A revised stratigraphy for the Palaeocene Agatdalen flora (Nuussuaq Peninsula, western Greenland): correlating fossiliferous outcrops, macrofossils, and palynological samples from phosphoritic nodules

Abstract

ABSTRACT. The Cretaceous and Palaeogene floras of western Greenland that were initially described as part of the classical work "Flora fossilis arctica" by Oswald Heer in the 19 th century are currently under revision. The Nuussuaq Basin has repeatedly been investigated by geologists and marine invertebrate palaeontologists. These studies provide a modern stratigraphic framework and a basis for revisions of various Cretaceous to Eocene floras from this region, and the correlation of fossil material to stratigraphic units and formal formations. This paper is the first in a series of papers that (i) correlate macrofossil (museum) material and fossil-rich localities with the modern lithostratigraphic framework, (ii) describe new pollen, spores, and other marine/freshwater palynomorphs, and (iii) revise the macrofossil remains from the Agatdalen area (particularly the Danian Agatdal Formation). Since the work of B. Eske Koch in the 1960s and 70s, questions emerged about the correlation of plant fossiliferous outcrops and whether the so-called Agatdalen flora, referred to the Agatdal Formation, originates from a single sedimentary unit or not. In this paper, we summarise the stratigraphy of the Agatdalen area and correlate the fossil plant-bearing outcrops described by Koch to the current lithostratigraphy. We establish which plant fossils belong to the Agatdal Formation and re-assign a great number of other plant fossils to their correct formations. New palynological material is briefly described and correlated to the macrofossil localities and the Agatdal Formation. Previous accounts on the macrofossils (leaves, fruits, seeds) are briefly discussed and directions for future revisions are outlined.

Combined LM and SEM study of the middle Miocene (Sarmatian) palynoflora from the Lavanttal Basin, Austria: Part V. Magnoliophyta 3 – Myrtales to Ericales

“…How, if and when Arceuthobium migrated across the North Atlantic land bridge is uncertain. Palynological data place the genus at the gate of the corridor during the late Eocene (UK record, unpublished data, F. Grímsson), but studies on Palaeogene floras of Greenland hold no such records (Grímsson et al 2014(Grímsson et al , 2015b2016b, 2016c, 2018a. Also, the Miocene floras of Iceland, both macrofloras and microfloras, have been studied in detail and yield no records of Arceuthobium, but Viscum is present (e.g.…”

A Winteraceae pollen tetrad from the early Paleocene of western Greenland, and the fossil record of Winteraceae in Laurasia and Gondwana

“…Type locality. Turritellakløft (‘Big section’) locality, Agatdalen valley, situated in the central part of the Nuussuaq Peninsula, western Greenland (see Grímsson, Pedersen, et al., ).…”

“…The palaeoflora of the Agatdal Formation suggests a fully humid warm temperate climate ( Cfa ) and indicates diverse, mixed deciduous–evergreen forests as today found in subtropical, perhumid or monsoonal regions. Palaeofloristic elements include representatives of Adoxaceae, Altingiaceae, Amaranthaceae, Araceae, Araliaceae, Betulaceae, Cannabaceae, Cercidiphyllaceae, Chloranthaceae, Clethraceae, Cornaceae, Cupressaceae, Cycadaceae, Daphniphyllaceae, Ericaceae, Fabaceae, Fagaceae, Gingkoaceae, Hamamelidaceae, Icacinaceae, Juglandaceae, Liliaceae, Magnoliaceae, Menispermaceae, Myricaceae, Oleaceae, Platanaceae, Pinaceae, Ranunculaceae, Rhamnaceae, Rosaceae, Rutaceae, Salicaceae, Sapindaceae, Schisandraceae, Trochodendraceae and Vitaceae (Grímsson, Grimm, Zetter, & Denk, ; Grímsson, Pedersen, et al., ; Manchester et al., ). Judging from this mix of taxa, forest biomes in Paleocene Greenland may have been analogous to those now occupied by Tasmannia and Pseudowintera in Australasia.…”

“…For a comprehensive geological, stratigraphic and preliminary palaeobotanical backgrounds as well as information on the localities of this formation see Grímsson, Pedersen, et al. ().…”

“…Paleogene (66–23 Ma) sedimentary formations in Greenland have yielded numerous fossils of angiosperm lineages that today are restricted to low latitudes or the Southern Hemisphere. Examples include Aponogetonaceae (Grímsson, Zetter, Halbritter, & Grimm, ), today in tropical Africa, Madagascar and Southeast Asia; Araliaceae (Manchester, Grímsson, & Zetter, ), today tropical with but few species in the temperate zone; Clethraceae (Grímsson, Pedersen, Grimm, & Zetter, ), today on tropical mountains; as well as the now tropical Icacinaceae ( Platea ; Manchester et al., ); Psittacanthinae, today South and Central American Loranthaceae clade (Grímsson, Grimm, & Zetter, ); Rutaceae (Grímsson, Pedersen, et al., ); Sloanea (Elaeocarpaceae; Manchester, ), and others. Ideally, information from such fossils, namely ‘when’ and ‘where’, would be included in biogeographic reconstructions of the respective clades.…”