|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Articles |
UREANU MOUNTAINS, ROMANIA: REPLY
tefan Marincea
Geological Institute of Romania, 1 Caransebe Street, Bucharest, RO–012271 Romania
E-mail address: marincea{at}igr.ro
In a recent paper, Dumitra et al. (2008) described apatite-(CaOH) from the "dry" Cioclovina Cave, in the ureanu Mountains, Romania. The paper, submitted to the journal in February 2007, ignored, as a matter of course, the intention of Onac & Effenberger (2007) and Cînta Pânzaru & Onac (2008) to re-examine the berlinite samples claimed to be taken from the cave. This fact, as well as other critical opinions about the previous description by Onac et al. (2002, 2005) and Onac & White (2003) of some "exotic" mineral species such as berlinite, burbankite, churchite-(Y), ellestadite-(OH), ellestadite-(Cl), foggite, paratacamite, collinsite and sampleite, led to the Discussion by Onac & Effenberger presented above. The authors stated that "the list of references given by Dumitra et al. (2008) is incomplete, resulting in an incorrect overall statement". The list was, however, as complete as possible when our paper was conceived, and respected the principles of the concision and relevance, which restrict the quotations in a paper to the relevant ones for the paper itself. The paper of Dumitra et al. (2008) thoroughly described a quite common apatite-(CaOH), with no peculiar characteristics as compared with other apatite- (CaOH) sampled from other cave occurrences. Briefly, the chemical pattern of apatite-(CaOH) from the "dry" Cioclovina Cave, as well as the patterns of all other Ca phosphates from the cave (i.e., brushite and ardealite) does not fit with the presence in the association of (REE+Y)-bearing species such as churchite-(Y) or burbankite mentioned by Onac et al. (2002, 2005) and Onac & White (2003), or with high-temperature species such as berlinite or ellestadite-(OH) mentioned by Onac et al. (2006) and Onac & Effenberger (2007).
The basic principles of the REE + Y geochemistry (e.g., Clark 1984) clearly show that the speciation of a REE- and Y-bearing mineral species must affect all the Ca phosphates in association, which will be, normally, richer in (REE+Y). The association of churchite or burbankite with apatite-(CaOH) containing up to 22.3 ppm Y (Dumitra et al. 2008), but also with brushite containing up to 5.78 ppm Y (Dumitra et al. 2004) and with ardealite containing up to 1.82 ppm Y (Dumitra et al. 2005) is quite improbable. As the surrounding limestones contain only up to 8.26 ppm Y, and the other sediments in the cave, only up to 9.56 ppm Y (Dumitra, unpubl. Ph.D. thesis), the explanation of the presence of Y-bearing species is quite obscure and seems to indicate allochthonous materials. The diagenesis and subsequent alteration of churchite-(Y) and burbankite, if these species exist at Cioclovina, are not at all reflected by the composition of the secondary Ca phosphates, such as brushite or ardealite, and this behavior is really difficult to explain.
Could apatite-(CaOH) described by Dumitra et al. (2008) be associated with berlinite or ellestadite-(OH), known as high-temperature minerals? As already shown by Marincea & Dumitra (2005), apatite from high-temperature deposits, such as skarns, is well known as particularly sensitive to Si-for-P substitutions (e.g., Rouse & Dunn 1982), which is not at all the case for the apatite-(CaOH) from Cioclovina, which does not contain any trace of Si. We do not believe that Si-poor apatite-(CaOH) could be associated with ellestadite- (OH), as described by Onac et al. (2006) or Onac & Effenberger (2007).
In conclusion, quotations of the new papers revealed by Onac & Effenberger in their comments are not of any relevance for the work of Dumitra et al. (2008). If churchite-(Y), berlinite, burbankite, ellestadite-(OH), ellestadite-(Cl), paratacamite do exist at Cioclovina, these species would seem not to be associated with the very common apatite-(CaOH) described by Dumitra et al. (2008). More difficult to explain is the reason why the geochemical and structural pattern of the Ca phosphates in the cave does not fit with the presence of such "exotic" species.
Another criticism of Onac & Effenberger (2009) refers to the sketch of the mined part of the cave presented by Dumitra et al. (2008). It is quite surprising that the critics ignore that the mined part of the "dry" Cioclovina Cave, whose actual tract as established during the exploratory works in the late 1990s (Breban et al. 2003), does not fit with the map of the cave. An example is the short anthropic gallery under the Bivouac Room, that permitted excellent sampling of common apatite-(CaOH), Si-free and too poor in (REE+Y) to associate with heavy REE-selective species such as churchite or light REE-selective species such as burbankite. The sketch presented by Dumitra et al. (2008) was first given by Constantinescu et al. (1999) and is a compass-oriented, quite imprecise sketch from a working plan, now in the archives of the Geological Institute of Romania. Recent studies proved that the real length of the "dry" Cioclovina cave is only 1406 m (B. Tomu, private communication), whereas the mined gallery reaches only about 450 m. Two different levels of exploitation, still visible in part, as well as a lot of short lateral adits, raise the length of the mining galleries and working face drifts to about 800 m, explaining the huge mass of guano mined out (32,000 tonnes, according to Breban et al. 2003). Taking into account the omnipresence of apatite-(CaOH) in the cave and its quite homogeneous behavior (Dumitra et al. 2008), the reader of the work of Dumitra et al. (2008) is not deprived of a correct statement.
As a last remark, the precision of the sampling location should not be criticized by the authors, who did not locate on any map their samples of berlinite, ellestadite-(OH), burbankite, paratacamite or churchite, which are not at all common in such a setting, left no visible traces on the other mineral associations from the cave, and were not found by many other visitors of the cave. We have no doubt that the samples analyzed by Onac & Effenberger (2007) are, indeed, berlinite, but the photograph of "berlinite from Bivouac Room" presented by Breban et al. (2003) and Onac et al. (2007) was recognized in situ, and the analyses of the samples taken from the outcrop depicted in the photo proved that the white material labeled as "berlinite" is a common mixture of taranakite and quartz.
 |
AKNOWLEDGEMENTS |
|---|
 Top Aknowledgements References |
|---|
for his help during this last visit and for valuable information about the new exploratory works. |
References |
|---|
|
TopAknowledgementsReferences |
|---|
ERBAN, M., VIEHMAN, I. & BAICOANA, M. (2003): History of the mining of guano-phosphate and of the discovery of the Homo fossilis in the "dry" Cioclovina Cave. Proteus SpeleoClub, Deva, Romania (in Romanian).BURKE, E. (2008): Tiding up mineral names: an IMA–CNMNC scheme for suffixes, hyphens, and diacritical marks. Mineral. Rec. 39, 131–135.
CINTA PINZARU, S. & ONAC, B.P. (2008): Raman study of natural berlinite from the Cioclovina Cave phosphate deposit. Vib. Spectrosc. (doi:10.1016/j.vibspec. 2008.05.003).
CLARK, A.M. (1984): Mineralogy of the rare earth elements. In Rare Earth Element Geochemistry 2 (P. Henderson, ed.). Elsevier, Amsterdam, The Netherlands (33–61).
CONSTANTINESCU, E., MARINCEA, . & CRACIUN, C. (1999): Crandallite in the phosphate association from Cioclovina cave (ureanu Mts., Romania). In Scientific Works by Emil Constantinescu. Mineralogy in the System of Earth Sciences. Imperial College Press, London, U.K. (1–5).
DUMITRAS, D.G, CONSTANTINESCU, E., MARINCEA, . & BOURGIER, V. (2005): New data on ardealite from the type locality (the "dry" Cioclovina Cave, ureanu Mountains, Romania). Proc. Annual Scientific Session "Geo 2005" (Roia Montan
), 31–36.
DUMITRAS, D.G., MARINCEA, ., BILAL, E. & HATERT, F. (2008): Apatite-(CaOH) in the fossil bat guano deposit from the "dry" Cioclovina Cave, ureanu Mountains, Romania. Can. Mineral. 46, 431–445.
DUMITRAS, D.-G., MARINCEA, . & FRANSOLET, A.M. (2004): Brushite in the bat guano deposit from the "dry" Cioclovina Cave (ureanu Mountains, Romania). Neues Jahrb. Mineral., Monatsh., 45–64.
MARINCEA, . & DUMITRAS, D.-G. (2003): The occurrence of taranakite in the "dry" Cioclovina Cave, ureanu Mountains, Romania. Neues Jahrb. Mineral., Monatsh., 127–144.
MARINCEA, . & DUMITRAS, D.-G. (2005): First reported occurrence of berlinite (AlPO4) in phosphate-bearing sediments from Cioclovina Cave, Romania – comment. Am. Mineral. 90, 1203–1208.
MARINCEA, ., DUMITRAS, D.-G. & GIBERT, R. (2002): Tinsleyite in from the "dry" Cioclovina Cave (ureanu Mountains, Romania): the second occurrence. Eur. J. Mineral. 14, 157–164.[CrossRef][GeoRef]
ONAC, B.P., BREBAN, R., KEARNS, J. & TAMAS, T. (2002): Unusual minerals related to phosphate deposits in Cioclovina Cave, ureanu Mts. (Romania). Theor. Appl. Karstol. 15, 27–34.
ONAC, B.P. & EFFENBERGER, H. (2007): Re-examination of berlinite (AlPO4) from the Cioclovina Cave, Romania. Am. Mineral. 92, 1998–2001.
ONAC, B.P., EFFENBERGER, H. & BREBAN, R. (2007): Hightemperature and "exotic" minerals from the Cioclovina Cave, Romania: a review. Studia Univ. Babe-Bolyai, Geol. 52(2), 3–10.
ONAC, B.P., EFFENBERGER, H., ETTINGER, K. & PINZARU CINTA, S. (2006): Hydroxylellastadite from Cioclovina Cave (Romania): microanalytical, structural, and vibrational spectroscopy data. Am. Mineral. 91, 1927–1931.
ONAC, B.P., ETTINGER, K., KEARNS, J. & BALASZ, I.I. (2005): A modern, guano-related occurrence of foggite, CaAl(PO4) (OH)2 · H2O and churchite-(Y), YPO4 · 2H2O in Cioclovina Cave, Romania. Mineral. Petrol. 85, 291–302.[CrossRef]
ONAC, B.P. & WHITE, W.B. (2003): First reported sedimentary occurrence of berlinite (AlPO4) in the phosphate-bearing sediments from Cioclovina Cave, Romania. Am. Mineral. 88, 1395–1397.
ROUSE, R.C. & DUNN, P.J. (1982): A contribution to the crystal chemistry of ellestadite and the silicate sulfate apatites. Am. Mineral. 67, 90–96.[Abstract]
SCHADLER, J. (1932): Ardealit, ein neues Mineral CaHPO4 · CaSO4 · 4H2O. Zb. Mineral. A, 40–41.
TOMUS, B. (1999): The Ciclovina Karst Complex – Basin 2063. Clubul Speologilor Proteus, Hunedoara, Romania (in Romanian).
| ||||||||||||||||||||||||||||||||||||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
