Lucyna Natkaniec-Nowak

Raman microspectroscopy of organic inclusions in spodumenes from Nilaw (Nuristan, Afghanistan).

The color varieties of spodumene (green spodumene, kunzite) from Nilaw mine (Nuristan, Afghanistan) have been investigated by microthermometry and Raman spectroscopy analyses. These minerals are rich in primary and secondary fluid inclusions. Measured values of temperature homogenization (T(h)) and pressure (P) for selected fluid-inclusion assemblages (I-IV) FIA in green spodumene and (I-II) FIA in kunzite ranges from 370 to 430°C, 1.16 to 1.44 kbar and 300 to 334°C, 0.81 to 1.12 kbar, respectively. The brine content and concentration varies from 4.3 to 6.6 wt.% eq. NaCl. Numerous and diverse mineral phases (quartz, feldspars, mica, beryl, zirconium, apatite, calcite, gypsum) present in this mineral as solid inclusions were studied by Raman microspectroscopy. Raman spectra of selected fluid, organic and solid inclusions were collected as line or rectangular maps and also depth profiles to study their size and contents. There appeared very interesting calcite (156, 283, 711 and 1085 cm(-1)), beryl (324, 397, 686, 1068 and 3610 cm(-1)), topaz (231, 285, 707, 780 and 910 cm(-1)) and spodumene (355, 707 and 1073 cm(-1)) inclusions accompanied by fluid and/or organic inclusions (liquid and gas hydrocarbons) with bands at 2350 cm(-1) (CO(2), N(2)), 2550 cm(-1) (H(2)S) and 2900 cm(-1) (C(2)H(6)-CH(3)). Some solid inclusions contain carbonaceous matter (D-band at ca. 1320 cm(-1) and/or G-band at ca. 1600 cm(-1)).

Inclusions in topaz from miarolitic pegmatites of the Volodarsk-Volynski Massif (Ukraine) – A Raman spectroscopic study

The differently coloured (colourless, brown-pinkish and blue-pinkish) crystals of topaz from granitic pegmatites of Volodarsk-Volynsky Massif (VVM) have been investigated by scanning electron microscopy (SEM) and Raman microspectroscopy (RS) methods. Topaz (287, 522, 855, 929 cm(-1)), goethite (390 cm(-1)), pyrite (377-379 cm(-1)), marcasite (397 and 331 cm(-1)) and monazite (460 and 970-1070 cm(-1)) were identified as mineral inclusions in analysed crystals. On the basis of RS spectra some of this inclusions contain also organic matter, represented by carbonaceous matter (D-band at ca. 1320-1340 cm(-1) and G-band at ca. 1590-1600 cm(-1)) and liquid simple hydrocarbons consisting of aliphatic and aromatic groups (1240, 1325 and 1420 cm(-1)). Other solid phases found the host topaz, i.e. quartz, orthoclase, very rare minerals (micas) as lepidolite, zinnwaldite and also beryl and rutile, were identified with SEM-EDS analyses. All these mineral inclusions have been formed by post-magmatic, fluid-induced processes, extended from pegmatite to hydrothermal stages of magma crystallization.

Lattice deformation of blue halite from Zechstein evaporite basin: Kłodawa Salt Mine, Central Poland

Outcrops of natural blue and purple halite crystals have been found in Kłodawa (Poland) salt deposit originating from the Permian (Zechstein) salt formation within tectonic zones. Field works carried out on various levels of Kłodawa Salt Mine indicated differences both in intensity of the hue and in the size of the outcrops. Their occurrence was connected with the presence of epigenetic sediments rich in potassium. For the samples of blue halite, an optical anisotropy (birefringence) was observed for both standard mineralogical thin sections and thick plates, indicating a deviation from cubic symmetry. The blue colouration of the halites, described by ultraviolet–visible spectroscopy, is due to the presence of colour centres. The colour centres have been recently identified as: F, R1 (F3), R2 (F3), M and plasmons (Wesełucha-Birczyńska et al., Vib Spectrosc 60:124–128, 2012). The trace amount of impurities detected in the blue halites by means of scanning electron microscopy–energy dispersive X-ray spectroscopy and micro-X-ray fluorescence techniques were connected mainly with solid inclusions such as KxNa(1 − x)Cl, KMgCl3·6H2O, KCl, orthorhombic sulphur, quartz and some other phases like pyrite. Crystallographic data obtained by X-ray diffraction experiments for the single crystals of the halite from Kłodawa with different saturation of blue or purple colours, as well as for natural colourless halite, revealed lowering of space-group symmetry to monoclinic, orthorhombic, trigonal, tetragonal or even triclinic systems while the space group typical for pure NaCl is Fm-3m.

Raman spectroscopic and microthermometric studies of authigenic quartz (the Pepper Mts., Central Poland) as an indicator of fluids circulation

Differently colored authigenic quartz crystals were found as the druses compound within mudstone heteroliths from the Pepper Mts. Shale Formation (Cambrian unit of the Holy Cross Mts., Central Poland). The genesis of this mineral was established on the basis of fluid inclusion study. Raman microspectroscopy was the key instrumental technique to identify the nature of the compounds trapped in the fluid inclusions. Methane (2917cm-1) or water vapor (broad band ~2500-3000cm-1) occur within two-phased primary inclusion assemblages, while nitrogen (2329cm-1) associated with methane and trace amount of carbon dioxide (1285, 1388cm-1) occur within secondary fluid inclusion assemblage. Temperatures of homogenization of primary fluid inclusions was obtained on the basis of heating experiments and ranged from 171° to 266°C. These values are much higher than expected for the diagenetic system without metamorphic changes what may imply hydrothermal origin of quartz crystals. The source of fluids is uncertain as in the Holy Cross Mts. there was no volcanic activity to the end of Late Devonian. However, fluids originated in metamorphic basin could use deep faults as the migration paths.

“Watermelon” tourmaline from the Paprok mine (Nuristan, Afghanistan)

The “watermelon” tourmaline from the Paprok mine (Nuristan, Afghanistan) shows different tourmaline components. Four zones differ widely what is refl ected by different chemistry and various colours (pink core and green rim). All zones show a relatively low Mn content (~0.05 apfu) but different Fe contents. While Fe is in the (pink) core at the detection limit, it increases signifi cantly in the outer (green coloured) zones. In the core (zone I) “fl uor-elbaite” could be identifi ed for the fi rst time for the Nuristan region. Tourmaline compositions of this zone show an elbaitic component of ~55 mol%, ~30 mol% rossmaniteand ~15 mol% liddicoatite-component. Zone II shows an increasing schorland rossmanite-component (up to 40 mol%), while the liddicoatiteand elbaite-components are decreasing. The intermediate zone III shows the highest schorl-component of all zones (up to ~11 mol%), while the elbaite-component is decreasing. In the rim (zone IV) the schorl-component decreases to ~6 mol%, while simultaneously the elbaite-component increases. Our investigation shows that during tourmaline crystallization only the amounts of Fe and Li, which were available for the tourmaline crystallisation, have changed to a signifi cant degree. We believe that at beginning of the crystallisation of the Fe-bearing zones the formation of Fe-rich tourmalines (schorl, foitite) in this pegmatite was in a fi nal stage and therefore in this pegmatitic system Fe increasingly was available. The Mn/(Mn+Fe) ration ranges from ~0.10 to ~1.00. The presence of different mineral inclusions such as stannite and Ca carbonates point to a hydrothermal origin of this tourmaline.

Organic‐walled Microfossils from the Early Middle Cambrian sediments of the Holy Cross Mountains, Poland: Possible Implications for Sedimentary Environment in the SE Margin of the Baltica

An association of organic-walled microfossils consisting of filamentous cyanobacteria, algal coenobia and acanthomorphic acritarch have been documented from non-calcareous claystones and mudstones of the Pepper Mountains Shale Formation (PMSF), located in its stratotype area in the Pepper Mountains, which are part of the Holy Cross Mountains in Poland. These sediments represent the oldest strata of the Łysogóry Unit, deposited on the edge of the East European Craton (Baltica). Non-branched, ribbon-like and thread-like cyanobacteria trichomes exhibit morphological similarities to families Nostocaceae and Oscillatoriaceae. Cells assembled in rounded to irregular clusters of monospecific agglomerations represent multicellular algal coenobia, attributed to the family Scenedesmaceae. The co-occurrence of acritarchs belonging to species as Eliasum llaniscum, Cristallinium ovillense and Estiastra minima indicates that the studied material corresponds to the lower Middle Cambrian. Deposition of the PMSF took place in shallow marine environment, influenced by periodical freshwater inputs. The varying degree of coloration of organic-walled microfossils is interpreted in this study as factor indication of possible different source of their derivation. Dark brown walls of cells assembled in algal coenobia might have sustained previous humification in humid, terrestrial environments, which preceded their river transport into the sea together with nutrients, causing occasional blooms of cyanobacteria in the coastal environment and the final deposition of both groups of organisms in marine deposits.