Notes: On to the petrography - point counts keeping track of 20 different grain types were done on 68 Cretaceous and 3 overlying Tertiary samples. This is a Qm,F,L plot of all the Cretaceous samples by Formation. Evident here is the clear change from a quartz arenite composition for the Rurikfjellet and Helvetiafjellet Formations to a sublitharenite and subarkose for the Carolinefjellet Formation. The feldspar is mainly plagioclase and reflects a volcanic source. Outliers from the Helvetiafjellet come from the marine incursions, suggesting that a volcanic source was not initially immediately to the north, but to the northeast and introduced by long shore drift.. The feldspar and lithics are attributed to Barremian HALIP volcanism and associated uplift. Interestingly, the increase of basement lithics precedes a bit the appearance of any volcanic debris.

Next slide. Return to index.