Mona-Liza C. Sirbescu

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Central Michigan University | CMU · Department of Earth and Atmospheric Sciences

The crystallization kinetics of silicate liquids were studied experimentally in the system haplogranite– B–Li–H2O, at variable degrees of undercooling and variable water concentration. We investigated the kinetics of nucleation and crystallization of unseeded synthetic hydrous haplogranite with 1wt % Li2O, 2.3wt % B2O3 added (composition C1) and 2w...

We propose that the internally zoned, Li-bearing Tin Mountain pegmatite in the Harney Peak granite-pegmatite system of the Black Hills, South Dakota, crystallized from fluid-rich, compositionally complex melts at ˜400 350 °C. The low crystallization temperatures resulted from the combined fluxing effects of Li, B, P, H2O, and carbonate anions. The...

We evaluated the crystallization regime of a zoned pegmatite dike and the degree of magma undercooling at the onset of crystallization by analyzing coeval fluid and melt inclusion assemblages. The liquidus temperature of the pegmatite magma was ~720°C, based on re-melting of crystallized-melt inclusions in heating experiments. The magma crystal...

Understanding processes that occur during pegmatite crystallization are important for understanding magma evolution and enrichment processes of e.g. strategic and rare metals in pegmatites. Several processes are involved in the formation of pegmatites, and among these the timing of fluid saturation and exsolution is a critical area of investigation...

The anisotropic textures, including unidirectional solidification textures and graphic intergrowths, characteristic for pegmatites, are interpreted to result from disequilibrium crystallization at high degrees of undercooling. Experimental studies have revealed the existence of thin boundary layers surrounding the rapidly growing crystals. Here, to...

Pegmatites are an important source of critical and rare metals (e.g., Li, Ta, Sn, Nb). Understanding processes occurring during pegmatite crystallization are therefore key to understanding the mechanisms responsible to concentrating these elements. Several contrasting models for pegmatite formation have been put forward but it is still unclear when...

Although parent material (PM) is one of the five soil formation factors providing key information on soil variability, the complexity of PM distributions and the difficulty of reaching PM in deep soils prevent its detailed assessment. Proximal sensors such as portable X-ray fluorescence (pXRF) spectrometer and magnetic susceptibility (MS) may be he...

Lithium (Li) is a critical metal that requires additional granitic pegmatites of the lithium-cesium-tantalum (LCT) family to meet demands. Currently, pegmatite exploration in Southwestern Maine relies on drilling. Potentially, soil geochemistry could be used. This study explores the fate of LCT pegmatite pathfinder elements during soil formation pr...

Beryl - Be3Al2(Si6O18) - is the predominant mineral of beryllium. It is a cyclosilicate with hexagonal structure and is common in fractionated pegmatites of Li-Cs-Ta (LCT), Nb-Y-F (NYF), and hybrid (NYF-LCT) families. The trace element contents of beryl may provide insight into magmatic fractionation leading to economic concentrations of critical m...

Iron is among the most abundant elements in Earth's crust and is also a major aqueous solute in a variety of hydrothermal settings, yet major questions remain regarding the solubility and speciation of iron at hydrothermal conditions. Here, we conducted hydrothermal diamond-anvil cell experiments using synchrotron-radiation micro-XRF and XANES anal...

Fractal and two-point radial autocorrelation analysis has been performed on 16 images of experimental products and 44 images of natural graphic K-feldspar-quartz textures from several pegmatite localities. The box-counting fractal dimension and the lacunarity of experimental and many natural images overlap, although natural samples from one of the...

Poster at Second Eugene E. Foord Pegmatite Symposium, Golden, Colorado

The onset of crystallization of synthetic pegmatite liquids was visualized and documented in dynamic crystallization experiments using a Diamond Anvil Cell (DAC) optimized for water-undersaturated conditions. The mineral assemblages were documented using Raman spectroscopy and EMPA. Time-lapse photographs served to measure crystal growth rates and...

The Fisher quarry is a relatively poorly differentiated, zoned, miarolitic pegmatite belonging to the beryl-columbite Brunswick pegmatite field of southwestern Maine. Fluid inclusion research on graphic and miarolitic quartz from the zoned Fisher pegmatite dike was conducted using microthermometry and Laser Ablation-ICP MS to better understand the...

Abstract V23D-4824 Comparative fluid inclusion chemistry of miarolitic pegmatites from San Diego County, California, USA David Nymberg and Mona-Liza C Sirbescu, Central Michigan University, Mount Pleasant, MI, United States Abstract Text: Miarolitic Li-Cs-Ta pegmatites are an important source of gemstones such as tourmaline var. elbaite and spod...

In Situ Observations of Crystallization of Water-Undersaturated Pegmatite Liquids Mona-Liza C Sirbescu1, Max Wilke2, Stefan Gehrmann2, Christian Schmidt2 1Geology Department, Central Michigan University, Mount Pleasant, USA 2GFZ German Research Centre for Geosciences, Potsdam, Germany Crystallization behavior of water-undersaturated haplograni...

Traditionally, cyanide, mercury, and acid mine drainage are considered critical environmental hazards associated with gold mining. To our knowledge, this is the first study of hazardous concentrations of soluble boron (B) in a gold mine impoundment tailings dam. We suggest that the B anomaly is a consequence of disposal of gold pyrometallurgical wa...

Crystallization of pegmatites: Insights from chemistry of garnet, Jacumba pegmatites, San Diego County, California THOMPSON, Matt S., thomp2ms@cmich.edu and SIRBESCU, Mona-Liza, Earth and Atmospheric Science Department, Central Michigan University, MI Systematic mineral and textural variations from the border zone to the core of a zoned pegmatit...

Environmental hazards of metallurgical waste produced by the gold industry Amanda J. VanHaitsma, Lewis Matthews, Mona-Liza C. Sirbescu, and Edmond H. van Hees Boron anomalies were recently reported in >30 year old McIntyre gold mine tailings in Timmins, Ontario, Canada (Paliewicz et al., Mine Waste and the Environment, in review). The levels of so...

FLUID EVOLUTION DURING CRYSTALLIZATION OF THE KING'S X PEGMATITE, FLORENCE COUNTY, WISCONSIN, USA PRICE, Thomas J. and SIRBESCU, Mona-Liza C., Earth and Atmospheric Sciences, Central Michigan University, Mount Pleasant, MI 48859, price3tj@cmich.edu The King’s X-2 pegmatite (KX-2) is a 1-3 m thick, >600 m long dike in the Hoskin Lake pegmatite fie...

Pegmatites are intrusive magmatic rocks with unusually large crystals, graphic, skeletal, or spherulitic textures, and internal zoning, thought to crystallize inwardly, sequentially, at large values of undercooling (London, Pegmatites, 2008). Boundary layers (BL’s) enriched in incompatible components may form ahead of crystallization fronts if the...

Granite pegmatite sheets in the continental crust are characterized by very large crystals. There has been a shift in viewing pegmatites as products of very slow cooling of granite melts to viewing them as products of crystal growth in undercooled liquids. With this shift there has been a renewed debate about the role of H2O in the petrogenesis of...

1] Li isotopes may be useful tracers of fluid flow in a number of geological environments and case studies of contact aureoles have highlighted the very large Li isotopic fractionation that can be generated in these settings. However, the amount of isotopic fractionation and the distance that Li travels into the country rocks vary greatly from plac...

We investigated the crystallization behavior of haplogranite-Li-B-H2O melts in a series of dynamic experiments in order to constrain development of texture in Li-rich pegmatites. Current models propose that salient pegmatitic features such as sub-millimeter to meter scale crystal sizes and unidirectional, spherulitic, and skeletal intergrowths are...

ABSTRaCT Unidirectional and skeletal textures in the thin inward-crystallizing Animikie Red Ace (ARA) pegmatite dike, in northeastern Wisconsin, suggest rapid, disequilibrium crystallization of the outer zones as the pegmatite-forming magma came in contact with much cooler country-rocks. The rock textures support the cooling and solidification of t...

Two distinct mineralizing fluids formed the Hollinger-McIntyre-Coniaurum (HMC) deposit. The earliest fluid was associated with emplacement of a disseminated Cu-Au-Mo zone in the Pearl Lake Porphyry (PLP). The alteration pattern of the felsic rocks in the PLP is characterized by increased concentrations of K2O, Au, Cu, Mo, W, and Sn, and K/Al, Seric...

In the lithium-cesium-tantalum-type pegmatite dikes of San Diego County, California, USA, tourmaline is the main reservoir for Li, except in the cores and the pockets of the dikes where other Li-bearing minerals also occur. Tourmaline from three subhorizontal dikes was analyzed for bulk Li concentrations and Li isotope ratios. The bottom portion of...

Textural, chemical, and inclusion records of rapid crystallization MONA-LIZA C. SIRBESCU AND JAMES J. STUDENT 314 Brooks Hall, Central Michigan Univ., Mt. Pleasant, MI, 48859, sirbe1mc@cmich.edu (stude1jj@cmich.edu) Microthermometry on coeval fluid and melt inclusions combined with conductive-cooling modeling document cases of rapid and highly unde...

Modern acid saline systems in Chile, Western Australia, and Victoria, Australia are good analogs for martian strata. In addition, physical sedimentology and water-rock interaction experiments show acid brines may be responsible for martian surface features.

To study Li isotopic fractionation during granite differentiation and late-stage pegmatite evolution, Li isotopic compositions and concentrations have been measured for the S-type Harney Peak Granite, the spatially associated Tin Mountain pegmatite, and possible metasedimentary source rocks in the Black Hills, South Dakota. The Harney Peak Granite...

A microthermometric study of inclusions in granites and pegmatites in the Proterozoic Harney Peak Granite system identified four types of inclusions. Type 1 inclusions are mixtures of CO2 and H2O and have low salinities, on average 3.5 wt.% NaCleq; type 2 inclusions are aqueous solutions of variable salinities, from 0 to 40% wt.% NaCleq; type 3 inc...

Dawsonite-NaAl(CO3)(OH)2-was identified in primary fluid inclusions in quartz from the Li-rich Tin Mountain pegmatite, Black Hills, South Dakota, by petrography, SEM-EDS analysis, and Raman spectroscopy. This is the first report of dawsonite as an inclusion mineral in a pegmatite. The presence of dawsonite in the inclusions is evidence for the exis...

Typescript. Thesis (Ph. D.)--University of Missouri-Columbia, 2002. Vita. Includes bibliographical references (leaves 106-127). Microfilm.

This paper evaluates thermotectonic models for metamorphism and leucogranite generation during the Proterozoic Trans-Hudson orogeny, as recorded in rocks exposed in the Black Hills, SD. Intrusion of the Harney Peak Granite and associated pegmatites at ∼1715 Ma occurred at the waning stages of regional deformation and staurolite-grade regional metam...

The synthesis and upper thermal stability of cancrinite were investigated experimentally in the system Na 2 O - CaO - Al 2 O 3 - SiO 2 - CO 2 - H 2 O at 2 kbar and in the presence of a mixed H 2 O - CO 2 fluid. Cancrinite could only be formed under water-rich conditions in this system. The breakdown of cancrinite to nepheline + calcite occurred at...

The synthesis and upper thermal stability of cancrinite were investigated experimentally in the system Na2O-CaO-Al2O3-SiO2-CO2-H2O at 2 kbar and in the presence of a mixed H2O-CO2 fluid. Cancrinite could only be formed under water-rich conditions in this system. The breakdown of cancrinite to nepheline + calcite occurred at decreasing temperatures...

Intrusion and crystallization of the Harney Peak Granite and associated plutons and pegmatites were the culminating events of the Trans-Hudson orogeny as expressed in the Black Hills. The granite was emplaced as thousands of sills and dikes at 1715 Ma, following an approximately 45 m.y. period of regional metamorphism and deformation of now exposed...

The crystalline terrane exposed in the Black Hills represents the southernmost portion of the Proterozoic Trans-Hudson orogen. Early Proterozoic metasedimentary rocks, deformed and regionally metamorphosed at 1.76 Ga above staurolite isograd, were uplifted for several kilometers and cooled to 300-500 degrees C (Holm et al., Tectonics, 1997) prior t...