| Studia Geologica Polonica |  |
Vol. 133 (2010) 
Geological Results of the Polish Spitsbergen Expeditions
Edited by K. Birkenmajer
Part XVII
Krzysztof Birkenmajer
The Kapp Lyell diamictites (Upper Proterozoic) at Bellsund, Spitsbergen: rock-sequence, sedimentological features, palaeoenvironment
Studia Geologica Polonica, 133: 7-50 | PDF - Full-text Article
Abstract
Krzysztof Birkenmajer
Institute of Geological Sciences, Cracow Research Centre, Polish Academy of Sciences, ul. Senacka 1, 31-002 Kraków, Poland; ndbirken@cyf‑kr.edu.pl
The Upper Proterozoic meta-diamictites (Kapp Lyell Formation) exposed south of Bellsund, central Spitsbergen, believed by many authors to represent the Vendian (Varangian) glacial tillites, have been investigated. Character of their relictic sedimentary features does not confirm, however, its glacial origin. The diamictites formed mainly as debris-flow and slope-creep terrestrial covers derived from frost-shattered steep rocky margins of a predominantly fresh-water depositional basin. The deposition took place under seasonally differentiated moderate-cool climatic conditions comparable to the modern Subarctic periglacial zone, however outside the reach of glaciers and ice-sheet. Uncommon finer-grade varved deposits containing haphazardly distributed clasts (drop- stones) probably formed in shallow fresh-water lakes that froze during winter; the clasts were subsequently dispersed during summer in the lakes as ice-rafted dropstones. Shallow erosional channels infilled with sandstone within the diamictite complex, might be evidences for braided river systems that were active during summer. Rare, well-rounded cannonball-size cobble/boulder beds represent a fossil high-energy, probably marine beach.Uncommon thin limestone intercalations, found in a predominantly coarse-clastic suite, might suggest occasional incursions of a shallow sea.
Key words: Spitsbergen, Upper Proterozoic, diamictite, periglacial sedimentary environment
Institute of Geological Sciences, Cracow Research Centre, Polish Academy of Sciences, ul. Senacka 1, 31-002 Kraków, Poland; ndbirken@cyf‑kr.edu.pl
The Upper Proterozoic meta-diamictites (Kapp Lyell Formation) exposed south of Bellsund, central Spitsbergen, believed by many authors to represent the Vendian (Varangian) glacial tillites, have been investigated. Character of their relictic sedimentary features does not confirm, however, its glacial origin. The diamictites formed mainly as debris-flow and slope-creep terrestrial covers derived from frost-shattered steep rocky margins of a predominantly fresh-water depositional basin. The deposition took place under seasonally differentiated moderate-cool climatic conditions comparable to the modern Subarctic periglacial zone, however outside the reach of glaciers and ice-sheet. Uncommon finer-grade varved deposits containing haphazardly distributed clasts (drop- stones) probably formed in shallow fresh-water lakes that froze during winter; the clasts were subsequently dispersed during summer in the lakes as ice-rafted dropstones. Shallow erosional channels infilled with sandstone within the diamictite complex, might be evidences for braided river systems that were active during summer. Rare, well-rounded cannonball-size cobble/boulder beds represent a fossil high-energy, probably marine beach.Uncommon thin limestone intercalations, found in a predominantly coarse-clastic suite, might suggest occasional incursions of a shallow sea.
Key words: Spitsbergen, Upper Proterozoic, diamictite, periglacial sedimentary environment
Krzysztof Birkenmajer & Dariusz Gmur
Coals of the Calypsostranda Group (Palaeogene) at Bellsund, Spitsbergen
Studia Geologica Polonica, 133: 51-63 | PDF - Full-text Article
Abstract
Krzysztof Birkenmajer & Dariusz Gmur
Institute of Geological Sciences, Cracow Research Centre, Polish Academy of Sciences, ul. Senacka 1, 31-002 Kraków, Poland; ndbirken@cyf‑kr.edu.pl, ndgmur@cyf‑kr.edu.pl
Numerous thin coal seams occur in terrestrial deposits of the Skilvika Formation, Calypsostranda Group (Late Palaeogene), at Bellsund, central Spitsbergen. According to coal-petrographic study, they mainly belong to the vitrinite-fusinite facies. At Calypsostranda (Tyvjobekken), Calypsobyen (abandoned coalmine) and Skilvika (coastal main section), they are represented mainly by telocollinite subfacies which developed in a wet forest swamp at high groundwater level condition (the "shale with coal streaks" subfacies) close to a delta distributary or main river channels. At Rensdyrbekken (NW Calypsostranda), an increased share of herbaceous swamp facies was recognized in coal formation: a sapropelic coal facies was generated there under condition of inner parts of interchannel lakes.
Key words: Spitsbergen, Bellsund, Palaeogene, coals, petrography, origin
Institute of Geological Sciences, Cracow Research Centre, Polish Academy of Sciences, ul. Senacka 1, 31-002 Kraków, Poland; ndbirken@cyf‑kr.edu.pl, ndgmur@cyf‑kr.edu.pl
Numerous thin coal seams occur in terrestrial deposits of the Skilvika Formation, Calypsostranda Group (Late Palaeogene), at Bellsund, central Spitsbergen. According to coal-petrographic study, they mainly belong to the vitrinite-fusinite facies. At Calypsostranda (Tyvjobekken), Calypsobyen (abandoned coalmine) and Skilvika (coastal main section), they are represented mainly by telocollinite subfacies which developed in a wet forest swamp at high groundwater level condition (the "shale with coal streaks" subfacies) close to a delta distributary or main river channels. At Rensdyrbekken (NW Calypsostranda), an increased share of herbaceous swamp facies was recognized in coal formation: a sapropelic coal facies was generated there under condition of inner parts of interchannel lakes.
Key words: Spitsbergen, Bellsund, Palaeogene, coals, petrography, origin