Type section of the Bravaisberget Formation (Middle Triassic) at Bravaisberget, western Nathorst Land
Abstract: The Bravaisberget Formation in Spitsbergen embraces an organic carbon−rich, clastic sequence that reflects a general shallow shelf development of the Middle Triassic depositional system in Svalbard. New observations and measurements of the type section of the formation at Bravaisberget in...
| Main Authors: | , , , , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.549.2394 http://www.polish.polar.pan.pl/ppr28/PPR28-079.pdf |
| Summary: | Abstract: The Bravaisberget Formation in Spitsbergen embraces an organic carbon−rich, clastic sequence that reflects a general shallow shelf development of the Middle Triassic depositional system in Svalbard. New observations and measurements of the type section of the formation at Bravaisberget in western Nathorst Land allow to present detailed litho− stratigraphical subdivision of the formation, and aid to reconstruct its depositional history. The subdivision of the formation (209 m thick at type section) into the Passhatten, Somovbreen, and Van Keulenfjorden members is sustained after Mørk et al. (1999), though with new position of the boundary between the Passhatten and Somovbreen mbs. The Passhatten Mb is defined to embrace the black shale−dominated sequence that forms the lower and middle parts of the formation (160 m thick). The Somovbreen Mb (20 m thick) is confined to the overlying, calcite−cemented sequence of marine sandstones. The Van Keulenfjorden Mb (29 m thick) forms the topmost part of the formation composed of sili− ceous and dolomitic sandstones. The formation is subdivided into twelve informal units, out of which eight is defined in the Passhatten Mb (units 1 to 8), two in the Somovbreen Mb (units 9 and 10), and also two in the Van Keulenfjorden Mb (units 11 and 12). Units 1, 3, 5, 7 |
|---|