Dr Cristiana Ciobanu

Biography/ Background

I am trained as a field geologist with exposure to the mining industry gained during my appointment at the Geological Survey of Romania (prior to my Ph.D awarded in 2000). This was an asset in subsequent international collaborative research programs. My present expertise in ore mineralogy/petrology and sulphide geochemistry was built-up on the opportunity to have access to microanalytical techniques: Scanning Electron Microscopy (SEM), Electron Probe Microanalysis (EPMA), X-ray diffraction (XRD), Laser-Ablation Inductive Coupled Mass Spectrometry (LA-ICPM), High Resolution-Transmission Electron Microscopy (HR-TEM), Focused Ion Beam (FIB), (SEM, EPMA, XRD, LA-ICPMS, FIB/HR-TEM) prompted by my post-doc appointments in Norway and Australia.

My post-doctoral appointment in Norway (2001-2003); NATO project: “Characterisation of Bi-Te-Se phases and their mineral assemblages: Markers of ore-forming processes and potential high-tech applications”) was a full time research position during which I conducted fieldwork in Norway, Sweden, Finland, Ukraine, Romania, Bulgaria, Namibia necessary for sample material acquisition. The research comprised investigation by optical microscopy and SEM (NGU), microprobe analysis (Bristol, London, Salzburg, Adelaide) and HR-TEM (Adelaide).

My APD appointment (2005-2008 DP: ‘Order-disorder in Bi-tellurides: a tool to monitor gold scavenging by Bi-melts’) was a full time research position during which I have conducted analytical investigations using facilities at the Microscopy Centre in Adelaide (EPMA, SEM, LA-ICPM, HR-TEM, FIB), at CODES (Tasmania; LA-ICPMS), University of New South Wales (Sydney; FIB), at the Chemistry Department in Cambridge (UK; HR-TEM) and annealing-quenching experiments at ANU (Canberra).

 

Qualifications

2005-2008: Australian Postdoctoral Fellow, Department of Earth and Environmental Sciences, University of Adelaide, Australia / South Australian Museum, Adelaide, S.A. Australia.

 

2001-2003: NATO postdoctoral fellow, Geological Survey of Norway (NGU).

 

2000: Doctorate degree “Magna Cum Laude“ in Geology (Metallogeny) from the University of Bucharest, Thesis title: ‘Ore mineralogy of skarn mineralisation at Ocna de Fier, Banat, Romania’

1984: Graduated with BSc degree from University of Bucharest, Romania

Teaching Interests

2003 & 2004 Contract lecturer, Norwegian Technical and Natural Science University, Trondheim, Norway. I was responsible for teaching the undergraduate course 'Geology of Ore Deposits'.

2002 & 2004 Guest lecturer at Department of Geology, University of Turku, Finland 'Advanced Ore Mineralogy of Gold Deposits’. One-week full-time intensive course.

Research Interests

Central to my present research are ore minerals and how they reveal ore-forming processes. Like rock-forming silicates, ore minerals also record the history of geological events. This can be expressed in many ways: textures, distribution of trace/minor elements, crystal-structural modifications, and order-disorder state at the lattice-scale are those that I am most familiar with. Such aspects are central to understanding processes such as self-patterning and mineral replacement via dissolution-reprecipitation reactions inherent to geologic environments.

Studies of trace elements in ore minerals by in situ techniques (e.g., LA-ICPMS) and their nanoscale characterisation (by FIB/HR-TEM) are new, unexplored fields of research that have excellent potential in defining alternatives to conventional views on ore-forming processes and methods of studying them.

Contributions to economic geology/ore petrology include: geodynamic correlations and geochronology, skarn deposits: orefield zonation, key textures in skarns.

Novel ideas:

• Textural control and the role of chalcophile elements during replacement reactions on local (re)distribution of invisible Au in pyrite (Sunrise Dam, Yilgarn Craton, W.A.); first example of invisible Au in As-free, Te-bearing pyrite (deposits from the North China Craton).
• First recognition of bismuth minerals as gold carriers: pioneering LA-ICPMS study.
• Involvement of Bi-Te melts - an alternative Au-enrichment mechanism to precipitation-upon saturation; deposit application and the thermodynamic modelling of Au-Bi melts co-existing with hydrothermal fluids - demonstrates the efficiency of melts in scavenging Au from fluids.

Contributions to sulphide mineralogy and geochemistry:

• Minor and trace elements in sphalerite (LA-ICPMS): interpretation of correlation trends.
• Nagyagite (Sunrise Dam, W.A.; Sacarimb, Romania) – a complex Au-sulphotelluride that records gold redistribution during pseudomorphic replacement.
• Bismuth-sulphosalts and -tellurides from epithermal, skarn, pegmatite, PGE deposits: clues to understanding genesis, deposit zonation and correlation trends in magmatic belts; other ‘exotic’ mineral associations as tracers of transient fluid-plume in skarn systems.

My latest specialisation (achieved during my APD) is use of HR-TEM and FIB techniques for nanoscale characterisation of mineral properties with application to petrogenesis.

• Chemical-structural modularity and homology in the tetradymite group - underpinning stacking sequences and implications for defining equilibrium in the Bi-Te (Se, S) systems.
• Short-range polysomes of Pb-Bi-sulphosalts (lillianite series) – record of chemical oscillations in a closed hydrothermal system.
• Coarsening from nano- to micron-scale of polysomatic intergrowths between various Cu-Bi-sulphosalts (cuprobismuthite-paderaite) - self-patterning in a skarn system.

Pending projects:

• Behaviour of gold in minerals with modular structures (FT)
• A fresh look at the paradigm of invisible gold in pyrite (ARF/QEII)

 

Publications

 

Book chapters

Pring, A., Ciobanu, C.L. (2008): Chemical modulations in Pb-Bi-sulphosalts: a glimpse at minerals in solid-state chemistry. In: K. Harris, P. Edwards (Eds.), Turning Points in Solid State, Materials and Surface Chemistry. Royal Society of Chemistry Publishing, p. 239-249.

Journal Articles

Sung, Y.H, Brugger, J., Ciobanu, C.L., Pring, A., Skinner, W. and Nugus, M. (in press): Invisible gold in arsenian pyrite and arsenopyrite from a multistage Archean gold deposit: Sunrise Dam, Eastern Goldfields Province, Western Australia. Mineralium Deposita. doi: 10.1007/s00126-009-0244-4.

Cook, N.J., Ciobanu, C.L., Pring, A., Skinner, W., Shimizu, M., Danyushevsky, L., Saini-Eidukat, B. and Melcher, F. (2009): Trace and minor elements in sphalerite: a LA-ICPMS study. Geochimica et Cosmochimica Acta. 73, 4761-4791

Cook, N.J., Ciobanu, C.L. and Mao, J.W. (2009): Textural control on gold distribution in As-free pyrite from the Dongping, Huangtuliang and Hougou gold deposits, North China Craton (Hebei Province, China). Chemical Geology. 204, 101-121.

Ciobanu, C.L., Cook, N.J., Pring, A., Brugger, J. and Danyushevsky, L. (2009): Invisible gold in Bi-chalcogenides: evidence from LA-ICPMS data. Geochimica et Cosmochimica Acta 73, 1970-1999.

Ciobanu, C.L., Pring, A., Cook, N.J., Self, P., Jefferson, D., Dima, G.I., and Melnikov, V. (2009): Chemical-structural modularity in the tetradymite group: a HRTEM study. American Mineralogist. 94, 517-534.

Damian, G., Ciobanu, C.L., Cook, N.J. and Damian, F. (2008): Bismuth sulphosalts from the galena-matildite series in the Cremenea vein, Şuior, Baia Mare district, Romania. Neues Jahrbuch für Mineralogie Abhandlungen 185, 199-213.

Tooth, B., Brugger, , J., Ciobanu, C.L. and Liu, W. (2008): Modelling of gold-scavenging by bismuth melts coexisting with hydrothermal fluids. Geology 36/10, 815-818.

Ciobanu, C.L., Cook, N.J., Pring, A., Damian, G., Căpraru N. (2008): Another look at nagyágite from the type locality, Săcărîmb, Romania. Replacement, chemical variation and petrogenetic implications. Mineralogy and Petrology 93, 273-307.

Sung, Y.H., Ciobanu, C.L., Pring, A., Brugger, J., Skinner, W., Cook, N.J. and Nugus, M. (2007): Tellurides from Sunrise Dam gold deposit, Yilgarn Craton, Western Australia: a new occurrence of nagyágite. Mineralogy and Petrology 91, 249-270.

Cook, N.J., Ciobanu, C.L., Stanley, C.J., Paar, W. and Sundblad, K. (2007): Compositional data for Pb-Bi tellurosulphides. The Canadian Mineralogist 45, 417-435.

Cook, N.J., Ciobanu, C.L., Wagner, T. and Stanley, C.J. (2007): Minerals of the system Bi-Te-Se-S related to the tetradymite archetype: review of classification and compositional variation. The Canadian Mineralogist 45, 665-708.

Ciobanu, C.L., Cook, N.J. and Spry, P.G., eds. (2006): Telluride and selenide minerals in gold deposits - how and why? Mineralogy and Petrology Special Issue, 87 (3/4), 163-384. [Guest editors preface, p. 163-169].

Ciobanu, C.L., Cook, N.J., Damian, F. and Damian, G. (2006): Gold scavenged by bismuth melts: An example from Alpine shear-remobilisates in the Highiş Massif, Romania. Mineralogy and Petrology 87, 351-384.

Bonev, I.K., Petrunov, R., Cook, N.J. and Ciobanu, C.L. (2005): Kostovite and its argentian varieties: Deposits and mineral associations. Geochemistry, Mineralogy and Petrology 42, Bulgarian Academy of Sciences, Sofia, Bulgaria, p. 1-22.

Ciobanu, C.L. and Cook, N.J. (2004): Skarn textures and a case study: the Ocna de Fier- Dognecea orefield, Banat, Romania. Ore Geology Reviews 24, 315-370.

Ciobanu, C.L., Pring, A. and Cook, N.J. (2004): Micron- to nano-scale intergrowths among members of the cuprobismutite series and padĕraite: HRTEM and microanalytical evidence. Mineralogical Magazine 68, 279-300.

Cook, N.J. and Ciobanu, C.L. (2004): Bismuth tellurides and sulphosalts from the Larga hydrothermal system, Metaliferi Mts., Romania: Paragenesis and genetic significance. Mineralogical Magazine 68, 301-321.

Cook, N.J. and Ciobanu, C.L. (2003): Lamellar minerals of the cuprobismutite series and related padĕraite: a new occurrence and implications. The Canadian Mineralogist 41, 441-456.

Cook, N.J. and Ciobanu, C.L. (2003): Cervelleite, Ag4TeS, from three localities in Romania, substitution of Cu, and the occurrence of the associated phase, Ag2Cu2TeS. Neues Jahrbuch für Mineralogie Monatshefte, 7/2003, 321-336.

Ciobanu, C.L., Cook, N.J. and Stein, H. (2002): Regional setting and geochronology of the Late Cretaceous Banatitic Magmatic and Metallogenic Belt. Mineralium Deposita 37, 541-567.

Cook, N.J., Ciobanu, C.L., Merkle, R.K.W. and Bernhardt, H-J. (2002): New data on sobolevskite, taimyrite and Pt2CuFe (tulameenite?) in complex massive talnakhite ore, Noril'sk orefield, Russia. The Canadian Mineralogist 40, 329-340.

Cook, N.J. and Ciobanu, C.L. (2001): Paragenesis of Cu-Fe ores from Ocna de Fier-Dognecea (Romania), typifying fluid plume mineralisation in a proximal skarn setting. Mineralogical Magazine 65, 351-372.

Ciobanu, C.L. and Cook, N.J. (2000): Intergrowths of bismuth sulphosalts from the Ocna de Fier Fe-skarn deposit, Banat, Southwest Romania. European Journal of Mineralogy 12, 899-917.

Peer-reviewed extended abstracts (ISI recognised) 

Cook, N.J. and Ciobanu, C.L. (2005): Tellurides in Au deposits: implications for modelling. In: Mineral Deposit Research: Meeting the Global Challenge (J.W. Mao and F.P. Bierlein, eds.), Springer, Berlin-Heidelberg-New York, p. 1387-1390.

Ciobanu, C.L., Cook, N.J. and Pring, A. (2005): Bismuth tellurides as gold scavengers. In: Mineral Deposit Research: Meeting the Global Challenge (J.W. Mao and F.P. Bierlein, eds.), Springer, Berlin-Heidelberg-New York, p. 1383-1386.

Cook, N.J., Ciobanu, C.L., Damian, G. and Damian, F. (2003): The mineralogy of two Neogene ore provinces in Romania: review and additional data. In: Mineral Exploration and Sustainable Development. Proc. 7th Biennial SGA Meeting, Athens, Greece (D.G. Eliopoulos et al., eds.). Millpress Science Publishers, Rotterdam, p. 1157-1160.

Ciobanu, C.L., Cook, N.J., Bogdanov, K., Kiss, O and Vučković, B. (2003): Gold enrichment in deposits of the Banatitic Magmatic and Metallogenetic belt. In: Mineral Exploration and Sustainable Development. Proc. 7th Biennial SGA Meeting, Athens, Greece (D.G. Eliopoulos et al., eds.). Millpress Science Publishers, Rotterdam, p. 1153-1156.

Professional Associations

2004- International Mineralogical Association Commission on Ore Mineralogy (IMA-COM)

2002- International Association on the Genesis of Ore Deposits (IAGOD)

2001-2002 Society of Economic Geologists

Professional Interests

During 2003-2008, I served as Vice-Chairman of International Geosciences Correlation Programme project 486: ’Au-Ag-Te-Se deposits’, edited a field guide, co-convened a number of scientific sessions at international conferences (IGC, Florence, 2004; SGA, Beijing, 2005; GSA, Denver, 2007) and coordinated a journal special issue.

 

Since 2004, I am member of the editorial board of the journal Ore Geology Reviews (OGR). 2008 Impact Factors (IF) show OGR in the premium position among the 3 main ore geology journals (OGR IF=2.374; Mineralium Deposita IF=2.037, Economic Geology IF=1.265).

 

I also act as reviewer for several journals in the fields of mineralogy and geochemistry (Mineralogical Magazine, Canadian Mineralogist, Mineralogy and Petrology, Geochemistry Exploration, Environment, Analysis).

 

Entry last updated: Tuesday, 12 Jul 2011