André Jasper

Applied investigation on the interaction of hazardous elements binding on ultrafine and nanoparticles in Chinese anthracite-derived fly ash.

A multifaceted instrumental approach was employed to determine the chemistry and mineralogy of pulverized-coal-combustion fly ashes from two Chinese power plants. Techniques included traditional optical microscopy, X-ray diffraction, and chemical analysis along with a variety of electron beam methods. The aim is to demonstrate and bring together the wide variety of procedures dealing with F as the key element of concern, and determining its location in the mineral nanoparticles. The Hg content of the Anwen (Songzao coalfield) fly ashes is higher than that of the Diandong (East Yunnan) fly ashes, possibly owing to the greater C and Cl in the Anwen fly ashes. Both fly ash sources contain a variety of amorphous and nano-crystalline trace-element-bearing particles, both associated with multi-walled carbon nanotubes and as particles independent of carbons.

EVIDENCE OF PALEOWILDFIRE IN THE EARLY MIDDLE TRIASSIC (EARLY ANISIAN) VOLTZIA SANDSTONE: THE OLDEST POST-PERMIAN MACROSCOPIC EVIDENCE OF WILDFIRE DISCOVERED SO FAR

Abstract As direct evidence of paleowildfires, fossil charcoal has so far rarely been reported from Triassic rocks around the world. Indeed there seems to be a scarcity of reports of charcoal between the Permian–Triassic boundary (PTB) and the Ladinian (upper Middle Triassic), an interval of ∼16 myr. There are only a few published records in this time period, consisting either of microscopic charcoal in palynological samples or of indirect evidence such as potential fire scars in wood. Macroscopic charcoal has recently been discovered in the early Middle Triassic (early Anisian) Voltzia Sandstone fossil Lagerstätte in southwestern Germany, providing the oldest macroscopic post-Permian evidence of wildfire currently known. Previous authors have suggested a lack of fuel as a reason for the scarcity of charcoal in Lower-Middle Triassic rocks. As the Voltzia Sandstone includes the oldest known, moderately diverse regional paleoflora after the PTB (interpreted by some authors as representing the recovery of the land flora after end-Permian biotic events), a lack of fuel cannot be claimed as a possible reason for the scarceness of charcoal in these rocks. It seems possible in this particular case that previous researchers simply may have overlooked charcoal remains from this formation, either because they were not recognized or were not considered important at the time.

Charcoal remains from a tonstein layer in the Faxinal Coalfield, Lower Permian, southern Paraná Basin, Brazil

Fossil charcoal has been discovered in the Faxinal Coalfield, Early Permian, Rio Bonito Formation, in the southernmost portion of the Parana Basin, Brazil. Three types of pycnoxylic gymnosperm woods recovered from a single tonstein layer are described and confirm the occurrence of paleowildfire in this area. A decrease of the charcoal concentration from the base to the top within the tonstein layer indicates that the amount of fuel declined during the deposition probably due to the consumption of vegetation by the fire. The presence of inertinite in coals overlying and underlying the tonstein layer indicates that fire-events were not restricted to the ash fall interval. The integration of the new data presented in the current study with previously published data for the Faxinal Coalfield demonstrates that volcanic events that occurred in the surrounding areas can be identified as one potential source of ignition for the wildfires. The presence of charcoal in Permian sediments associated with coal levels at different localities demonstrates that wildfires have been relatively common events in the peat-forming environments in which the coal formation took place in the Parana Basin.

Record of the genus Lycopodites in the Lower Permian of Paraná Basin, Brazil

The genus Lycopodites, which encompasses the herbaceous forms of the lycopsids, presents broad time and spacial distribution during the Paleozoic in the Northern Hemisphere, with its initial records dating from the European Devonian. As to Gondwanan Paleozoic, to this moment, only Lycopodites amazonica Dolianiti had been reported for the Amazonian Middle Devonian (Curuá Group). Thus, the specimens reported in this study such as Lycopodites sp., coming from sedimentary rocks of the Itararé Subgroup, São Paulo State, and Lycopodites riograndensis sp. nov., collected in Rio Bonito Formation, Rio Grande do Sul, represent the oldest fertile forms recorded for Gondwana and the first ones to be described for the Paraná Basin. Its presence in layers, deposited after the end of the Neopaleozoic Glaciation, shows the appearance of new taxa in high latitudes, as well as the diversity of the lycopsids present in the Basin, previously indicated through the abundance of spores associated to the Class Lycopsida present in the palinomorphous assemblages.

Charcoal in the Late Jurassic (Kimmeridgian) of Western and Central Europe—palaeoclimatic and palaeoenvironmental significance

Although fossil charcoal, as direct evidence of palaeo-wildfires, occurs in the fossil record at least since the Late Silurian, it is not equally distributed in sedimentary rocks from different ages. As the occurrence of wildfires is indeed not only controlled by climatic and environmental parameters, but also by the concentration of atmospheric oxygen, it has been argued by various authors that the fossil record of charcoal must also be influenced by (long-term) variations in atmospheric oxygen concentrations. Geochemical models have reconstructed low oxygen concentrations during almost the entire Jurassic, resulting, at least theoretically, in very low fire frequencies during this period. Here we describe new discoveries of fossil charcoal fragments from two Late Jurassic (Kimmeridgian) localities in Western (Boulonnais area in northern France) and Central Europe (Nusplingen Lithographic Limestone Fossillagerstätte in southwestern Germany). Combining our new data with currently available—but rather scarce—data on the occurrences of charcoal fragments during this particular interval of time demonstrates that all of these occurrences lie either within a Late Jurassic winter-wet climate belt, characterised by a marked seasonality, or within the assumedly drier part of a temperate climate belt, near the boundaries of the winter-wet climate belt. This is somewhat surprising as the preservation potential of charcoal is generally considered to be rather low under comparable climatic conditions, although charcoal production is usually high under seasonally dry climatic conditions. As almost all Kimmeridgian charcoals discovered to date come from marine deposits, it seems likely that taphonomic factors may have favoured the preservation of charcoal in such environments. Considering all data and interpretations, it seems possible that on a global scale fire frequencies were low during the Kimmeridgian due to relatively low atmospheric oxygen conditions during this period. Only in areas with a pronounced seasonality (i.e. under a winter-wet climate) could fires have occurred frequently enough to produce a certain amount of charcoal, and this charcoal has only been preserved under favourable conditions in marine sediments or in peat bogs with relatively high fire frequencies.

Coricladus quiteriensis gen. et sp. nov., a new conifer in Southern-Brazil Gondwana (Lower Permian, Paraná Basin)

A new taxon of conifers (Coricladus quiteriensis) is described based on megafloristic remains from the roofshale level at the Quiteria Outcrop (Rio Bonito Formation-Lower Permian-Southern Parana Basin-Rio Grande do Sul-Brazil). This megafloristic community is included in the Botrychiopsis Zone--Botrychiopsis valida Sub-Zone (Kungurian/Roadian). The assemblage, preserved as impressions, do not present remains of epidermic characters, and is composed mainly of isolated vegetative branches with spirally disposed acicular leaves, presenting a conspicuous central vein and also isolated fertile branches with sparse and irregular leaves and terminal cones. Leafless principal branches, organically connected with sterile and fertile branches, are rare. Reproductive feminine scales, disposed in a plane, are organized in lax terminal cones on branches, composed by 4 (four) distal ovuliferous scales, and 8 (eight) elliptical-elongated anatropous seeds. Paleoecological data pointed out to a mesophylous to higrophylous habitat in swampy environments.

The Botrychiopsis genus and its biostratigraphic implications in Southern Paraná Basin

Botrychiopsis has been considered an important floristic element of Westphalian/Artinskian associations of the Paraná Basin. The occurrence of Botrychiopsis in roof-shales of the Rio Bonito Formation in Southern Paraná Basin (Quitéria area), supported by the identification of Botrychiopsis valida, enlarges the genus biochron. Consequently, the stratigraphic hierarchy for Botrychiopsis plantiana and Botrychiopsis valida was defined for the Paraná Basin. Although it is climatically controlled and related to a deglaciation icehouse stage, stratigraphic distribution of the genus presents a substantial climate tolerance, from cold/cool to warm/temperate conditions. A new phytostratigraphic zonation is proposed for the southern portion of the basin that includes the Botrychiopsis Zone (Asselian/Kungurian), which is subdivided into the Botrychiopsis plantiana (Asselian/Artinskian) and Botrychiopsis valida (Late Artinskian/Kungurian) subzones.

Palaeoclimatic inferences based on dendrological patterns of permineralized wood from the Permian of the Northern Tocantins Petrified Forest, Parnaíba Basin, Brazil

The Northern Tocantins Petrified Forest is classified in the scientific literature as one of the most important Permian assemblages of permineralized plant remains from the warm temperate palaeobiome of the Southern Hemi-sphere. Part of this forest is located in the Tocantins Fossil Trees Natural Monument, which is a Full Protection Conservation Unit in the northeastern part of the Brazilian state of Tocantins. Geologically, the Petrified Forest is part of the Parnaíba Basin, and the studied stems originate from the Permian Motuca Formation. The aim of the present work is to reconstruct aspects of the regional climate during the Permian by using proxy data obtained from the analysis of gymnospermous fossil stems preserved in the Northern Tocantins Petrified Forest. The material analysed comes from 32 gymnospermous fossil wood fragments derived from nine sampling points located inside and outside the park area. In order to determine climatic influence on wood growth, a total number of 682 growth increments were investigated using mean sensibility and annual sensibility analysis. Moreover, thin sections were made and the anatomical details of the growth patterns of the stems were investigated. The results obtained from these analyses allowed the establishment of the presence of growth zones in the gymnospermous fossil stems. Detailed analysis of these growth zones led to the reconstruction of a seasonal climate with periods of high precipitation alternating with periods of more or less severe dryness, probably in a semi-arid palaeoenvironment. This result is in agreement with previous reconstructions for the Northern Tocantins Petrified Forest area, which postulated a kind of monsoonal climate, characterised by marked seasonality, with strong rains and distinct dry periods.

Hepaticites iporangae n. sp., Rio Bonito Formation, Early Permian (Sakmarian), Paraná Basin, Brazil, Western Gondwana

Abstract The formal description of a liverwort from the Paraná Basin is presented. The fossil was found in the Rio Bonito Formation, Early Permian (Sakmarian), and is identified as a new species of the genus Hepaticites, named H. iporangae n. sp. The samples studied were collected from the macrofossil-rich roof-shale layer of the Quitéria Outcrop in the municipality of Encruzilhada do Sul, state of Rio Grande do Sul, Brazil. H. iporangae is one of the oldest liverworts reported from South America. The fossil described here provides more evidence of the relative diversity of liverworts in Paleozoic Gondwana despite the severe climatic conditions during the glaciations of the Permo-Carboniferous.

A Multi-analytical Approach to Understand the chemistry of Fe-minerals in Feed Coals and Ashes

Seven feed coals used in the Brazilian power generation industry were obtained and subsequently analysed together with fly ash and bottom ash from a major Brazilian power plant. The samples were investigated by means of room temperature FeMossbauer analyses, X-ray diffraction, Raman spectroscopy, scanning electron microscope and petrographic analysis. In addition, nanometer-sized crystalline phases in coals and ashes were characterised using an energy-dispersive X-ray spectrometer and a high-resolution transmission electron microscope. The major identified Fe-bearing minerals in the coals were found to be actinolite, ankerite, chalcopyrite, chlorite, goethite, illite, ilmenite, magnesioferrite, natrojarosite, pyrite, pyrrhotite, and siderite; whilst in the fly ash and bottom ash, ankerite, chlorite, chromite, goethite, hematite, hercynite, jarosite, maghemite, magnesioferrite, and magnetite were identified. Most of the Fe in the ash samples was present as Fe resulting from the melting of Fe and silicates during combustion. The fraction of glassy Fe in those particles is high because of the high contact probability between Fe melt and silicates. The combination of the various methods offers a powerful analytical technique in the study of coal and coal ashes. This investigation can be regarded as an introductory and prospective study prior to further quantification. f 2011 The University of Kentucky Center for Applied Energy Research and the American Coal Ash Association All rights reserved. A R T I C L E I N F O Article history: Received 22 April 2011; Received in revised form 12 August 2011; Accepted 15 August 2011