Upper Carboniferous–Lower Permian Palaeoaplysina build-ups on Svalbard: the influence of climate, salinity and sea-level

Abstract

Upper Carboniferous–Lower Permian Palaeoaplysina build-ups on Svalbard developed on a partly restricted marine warm-water carbonate platform at low palaeo-latitudes. The Palaeoaplysina build-ups mostly have a flat-topped tabular geometry, representing the mature stage of build-up growth. With decreasing accommodation space, continued vertical growth was hampered and lateral growth became dominant. The tabular growth form of the build-ups is probably a result of lateral amalgamation of several minor mounds. In central Spitsbergen many of the tabular build-ups form parts of continuous ridges or ring-shaped to polygonal build-up complexes encircling a lagoon. Lateral interfingering between bedded fusulinid dolostones along the build-up margins and barren dolostones further out in the lagoon may indicate increasing salinity from the lagoon margin to the central part. These lateral facies changes are often associated with evaporites (gypsum) and low biodiversity, especially abundant euryhaline fusulinids or even barren beds. On the sea side of the Palaeoaplysina build-ups, the frequent renewal of normal saline seawater allowed the highest biodiversity (e.g. stenohaline crinoids). The uppermost part of some build-ups contain Microcodium, indicating intermittent subaerial exposure and vegetation cover during lowstand, probably caused by eustatic sea-level changes and/or local tectonics. The biota of the build-ups and their lateral sediments is typical for a shallow marine chloroforam association, indicating a tropical climate during deposition.

Depositional evolution of the Upper Carboniferous – Lower Permian Wordiekammen carbonate platform, Nordfjorden High, central Spitsbergen, Arctic Norway

“…The Paleoaplysina floatstones and bindstones have been interpreted as similar to the Palaeoaplysinid Boundstone Facies recognised by Hüneke et al (2001) and the Palaeoaplysina mound facies of Blomeier et al (2008), while the floatstones and the bindstones resemble the Paleoaplysina wackestones and Paleoaplysina boundstones described by (Hanken & Nielsen, 2013).…”

Morphometric patterns in Modern carbonate platforms can be applied to the ancient rock record: Similarities between Modern Alacranes Reef and Upper Palaeozoic platforms of the Barents Sea

“…5 matrix between the plates which has been interpreted by Hanken and Nielsen (2013) to be an early marine, possibly autochthonous, cement. This interpretation is consistent with theories that microbial carbonate production was crucial for the stabilization of Phanerozoic reefs and mounds (e.g.…”

“…Outcrop studies report the uppermost part of some Palaeoaplysina buildups contain Microcodium, root calcification products of terrestrial plants, indicating intermittent subaerial exposure and vegetation cover during lowstand, probably caused by eustatic sea-level changes (which were on the order of 50 m amplitude) and/or local tectonics (Hanken and Nielsen, 2013). It appears that the Palaeoaplysinaencircled lagoons, characterised by a fine-grained bedded dolostone, became cut off from normal seawater outside the buildups during the low stands and in dry climates, evaporation caused hypersalinity.…”

Warm water benthic foraminifera document the Pennsylvanian–Permian warming and cooling events — The record from the Western Pangea tropical shelves

“…Copyright restrictions may apply. doi: 10.1016/ j.palaeo.2014 4 Finally, the third phenomena and paradox is the common occurrence of faunas characteristic of temperate climate including foraminifera, brachiopods, pelecypods and other fossils like Palaeoaplysina (Mamet, 1977;Clapham, 2010;Wahlman and Konovalova, 2002;Weldon andShi, 2003 Perez-Huerta, 2007;Hanken and Nielsen, 2013, ) in North American at tropical paleolatitude.…”