Middle jurassic-lower cretaceous transgressive-regressive sequences and facies distribution off northern nordland and troms, Norway

摘要: Application of sequence stratigraphic principles, detailed facies analyses, mineralogy, organic geochemistry and high-resolution biostratigraphic correlations to continuously cored units from the Middle Jurassic-Lower Cretaceous succession Troms III Nordland VII areas provide new information on sedimentary history offshore northern Norway. Two lithostratigraphical units, Masnykan Formation Rauate Member, are formally described. In area, lowermost boundary late Bajocian-early Bathonian age occurs in upper part Sto Formation, while at Andoya area it top weathered basement. The Oxfordian is dominated by transgressive systems tracts formed proximal sandstones (new unit area) Ramsa (Andoya) formations which distally grade into Fuglen area. Hekkingen all above boundary. siltstones Member (new) represent most deposits Formation. Basinward grades very organic-rich claystone Alge Member. We explain deposition a modified "expanding puddle" model. Overlying thick (Volgian-Berriasian), highstand tract forms dark claystones Krill areas. Sediments reflecting tectonic activity earliest overlain regional early Valanginian that marks clear shift regime. Slow sedimentation rate high bioclastic input resulted condensed marly shallow shelf (Klippfisk Nybrua formations). Hauterivian-earliest Barremian followed renewed marine (Kolje Formation). change depositional regime across associated with mineralogy changes claystones, suggest increased influence erosion feldspar-rich rocks towards end this period.