Review of Fossil Floras and Nonmarine Deposits of West Greenland

Abstract

The sedimentary area of central West Greenland comprises, besides marine sediments, a number of plant-bearing, nonmarine, and transitional-facies formations. Mainly because of insufficient field studies and conclusions based on scanty geological information, the generally accepted ideas about these formations and their floras have been affected by severe misunderstandings. However, recent geological investigations under the auspices of The Geological Survey of Greenland have provided a sounder basis for the stratigraphic interpretations and exposed a number of mistakes, e.g.: in the Lower Cretaceous Kome formation the often-cited “oldest” angiosperms are dubious, and those of the Upernivik Nses formation may be younger than assumed by Seward; the Atane flora, ordinarily cited as Cenomanian, consists of fossils from localities the beds of which are not exactly of the same age—one collection (Alianaitsunguaq) belongs to the Coniacian (marine evidence), whereas another (Pautut: Lower Pautut flora) is at the Santonian-Campanian boundary (marine evidence) and comes from exactly the same level as the Pautut flora sensu stricto. Furthermore, the Atane formation (ordinarily accepted as Cenomanian, although this has never been convincingly proven) and the Pautut formation (Senonian) may be exposures of a continuous Senonian sequence along the south coast of the Nugssuaq Peninsula. The Kingigtoq constituent of the Pautut flora is a mixture of Cretaceous and Tertiary fossils, which were collected from a landslide. Recent paleontologic and stratigraphic studies are attempts to solve the remaining problems. In Tertiary stratigraphy, such positive results as defining the age of the classic Upper Atanikerdluk floras as early Paleocene have been achieved. Study of the Cretaceous formations has been advanced, especially through the investigation of spores and pollen. These studies have been facilitated by discoveries of marine zones and new faunal localities. This paper attempts to clarify present knowledge of the formations mentioned and to correct the misinterpretations and possible mistakes that have been widely accepted. It is not intended to give a complete survey of the formations in question.