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Title: Petrographic characteristics of the Kardia lignites (core KT6A-3), Ptolemais basin (Greece)

Abstract

The aim of this study is to provide useful coal-petrographic data, which will further help the characterization, exploitation, and utilization of the Kardia lignite deposit and also initially to access the depositional conditions mainly in terms of water table level and subsidence rate of the fen substrate. Ash contents, as well as the C, H, N, O, and S were determined in nine lignite samples from core KT6A-3. The ash contents (750{sup o}C) of the studied lignite seams range among 14-37% (on dry basis). Contents of C, H, N, and O have values between 34-52%, 2.5-4.2%, 0.8-2%, and 21-30.6%, respectively. Sulfur does not exceed 1.2%. Huminite group dominates with values between 84-99 vol%, mmf. All samples display a distinct prevalence in detrohuminite (up to 82 vol%) with attrinite being most abundant. Liptinite and inertinite macerals have low contents, which do not exceed 8% and 12%, respectively. The Kardia lignites are medium to very low-grade coals. They formed in fens under limnotelmatic regime and originated from herbaceous vegetation. During peat deposition, conditions were well moist, intense reducing, and favored increased bacterial activity. The ratio of plant growth and peat accumulation versus rise of water table due to the subsidence rate wasmore » not well balanced. The petrographical composition of the Kardia lignites is related either to a long residence time of the organic matter in the acrotelm or to an herbaceous vegetation origin.« less

Authors:
; ; ; ;  [1]
  1. CDX Canada Co., Calgary, AB (Canada)
Publication Date:
OSTI Identifier:
20752180
Resource Type:
Journal Article
Resource Relation:
Journal Name: Energy Sources, Part A: Recovery Utilization and Environmental Effects; Journal Volume: 28; Journal Issue: 4
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; LIGNITE; BROWN COAL; CHEMICAL COMPOSITION; ASH CONTENT; SULFUR CONTENT; MACERALS; ORIGIN; PETROGRAPHY; GREECE; COAL DEPOSITS

Citation Formats

Antoniadis, P., Mavridou, E., Papazisimou, S., Christanis, K., and Gentzis, T. Petrographic characteristics of the Kardia lignites (core KT6A-3), Ptolemais basin (Greece). United States: N. p., 2006. Web. doi:10.1080/009083190965118.
Antoniadis, P., Mavridou, E., Papazisimou, S., Christanis, K., & Gentzis, T. Petrographic characteristics of the Kardia lignites (core KT6A-3), Ptolemais basin (Greece). United States. doi:10.1080/009083190965118.
Antoniadis, P., Mavridou, E., Papazisimou, S., Christanis, K., and Gentzis, T. Wed . "Petrographic characteristics of the Kardia lignites (core KT6A-3), Ptolemais basin (Greece)". United States. doi:10.1080/009083190965118.
@article{osti_20752180,
title = {Petrographic characteristics of the Kardia lignites (core KT6A-3), Ptolemais basin (Greece)},
author = {Antoniadis, P. and Mavridou, E. and Papazisimou, S. and Christanis, K. and Gentzis, T.},
abstractNote = {The aim of this study is to provide useful coal-petrographic data, which will further help the characterization, exploitation, and utilization of the Kardia lignite deposit and also initially to access the depositional conditions mainly in terms of water table level and subsidence rate of the fen substrate. Ash contents, as well as the C, H, N, O, and S were determined in nine lignite samples from core KT6A-3. The ash contents (750{sup o}C) of the studied lignite seams range among 14-37% (on dry basis). Contents of C, H, N, and O have values between 34-52%, 2.5-4.2%, 0.8-2%, and 21-30.6%, respectively. Sulfur does not exceed 1.2%. Huminite group dominates with values between 84-99 vol%, mmf. All samples display a distinct prevalence in detrohuminite (up to 82 vol%) with attrinite being most abundant. Liptinite and inertinite macerals have low contents, which do not exceed 8% and 12%, respectively. The Kardia lignites are medium to very low-grade coals. They formed in fens under limnotelmatic regime and originated from herbaceous vegetation. During peat deposition, conditions were well moist, intense reducing, and favored increased bacterial activity. The ratio of plant growth and peat accumulation versus rise of water table due to the subsidence rate was not well balanced. The petrographical composition of the Kardia lignites is related either to a long residence time of the organic matter in the acrotelm or to an herbaceous vegetation origin.},
doi = {10.1080/009083190965118},
journal = {Energy Sources, Part A: Recovery Utilization and Environmental Effects},
number = 4,
volume = 28,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
  • The aim of this study is to interpret the palaeoenvironmental conditions established during the formation of several lignite seams at the Mavropigi deposit, Ptolemais, Greece (corehole MAK-48). In nine representative lignite samples, ash contents, as well as the contents of the elements C, H, N, O, and S were determined. Polished block sections from the same samples were examined under the microscope. The ash contents (750{sup o}C) of the studied lignite seams range between 10-29% (on dry basis). The contents of C, H, N, and O display values between 36-55%, 2.4-4.6%, 0.7-2%, and 21-37.5%, respectively, while S contents do notmore » exceed 1.4%. Huminite is the prevailing maceral group (87-95%). All the samples, except No. 35, display a distinct prevalence in detrohuminite maceral subgroup (up to 69 vol%, mmf). Liptinite and inertinite maceral groups show low contents, which do not exceed 9% and 7%, respectively. The Mavropigi lignites are medium to low grade coals and can be regarded as peat to lignite in terms of thermal maturity. The studied lignite seams formed in fens, possibly from herbaceous plants under limnotelmatic regime. During peat deposition, conditions were very moist and intense reducing with increased bacterial activity. The ratio of plant growth and peat accumulation versus rise of water table due to the subsidence rate was not well balanced. As a result, the petrographical composition of the Mavropigi lignites is related either to a long residence time of the organic matter in the acrotelm or to a herbaceous vegetation origin.« less
  • Seven core samples (five lignite samples and two intraseam nonlignite rock samples) from the Achlada open-cut mine in northern Greece were characterized by X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques. Quantitative evaluation of the mineral phases in each sample was made from the powder X-ray diffractograms using Siroquant commercial interpretation software, which is based on Rietveld principles. The main minerals in the low-temperature ash (LTA) ash of the lignites are kaolinite and illite, with bassanite and quartz in minor proportions. The nonlignite rock samples mainly consist of illite, mica (2M1), and kaolinite (poorly ordered), along with quartz, chlorite (ferroan),more » feldspar (albite), rutile, and dolomite. Oriented-aggregate XRD study further shows the presence of smectite, and interstratified illite/smectite (I/S), in the clay fractions of the lignite and rock samples, with the mineral matter of the lignites being richer in kaolinite, smectite, and I/S than in mineral matter of the nonlignite materials. The differences in mineralogy between the lignite and the rock materials probably reflect selective concentration of minerals in the original peat during deposition, combined with authigenic precipitation of minerals such as kaolinite in the peat deposit. Inferred chemical analyses derived from the XRD data show reasonably good correlations with chemical data obtained by direct ash analysis, especially if the smectite and I/S are taken into account. This provides a link between mineralogical and chemical studies that may be valuable in evaluating the behavior of the lignite under different utilization conditions. 27 refs., 4 figs., 6 tabs.« less
  • Several minor lignite deposits of Palaeogene (Eocene to Oligocene) age occur in the vicinity of Alexandroupolis, Thrace, northern Greece. A few, rather thin seams were mined in the past by small private operations for local use. Coal samples have been collected from old mine dumps and outcrops around abandoned mine posts to be studied by means of maceral analysis at high magnification. The groundwater and vegetation index are calculated from the maceral composition and used to draw conclusions concerning the environment of deposition. In addition, block samples of coal cut perpendicular to bedding were studied at intermediate magnification and underfluorescence,more » thus revealing some interesting bedding features as well as well-preserved plant organisms. The coals are characteristically finely laminated and highly gelified. Palynological preparations have thus far yielded only poorly preserved palynomorph assemblages, rather low in diversity and dominated by fern spores. This fern dominance is rather unusual: however, it is compatible with the occurrence of fertile fern fronds observed in petrographic coal sections. Accompanying clastic sediments exhibit cyclic fining-upward sequences at a scale averaging about 1 m in vertical extent. Grain sizes range from small gravel to clay and silt. In some cases, siltstones in the roof of coal seams include abundant plant fragments showing parallel venation. The evidence presented from various sources suggests a rather unstable fluvial environment and a generally high water table on the flood plain for the formation of these lignites.« less
  • This paper presents a study of hydrothermal alteration on Milos Island, Greece. Examination of cores and cuttings from the two drill sites, obtained from a depth of about 1100 m in Milos geothermal field, showed that the hydrothermal minerals occurring in the rock include: K-feldspar, albite, chlorite, talc, diopside, epidote, muscovite, tremolite, kaolinite, montmorillonite, alunite, anhydrite, gypsum, calcite, and opaque minerals. The chemical composition of the minerals (104 analyses) was determined with Electron Probe Microanalysis. The composition of the hydrothermal fluid was determined and correlated with the mineralogy. Isotopic ratios of C and O for one calcite sample taken frommore » 341 m depth were determined and used for geochemical calculations. A number of reactions feasible at the P-T conditions of the geothermal field are given to establish the chemical evolution of the hydrothermal fluid. The distribution of the hydrothermal minerals indicates the dilution of the K-, Na- Cl-rich hydrothermal fluid of the deep reservoir by a Ca-, Mg-rich cold water at a shallower level.« less
  • The opening of the Ionian basin and its internal differentiation is attested to by lateral facies and thickness variations of the formations deposited during the Pliensbachian and Tithonian (synrift formations). The beginning of the synrift sequence is represented by the Siniais Limestones (Pliensbachian) and their lateral equivalent, the Louros Limestones. The geometric characteristics of the extensional basin depend on both extension related to the latest opening of the Tethys ocean and halokinesis of the Ionian zone evaporitic substratum. The accumulation of organic matter in the {open_quotes}Lower and Upper Posidonia beds{close_quotes} of the Ionian zone during the Toarcian and Tithonian ismore » directly related to the geometry of the synrift period of the Ionian basin. Restricted subbasins were formed where the geometry of the basin favored stagnation and consequently the locally euxinic conditions of bottom waters. Anoxic conditions persisted locally to the postrift period in areas where the {open_quotes}Upper Siliceous Zone{close_quotes} (Albian-Cenomanian) of the Vigla Limestones is well developed; these areas probably represent subbasins that were preserved by the continuation of halokinetic movements during the postrift period. During the early Miocene Alpine orogeny, collision-related compressive stresses on the margin induced the reactivation of preexisting fractures, which were responsible for the inversion tectonics that affected the Mesozoic basin. The geometric characteristics of the inverted basin were dependent on lithology (evaporates), geometry of the extensional structures, and direction of the compressional phase. The geological evolution in the Ionian basin is an example of inversion tectonics of a basin with an evaporitic substratum. The opening of the Ionian basin and the inversion tectonics influence both the source rocks and the probable hydrocarbon traps of the Ionian zone.« less