Nb-Ta-Ti-W-Sn-oxide minerals as indicators of a peraluminous P- and F-rich granitic system evolution: Podlesí, Czech Republic     

K. Breiter  R. Škoda  P. Uher 《Mineralogy and Petrology》2007,91(3-4):225-248

Summary The strongly peraluminous, P- and F-rich granitic system at Podlesí in the Krušné Hory Mountains, Czech Republic, resembles the zonation of rare element pegmatites in its magmatic evolution (biotite → protolithionite → zinnwaldite granites). All granite types contain disseminated Nb-Ta-Ti-W-Sn minerals that crystallized in the following succession: rutile + cassiterite (in biotite granite), rutile + cassiterite → ferrocolumbite (in protolithionite granite) and ferrocolumbite → ixiolite → ferberite (in zinnwaldite granite). Textural features of Nb-Ta-Ti-W minerals indicate a pre-dominantly magmatic origin with only minor post-magmatic replacement phenomena. HFSE remained in the residual melt during the fractionation of the biotite granite. An effective separation of Nb + Ta into the melt and Sn into fluid took place during subsequent fractionation of the protolithionite granite, and the tin-bearing fluid escaped into the exocontact. To the contrast, W contents are similar in both protolithionite and zinnwaldite granites. Although the system was F-rich, only limited Mn-Fe and Ta-Nb fractionation appeared. Enrichment of Mn and Ta was suppressed due to foregoing crystallization of Mn-rich apatite and relatively low Li content, respectively. The content of W in columbite increases during fractionation and enrichment in P and F in the melt. Ixiolite (up to 1 apfu W) instead of columbite crystallized from the most fluxes-enriched portions of the melt (unidirectional solidification textures, late breccia).  相似文献   

Explicit Symplectic Integrator for Highly Eccentric Orbits     

Sławomir Breiter 《Celestial Mechanics and Dynamical Astronomy》1998,71(4):229-241

An explicit symplectic integrator is constructed for perturbed elliptic orbits of an arbitrary eccentricity. The perturbation should be Hamiltonian, but it may depend on time explicitly. The main feature of the integrator is the use of KS variables in the ten-dimensional extended phase space. As an example of its application the motion of an Earth satellite under the action of the planet's oblateness and of lunar perturbations is studied. The results confirm the superiority of the method over a classical Wisdom–Holman algorithm in both accuracy and computation time. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Lunisolar Resonances Revisited     

Sławomir Breiter 《Celestial Mechanics and Dynamical Astronomy》2001,81(1-2):81-91

Lunisolar resonances arise in the artificial satellite problem without short-periodic terms. The basic model including the Earth's J ₂and a Hill-type model for the Sun or the Moon admits 20 different periodic terms which may lead to a resonance involving the satellite's perigee, node and the longitude of the perturbing body. Some of the resonances have been studied separately since 1960s. The present paper reviews all single resonances, attaching an appropriate fundamental model to each case. Only a part of resonances match known fundamental models. An extended fundamental model is proposed to account for some complicated phenomena. Most of the double resonance cases still remain unexplored.  相似文献   

Phosphorus – an omnipresent minor element in garnet of diverse textural types from leucocratic granitic rocks     

K. Breiter  M. Novák  F. Koller  J. Cempírek 《Mineralogy and Petrology》2005,85(3-4):205-221

Summary Elevated P contents of up to 0.086 apfu (1.21 wt.% P₂O₅) were found in garnet from leucocratic granitic rocks (orthogneisses, granites, barren to highly evolved pegmatites) in the Moldanubicum and Silesicum, Czech Republic, and in complex granitic pegmatites from southern California, USA, and Australia. Minor concentrations (0.15–0.55 wt.% P₂O₅) appear ubiquitous in garnet from leucocratic granitic rocks of different origins and degrees of fractionation. Concentrations of P are not related to Mn/(Mn + Fe) that vary from 0.12–0.86 and to textural types of garnet (i.e., isolated anhedral to euhedral grains and nodules, graphic and random garnet–quartz aggregates, subsolidus veins of fine-grained garnet). Garnet compositions exhibit negative correlations for P/Si and P/R²⁺ where R²⁺ = Fe + Mn + Mg + Ca, while Al is constant at ∼2.05 apfu. Concentrations of Na are largely below 0.02 apfu but positively correlate with P. The main substitution may involve A-site vacancy and/or the presence of some light element(s) in the crystal structure. The substitution □P₂ R²⁺ ₋₁Si₋₂ and/or alluaudite-type Na□P₃ R²⁺ ₋₁Si₋₃ seem the most likely P-incorporating mechanisms. The partitioning of P among garnet and associated minerals in granitic systems remains unclear; however, it directly affects the distribution of Y and REEs.  相似文献   

Extreme P-, Bi-, Nb-, Sc-, U- and F-rich zircon from fractionated perphosphorous granites: The peraluminous Podlesí granite system, Czech Republic     

Karel Breiter  Hans-Jürgen Frster  Radek &#x;koda 《Lithos》2006,88(1-4):15-34

The strongly peraluminous and P-rich, protolithionite and zinnwaldite leucogranites from Podlesí, western Krušné Hory Mts., Czech Republic, contain accessory zircon with extraordinary enrichment of several elements, which constitute trace elements in common zircon. Elements showing a not yet reported anomalous enrichment include P (up to 20.2 wt.% P₂O₅; equivalent to 0.60 apfu, formula calculated on the basis of 4 oxygen atoms), Bi (up to 9.0 wt.% Bi₂O₃; 0.086 apfu), Nb (up to 6.7 wt.% Nb₂O₅, 0.12 apfu), Sc (up to 3.45 wt.% Sc₂O₃; 0.10 apfu), U (up to 14.8 wt.% UO₂; 0.12 apfu) and F (up to 3.81 wt.% F; 0.42 apfu). Strong enrichment of P preferentially involved the berlinite-type substitution (2 Si⁴⁺  P⁵⁺ + Al³⁺) implying that significant Al may enter the Si position in zircon. Incorporation of other exotic elements is primarily governed by the xenotime (Si⁴⁺ + Zr⁴⁺  P⁵⁺ + Y³⁺), pretulite (Sc³⁺ + P⁵⁺  Zr⁴⁺ + Si⁴⁺), brabantite-type (Ca²⁺ + (U, Th)⁴⁺ + 2P⁵⁺  2Zr⁴⁺ + 2Si⁴⁺), and ximengite-type (Bi³⁺ + P⁵⁺  Zr⁴⁺ + Si⁴⁺) substitution reactions. One part of the anomalous zircons formed late-magmatically, from a strongly peraluminous, P–F–U-rich hydrous residual melt that gave rise to the zinnwaldite granite. Interaction with aggressive residual fluids and metamictization have further aided in element enrichment or depletion, particularly in altered parts of zircon contained in the protolithionite granite. Most of the zircon from F-rich greisens have a composition close to endmember ZrSiO₄ and are chemically distinct from zircon in its granite parent. This discrepancy implies that at Podlesí, granitic zircon became unstable and completely dissolved during greisenization. Part of the mobilized elements was reprecipitated in newly grown, hydrothermal zircon.  相似文献