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Ratih Damayanti - One of the best experts on this subject based on the ideXlab platform.

  • paleobotani dryobalanoxylon fosil kayu asal jambi paleobotany dryobalanoxylon fossil wood origin jambi
    Jurnal Ilmu dan Teknologi Kayu Tropis, 2018
    Co-Authors: Andianto Andianto, Agus Ismanto, Ratih Damayanti
    Abstract:

    Jambi Province is known as an area with abundant source of geological diversity (Geodeversity), including fossil woods. Specimen of Fossil wood from Merangin District-Jambi was observation its anatomical structures on thin slices of cross, radial and tangential-section  using Carl Zeiss-Axio Imager A1m microscope. The description of wood anatomical structures referred to the International Association of Wood Anatomists (IAWA) list of microscopic features for hardwood identification. The age estimate of fossil wood is based on geological map (scale 1: 100.000) of Sarolangun sheet, Sumatra. The anatomical structures of the fossil wood are as follow: vessel exclusively solitary, simple perforation plates, intervessel pits alternate, very thick fibre wall, apotracheal parenchyma diffuse-in-aggregates, paratracheal parenchyma vasicentric, axial canals in long tangential lines, Prismatic Crystal in chambered axial parenchyma cells, and silica bodies present in ray cells and axial parenchyma cells. The anatomical structures mentioned are similar to Kamper/Kapur wood species ( Dryobalanops sp.) which it is member of Dipterocarpaceae family, with the result that  this fossil is Kamper wood ( Dryobalanoxylon sp.). Based on age analysis through the geological map, it is estimated that this fossil wood was formed between 3.60 and 2.58 million BP (Before Present), which was between the late Pliocene and the early Plistocene era.

Zaccarini F. - One of the best experts on this subject based on the ideXlab platform.

  • Jordanite homologues from the Pollone mine (Apuan Alps, Italy): the geocronite-jordanite isotypic pair and the new N = 3.5 homologue marcobaldiite
    2016
    Co-Authors: Biagioni C., Dini A., Merlino S., Moëlo Y., Orlandi P., Paar W.h., Pasero M., Zaccarini F.
    Abstract:

    The jordanite homologous series has the general formula Pb4N-2Me3+ 6S4N+7 (Makovicky et al., 2006). The minerals belonging to this series are characterized by the stacking, along b, of trigonal Prismatic layers with N-octahedra-thick layers. The N = 4 homologue is represented by the most common members of this series, jordanite, ideally Pb14As6S23, and geocronite, Pb14Sb6S23, whereas the N = 3 member, kirkiite, Pb10(As3Bi3)S19, is exceptional. These structural differences are reflected in the unit-cell parameters. Both N = 3 and N = 4 homologues are characterized by two short unit-cell axes of ≈ 8.5 and 8.9 Å, whereas the third long axis increases from 26 to 32 Å from kirkiite to the jordanite-geocronite pair. One of the classic localities for the occurrence of geocronite is represented by the Pollone mine, Valdicastello Carducci (Apuan Alps, Tuscany, Italy), where it has been known since XIX Century (Kerndt, 1845). During our study of the baryte - pyrite - iron oxide ore deposits from southern Apuan Alps, historical as well as new specimens of geocronite from this locality were rexamined using single-Crystal X-ray diffraction coupled with electron-microprobe analysis. The chemistry of the studied samples ranges between As-bearing geocronite, Pb14Sb3.8As2.2S23, and Sb-bearing jordanite, Pb14As3.4Sb2.6S23. The Crystal structure of grains representative of the different compositions have been refined, allowing a better understanding of the pnictogen partitioning within the different structural sites of the jordanite-geocronite pair (Biagioni et al., 2016). Surprisingly, one of the studied specimens, together with the two short unit-cell parameters typical of the jordanite series, revealed for the third one a value of 29.4 Å, intermediate between those of the N = 3 and N = 4 homologues. Consequently, it was hypothesized that it could be the first N = 3.5 homologue. The Crystal structure solution confirmed this hypothesis, allowing the definition of the new mineral marcobaldiite, ideally Pb12(Sb,As,Bi)6S21 (IMA 2015-109). It was found in a quartz vein as a black Prismatic Crystal associated with tennantite. Marcobaldiite is triclinic, P-1, with unit-cell parameters a = 8.9248(9), b = 29.414(3), c = 8.5301(8) Å, α = 98.336(5), β = 118.175(5), γ = 90.856(5)°, V = 1944.1(3) Å3, Z = 2. Electron microprobe analysis gave (in wt.%): Pb 64.05, Bi 4.24, Sb 9.10, As 4.51, S 17.24, total 99.14. It corresponds to the chemical formula (on the basis of 18 cations per formula unit) Pb11.98(Sb2.90As2.33Bi0.79)Σ6.02S20.80. The Crystal structure of marcobaldiite (R1 = 0.0682) can be described as formed by the 1:1 alternation of two different layers of distorted octahedra, one three-octahedra thick (kirkiite-type slab) and the other fouroctahedra thick (jordanite-type slab). Layers are connected by one atomic layer of three bicapped triangular Prismatic Pb atoms and one triangular pyramidal As

Michele M Mcconn - One of the best experts on this subject based on the ideXlab platform.

  • genetic evidence for differences in the pathways of druse and Prismatic calcium oxalate Crystal formation in medicago truncatula
    Functional Plant Biology, 2007
    Co-Authors: Paul A Nakata, Michele M Mcconn
    Abstract:

    Current evidence supports a single pathway of oxalate biosynthesis utilising ascorbic acid as the precursor. In this study, we begin to address the possibility that more than one pathway of oxalate biosynthesis and calcium oxalate formation occurs in Medicago truncatula Gaertn. (cv. Jemalong genotype A17). Like the wild type, developing leaves of the calcium oxalate defective (cod) 4 mutant contain Prismatic Crystals along the vascular strand, but this mutant also hyper-accumulates druse Crystals within the mesophyll cells. A second mutant, cod5, fails to accumulate Prismatic Crystals along the vascular strand, but is capable of wild type druse Crystal accumulation in maturing leaves. To assess whether a single pathway of oxalate biosynthesis and calcium oxalate formation occurs in M. truncatula, we generated and characterised the cod4/cod5 double mutant. Microscopic examination of the cod4/cod5 revealed that the double mutant exhibits both cod4 and cod5 mutant Crystal phenotypes simultaneously, suggesting there are differences in the pathways leading to the two Crystal types. Measured ascorbic acid levels and ascorbate induction studies were consistent with the acid as precursor to oxalate in druse Crystal formation but not necessarily Prismatic Crystal formation. On the basis of these findings, we propose a working model depicting possible pathways of oxalate biosynthesis and calcium oxalate formation.

Andianto Andianto - One of the best experts on this subject based on the ideXlab platform.

  • paleobotani dryobalanoxylon fosil kayu asal jambi paleobotany dryobalanoxylon fossil wood origin jambi
    Jurnal Ilmu dan Teknologi Kayu Tropis, 2018
    Co-Authors: Andianto Andianto, Agus Ismanto, Ratih Damayanti
    Abstract:

    Jambi Province is known as an area with abundant source of geological diversity (Geodeversity), including fossil woods. Specimen of Fossil wood from Merangin District-Jambi was observation its anatomical structures on thin slices of cross, radial and tangential-section  using Carl Zeiss-Axio Imager A1m microscope. The description of wood anatomical structures referred to the International Association of Wood Anatomists (IAWA) list of microscopic features for hardwood identification. The age estimate of fossil wood is based on geological map (scale 1: 100.000) of Sarolangun sheet, Sumatra. The anatomical structures of the fossil wood are as follow: vessel exclusively solitary, simple perforation plates, intervessel pits alternate, very thick fibre wall, apotracheal parenchyma diffuse-in-aggregates, paratracheal parenchyma vasicentric, axial canals in long tangential lines, Prismatic Crystal in chambered axial parenchyma cells, and silica bodies present in ray cells and axial parenchyma cells. The anatomical structures mentioned are similar to Kamper/Kapur wood species ( Dryobalanops sp.) which it is member of Dipterocarpaceae family, with the result that  this fossil is Kamper wood ( Dryobalanoxylon sp.). Based on age analysis through the geological map, it is estimated that this fossil wood was formed between 3.60 and 2.58 million BP (Before Present), which was between the late Pliocene and the early Plistocene era.

Paar, Werner H. - One of the best experts on this subject based on the ideXlab platform.

  • Lead-antimony sulfosalts from Tuscany (Italy). XXII. Marcobaldiite, ∼Pb12(Sb3As2Bi)Σ6S21, a new member of the jordanite homologous series from the Pollone mine, Valdicastello Carducci
    'Schweizerbart', 2018
    Co-Authors: Biagioni Cristian, Pasero Marco, Moëlo Yves, Zaccarini Federica, Paar, Werner H.
    Abstract:

    The new mineral species marcobaldiite, ∼Pb12(Sb3As2Bi)Σ6S21, has been discovered in a single specimen collected in a quartz vein embedded in tourmaline-bearing schist from the Pollone mine, Valdicastello Carducci, Pietrasanta, Apuan Alps, Tuscany, Italy. It occurs as a black blocky Prismatic Crystal, up to 1 cm in size, with a metallic luster, associated with Sb-rich tennantite. Under the ore microscope, marcobaldiite is white, with a distinct anisotropism, with grey to bluish-grey rotation tints. Polysynthetic lamellar twinning is common and characteristic. Reflectance percentages for the four COM wavelengths are [Rmin, Rmax(%), (l)]: 31.6, 40.1 (470 nm), 30.9, 39.6 (546 nm), 30.4, 38.5 (589 nm), and 30.0, 37.6 (650 nm). Electron microprobe analyses gave (average of 10 spot analyses in wt%): Pb 64.05(34), Bi 4.24(6), Sb 9.10(14), As 4.51(8), S 17.24(19), total 99.14(53). On the basis of SMe =18apfu, the empirical formula is Pb11.98(4)Sb2.90(3)As2.33(3)Bi0.79(1)S20.80(20)The main diffraction lines, corresponding to multiple hkl indices, are [d in Å (relative visual intensity)]: 3.568 (ms), 3.202 (ms), 3.016 (ms), 2.885 (ms), 2.233 (vs), 2.125 (s), 1.848 (s), and 1.775 (s). The Crystal structure study gives a triclinic unit cell, space group P1 with a =8.9248(9), b = 29.414(3), c = 8.5301(8) Å, a = 98.336(5), b = 118.175(5), g =90.856(5)°, V = 1944.1(3) Å3, Z = 2. The Crystal structure has been solved and refined to R1= 0.067 on the basis of 6188 reflections with Fo> 4s(Fo)and363refined parameters. Marcobaldiite is a new N = 3.5 homologue of the jordanite homologous series, characterized by the 1:1 alternation of two kinds of layers of distorted octahedra, three-and four-octahedra thick, i.e. of the kirkiite and jordanite types, respectively. Layers are connected by one atomic layer of three bicapped trigonal Prismatic Pb atoms and one triangular pyramidal As atom in split position. The name of this new mineral species honours the mineral amateur Marco Baldi (b. 1944) for his contribution to the knowledge of the mineralogy of the pyrite ± baryte ± iron oxide ore deposits from southern Apuan Alps