN 0035-9173/04/0200123–27 $4.00/1 Studies on and its Occurrence in , including New South Wales Caves

jill rowling

Abstract: Aragonite is a minor secondary in many caves throughout the world and is probably the second-most common mineral after . It occurs in the vadose zone of some caves in New South Wales. Aragonite is unstable in fresh water and usually reverts to calcite, but it is actively depositing in some NSW caves. A review of the cave aragonite problem showed that chemical inhibitors to calcite deposition assist in the precipitation of carbonate as aragonite instead of calcite. Chemical inhibitors physically block the positions on the calcite lattice which otherwise would develop into a larger crystal. Often an inhibitor for calcite has no effect on the aragonite crystal lattice, thus favouring aragonite depositition. Several factors are associated with the deposition of aragonite instead of calcite in NSW caves. They included the presence of ferroan , calcite-inhibitors (in particular ions of magnesium, manganese, phosphate, sulfate and heavy metals), and both air movement and humidity.

Keywords: aragonite, cave , calcite, New South Wales

INTRODUCTION (Figure 1). It has one plane {010} (across the “steeples”) while calcite has a per- Aragonite is a polymorph of calcium - fect cleavage plane {1011¯ } producing angles ◦ ◦ ate, CaCO3. It was named after the province of 75 and 105 . Aragonite twins on {110}, of Aragon, Spain, where it occurs as pseudo- producing pseudo-hexagonal columnar , hexagonal twins. Calcite is the more common whereas calcite readily twins on the cleavage polymorph. plane. Compared with calcite, aragonite is Aragonite belongs to the orthorhombic crys- harder (3.5 to 4 cf. 3), denser (specific grav- tal system while calcite has been variously ity 2.930 cf. 2.711) and more brittle (Berry placed in the rhombohedral (Hurlbut 1970), et al. 1983). hexagonal, trigonal (Berry, Mason & Dietrich Aragonite is often produced in the growth of 1983) or triclinic (Glazer 1987) crystal systems. marine organisms, particularly in shells. When Another polymorph of CaCO3 in caves is va- the organism dies, proteins in the shell decay terite, which belongs to the hexagonal crys- exposing the aragonite. In time, aragonite re- tal system and is less dense than calcite. It verts to calcite in the near surface environment has been recorded from cave moonmilk, car- in the presence of fresh water. The deposition of bide dumps and in the shells of living gas- aragonite is also a the product of chemical influ- tropods.It is not stable in the vadose environ- ence, or high pressure on calcite. It also occurs ment and commonly reverts to calcite via arag- in secondary deposits in caves (Siegel 1965, Ford onite. Other polymorphs include the high tem- & Cullingford 1976) and igneous rocks. perature and pressure Calcite-IV and Calcite- It is probably the second most common cave V which are not stable in near-surface environ- mineral after calcite Hill & Forti (1997). This ments (Carlson 1983). reflects the discovery of extensive aragonite de- Aragonite often forms with a characteris- posits in caves such as (Carls- tic acicular habit known as “church steeples” bad Caves National Park, U.S.A.).

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Figure 1. Aragonite from Sigma Cave, Wombeyan. SEM image by Jill Rowling and Dr Ian Kaplin.

Aragonite is typically white or colourless. It allowed the precipitation of aragonite. has also been recorded as blue, green, brown, Hill & Forti (1997) noted that since Curl’s yellow or orange depending on which trace met- theoretical work, more experimental work was als are dissolved in the aragonite lattice. In the available on aragonite deposition in both cave cave environment, aragonite tends to be either and non-cave environments, so there was some white or coloured by metal impurities such as consensus on determining the factors that cause copper, whereas calcite deposits are frequently aragonite to occur in caves. Hill and Forti dis- coloured by organic (humic and fulvic) acids. cussed the following factors: magnesium, stron- The brown colouration of cave calcite was of- tium, pH, supersaturation and rate of precipi- ten incorectly attributed to iron oxy-hydroxide tation, temperature, pressure, sur- staining (Hill & Forti 1997). Kaolinite is fre- faces and content. These aspects quently coloured by iron oxy-hydroxides and in will be discussed below. some cases it is clay which coats speleothems. Aragonite is also reported from the caves of NSW which have a vastly different geological THE CAVE ARAGONITE PROBLEM history to those of Europe and North Amer- ica. This article will investigate the presence Aragonite is being actively deposited in the va- of aragonite in cave deposits from both the in- dose zones of many limestone caves around the ternational and local aspect. world (Hill & Forti 1997). Similarly, aragonite is also deposited in the phreatic zones of thermal PREVIOUS STUDIES ON and hydrothermal caves (Dublyansky 2000). ARAGONITE Curl (1962) recognised that these occurrences are thermodynamically unstable in fresh water Introduction to Studies and readily revert to calcite. So, why does arag- onite exist at all in caves? What allows arag- Shaw (1992) discussed cave aragonite in a his- onite to deposit in caves without reverting to torical context. The earliest reference he found calcite? was by Dr Charles S. Dolley in 1887 describing Curl suggested that aragonite forms and aragonite spicules depositing in a hollow on a persists in caves because calcite is prevented helictite in Luray Cavern (U.S.A.). Shaw also from forming, a concept arising from Saylor in included earlier references to flos ferri speleo- 1928 who suggested that various substances in- thems by John Hill in 1748 and sketches by Pa- hibited the crystallisation of calcite and thereby trin in 1803.

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Most work on carbonate diagenesis has fo- cused on the marine environment, where arag- onite is relevant to marine diagenesis. M Work on carbonate chemistry is also vital to in- dustry, for example the curing of concrete for C structural stability. Figure 2. Schematic of a developing crystal, Descriptions of research on the chemistry of with a sheet of unit cells such as calcite (C) aragonite were summarised in Bathurst (1974) whose growth points are being blocked by an and Morse (1983). They referred to the exper- inhibitor such as a magnesium compound (M). iments on solutions of using Based on ideas in Morse (1983) and Mer- varying amounts of chemical inhibitors such as cer (1990). magnesium ions. Bathurst noted that the solu- tion needed to be supersaturated with respect Morse noted that inhibitors for calcite gen- to both calcite and aragonite in order for arag- erally did not effect the aragonite crystal struc- onite to deposit, and discussed the chemistry of ture and may form solid solutions in the arago- aragonite precipitation in the marine setting, in nite crystal. Both precipitation and dissolution lime muds, beachrock and mollusc shells. of calcite are affected by inhibitors, including: Tucker & Wright (1990) discussed arago- • magnesium nite chemistry with more accent on diagenesis • heavy metals and rare earths (Cu, Sc, Pb, of marine carbonates. Tucker (1991) defined La, Y, Cd, Au, Zn, Ge, Mn, Ni, Ba, Co) low magnesium calcite as containing less than 4 • sulfate, phosphate mole% MgCO3, while high magnesium calcites commonly ranged between 11 and 19 mole% Some organic compounds such as humic MgCO3. Walter (1985) compared the relative acids may inhibit precipitation of aragonite, of several carbonate minerals and while other organic materials apparently inhibit found that the theoretical dissolution rates of both calcite and aragonite precipitation. This the minerals varied with pH. For a given pH, may result from substances coating the mineral high Mg-calcite dissolved fastest, then low Mg- rather than any chemical kinetic effect. calcite, then aragonite and then calcite which For the cave environment, the review and was the slowest. For a given dissolution rate, discussion of cave aragonite by Hill & Forti high Mg-calcite dissolves at a higher pH than (1997) is considered the main current reference. does low Mg-calcite, aragonite or calcite. For either aragonite or calcite to deposit, − there needs to be bicarbonate ion, HCO3 in Morse reviewed the kinetics in dissolution of solution, a means of allowing carbon dioxide to calcite, and noted that both precipitation and outgas or be otherwise leave the reaction, and dissolution of calcite are hindered by the pres- the solution needs to be supersaturated with re- ence of chemical inhibitors. If these chemical spect to calcium carbonate. In caves, these con- inhibitors are available in the drip water of a ditions usually deposit calcite as the most stable cave, and the water is also supersaturated with polymorph of calcium carbonate. respect to calcium carbonate, then aragonite de- Figure 3 illustrates the portion of the cal- posits in preference to calcite. cium carbonate phase diagram for the temper- ature and pressure ranges typical for caves in a Calcite-inhibitors work by blocking crys- meteoric environment. This is well within the tal growth points on the calcite lattice, which stability region for calcite. For meteoric caves, are frequently at edges or around dislocations the temperature of the cave is approximately (Mercer 1990). This concept is shown in Fig- that of the average annual temperature for the ure 2. area.

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7 Low temperature / pressure phase relations 6

5 Aragonite Pressure (kbar) 4 Calcite 3

2 Meteoric cave environment

1 Open hydrothermal cave environment

−30 0 50 100

Temperature (C)

Figure 3. Stability Diagram for CaCO3 at low temperatures and pressures shows that calcite is the expected polymorph in caves at atmospheric pressure. Based on Carlson (1983)

Included in this diagram are the typical types of moonmilk and as hydrated spheroids ranges of temperatures for caves in a hydrother- in pools in cold caves and sometimes accompa- mal environment which are open to the atmo- nies aragonite. Aragonite is apparently unstable sphere. In a closed environment, however, a at sub-zero temperatures, but at much higher water-filled cavity can experience much higher temperatures and pressures is sufficiently stable ranges of temperature and pressure. to designate the P-T of formation of particular rocks such as blueschists at around 4 to 6 kbar Although Hill and Forti stated that tem- (Turner 1981, Essene 1983). The high magne- perature is not a factor in the precipitation of sium content of serpentinites was noted by Es- aragonite in caves, it is interesting to note the sene to alter the P-T stability at which arago- family of carbonate minerals which deposit at nite will form, but these P-T conditions are way ambient pressures and low temperatures. The above that found in meteoric caves. For a given Pressure - Temperature (P-T) diagram of Carl- pressure, as temperature is increased, aragonite son (1983) was extended by Tucker & Wright will generally convert to calcite. Similarly, for (1990) to include temperatures below 0◦C and a given temperature, as pressure is increased, the hydrated calcium carbonates. At at sub- calcite will convert to aragonite. zero temperatures ikaite is stable (albeit at high pressure). Ikaite is CaCO3·6H2O which forms In the marine environment, there are a num- calcite after ikaite as the tem- ber of factors that govern which polymorph of perature is increased above zero. Another hy- calcium carbonate is deposited. They include drated mineral, CaCO3·H2O, whether or not the deposition is related to the is also unstable at the earth’s surface and reverts life processes of marine organisms and the chem- to calcite. Monohydrocalcite occurs in some istry of the water.

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Palaeodeposits, Paramorphs and (the c axis), and length-slow calcite crystals Marine Cave Cements are elongated in the optically slower direction. They commonly exhibit undulatory optical ex- The aragonite is sometimes tinction. preserved in , even after conversion to Assereto & Folk (1979) described the vari- calcite. ous aragonite, calcite and dolomite cements in Kendall & Tucker (1973) described a crys- metre-sized cavities in marine shoreline tepee tal fabric in which resembled pseu- structures from the Calcare Rosso lime- domorphs of calcite after a “an acicular car- stone of the Southern Alps of northern Italy. bonate”, potentially aragonite. The main argu- Although the original aragonite was now cal- ments as to the precursor being an acicular car- cite, all of the original fabric was preserved. bonate included subcrystals diverging from the The original depositional environment was de- , convergent optical axes, and curved scribed as near-marine semi-arid. The origi- twin lamellae. nal aragonite formed in the tops of the cavi- Samples of marine aragonite in a in ties as hemispherical crystal aggregates approx- Belize (British Honduras) (Ginsburg & James imately 10 cm long, with aragonite flowstones 1976) came from cavities and small caves within deposited in the sides and bottoms. Aragonite the barrier reef, at depths between 65 m and hemispheres had been deposited on the bottoms 120 m. The aragonite formed “mamelons”: of the cavities. Dolomite was deposited in small hemispherical aggregates of aragonite deposited cavities within the original carbonate tepees. on the ceilings of the voids in the reef bedrock. The aragonite became converted to calcite after Some were deposited on the floors or filled the Mg/Ca ratios of water percolating through the whole cavity. The limestone bedrock and the deposit became less than about 2:1. the aragonite were both dated as Holocene Mazzullo (1980) examined samples from the (samples ranged from 7000 to 13000 years). Capitan Limestone deposit, Guadalupe Moun- The substrates to the aragonite included high tains, New Mexico (U.S.A.) and found fan- Mg calcite, aragonitic or aragonitic al- shaped crystal aggregates in a replacement cal- gal plates. The development of needle crystals cite fabric. The crystal terminations were was influenced by the substrate, for example, squared, as is aragonite, but no curved twin oriented aragonite substrate grains produced lamellae could be found. Some fabrics had no larger mamelons than did unoriented grains. uniform crystal optical extinction. Some inclu- The strontium in the crystals was similar in sions followed the original aragonite crystal out- relative concentrations to that of Sr/Ca in sea lines. water. Carbon and isotope ratios were consistent with that of marine limestones. The Temperature authors concluded that the mamelons formed shortly after the deposition of the limestone. Cser & Fej´erdy (1962) analysed samples from A piece of flowstone from Carlsbad Caverns, hydrothermal caves near Budapest but very few New Mexico (U.S.A.) contained crystals of cal- of their subaerial samples contained any arago- cite which had once been aragonite (Folk & nite. Dublyansky (2000) discussed the speleoge- Assereto 1976). The original aragonite fabric nesis of hydrothermal caves of the Buda Hills in such as feathery or squared terminations were Hungary, and noted that thermal springs in the preserved. Small needle crystals were consid- area had temperatures up to 65◦C. Aragonite ered to be remaining aragonite. Unusually long was detected in the water coming out of nearby length-slow calcite crystals were attributed to hot springs (subaqueous deposition), but con- previous aragonite or . Length-fast cal- verted to calcite on exposure. cite crystals were the most common type of cal- In various aqueous solutions prepared from cite crystal development, with crystal elonga- calcite or aragonite, calcite was the only pre- tion in the direction of the calcite optical axis cipitate in a variety of temperature regimes

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(Siegel & Reams 1966). When carbon diox- sive dolostone. Fischbeck & M¨uller (1971) ide was bubbled through a solution prepared found a number of minerals precipitating as from artificially produced calcites and arago- surface coatings and as cave coral, includ- nites, there was a tendency to produce arag- ing monohydrocalcite, , nesque- onite at higher temperatures e.g. above 65◦C. honite, dolomite, aragonite and calcite. Both This could explain the temporary aragonite pre- primary (from weathering of bedrock) and sec- cipitation in the hydrothermal springs near Bu- ondary dolomite was being deposited. The pre- dapest. With solutions made from dolomite, cipitation of aragonite was ascribed to the high Siegel and Reams found the precipitates were magnesium content present in the cave seep- 90% magnesian calcite. More aragonite was pre- age water. Monohydrocalcite was ascribed to cipitated at temperatures above 50◦C. Carbon an aerosol mode of formation after comparison dioxide exposure in this case did not affect the with an industrial aerosol system. outcome. Thrailkill (1971) sampled drip water and Previously, an increase in temperature was speleothems from various sites in Carlsbad thought to aid the formation of aragonite, but Caverns and found that the “moonmilk” de- this became disputed (Morse 1983). Later re- posits were aragonite, hydromagnesite, search shows that the long-term stability for or dolomite and hydromagnesite. The drip- aragonite at high temperatures is only achieved ping water was considerably undersaturated at high pressures. The stability diagram for with respect to hydromagnesite, but saturated aragonite (Figure 3) suggests that for the mete- with respect to calcite, aragonite, huntite and oric cave environment, temperature should not dolomite. Hydromagnesite only occurred where normally be a factor. Temperature was not con- slow seepage allowed evaporation to take place. sidered a factor by Hill & Forti (1997), but they Dolomite and huntite are said to be formed by noted that more aragonite appears in cold caves alteration from one of the other carbonates. than in tropical ones, which is the inverse of that Aragonite appears in minerals of the Frauen- suggested by previous researchers. Nearly all mauer - Langstein cave system in Austria minerals listed in Hill and Forti were recorded (Seemann 1985). It forms in small amounts as from the vadose zone of caves. hard, small fine spikes, coralloids, and Aragonite will convert back to calcite at ◦ crusts. These caves also had hydromagnesite high temperatures (e.g. over 100 C) and pres- and sulfate minerals. As the Mg content is in- sures around 3 kbar (conditions unlike meteoric creased, protodolomite and then dolomite can caves). be produced (rather than aragonite, huntite and Leel-Ossy (1997) examined cave minerals hydromagnesite). in the Jozsefhegy hydrothermal cave near Bu- A summary of Austrian cave minerals dapest, Hungary, that included aragonite with (Seemann 1987) shows aragonite occurs in many gypsum. However the aragonite and gypsum Austrian caves although not abundantly. It as- considerably post-dated both the caves and the sociates with magnesium minerals as flowstone hydrothermal activity which formed them. (often interlayered with calcite), in moonmilk Association with Magnesium growths, cave coral and type helic- tites. Aragonite is deposited when the Mg/Ca The relationship between aragonite and magne- ratio is 3:1 to 5:1. sium has been described by Curl (1962) as being The relationship between aragonite and the strongest chemical influence in preventing magnesium compounds such as hydromagnesite calcite from depositing and allowing aragonite has been described by others e.g. Hill (1987). to deposit. Morse (1983) also listed magnesium Magnesium is a key component to aragonite de- as one of the calcite crystal poisoners. position in many caves. Hill & Forti (1997) Eibengrotte is a cave in the Fr¨ankische noted that on increasing magnesium in a mixed Schweiz (Germany) which is developed in mas- solution of magnesium and calcium carbonate,

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the following mineral sequence is deposited: cal- drocalcite, nesquehonite and hydromagnesite. cite, high magnesium calcite, aragonite, huntite and hydromagnesite, . The presence Bohemia Cave in the Mount Owen of magnesium ions disrupts the calcite crystal Area of the South Island of New Zealand was lattice but not that of aragonite, suggesting that discovered in 1990 by members of the Czech crystal poisoning by magnesium ions only af- speleological club Alberice. A large cavity and fects the calcite crystal lattice, leaving aragonite its was briefly summarised in T´asler to deposit freely given appropriate conditions of (1998). The cavity, called “Dream of Alberice supersaturation. Cavers”, measures approximately 80 m wide by 650 m long which is a large cavern by world stan- Urbani (1997) listed several Venezuelan dards. Most of the ceiling, walls and floor of this caves as having aragonite. One occurrence was cavern were covered with various aragonite spe- associated with sepiolite (a hydrated magne- leothems together with hydromagnesite “snow”. sium ) and another was associated with The overlying bedrock was dolomitic Ordovi- dolomite. Urbani suggested that the aragonite cian units of the Mount Arthur Group whereas crystallisation was promoted by a high concen- the underlying rock to most of the cavern was tration of strontium. phyllite. Deposits of limonitised pyrrhotite were Frisia, Borsato, Fairchild & Longinelli found near the junction area. About 90% of the (1997) examined and drip points speleothems are aragonite, and other minerals in Clamouse cave (France). Aragonite speleo- include calcite, hydromagnesite, dolomite, opal, thems were being precipitated only where there Fe- and Mn- hydroxides, gypsum and sepio- was dolomitic bedrock, and only when the drip lite. The contact area between the two bedrocks rate was very low. The authors suggested that was exceptionally rich in aragonite. Aragonite magnesium inhibited the growth of calcite, ei- speleothems include , flowstone (in- ther by crystal poisoning or by “difficulties in cluding some yellow and yellow-red flowstone), rapid dehydration of the Mg2+ ion”. Clam- stalagmites, soda straws, flos ferri (as thin in- ouse cave water was not particularly high in tertwined branching forms), “winding needles”, dissolved Mg compared with other sites, so that helictites, crystal coatings, linear needles, an- the structure of the nucleation sites may play thodites, “ball of threads”, needle clusters. The a greater role. Frisia, Borsato, Fairchild & needles and helictites were often hollow, with Selmo (2001) examined both aragonite and cal- some solid needles. The different speleothem cite speleothems in Clamouse cave. Calcite spe- types were often clustered together and some- leothems had transformed from aragonite pre- times with hydromagnesite coatings on the tips. cursors over about 100 years. They suggested Grass shaped aragonite crystals as ultra thin speleothem aragonite is a palaeo-aridity indica- needles were found in the insides of some hol- tor. low speleothems such as straws. Niggeman, Habermann, Oelze & Richter In several caves near Waitomo, New (1997) examined coralloids deposited in windy Zealand, aragonite occurs with hydromagne- areas of several caves in Germany and Aus- site or other magnesium-based mineral. Over- tria. More aragonite was deposited in the ar- lying pyroclastic deposits influence mineralogy eas where the bedrock contained dolomite, ei- and cave water chemistry at Waitimo Caves (P. ther primary dolomite or from hydrothermal al- Maynard, pers. comm.). teration of bedrock. They recorded the follow- ing data regarding the Mg/Ca ratio as mole % In France, several caves have outstand- and the polymorph deposited: At Site 1 with ing aragonite deposits, usually associated with Mg/Ca < 0.5: calcite; At Sites 2, 3 and 4 with metamorphosed dolostone. Some deposits are Mg/Ca increasingly > 2: calcite + aragonite, associated with gypsum and sulfur, and some with Mg/Ca 3–23 at site 4. Site 4 (Grauner with hydromagnesite (Cabrol, Gill & Gunn Walls) included Mg calcite, aragonite, monohy- 2001).

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Strontium Possible Association with Carbide Dumps Tucker & Wright (1990) found that strontium substitutes for calcium in both lattice and non- Carbide (calcium carbide) is used as a lighting lattice sites for both calcite and aragonite. This source for caves in many parts of the world. complicates the chemistry. Strontium ions are Dripping water on calcium carbide produces a common trace constituent of seawater. How- acetylene gas which is controlled and ignited ever strontium often deposits as strontium sul- to provide a bright flame. The solid waste is fate and it may be the sulfate component which mostly calcium hydroxide with minor arsenic, is the calcite-inhibitor. and is occasionally dumped in caves. Cavers have noticed an unusual heligmite known as Strontium carbonate () is rarer “carbidimites” associated with disused carbide in meteoric caves than strontium sulfate (ce- dumps (Hill & Forti 1997). These form by lestite) (Hill & Forti 1997), but can occur with the reaction between the spent calcium carbide aragonite and sometimes with high or low Mg dump with cave seepage water. Carbidimites calcite. Strontium is often considered a factor in have an inverted horn shape, and a tendency the precipitation of aragonite, but Hill and Forti to change shape over months compared with noted strontium readily substitutes for calcium other speleothems (decades). Sarigu (1999) in- without disrupting the aragonite crystal lattice. cluded photographs of carbidimites from a cave in Italy and discussed their formation. Sarigu suggested that they form by the carbonation of Association with Clastics and Clay calcium hydroxide with CO2 to calcium carbon- ate and water, further carbonation to calcium Craig, Horton & Reams (1984) suggested that bicarbonate and also the direct carbonation of aragonite is nucleated by clastics in caves, af- calcium hydroxide to calcium bicarbonate. The ter studying speleothems from caves in Missouri photographs and text note that the crystals de- (U.S.A.) but were only able to produce vaterite posited in the tubes as feathery shapes, more in an experiment mimicking current cave condi- like aragonite or possibly vaterite rather than tions. calcite. Hill and Forti claim that most car- In the aragonite caves of France, the arag- bidimites are calcite but some are vaterite. onite is often associated with clays (Cabrol et al. 2001), exclusively in the clayey areas Influence by Sulfates (David Gill, pers. comm. in 2001). However, In caves containing gypsum (hydrated calcium clays are common minerals in caves, often as the sulfate), both calcite and aragonite can oc- substrate for a number of calcite speleothems cur, e.g. Great Onyx Cave, Kentucky, U.S.A. such as flowstone and stalagmites. (Siegel 1965). Morse (1983) lists the sulfate ion as a calcite crystal inhibitor. Carlsbad Caverns in the Guadalupe Moun- Association with Vaterite tains, Carlsbad National Park, U.S.A., contain extensive deposits of aragonite associated with Hill & Forti (1997) noted that vaterite oc- gypsum and sulfur (Thrailkill 1971, Hill 1987). curs in caves associated with moonmilk and Thrailkill noticed that where there was gypsum, sediments, and is found with hydromagnesite, there was very little calcite. According to Hill, baylissite, calcite, aragonite and monohydrocal- the caves were formed in several stages. A late cite. Vaterite can form when calcium carbonate stage involved H2S seeping though joints from is precipitated under conditions of high CO2 de- nearby oil well brines. The reaction between gassing, but reverts to aragonite and calcite over H2S and water formed sulfuric acid which cor- time. roded the porous limestone to form gypsum and

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large caves. The origin of this H2S is apparently gypsum. bacterial. The caves were probably not formed Wall crusts in Humpleu cave in Romania at high temperatures (the present cave temper- (Ghergari, Onac & Fratila 1997) included gyp- atures are about 20◦C). sum, calcite, aragonite and a variety of sulfate According to Hill, aragonite in Carlsbad minerals, apparently the breakdown products of Caverns occurred as rims, stalactites, hollow bat guano. Some of the calcite was a paramorph stalagmites, moonmilk, frostwork, , after aragonite. flowstone, beaded helictites. Secondary sulfate In Flower Cave, in the Puketiti district near in Carlsbad Caverns was less than carbonates, Waitomo, New Zealand, cavers have reported despite the large gypsum blocks present. The aragonite deposits associated with large gypsum sulfate speleothems apparently had a sulfur iso- extrusions and crusts. The gypsum extrusions tope signature closer to that of the overlying are typically 200mm long. Pool crystal deposits pyritic beds rather than that of the gypsum there have been described as aragonite, but re- blocks. quire confirmation. Photographs with cavers Hill listed speleothems and minerals that suggest crystal sizes of around 20 to 30mm long were deposited near lakes in Carlsbad Caverns. in aggregates and a hydrothermal influence on In the pools were calcite “cave clouds” (a mam- cave development has been suggested. millary coating). Closest to the pools were rounded cave popcorn (mostly aragonite). Fur- Influence by Humidity ther up were shrub-shapes of aragonite frost- Siegel & Reams (1966) cited the work of work and further up again were corroded spe- Pob´eguin in 1955 and 1957 which suggested leothems. that aragonite precipitation is enhanced by high Lechuguilla Cave in Carlsbad National Park rates of evaporation. Aragonite is 16% more sol- was well illustrated in Speleo Projects (1998) uble than calcite, so to precipitate aragonite the and has a similar sulfuric acid to solution must already be saturated with respect Carlsbad Caverns. Both subaerial and sub- to calcite. To get aragonite to precipitate first aqueous gypsum and aragonite speleothems oc- needs an increased rate of precipitation, too fast cur, but not together (or not photographed for calcite precipitation. Siegel and Reams sug- together). Possibly in these caves, aragonite gest that a rapid rate of evaporation can result and gypsum speleothems have a different ori- in the product of aragonite to be ex- gin. Lechuguilla cave has subaqueous speleo- ceeded, allowing both calcite and aragonite to thems such as selenite needles, calcite pool crys- form. tal and subaqueous calcite helictites, but lacks Hill & Forti (1997) described a “popcorn aragonite in pool deposits. Calcite speleothems line” in Carlsbad Caverns as being due to a are less common in Lechuguilla Cave compared humidity effect. Cave Popcorn is a speleothem to other caves (Speleo Projects 1998). form of either calcite or aragonite, and probably Other outstanding caves which contain arag- forms by air moving over the speleothem sur- onite associated with gypsum include Cupp- face, promoting mineral precipitation by evap- Coutunn Cave (Turkmenistan) and Alum Cave oration of water at the outer surfaces. Some (Vulcano Island, Sicily - Italy) (Hill & Forti caves have a pronounced flow of cold dry air into 1997). the cave during winter, which may be more sig- Cser & Fej´erdy (1962) described aragonite nificant to the development of this speleothem precipitating in hot springs in hydrothermal than is the loss of CO2. Aragonite frostwork and caves in Hungary as well as subaerial deposits. coralloids are similar speleothem forms, with Leel-Ossy (1997) mentioned that aragonite was frostwork being formed at times of high humid- a relatively young (subaerial) deposit in the in ity and coralloids formed when the humidity is the Jozsefhegy Hydrothermal Cave (Hungary). lower and the rate of precipitation higher, pro- Other reported minerals included calcite and ducing a smaller crystal size.

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On the other hand, Cilek, Bosak, Melka, vaterite). For example, the addition of calcium Zak, Langrova & Osborne (1998) argued that sulfate to a supersaturated solution of calcium the high humidity in the Ochtin´a Aragonite carbonate will cause the less soluble substance Cave helped aragonite to deposit in the cave. (calcium carbonate) to deposit. The humidity was kept constant by the buffer- Fast deposition commonly occurs near cave ing effect of saturated ochres. The ochres con- entrances where evaporation is highest, yet the tained 47% to 56% water by weight, and this sig- material deposited is primarily calcite. Arago- nificantly influenced the cave’s climate, which nite has been found near cave entrances associ- could aid the precipitation of large aragonite ated with monohydrocalcite (Hill & Forti 1997). speleothems. However most caves have a high Aragonite also occurs in areas with slow deposi- humidity buffered by clays and sediments. It tion rates, e.g. Ochtin´aAragonite Cave (Bos´ak, is more likely that the constant high humid- Bella, C´ılek, Ford, Hercman, Kadlec, Osborne ity controls the crystal size and growth rate of & Pruner 2002) in which three generations of the deposited calcium carbonate rather than the aragonite deposition were identified. The oldest polymorph. generation detected (U/Th dating) was 138000 years old. Supersaturation and Rate of In Clamouse Cave (France), Frisia et al. Deposition (1997) found that the drip rate controlled Only minute amounts of foreign material is re- aragonite or calcite precipitation. Aragonite quired to alter the form deposited (both crystal formed only under the slow drips in areas with shape and polymorph) (Curl 1962), while a high dolomitic bedrock, which allowed more takeup rate of deposition favours aragonite a little more of magnesium from the bedrock, and reduced than calcite (Siegel & Reams 1966). Theoretical the rate of outgassing of CO2. growth rates of stalagmites with both stagnant and flowing water were calculated by Dreybrodt (1981). The limits to precipitation in the case Carbon Dioxide of stagnant films was the ability for the film to outgas CO2, which did not occur for running Carbon dioxide content is also a factor in the water. precipitation of aragonite in caves, based on the Supersaturation and rate of deposition are work of Cabrol in 1978 and Courdry and Cabrol factors in the precipitation of aragonite Hill & in 1982 in which a stratification line was noted Forti (1997). Unlike Siegel & Reams, Hill & in some caves in France (Hill & Forti 1997). Forti considered very low rates of deposition Above this line was only calcite whereas below favour aragonite over calcite, while very high the line, aragonite was deposited. This was as- rates of deposition favour vaterite which may cribed to a lowering of the supersaturation of convert to aragonite. At other rates, calcite the seepage water to favour the deposition of is the favoured polymorph. They noted that aragonite. supersaturation can be achieved in dry caves with a high loss of CO2 or a high evaporation rate, which could to increased percentage Pressure of magnesium in the remaining solution. Supersaturation is necessary for the precipi- Pressure was also a possible factor in the pre- tation of either calcite or aragonite, and can be cipitation of aragonite in caves (B. Rogers, pers. achieved either by physical means (e.g. evapo- comm. in Hill & Forti (1997)). Aragonite was ration) or chemical means. By allowing CO2 described from an active fault in a cave. Calcite to escape, or by application of the common ion will readily convert to aragonite at high pres- effect, the solution may become supersaturated sures. This situation is unlikely for most cave with respect to either calcite or aragonite (or environments.

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Speleothem Surfaces calcium carbonate as calcite or aragonite. Such microorganisms are not present in moonmilk Speleothem surfaces may also assist the depo- composed of magnesium minerals. sition of aragonite, where aragonite was formed over corrosion surfaces, or over older aragonite Stable Isotope Studies speleothems. However, it can be difficult to distinguish between calcite and aragonite and Cilek & Smejkal (1986) sectioned calcite- one researcher found one fifth of a supposedly aragonite stalactites from the Star´yhrad cave aragonite collection was in fact calcite (Hill & (Low Tatras) and from two Bohemian Karst Forti 1997). caves. They analysed the stable C and O iso- Speleothem surfaces and substrates aid the topes of the calcite and aragonite. The values precipitation of most speleothems. Seed crys- for δ13C were mostly negative for calcite and tals start crystal growth, so calcite accumulates positive for aragonite. In general, the values for on an existing calcite substrate following the δ13C and δ18O for aragonite were greater than pre-existing crystal boundaries, while aragonite those for calcite. Generally, an enrichment in may be similarly precipitated from solutions al- the heavier isotope can indicate a higher rate ready supersaturated with respect to aragonite. of evaporation. It is also temperature depen- Some substances, if present on the surface of a dent. Cilek and Smejkal interpreted the differ- speleothem, inhibit the precipitation of either ence as a change in the way the two minerals polymorph. Tucker & Wright (1990) noted that had been precipitated. Formation of the cal- in the marine situation, o¨oids are frequently in- cite was based on the outgassing of CO2 (the hibited in development because of a coating of normal karst process) with minimal evaporation organic material. Grains of quartz and clays whereas the aragonite mainly formed by very were observed to be nucleation sites for arag- slow evaporation, so slow that biogenic effects onite in some Missouri (U.S.A.) speleothems are suppressed. (Craig et al. 1984). In an attempt to produce However, in Gillieson (1996), such biological aragonite, they made solutions of calcium car- processes apparently enrich the calcite or arago- bonate and added various concentrations of clay nite with heavier oxygen isotopes. This process in suspension. The clays comprised illite, kaoli- is also temperature dependent, with higher tem- nite and chlorite (no carbonates or quartz). The peratures leading to heavier oxygen isotopes in resulting precipitate was vaterite and calcite, precipitates. not aragonite, with the ratio of vaterite to cal- Where the C and O isotopes are correlated cite increasing in proportion to the clay present. (as in these samples), both authors favoured Above 80 mg/l clay concentration, only vaterite an evaporative condition. In Clamouse Cave was produced. (France), Frisia et al. (1997) similarly found iso- tope ratios that suggested that the aragonite Associations with Biological Activity deposits were formed under more evaporative conditions. They found this interpretation dif- In the marine environment, aragonite often ficult because all their aragonite samples were forms due to biological activity, e.g. the in- collected in areas of no wind, constant tem- fluence of proteins in sea shells (Tucker & perature and very high (∼99%) humidity. In- Wright 1990). The variety of carbonates pre- stead, they suggested another mechanism con- cipitated in response to biological processes are centrated the heavier isotopes in the aragonite calcite, Mg-calcite, aragonite, vaterite, monohy- samples, a chemical kinetic effect caused by the drocalcite, dolomite and amorphous carbonate. slow outgassing of CO2. “Moonmilk” is a white pasty material found Niggeman et al. (1997) compared the sta- in many meteoric caves. Northup, Reyenback & ble isotopes of calcite and aragonite coralloids. Pace (1997) described evidence for microorgan- The aragonite samples tended to have higher isms in meteoric cave moonmilk comprised of concentrations of these heavier isotopes. They

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attributed this to prior concentration of the iso- the oldest material was kidney-shaped and re- topes in the solutions from which the carbon- crystallised; the intermediate aragonite speleo- ates were precipitated, because all samples came thems form long needles and helictites; the from draughty areas with similar climatic con- youngest as small fan-shapes (frostwork) and ditions. helictites. Aragonite also occurred as flowstone. Cilek et al. (1998) also measured C and O Ochtin´aAragonite Cave also has deposits of isotopes in Ochtin´aAragonite Cave which has goethite and limonite, with the goethite of a very little air movement and very high humidity. particularly small crystal size. The ochres have The isotope ratios for the aragonite were similar high water content, 47% to 56%, which may to those for calcite speleothems from the well- buffer the humidity in the cave, keeping it at ventilated Star´yhrad Cave. They concluded a constant high level. The two main factors that the aragonite was deposited as a result of in the deposition of aragonite in the cave were slow CO2 outgassing. the presence of Fe and Mn in solutions, and the high humidity. Interspersed with the ochres Association with Phosphates were black manganese oxides including asbolane and birnessite. Some of these manganese min- In describing the mineralogy of Kartchner Cav- erals were ascribed to microorganism activity. erns, Arizona (U.S.A.), Hill (1999) mentioned Hydromagnesite was found in small quantities some deposits of aragonite. Magnesium plays associated with the ochres. little part in its deposition as the limestones Iron was not one of the elements listed by are particularly pure. Kartchner Caverns has Morse (1983) which could cause aragonite to large deposits of phosphatic minerals derived precipitate. It is more likely that it precipitates from bat guano, as well as a large quantity of under the influence of other materials present iron oxides, and unusual clays includ- such as manganese, apatite or La-Nd-bearing ing rectorite. Sulphates were associated with phosphates. Commonly, cave sediments con- the bat guano. Cave mineralisation may have tain of layers of clastics and calcite. The clas- had a partially hydrothermal origin. The arag- tics usually include a component of iron oxy- onite deposits were located at the ends of pas- hydroxides. The calcite layers usually contain sages where one would expect the humidity to no iron oxy-hydroxide (although they may be be high. stained brown by humic acids) and aragonite is Humpleu cave in Romania also has arago- rarely present in such sediments. Where arago- nite with bat guano phosphates. However Gher- nite occurs with iron-rich sediments, the sed- gari et al. (1997) considered the phosphate to be iments are often hard yet porous, and these more recent than the aragonite, with phosphate physical qualities may assist ions (e.g. magne- on the lower parts of the passage and arago- sium or sulfate) to influence the form of pre- nite in the upper parts. Gypsum, aragonite and cipitating calcium carbonate by keeping the hu- ochres were also present. midity high, acting as a sturdy substrate and allowing slow movement of ions in solution. Association with Ochres and Gossans Flos Ferri A photograph in Speleo Projects (1998) showed a cluster of aragonite popcorn and frostwork On page 206 of Hurlbut (1970) is a photograph with a red, black and orange ochreous substrate, of tangled aragonite helictites (“flos ferri” from contrasting with the corroded and porous white Styria (Steiermark, Austria): bedrock. In Slovakia, extensive aragonite deposits in “When aragonite in coral-like ag- show caves are associated with “ochres” con- gregates is found on the walls of taining Fe, Mn and Mg (Cilek et al. 1998, Bos´ak iron mines it is called “Flos Ferri,” et al. 2002). Aragonite occurred as three forms: meaning iron flower. This specimen

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(depicted) is from Styria, Austria, which is famous for this variety of aragonite.”

Most of this material has now been mined away (Stephan Kempe, pers. comm., August 1997). Rowling saw large specimens of flos ferri aragonite in the private museum at the Glacier Gardens at Lucerne (Switzerland) in 1997. Here, it is known as Eisernblut (iron blood) although it is white. The tangled masses of helictites have a radius of curvature of around 5 to 10 mm. Other museums also hold this ma- terial, such as the Natural History museum at Lucerne and the collection, cat. no. D19158. Although Hurlbut (1970) did not specify which iron mineral was associated with flos ferri, he did say: “the Austrian deposit at Erzberg in Styria is the only concentration of siderite of sufficient size and pu- rity to be considered a major source of iron. Here a folded limestone has been replaced by massive siderite through the agency of iron-bearing waters to form a deposit of many Figure 4. Part of The Arabesque, behind wire tens of million tons.” netting at Cerberus Cave, , fea- Eisenerz is now a show-mine and is no longer turing flos ferri. Speleothem is about 20 cm worked (Austrian tourist bureau). high. According to Shaw (1992), the term flos ferri was first used by John Hill in 1748 for a twisted form of helictite found in mines and Blue Speleothems in some Mendip (UK) caves. Shaw included two sketches by Patrin (1803) depicting “flos- The copper ion can form a solid solution in ferri” which resembled the flos ferri samples the aragonite crystal structure (Morse 1983). mentioned earlier. Shaw described flos ferri as a Blue aragonite speleothems occur in conjunc- particularly slender variety of helictite which is tion with deposits of heavy metals (e.g. copper) made of aragonite and often found in iron mines. e.g. the Blue Cave, France, (Hill & Forti 1997). In contrast, Hill & Forti (1997) described flos Not all blue speleothems are aragonite, but can ferri as a variety of anthodite which resembles include minerals such as allophane and some a sea urchin (Hill & Forti 1997), and defined it clays, and some calcite speleothems are de- as a quill-like variety of anthodite. These differ- scribed as “blue”. The colour is not diagnostic ences in terminology appear to be localised to tool as to whether the speleothem is calcite or particular countries and show caves. aragonite. This article follows the definition of flos ferri Blue “Larium stone” from a mine near Lar- as used by Patrin, Shaw and Hurlbut. Flos ferri ium, Greece has been traded amongst mineral occurs at Jenolan Caves (Figure 4). collectors. Material I have seen is aragonite

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with copper carbonate present as discrete cen- ence in NSW from 1830 to 1987 were discussed tres rather than being dissolved in the arago- by Osborne (1991). nite. A photograph of this material held by Dunlop (1977) described the show caves at collectors and advertised on the Internet shows Jenolan. In 1903 the Skeleton Cave (now Cer- a light blue stone with light and dark banding berus Cave, a branch of the southern show characteristic of a sedimentary deposit. Smith- caves) was discovered, although other reports sonite was also mined near Larium. Zn is one suggest an earlier date (Middleton 1991). It has of the calcite-inhibitors listed by Morse (1983). a speleothem group known as the Arabesque: a combination of (apparently aragonite) stalac- HISTORICAL PERSPECTIVES OF tites, stalagmites and helictites (Figures 4 and 6). Also in 1903 the River Cave was discovered. ARAGONITE IN NSW CAVES This is also a branch of the southern show caves and has speleothems known as “Furze Bushes” C.S. Wilkinson, NSW Government Geologist, which are very similar to the Arabesque. They visited the “Belubula Caves” (Walli Caves – see are now known to be aragonite (Ross Pogson Figure 5) near Licking Hole Creek, which is a pers. comm.). tributary of Liscombe Pools Creek, between Or- Frank (1974) described the development of ange, Canowindra and Mandurama about 1870 Walli caves based on work done in 1968 and shortly after their discovery by road contractors 1969. This is the first published reference to the (Wilkinson 1892). This article was reproduced use of XRD to analyse aragonite from a NSW posthumously by the Department of Mines from cave. Concerning aragonite in Deep Hole (Deep an original publication in the Town and Cave), Frank said: Country Journal, Sept. 9, 1876, p. 419. Con- cerning aragonite in “The Long Cave,” Wilkin- X-ray diffraction of some speleo- son said: thems on the wall at 105036, Fig- ure 5, showed them to be aragonite. Another small cavern, rather dif- ficult to get into, has a mound Welch (1976) published a catalogue of caves of white with a tracery- at Jenolan, north of the show caves. Glass, marked surface, meeting which, and Hennings and Wards Mistake caves were said hanging in the centre are two stalac- to contain “aragonite”. A photograph showed tites covered with translucent spikes an acicular mineral in Hennings Cave. Dunkley curving in all directions. These sin- & Anderson (1978) included a photograph of gular stalactites are seen in some “aragonite” near Upper Oolite Cavern, Mam- of the other caverns; also groups of moth Cave, Jenolan. Near the Pisa Chamber, long radiating crystals of aragonite. there were “a number of mud tunnels ...one containing a unique cluster of aragonite crys- There was very little further reference to tals”. Webb & Brush (1978) analysed aragonite NSW cave aragonite until Frank (1974) de- from Wyanbene Cave near Braidwood, south- scribed the Deep Hole (cave) at Walli. The lack ern NSW. The samples were found loose on the of scientific interest in the subject in NSW in the ground underneath anthodites near Frustration interim is perplexing, given the amount of re- Lake. XRD analysis identified both aragonite search on cave aragonite in other countries dur- and calcite. SEM photographs showed the gen- ing that period. Historical aspects of cave sci- eral habit of the anthodite fragments.

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o 141 E 143 145 147 149 151 153

Queensland Lismore Tenterfield 29o S Lightning Ridge CLARENCE MORTON KANMANTOO OCEAN GREAT AUSTRALIAN BASIN BASIN FOLD BELT Inverell Grafton Walgett Bourke

Narrabri NEW ENGLAND

Armidale PACIFIC White Cliffs

31 Gunnedah Tamworth

SOUTH Cobar Nyngan FOLD BELT Gilgandra Broken Hill LORNE

LACHLAN Dubbo BASIN Musswellbrook

ADELAIDE Singleton FOLD BELT SYDNEY BOWEN Newcastle 33 Orange MURRAY Bathurst BASIN Forbes Lithgow WALLI CAVES Sydney Wentworth FOLD Cowra JENOLAN CAVES

Hay WOMBEYAN CAVES Wollongong Goulburn BASIN BUNGONIA CAVES 35 Wagga Wagga TN Canberra BELT WYANBENE CAVES

Cooma Victoria

NSW 37 0 100 200 km Bega

Figure 5. Map of NSW showing location of caves mentioned, with major tectonic features. Tectonic overlay re-drawn from NSW Department of Mineral Resources; Australian map from Geosciences Australia.

Osborne (1978) reported calcite which may & Packham 1982), the one in Murder Cave is have inverted from aragonite, from Cliefden developed at the junction of two sub-units (up- Caves, central NSW. He also described blue per and lower) of the Belubula Limestone, and aragonite speleothems in the Australian Mu- the one in Boonderoo Cave is at the junction of seum minerals collection, specimens D36380 the Belubula Limestone and Vandon Limestone. and D23544 from Boonderoo Cave. A thin sec- Dyson, Ellis & James (1982) included a pho- tion (cat. No. USGD 54322) of the base of the tograph of fine spiky “aragonite” helictite clus- small blue (specimen D36380) showed ters on the walls of Shawl Cave, Wombeyan. an inner sparry calcite layer coated with a blue Ralston (1989) recalled the discovery in 1964 aragonite layer, determined by XRD. The arag- of the Barralong Cave, Jenolan (southern show onite layer had radially oriented acicular crys- caves), saying on page 57: “Hidden in its own tals. The same radial structure was noted on little crevice is a Christmas Tree of aragonite.” the broken tip of the stalactite in Boonderoo Osborne (1990), Osborne (1993) examined Cave. The blue stalactites in both Boonderoo palaeokarst deposits in the show caves at Cave and Murder Cave were developed at two Jenolan and mentioned aragonite deposits (he- different junctions of limestone members. Us- lictites) were hosted on a substrate of laminated ing revised stratigraphic nomenclature (Webby dolomitic internal sediments and palaeokarst

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deposits. Many of these sediments, found in mineralogical features of Wyanbene Cave, refer- River Cave, Mud Tunnels, Cerberus Cave, Im- ring to rock chip analyses of Richardson, Byrnes perial Cave, Jubilee Cave and Ribbon Cave, & Degeling (1981). “Aragonite” anthodites and were unconformable with the Jenolan Caves flos ferri were associated with “an oxide or Limestone and most had been dedolomitised. weathered ore body”. Osborne (1996) described how weathering of sulfides deposited in palaeokarst can lead to ochreous deposits associated with gypsum and red calcite speleothems, as in Wyanbene Cave, Jenolan Caves and caves in Tasmania. Arago- nite occurred with gypsum in a number of places in eastern Australia and where caves are asso- ciated with ore bodies. These bodies act as aquicludes: they prevent water from penetrat- ing the rock during initial speleogenesis. Later, as pyrite in the ore bodies is oxidised, it assists in breakdown of bedrock, exposing palaeokarst and aids speleothem development. Thus, large, well-decorated caves are often associated with ore bodies. Bauer & Bauer (1998) reported “aragonite” at Bungonia in the Coffin Chamber of the B- 4-5 Extension (cave). “Ribbon helictites” from Jubilee Cave, Jenolan Caves, were described as “aragonite”, but Rowling (1998a) showed them Figure 6. The Arabesque, Cerberus Cave, to be calcite. Jenolan Caves. Speleothem is about 30 cm high Vizjak (1998b) described the discovery in and features flos ferri, ribbed stalactites and 1997 of aragonite in a part of Mammoth Cave, beaded helictites. Jenolan called “The World of Mud”. The area lies near “a shale bed”: Osborne (1994) noted that in eastern Aus- tralia, the longest cave systems, and the ones There lay the “Aragonite Snow- with most extensive deposits of aragonite and fields” - a large, magnificent patch gypsum occur near areas of Permo-Triassic basi- of white powdery formation covered nal sediments, e.g. at Jenolan Caves (NSW), in aragonite crystals as large as Exit Cave at Ida Bay and caves at Mole Creek in pencils. (Further up, they found) Tasmania. Osborne suggested that dolomite in ... several basketball sized clusters the palaeokarst produced aragonite speleothems of aragonite crystals adorning the instead of calcite ones at Jenolan, such as the walls. Furze Bush, possibly the Arabesque, and the helictites in Ribbon Cave. He suggested that Breezes were noted in this area, although pyrite and dolomite were emplaced in buried no cave entrances are known nearby. Viz- palaeokarst deposits at low temperatures by jak (1998a) described more “aragonite” speleo- basinal fluids from above. In both the Western thems in the area: edge of the Sydney Basin, and in Tasmania, this resulted in the association of Permian caprocks ... at the “Mini Vortex” the arago- with large, well-decorated caves containing gyp- nite clusters on the roof are spectac- sum and aragonite speleothems. ular, with crystals as big as chop- Rowling (1995) described geological and sticks and there is an amazing white

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cross of calcite (or something) on helictite cluster resembling flos ferri. On the the ceiling. ... Beyond the “South- same page is a photograph by David Connard ern Cross”, Turfa entered “Pure of aragonite anthodites in Genghis Khan Cave, Dilemma”. This small chamber is Mole Creek, Tasmania. ... full of white crystal growths that are all over the walls.

Photographs of “The World of Mud” pre- sented by Mark Bonwick (pers. comm.) showed that it contains extensive deposits of “arago- nite” as anthodites and wall coatings. Some blue and green “aragonite” was present. Rowling (1998b) described the discovery of Aragonite Canyon in Sigma Cave, Wombeyan with Sydney University Speleological Society. Although the surveyors did not discover this part of the cave, they were the first to document it. Members of Sydney University Speleologi- cal Society, I. Cooper, P. Maynard and others have reported (pers. comm.) on “aragonite” in Wiburds Lake Cave during a re-survey of the cave in 1999. Rowling (1999) described speleo- Figure 7. Aragonite helictites (small, twisting thems in the Chevalier Extension of Glass Cave, bunches) and other speleothems at the Lyre Jenolan. Some of the “aragonite” was associ- Birds Nest, Ribbon Cave, Jenolan Caves. Area ated with a white moonmilk-like material. depicted is about 1 m high. Osborne (1999) mentioned Ribbon Cave (Jenolan) aragonite speleothems associated Osborne, Pogson & Colchester (2002) exam- with magnesium rich minerals: huntite, ined the white pasty substance found with arag- dolomite and ferroan dolomite. Dolomitic onite at “The Lyrebirds Nest” (Ribbon Cave, palaeokarst was the most likely source of magne- Jenolan). It was huntite. Aragonite occurs in sium. Sulfates were also deposited. Weathering Ribbon Cave as spherulites about 2 cm diam- of pyrite was the most likely source of the sul- eter, embedded in gossan. Locally, these are fate. The cave is wet and there is little evapora- called “stars”, and they also occur near the pool tion. Aragonite was shown as spirals and spikes in the Orient Cave in a dark ochreous deposit in the feature known as the “Lyrebirds Nest” (R.A. Osborne, pers. comm.). Pogson, Osborne (Figure 7). Osborne suggested that pyrite was and Colchester used XRD to analyse the arag- hydrothermally emplaced in palaeokarst sedi- onite from Ribbon Cave, the Furze Bush and ments and its oxidation has formed sulfate and small deposits in River Cave (R.A. Osborne, aragonite speleothems. The pyrite was em- pers. comm.). placed between mid Permian and Late Creta- Turner (2002) analysed samples of blue and ceous to Early Tertiary, or related to hydrother- white speleothems from Cliefden Caves. One mal activity during opening of the Tasman 40 mg sample from the blue aragonite stalac- Sea (Late ). Osborne (2000) noted tite in Boonderoo Cave, collected by the Orange that aragonite in eastern Australian caves was Speleological Society in 1995 contained copper, mainly associated with dolomitic and pyritic barium, strontium, iron, , magnesium, lead, palaeokarst and also with igneous dykes and nickel and uranium. Very small samples of blue other intrusions. speleothems and white speleothems from Ta- A photograph of anthodites in Fife Cave, plow Maze cave were analysed. The blue speleo- Church Creek, N.S.W. (Pryke 2000) showed a thems contained copper, chromium and minor

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nickel at higher levels than in the white speleo- Creek, Tasmania. them. Turner suggested copper caused the blue Rowling (2003) examined subaqueous helic- colour, but did not determine whether the Ta- tites found by cave divers from lakes in Mul- plow Maze blue material was aragonite or cal- lamullang cave, Nullarbor Plain, Western Aus- cite. tralia. Minerals in one helictite, determined Aragonite (XRD analysis) is the main con- by XRD, were calcite, magnesian calcite, arag- stituent of boiler scale on heating elements onite, hydromagnesite, gypsum, celestite and in electric kettles at Jenolan Caves supplied halite. A subaqueous helictite from another lake by water from the Jenolan underground river in the cave contained calcite, magnesian calcite, (R.A. Osborne, pers. comm.). A small quantity aragonite, hydromagnesite, gypsum, huntite, of calcite was present. cristobalite and halite.

ARAGONITE IN OTHER RECENT STUDIES ON CAVE AUSTRALIAN CAVES ARAGONITE IN NSW

The caves of Tasmania are well-known for their Rowling (2004) examined aragonite in NSW displays of aragonite, yet there was little scien- caves, including Jenolan, Wombeyan and Walli. tific work done on their mineralogy in the 19th Aragonite in some NSW caves appeared to be century. Most people visiting the caves did so associated with high evaporation rates allowing out of curiosity and not research. Generally calcite, aragonite and vaterite to deposit, e.g. cavers and tourists are not mineralogists and in cave sediments in areas with low humidity in do not have the resources to analyse minerals. Wollondilly Cave, Wombeyan. Several factors One problem with reporting minerals from influence the deposition of aragonite instead of caves is an ethical one. Over-collecting is calcite speleothems in NSW caves, such as pres- a world-wide problem coupled with the lack ence of ferroan dolomite, calcite-inhibitors (in of protection for the caves’ contents in many particular ions of magnesium, manganese, phos- places. This has meant that discoverers of un- phate, sulfate and heavy metals), and both air usual cave minerals have often had to keep their movement and humidity. discoveries secret. Several reported aragonite deposits were ex- Pisoliths from a mine at Bendigo, Victo- amined to confirm whether the material is arag- ria were found to contain aragonite and pos- onite. Substrates to the deposits were ex- sibly MgCO3 associated with siderite (Baker & amined, as was the nature of the bedrock. Frostick 1947). The work concentrated on Contact Cave and In South Australia, aragonite occurs in caves Wiburds Lake Cave at Jenolan; Sigma Cave, associated with dolostone (Grant Gartrell, pers. Wollondilly Cave and Cow Pit at Wombeyan comm.). Quarrying at Sellicks Hill Quarry un- and Piano Cave and Deep Hole (Cave) at Walli. covered a cave in September 1991. Photographs The study sites were all within Palaeozoic rocks of the mined cave showed anthodites, pop- in the Lachlan Fold Belt. Two sites, Jenolan corn, coralloids, and coatings of (apparently) and Wombeyan, are close to the western edge dolomite and hydromagnesite. The cave has of the Sydney Basin. The third site, Walli, been closed by the quarry since 9th Novem- is close to a warm spring. The physical, cli- ber 1991 and was the subject of a Parlia- matic, chemical and mineralogical influences on mentary enquiry (Environment, Resources and calcium carbonate deposition in the caves were Development Committee, Parliament of South investigated. Australia 1995). Contact Cave lies near the eastern bound- Rowling (1993) sketched and described ary of the Late Silurian Jenolan Caves Lime- “aragonite” anthodites and helictites observed stone, in steeply bedded and partially dolomi- in Genghis Khan and Kubla Khan caves at Mole tised limestone close to its eastern boundary

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with the Jenolan volcanics. Aragonite in Con- doline with a dark zone). Sigma Cave is close tact Cave is precipitated on the ceiling as an- to the south east boundary of the Wombeyan thodites, helictites and coatings. The substrate marble, close to its unconformable boundary for the aragonite is porous, altered, dolomi- with effusive hypersthene porphyry and intru- tised limestone which is wedged apart by arag- sive gabbro, and contains some unmarmorised onite crystals. Aragonite deposition was asso- limestone. Aragonite occurs mainly in a canyon ciated with a concentration of calcite-inhibiting at the southern end of the cave and in some ions, mainly magnesium, manganese and to a other sites. In Sigma Cave, aragonite deposition lesser extent, phosphates. Aragonite, dolomite involves minerals containing calcite-inhibitors, and rhodochrosite are being actively deposited as well as some air movement in the cave. where these minerals are present. Calcite forms Calcite-inhibitors at Sigma Cave include ions of where minerals lack magnesium ions. The in- magnesium, manganese, sulfate and phosphate hibitors appeared to be mobilised by fresh water (possibly bat origin), partly from bedrock veins entering the cave as seepage along the steep bed- and partly from breakdown of minerals in sed- ding and jointing. During winter, cold dry air iments sourced from mafic igneous rocks. Sub- pooling in the lower part of the cave may con- strates to aragonite speleothems include cor- centrate minerals by evaporation and is most roded speleothem, bedrock, ochres, mud and likely associated with the “popcorn line” seen clastics. There is air movement at times in the in the cave. canyon, it has higher levels of CO2 than other Wiburds Lake Cave lies near the western parts of the cave and humidity is high. Air boundary of the Jenolan Caves Limestone, close movement may assist in the rapid exchange of to its faulted western boundary with Ordovi- CO2 at speleothem surfaces. cian cherts. Aragonite here is associated with Wollondilly Cave, in the eastern part of the weathered pyritic dolomitised limestone, an al- Wombeyan marble, has anthodites and helic- tered, dolomitised mafic dyke in a fault shear tites in an inaccessible area of the cave. Para- zone, and also with bat guano minerals. Arago- morphs of calcite after aragonite occurred at nite speleothems include a spathite, cavity fills, Jacobs Ladder and the Pantheon. Aragonite vughs, surface coatings and anthodites. Cal- at Star Chamber is associated with huntite and cite occurs in small quantities at the aragonite hydromagnesite. In The Loft, speleothem cor- sites. Calcite-inhibitors associated with arago- rosion is characteristic of bat guano deposits. nite include ions of magnesium, manganese and Aragonite, vaterite and calcite were detected sulfate. Phosphate is significant in some areas. in surface coatings in this area. Air move- Low humidity is significant in two areas. ment between the two entrances of this cave Other sites briefly examined at Jenolan in- has a drying effect which may serve to con- cluded Glass Cave, Mammoth Cave, Spider centrate minerals by evaporation in some ar- Cave and the show caves. Aragonite in Glass eas. The presence of vaterite and aragonite Cave may be associated with weathering of in fluffy coatings suggests vaterite inverting to dolomitised limestone (resulting in anthodites) aragonite. Calcite-inhibitors in the sediments and with bat guano (resulting in small cryp- included ions of phosphate, sulphate, magne- tic forms). Aragonite in the show caves, and sium and manganese. Cave sediment includes possibly in Mammoth and Spider Cave is as- material sourced from detrital mafic rocks. sociated with weathering of pyritic dolomitised Cow Pit is located near Wollondilly Cave, limestone. and cave W43 is located near the northern Wombeyan Caves are developed in sac- boundary of the Wombeyan marble. At Cow charoidal marble, in metamorphosed Silurian Pit, paramorphs of calcite after aragonite occur Wombeyan Caves Limestone. Three sites were in the walls as spheroids with minor huntite. examined at Wombeyan Caves: Sigma Cave, Aragonite is a minor mineral in white wall coat- Wollondilly Cave and Cow Pit (a steep sided ings and in red phosphatic sediments with mi-

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nor hydromagnesite and huntite. At cave W43, Development and Learning, University of Syd- aragonite and paramorphs were detected in a ney). Dr Ian Kaplin (Electron Microscope Unit, coralloid speleothem. Dolomite in the bedrock Sydney University) patiently showed how to use may be a source of magnesium-rich minerals the electron microscope. The text has been here. greatly improved, thanks to helpful suggestions Walli Caves are developed in the massive by the editor and reviewers. Belubula Limestone of the Cliefden Caves Limestone Subgroup (Barrajin Group). REFERENCES Here, the limestone is steeply bedded, contains chert nodules with dolomite inclusions, and has Assereto, R. & Folk, R. L. (1979), ‘Diagenetic gypsum and barite in veins. In Piano Cave fabrics of aragonite, calcite and dolomite and Deep Hole (Deep Cave), gypsum occurs in an ancient peritidal-spelean environ- both as a surface coating and as fine selenite ment: Triassic calcare rosso, Lombardia, needles on chert nodules in areas with low hu- Italy’, Journal of Sedimentary Petrology midity. Aragonite at Walli caves was associ- 50(2), 371–394. ated with vein minerals and coatings containing calcite-inhibitors and, in some areas, low humid- Baker, G. & Frostick, A. C. (1947), ‘Pisoliths ity. Calcite-inhibitors include sulfate (mostly as and ooliths from some Australian caves gypsum), magnesium, manganese and barium. and mines’, Journal of Sedimentary Petrol- ogy 17(2), 39–67. Other caves which contain aragonite were not major study sites, but sufficient informa- Bathurst, R. G. C. (1974), Carbonate Cements tion was available for a preliminary assessment and their Diagenesis, 1994 second enlarged as to why they may contain aragonite. These edn, Elsevier, Amsterdam. caves include Flying Fortress Cave and the B4- 5 Extension at Bungonia near Goulburn, and Bauer, J. & Bauer, P. (1998), Under Bungonia, Wyanbene Cave south of Braidwood. Arago- first edn, JB Books - Life on Paper, Oak nite deposition at Bungonia has some similari- Flats NSW Australia. ties with that at Jenolan in that dolomitisation Berry, L. G., Mason, B. & Dietrich, R. V. of the bedrock has occurred, and the bedding (1983), Mineralogy: Concepts, Descrip- or jointing is steep allowing seepage of water tions, Determinations, second edn, W. H. into the cave, with possible oxidation of pyrite. Freeman and Company, San Francisco, Aragonite is also associated with a mafic dyke. USA. Wyanbene Cave features some bedrock dolomi- tisation, and low grade ore bodies which include Bos´ak, P., Bella, P., C´ılek, V., Ford, D. C., several known calcite-inhibitors and aragonite Hercman, H., Kadlec, J., Osborne, A. occurs with both features. Brief notes were & Pruner, P. (2002), ‘Ochtin´aAragonite made of aragonite-like speleothems at Colong Cave (Western Carpathians, Slovakia): Caves (between Jenolan and Wombeyan), a cave Morphology, mineralogy of the fill and gen- at Jaunter (west of Jenolan) and at Wellington esis’, Geologica Carpathica 53(6), 399–410. (240 km NW of Sydney). Cabrol, P., Gill, D. W. & Gunn, J. (2001), ‘En- semble de grottes a concretions du sud de ACKNOWLEDGMENTS la France: Inscription au patrimoine de l’UNESCO’, unpubl . This research began in July 1999 as a part-time Carlson, W. D. (1983), The polymorphs of project and was completed in July 2004. Partic- CaCO3 and the Aragonite - Calcite Trans- ular thanks are given to my supervisors Dr Tom formation, in R. J. Reeder, ed., ‘Carbon- Hubble (School of Geosciences, University of ates: Mineralogy and Chemistry’, Miner- Sydney) and Dr Armstrong Osborne (School of alogical Society of America, pp. 191–226.

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Cilek, V., Bosak, P., Melka, K., Zak, K., Lan- Paper No. 8, Sydney Speleological Society, grova, A. & Osborne, A. (1998), ‘Miner- Sydney, NSW Australia. alogicke vyzkumy v Ochtinske Aragonitove Jeskyni (Mineralogy of Ochtinske Arago- Environment, Resources and Development nite Cave)’, Aragonit 3, 7–12. Committee, Parliament of South Australia (1995), Sellicks Hill Quarry Investigations Cilek, V. & Smejkal, V. (1986), ‘Puvod arago- (Report, 130pp), Parliament of South Aus- nitu v jeskynich: Studie stabilnich izotopu tralia, Adelaide, SA. (the origin of cave aragonite: the stable iso- Essene, E. J. (1983), Solid solutions and solvi tope study)’, Ceskoslovensky kras 37, 7–13. among metamorphic carbonates with ap- Craig, K. D., Horton, P. D. & Reams, M. W. plications to geologic thermobarometry, in (1984), ‘Clastic and solutional boundaries R. J. Reeder, ed., ‘Carbonates: Mineral- as nucleation surfaces for aragonite in spe- ogy and Chemistry’, Mineralogical Society leothems’, Bulletin of the National Speleo- of America, pp. 77–96. logical Society 46(1), 15–17. Fischbeck, R. & M¨uller, G. (1971), ‘Monohy- Cser, F. & Fej´erdy, I. (1962), ‘Formation of drocalcite, hydromagnesite, nesquehonite, the polymorphic forms of calcium carbon- dolomite, aragonite, and calcite in speleo- ate and their transition one into another’, thems of the Fr¨ankische Schweiz, West- Karszt es Barlangkutatas 4, 15–39. ern Germany’, Contr. Mineral and Petrol. 33, 87–92. Curl, R. L. (1962), ‘The aragonite-calcite prob- lem’, Bulletin of the National Speleological Fischer, H. (1988), ‘Etymology, terminology, Society 24(1), 57–73. and an attempt of definition of mond- milch’, Bulletin of the National Speleologi- Dreybrodt, W. (1981), ‘The kinetics of calcite cal Society 50(2), 54–58. precipitation from thin films of calcareous solutions and the growth of speleothems: Folk, R. L. & Assereto, R. (1976), ‘Comparitive Revisited’, Chemical Geology 32, 237–245. fabrics of length-slow and length-fast cal- cite and calcitised aragonite in a Holocene Dublyansky, Y. V. (2000), Hydrothermal speleothem, Carlsbad Caverns, New Mex- speleogenesis in the Hungarian karst, in ico’, Journal of Sedimentary Petrology A. B. Klimchouk, D. C. Ford, A. N. 46(3), 486–496. Palmer & W. Dreybrodt, eds, ‘Speleoge- nesis: Evolution of Karst Aquifers’, Na- Ford, T. D. & Cullingford, C. H. D. (1976), tional Speleological Society, Huntsville, Al- The Science of , Academic Press, abama, U.S.A., pp. 298–303. London, UK. Dunkley, J. R. & Anderson, E. G. (1978), Frank, R. (1974), ‘Sedimentary development of The Exploration and Speleogeography of the Walli Caves, New South Wales’, Helic- Mammoth Cave, Jenolan, 2nd edn, Syd- tite pp. 3–30. ney University Speleological Society and Frisia, S., Borsato, A., Fairchild, I. J. & Speleological Research Council Ltd, Syd- Longinelli, A. (1997), Aragonite precipi- ney, NSW Australia. tation at Grotte de Clamouse (Herault, Dunlop, B. T. (1977), Jenolan Caves (10th France): role of magnesium and drip rate, Edition), Department of Tourism, Sydney, in P.-Y. Jeannin, ed., ‘Proceedings of the Australia. 12th International Congress of Speleology’, Vol. 7: Physical Speleology, International Dyson, H. J., Ellis, R. & James, J. M., eds Union of Speleology and Swiss Speleologi- (1982), Wombeyan Caves. SSS Occasional cal Society, pp. 247–250.

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Frisia, S., Borsato, A., Fairchild, I. J. & Selmo, Leel-Ossy, S. (1997), Genesis of Jozsefhegy hy- E. M. (2001), Aragonite to calcite trans- drothermal cave, Budapest, in P.-Y. Jean- formation in speleothems: environmental nin, ed., ‘Proceedings of the 12th Inter- conditions and implications for palaeocli- national Congress of Speleology’, Vol. 7: mate reconstruction., in ‘21st IAS-Meeting Physical Speleology, International Union of of Sedimentology, Davos, Switzerland, 3-5 Speleology and Swiss Speleological Society, September’, Uli Wortmann. p. 116.

Ghergari, L., Onac, B. P. & Fratila, G. (1997), Mazzullo, S. J. (1980), ‘Calcite pseudospar re- Mineralogy of crusts and efflorescences placive of marine acicular aragonite, and from Humpleu cave system, in P.-Y. Jean- implications for aragonite cement diage- nin, ed., ‘Proceedings of the 12th Inter- nesis’, Journal of Sedimentary Petrology national Congress of Speleology’, Vol. 7: 50(2), 409–422. Physical Speleology, International Union of Speleology and Swiss Speleological Society, Mercer, I. (1990), Crystals, British Museum pp. 231–234. (Natural History).

Gillieson, D. (1996), Caves: Processes, Devel- Middleton, G. J. (1991), Oliver Trickett: Doyen opment, Management, Blackwell Publish- of Australia’s Cave Surveyors 1847 - 1934. ers Limited, Oxford, UK. SSS Occasional Paper No. 10, Sydney Ginsburg, R. N. & James, N. P. (1976), ‘Sub- Speleological Society and Jenolan Caves marine botryoidal aragonite in Holocene Historical and Preservation Society. reef limestones, Belize’, Journal of Geology pp. 431–436. Morse, J. W. (1983), The kinetics of calcium carbonate dissolution and precipitation, in Glazer, A. M. (1987), The Structures of Crys- R. J. Reeder, ed., ‘Carbonates: Mineral- tals, Adam Hilger, Bristol, UK. ogy and Chemistry’, Mineralogical Society of America, pp. 227–264. Hill, C. A. (1987), The Geology of Carlsbad Cavern and other caves in the Guadalupe Niggeman, S., Habermann, D., Oelze, R. & Mountains, New Mexico and Texas, Bul- Richter, D. K. (1997), Aragonitic / calcitic letin number 117, New Mexico Bureau coralloids in carbonate caves: evidence for of Mines and Mineral Resources, Socorro, solutions of different Mg influence, in P.-Y. NM, USA. Jeannin, ed., ‘Proceedings of the 12th In- ternational Congress of Speleology’, Vol. 7: Hill, C. A. (1999), ‘Mineralogy of Kartchner Physical Speleology, International Union of Caverns, Arizona’, Journal of Cave and Speleology and Swiss Speleological Society, Karst Studies 61(2), 73–78. pp. 251–256. Hill, C. A. & Forti, P., eds (1997), Cave Miner- Northup, D. E., Reyenback, A.-L. & Pace, N. R. als of the World, 2nd edn, National Speleo- (1997), Microorganisms and speleothems, logical Society, Huntsville Alabama, USA. in C. A. Hill & P. Forti, eds, ‘Cave Minerals Hurlbut, Cornelius S., J. (1970), Minerals and of the World’, 2nd edn, National Speleolog- Man, Random House, New York, USA. ical Society, Huntsville, Alabama, U.S.A., pp. 261–266. Kendall, A. C. & Tucker, M. E. (1973), ‘Radiax- ial fibrous calcite: a replacement after aci- Osborne, R. A. L. (1978), ‘Structure, sediments cular carbonate’, Sedimentology 20, 365– and speleogenesis at Cliefden Caves, New 389. South Wales’, Helictite 16(1), 3–32.

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Osborne, R. A. L. (1990), ‘Palaeokarst deposits Pryke, A. (2000), ‘Anthodites in Fife Cave, at Jenolan Caves, New South Wales’, Jour- Church Ck’, Bulletin of the Sydney Uni- nal and Proceedings of the Royal Society of versity Speleological Society 40(2-3), 49. New South Wales 123, 59–73. Ralston, B. (1989), Jenolan: the Golden ages Osborne, R. A. L. (1991), ‘Red earth and bones: of , Three Sisters Productions Pty. the history of cave sediment studies in New Ltd., Winmalee, NSW 2777 Australia. South Wales, Australia’, Earth Sciences History 10(1), 13–28. Richardson, S., Byrnes, J. & Degeling, P. (1981), ‘A rock chip geochemical survey Osborne, R. A. L. (1993), ‘Geological note: of the Wyanbene base metal prospect, Cave formation by exhumation of Palaeo- near Braidwood’, Geological Survey of New zoic palaeokarst deposits at Jenolan Caves, South Wales Department of Mineral Re- New South Wales’, Australian Journal of sources File M79/2979(GS1981/430), 1– Earth Sciences 40, 591–593. 19.

Osborne, R. A. L. (1994), Caves, dolomite, Rowling, J. (1993), ‘Genghis Khan and Kubla pyrite, aragonite & gypsum: The karst Khan caves, Mole Creek, Tasmania’, Bul- legacy of the Sydney & Tasmania Basins, letin of the Sydney University Speleological in ‘Advances in the Study of the Syd- Society 33(2), 21–28. ney Basin’, number 28 in ‘Newcastle Sym- posium, 15th to 17th April’, Department Rowling, J. (1995), ‘Investigations of the Wyan- of Geology, The University of Newcastle, bene Caves area’, Helictite 33(1), 29–34. NSW 2308, pp. 322–324. Rowling, J. (1998a), ‘Ribbon helictites: A new category’, Helictite 36(1), 2–10. Osborne, R. A. L. (1996), ‘Vadose weathering of sulfides and limestone cave development - Rowling, J. (1998b), ‘Sigma survey: Upstream evidence from eastern Australia’, Helictite of Aragonite Canyon: Wombeyan Caves, 34(1), 5–15. 23rd and 24th May 1998’, Bulletin of the Sydney University Speleological Society Osborne, R. A. L. (1999), ‘The origin of Jenolan 38(2), 25–26. Caves: Elements of a new synthesis and framework chronology’, Proceedings of the Rowling, J. (1999), ‘SUSS 50th: Chevalier trip, Linnean Society of NSW 121, 1–27. Chevalier Extension, Glass Cave, 2 May 1998’, Bulletin of the Sydney University Osborne, R. A. L. (2000), Palaeokarst and Speleological Society 38(3), 28–29. its significance for speleogenesis, in A. B. Klimchouk, D. C. Ford, A. N. Palmer & Rowling, J. (2003), ‘Underwater helictites of the W. Dreybrodt, eds, ‘Speleogenesis: Evolu- Nullarbor’, Proceedings of the 2003 ASF tion of Karst Aquifers’, National Speleolog- Conference (in prep). . ical Society, Huntsville, Alabama, U.S.A., pp. 113–123. Rowling, J. (2004), Cave of N.S.W., Master of Science Thesis (unpubl.), The Osborne, R. A. L., Pogson, R. E. & Colchester, School of Geosciences, Division of Geology D. M. (2002), ‘Minerals of Jenolan Caves and Geophysics, The University of Sydney. - Geosphere meets Biosphere (Abstract)’, Journal and Proceedings of the Royal Soci- Sarigu, S. (1999), ‘Segnalazione di carbidimiti ety of New South Wales 134, 3&4(401 - nella grotta degli scogli neri (Savona - Lig- 402), 111. uria)’, Speleologia 40, 17–24.

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Seemann, R. (1985), ‘Hydromagnesit und Be- Turner, F. J. (1981), Metamorphic Petrology: gleitmineralien aus dem Frauenmauer - mineralogical, field and tectonic aspects, Langstein - H¨ohlensystem, Hochschwab, 2nd edn, McGraw-Hill, USA. Steiermark’, Mitteilungen der Mineral- ogisch - Petrographische Abteilung das Turner, K. (2002), ‘Chromophores producing Landesmuseum Joanneum 53, 11(223)– blue speleothems at Cliefden, NSW’, He- 21(233). lictite 38(1), Cover, 3–6. Urbani, F. (1997), Venezuelan cave minerals: a Seemann, R. (1987), ‘Mineralparagenesen in short overview, in P.-Y. Jeannin, ed., ‘Pro- Osterreichen¨ Karsth¨ohlen’, Mitteilun- ceedings of the 12th International Congress gen der Osterreichen¨ Mineralogischen of Speleology’, Vol. 7: Physical Speleol- Gesellschaft 132, 117–134. ogy, International Union of Speleology and Shaw, T. (1992), History of Cave Science: The Swiss Speleological Society, pp. 243–246. exploration and study of limestone caves, Vizjak, M. (1998a), ‘More exploration in the to 1900, 2nd edn, Sydney Speleological So- World of Mud Extension (Eastern Exten- ciety, Broadway, NSW Australia 2007. sion), Mammoth Cave, Jenolan’, Jour- nal of the Sydney Speleological Society Siegel, F. R. (1965), ‘Aspects of calcium carbon- 42(5), 123–125. ate deposition in Great Onyx Cave, Ken- tucky’, Journal of Sedimentology 4, 285– Vizjak, M. (1998b), ‘World of Mud Exten- 299. sion: Eastern Extension, Mammoth Cave, Jenolan’, Journal of the Sydney Speleolog- Siegel, F. R. & Reams, M. W. (1966), ‘Tem- ical Society 42(3), 72–74. perature effect on precipitation of calcium carbonate from calcium bicarbonate solu- Walter, L. M. (1985), Relative reactivity of tions and its application to cavern environ- skeletal carbonates during dissolution: im- ments’, Journal of Sedimentology 7, 241– plications for diagenesis, in N. Schneider- 248. mann & P. M. Harris, eds, ‘Special Publi- cation 36: Carbonate Cements’, The Soci- Speleo Projects, ed. (1998), Lechuguilla Cave: ety of Economic Paleontologists and Min- Jewel of the Underground, 2nd edn, Caving eralogists, pp. 3–16. Publications International, Basel, Switzer- land. Webb, J. A. & Brush, J. B. (1978), ‘Quill an- thodites in Wyanbene Cave, Upper Shoal- T´asler, R. (1998), ‘Speleothems of giant domes haven District, New South Wales’, Helic- of Bohemia Cave’, N.Z. Speleological Soci- tite 16(1), 33–39. ety Bulletin 10(188-192), 683–695. Webby, B. D. & Packham, G. H. (1982), Thrailkill, J. (1971), ‘Carbonate deposition ‘Stratigraphy and regional setting of the in Carlsbad Caverns’, Journal of Geology Cliefden Caves Limestone Group (Late 79, 683–695. Ordovician), central-western New South Wales’, Journal of the Geological Society Tucker, M. E. (1991), Sedimentary Petrology, of Australia 29(3&4), 297–318. Blackwell Scientific Publications, Oxford, UK. Welch, B. R., ed. (1976), The Caves of Jenolan, 2: The Northern Limestone, Sydney Uni- Tucker, M. E. & Wright, V. P. (1990), Car- versity Speleological Society and the Spele- bonate Sedimentology, Blackwell Scientific ological Research Council Ltd, Sydney, Publications, Oxford, UK. NSW Australia.

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Wilkinson, C. S. (1892), ‘Description of the make-up. Examples occur near the en- Belubula Caves, Parish of Malongulli, Co. trance areas of caves where there is a mix- Bathurst’, Records of the Geological Survey ture of deposits and deposition mecha- of N.S.W. III(1), 1–5, plates I–III. nisms at work, resulting in speleothems with a mixture of characteristics and min- APPENDIX: GLOSSARY OF eral content. The term is also used for TERMS the transition forms taken by some arago- nite speleothems which alternate between Some terms used in speleology may be unfamil- anthodite-like and coral-like depending on iar to the general scientist. Most speleothem the growth conditions. terms used here are those defined by Hill & flowstone: A deposit of (usually) calcite as a Forti (1997) and are recognised internationally. surface coating on any substrate in a cave Other terms are used in Australian caving. so that the mass resembles melted wax. The overall shape is controlled by gravity anthodite: Speleothem, usually made of arag- and the surface tension of water. Surface onite, with an acicular and often branch- textures range from completely smooth ing appearance. Usually, anthodites de- to deeply pocketed depending on carbon- velop from the cave’s ceiling. Anthodites ate concentration, flow rate and other fac- often have a solid core of aragonite, and tors. is usually built up from may have huntite or hydromagnesite de- thin layers of calcite, caused by seep- posited near the ends of their branches. age or dripping water containing HCO3 Anthodites vary in size from a few mil- outgassing CO2 into the cave to precip- limetres to about a metre. itate CaCO3. Depending on the source cave: A natural cavity in rock that a person of water, flowstone can grade into stalag- can enter. Some show caves are subdi- mites and where flowstone builds up over vided into convenient sections, each called steep drops, furled shapes can resemble a “cave”, although this terminology is not draperies. encouraged. Thus, all the Jenolan show flos ferri: Helictite characterised by slender caves could be called one “cave” as they tightly twisted forms, usually aragonite. are all interconnected via underground Three different usages of this term in- passages, including the Grand Arch. clude its first usage in 1748 by John chamber: A cavity that a person can stand in, Hill for a twisting variety of speleothem varies from about 4 m diameter to about from mines and some Mendip (UK) caves 20 m diameter. (Shaw 1992). Hurlbut (1970) used a sim- ilar definition for aragonite in iron ore coral, cave: Speleothem characterised by mines in Austria. Hill & Forti (1997) de- hemispherical to globular appearance. fine flos ferri as a quill-like variety of an- Cave coral is often calcite, deposited on thodite, and define the earlier usage as “an surfaces where there is some air move- ancient word for aragonite and for frost- ment. Deposition is mostly by capillary work and helictites growing in the cavities movement across the surface, with the of iron deposits”. Herein, flos ferri means main deposit occurring at the outside the tightly twisted form of aragonite he- edge of the speleothem. Sizes usually lictite associated with iron ores. vary from a few millimetres to a couple of centimetres diameter. furze bush Combination helictite, stalagmite and anthodite characterised by a vertical coralloid: Speleothem resembling coral but carbonate deposit (stalagmite/tite or col- not sufficiently analysed to determine its umn), usually of aragonite, together with

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finely twisting (usually aragonite) helic- ally of walk-through dimensions. In Aus- tites. The helictites’ diameter is typically tralian speleology, a passage with reduced about 1 to 5 mm and their radius of curva- width is a “rift”, and one with reduced ture ranges from about 10mm to 100mm. height is a “crawlway” or a “flattener” The name was given by Jenolan Caves depending on the way a person moved guides for the fancied resemblance to a fir through it. tree, and a name was needed in the show popcorn: A speleothem which vaguely resem- caves. bles the snack, popcorn. Similar to “coral- helictite: Speleothem with a fine capillary loid”. A “popcorn line” is a horizontal de- tube surrounded by usually either calcite posit of popcorn in a cave passage which or aragonite. Helictites are often worm- marks a humidity change or layer. Hy- like, with typical diameter of a few mil- dromagnesite and huntite may occur with limetres and typical length of a few cen- aragonite. timetres. Development is usually out- spathite: A stalactite of aragonite with a wards from a wall. Beaded helictites have wider central tube than the conventional alternating deposits of calcite and arago- calcite stalactite. This is caused by the nite giving the speleothem a pipe-cleaner flaring of the aragonite crystal compared appearance. Ribbon helictites are flat- to calcite. Sometimes a spathite com- tened calcite helictites. prises a series of aragonite “petals” over- heligmite: Helictite that develops from the lapping each other to form a wide (2 or 3 floor of a cave, like small stalagmites, but cm) tube. they retain a fine capillary tube and de- speleothem: Secondary mineral deposit in a velop by mineral-rich water flowing grad- cave. May be subaerial or subaqueous. ually through the capillary and onto the They are classified according to mineral surface of the heligmite where it can out- and shape, for example, a calcite sta- gas CO2. lactite. Commonly calcite, but can be moonmilk: Speleothem with a pasty appear- other carbonates, sulfates, phosphates, ance, with a texture like cottage cheese oxy-hydroxides, etc. Most carbonate spe- when rubbed in the fingers. This material leothems are formed by bicarbonate-rich has a high water content. Most moon- water outgassing CO2. milk is made of needle-fibre calcite, some stalactite: Speleothem, usually of calcite, de- contain hydromagnesite and other miner- posited on the ceiling of a cave. Charac- als. Moonmilk may be biogenic. True terised by general conical shape and usu- moonmilk has to be at least 90% calcite ally a central hollow tube of calcite with (Fischer 1988). the C-axis pointing downwards. This is oolite: A loose spherical concretion, often pea- surrounded by layers of calcite with the sized but can be larger. Usually found in C-axis pointing at 90◦ to the surface. pools or underground creeks where calcite stalactite, straw: Also known as “soda or aragonite is precipitating. Oolites are straws”, these are central hollow tubes of rarely cube shaped. Outside of speleology, stalactites without surrounding deposits. the conventional term for similar concre- They usually occur where bicarbonate- tions is “pisolites”. O¨oids are smaller con- rich water comes from a single point or cretions (of any material) with a diameter crack, rather than running across the ceil- of 0.2 to 0.5 mm. ing. Diameters are typically 4 or 5 mm passage: Part of a cave which is much longer and lengths vary from a few cm to me- than it is wide, like a corridor and gener- tres.

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ARAGONITE, ITS OCCURRENCE IN NEW SOUTH WALES CAVES 149

stalagmite: Deposit on the floor of a cave un- flat disc about 4 cm diameter to massive der a drip point, resulting in a pile of deposits that are tens of metres high. The carbonate (usually calcite) that is often calcite C-axis is always directed at 90◦ to higher than it is wide. Often roughly the stalagmite surface. cylindrical symmetry, they vary from a

Jill Rowling 2 Derribong Place Thornleigh NSW Australia 2120. email: [email protected]

(Manuscript received 28.09.2004) (Manuscript received in final form 25.11.2004)

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