Analyses of petrified wood by electron, X-ray and optical microprobes

1999 ◽  
Vol 14 (3) ◽  
pp. 435-446 ◽  
Author(s):  
Andrzej Kuczumow ◽  
Bart Vekemans ◽  
Olivier Schalm ◽  
Walter Dorrin ◽  
Pierre Chevallier ◽  
...  
Keyword(s):  
X Ray ◽  
Petrified Wood

Analysis of Composite Structure and Primordial Wood Remains in Petrified Wood

2007 ◽  
Vol 61 (8) ◽  
pp. 889-895 ◽  
Author(s):  
J. Nowak ◽  
D. Nowak ◽  
P. Chevallier ◽  
J. Lekki ◽  
R. van Grieken ◽  
...  
Keyword(s):  
Cell Walls ◽  
Central Italy ◽  
Global Scale ◽  
Mineralization Process ◽  
Raman Spectrometry ◽  
X Ray ◽  
The Earth ◽  
Geological Past ◽  
Petrified Wood ◽  
Composite Nature

Among all the fossils, petrified wood belongs to the most impressive and most common of materials. Still, its study has not exceeded the purely phenomenological level. The recognition of the conserved structure of petrified wood seems to be of meaning for understanding the geological past, the complete carbon cycle inside the Earth, and the structure of potential new materials. The first ever published spatial distributions of the remains of the primordial organic material (lignin, cellulose, pectins) in the cells of permineralized wood, from Dunarobba (Central Italy), are presented here. They were collected using μ-Raman spectrometry. The composite nature of the petrified material (calcite located in the lumena of cells and goethite located in the cell walls) was confirmed by electron, proton, and X-ray microprobes. The structure of the cell walls was well preserved. The mineralization process was induced by the tracheidal water flow and was stopped after formation of pipe-like goethite shielding of the cell walls on the cellulose scaffolds. The chemical (Eh and pH ranges) and probable microbial conditions for such a pattern of mineralization were determined. We estimate that substantial amounts of the primordial organic matter were preserved in bodies of petrified wood on a global scale. The wood petrifaction process, if well understood, can be a basis for the production of “everlasting” organic–inorganic composite compounds.

scholarly journals Uranium Mineralization of Fossil Wood

Geosciences ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 133
Author(s):  
George E. Mustoe
Keyword(s):  
Fossil Wood ◽  
Metal Sulfides ◽  
Silicate Mineral ◽  
X Ray ◽  
Organic Debris ◽  
Petrified Wood ◽  
Uranium Minerals ◽  
Ancient Wood ◽  
Common Opal ◽  
Ore Zones

Uraniferous sandstone deposits commonly resulted when uranium in groundwater precipitated in reducing environments caused by degradation of ancient wood and organic debris. However, the mineralogy of uranium in fossil wood has received relatively little study. Previous microscopic observations of petrified wood from a few uranium mines have demonstrated that uranium in fossil wood primarily involves the oxide mineral uraninite or the silicate mineral coffinite, often in association with metal sulfides such as chalcopyrite. These observations are applicable to primary ore zones that are located below the water table, where oxidation is inhibited. New analyses utilizing scanning electron microscopy and X-ray fluorescence (SEM/EDS) reveal that fossil wood from oxidized ore zones may contain a diverse variety of uranium minerals, including carnotite, tyuyamunite, and zippeite, as well as various vanadate and sulfate minerals. Uranium-bearing common opalized wood and stratiform common opal from two prospects in Nevada, USA, contain no identifiable uranium minerals. Instead, the element is dispersed in trace amounts within the opal.

scholarly journals A preliminary study on the element abundance in the Hulusimpang Formation, Way Kalianda, Pesawaran, Lampung, Indonesia

2021 ◽  
Vol 882 (1) ◽  
pp. 012078
Author(s):  
D G Harbowo ◽  
B Priadi ◽  
T Julian ◽  
R N Amelia ◽  
D J P Sihombing ◽  
...  
Keyword(s):  
Trace Elements ◽  
Element Abundance ◽  
X Ray ◽  
Hydrothermal Mineralization ◽  
Petrified Wood ◽  
Preliminary Study ◽  
Fluorescence Analyzer ◽  
Magma Series

Abstract Hulusimpang Formation.has known as Oligocene-Miocene rocks that consisted of volcanoclastic rock. Its scope was wide, especially in southern Sumatra. This formation is supposed as a prospect host of various hydrothermal mineralization. A preliminary study was carried out to examine the abundance of elements located in Way Kalianda River, Pesawaran, Lampung. This study was conducted by easuring its stratigraphy and analyzing its composition using an X-Ray fluorescence analyzer. The lithologies generally consist of lapilli tuffs, volcanic breccias, interbeded by claystone and sandstone; in addition, it is also frequently found petrified wood and andesitic-lithic fragments. As a result, the significant abundant elements are Fe (35.5%), Si (27.9%), Al (17.4%), K (6.7%), Cl (5.5%), Ti (1.7%), and Ca (1.5%) and also Mn, Ag, P, Mg, Sr, Zr, and Co. It also presents trace elements such as Rb, Zn, Pb, Te, V, Ba, Cr, Sn, Ni, Ga, Nb, Mo, and Eu. These elements are suggested from distal facies of intermediates-magma series Tertiary volcano.

scholarly journals The fossil wood of East Cairo, Egypt: A mineralogical view

Mineralogia ◽  
2015 ◽  
Vol 45 (1-2) ◽  
pp. 47-57
Author(s):  
Kamaleldin M. Hassan
Keyword(s):  
Optical Microscopy ◽  
Powder Diffraction ◽  
Xrd Analysis ◽  
Optical Microscope ◽  
Fossil Wood ◽  
X Ray ◽  
Petrified Wood ◽  
Representative Samples ◽  
Petrified Forest

AbstractAs part of the characterization of the petrified wood of East Cairo at the New Cairo Petrified Forest, representative samples collected from the area were studied by X-ray powder diffraction (XRD) and optical microscopy. The samples, as indicated by XRD analysis, are composed of quartz ± some goethite ± minor moganite ± minor gypsum ± trace calcite. The absence of moganite in some samples has been attributed to the transformation of moganite to quartz or to leaching processes. Under the optical microscope, some of the 10 petrified-wood samples are permineralized with mainly microcrystalline quartz (chalcedony), some with a combination of chalcedony and microgranular quartz, and some with microgranular quartz. The sequence of silicification is likely to have been either opaline precursor to chalcedony and quartz, or directly to chalcedony and quartz. The crystallinity indices (C.I.) of the quartz in the samples studied, measured using a standard X-ray powder diffraction procedure, are consistent with the petrographic findings. The chalcedonic samples have the least C.I. values, and the microgranular quartz samples the highest values.

Investigation of petrified wood by synchrotron X-ray fluorescence and diffraction methods

2000 ◽  
Vol 55 (10) ◽  
pp. 1623-1633 ◽  
Author(s):  
Andrzej Kuczumow ◽  
Pierre Chevallier ◽  
Philippe Dillmann ◽  
Piotr Wajnberg ◽  
Michał Rudaś
Keyword(s):  
X Ray ◽  
Petrified Wood

scholarly journals Mineral composition and gemological characteristics of the petrified wood of the Ulyanovsk region

2019 ◽  
pp. 18-23
Author(s):  
D. A. Petrochenkov
Keyword(s):  
Organic Matter ◽  
Mineral Composition ◽  
Lower Cretaceous ◽  
Amorphous Substance ◽  
X Ray ◽  
Petrified Wood ◽  
Ulyanovsk Region ◽  
First Time ◽  
Cretaceous Deposits

For the first time, the mineral composition and gemological characteristics of the petrified wood from the Ulyanovsk region, of jewelry and ornamental quality, have been studied. The petrified wood is associated with the Lower Cretaceous deposits and consists mainly of calcite (up to 73 mass. %); pyrite, apatite, gypsum are present; dolomite, anhydrite, hematite, pyrolusite, organic matter and X-ray amorphous substance have been fixed. According to the technological and decorative characteristics, the petrified wood of the Ulyanovsk region is a quality jewelry and ornamental material of the florogenic group.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

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