Publication detail

Petrological and geochemical characteristics of Palaeogene low-rank coal on the Faroe Islands: Restricted effects of alteration by basaltic lava flows

KUBOUŠKOVÁ, S. KRMÍČEK, L. COUFALÍK, P. POKORNÝ, R.

Original Title

Petrological and geochemical characteristics of Palaeogene low-rank coal on the Faroe Islands: Restricted effects of alteration by basaltic lava flows

Type

journal article in Web of Science

Language

English

Original Abstract

The first combined petrographic and geochemical investigation of coal from the Faroe Islands was performed as a case study to understand thermal effects from basaltic lavaflows on immature coal. The samples were divided into two distinct groups:“normal”coal (xylite and detroxylite) and“altered organic matter”(charcoal and organic particles dispersed in samples rich in altered clastic mineral components or enriched via hydrothermal fluids). The“normal”coal consists primarily of huminite-group material dominated by ulminite. The proportions of material from inertinite and liptinite groups vary from sample to sample. The studied macerals are anisotropic with no observed reaction rims or vacuoles. According to the mean ulminite reflectance in combination with ultimate and proximate analyses, the coal reached the lignite and subbituminous stages. The maceral compositions together with coal palynology indicate a predominance of gelified wood-derived tissues and demonstrate that the coal evolved in wet forest swamps under limno-telmatic to telmatic conditions. Alteration effects on immature coals from overlying basalt flows were relatively limited. Due to relatively rapid heat loss from the basaltic lava, as verified by the presence of volcanic glass (tachylyte), its imposed thermal effects resulted only in development of a thin“anthracite-like”crust on samples with no elevated coal rank. Associated hydrothermal fluids induced coal hydrofracturing with subsequent mineral precipitation and decomposition of the ambient feldspar-rich volcaniclastic sediments. Altered organic matter is enriched in SiO2, Al2O3 and FeOtot, as well as in trace elements such as Ni and Cr. In contrast, these samples are depleted in Hg (<10 ppb).

Keywords

Faroe Islands; coal composition; alteration; depositional environment

Authors

KUBOUŠKOVÁ, S.; KRMÍČEK, L.; COUFALÍK, P.; POKORNÝ, R.

Released

10. 8. 2016

Publisher

Elsevier

Location

Amsterdam

ISBN

0166-5162

Periodical

INTERNATIONAL JOURNAL OF COAL GEOLOGY

Year of study

165

Number

8

State

Kingdom of the Netherlands

Pages from

157

Pages to

172

Pages count

16

URL

http://www.sciencedirect.com/science/article/pii/S0166516216304517

BibTex

@article{BUT127859,
  author="Simona {Kuboušková} and Lukáš {Krmíček} and Pavel {Coufalík} and Richard {Pokorný}",
  title="Petrological and geochemical characteristics of Palaeogene low-rank coal on the Faroe Islands: Restricted effects of alteration by basaltic lava flows",
  journal="INTERNATIONAL JOURNAL OF COAL GEOLOGY",
  year="2016",
  volume="165",
  number="8",
  pages="157--172",
  doi="10.1016/j.coal.2016.08.009",
  issn="0166-5162",
  url="http://www.sciencedirect.com/science/article/pii/S0166516216304517"
}