Results 171 to 180 of about 2,731 (208)
Some of the next articles are maybe not open access.
A Possible Bacterial Origin for Famennian Micrites
1977Since Drew (1911), the role of bacterias for preCipitation of calciwn carbonates (marine) has been recognized. Their biochemical effects on orgaDic sludge have been tentatively demonstrated by Trichet (1967–1972) and other workers. It should be stressed that blue-green algae playa passive role, as providers of organic substrate.
A. F. Maurin, D. Noël
openaire +1 more source
Frasnian-Famennian extinctions
1982Extinctions are continuous throughout the Phanerozoic. Although a single natural phenomenon brought about by environmental change at any scale, they may be conveniently divided into two classes: background extinction and mass extinction (Raup and Sepkoski, 1982).
openaire +1 more source
Famennian Reefs in Alberta, Canada: ABSTRACT
AAPG Bulletin, 1964The lowermost 200 feet of the Wabamun group of Famennian age may sporadically display an unusually abundant fauna in the subsurface of Alberta northeast of the then slowly submerging Poaco River landmass. This fauna, composed of stromatoporoids, coralline algae and various rod- and tube-shape bioclastic fragments in a sparry cement, is completely ...
openaire +1 more source
Carbon isotope geochemistry of the Frasnian–Famennian transition
Palaeogeography, Palaeoclimatology, Palaeoecology, 2002Abstract Carbon isotope records for inorganic and total organic carbon (TOC) as well as for individual organic biomarkers show two positive excursions in the Late Frasnian with comparable shape and amplitude in δ13C. The positive shifts in δ13C can be correlated with the deposition of the Kellwasser horizons.
Joachimski, MM +4 more
openaire +2 more sources
Famennian Stage of the Upper Devonian of Nakhichevan AR
2023Brachiopods are a widespread and rapidly evolving group of organisms that are extremely important for the development of the biostratigraphy of Devonian deposits. Devon was their heyday. Their special significance for the stratigraphy of Devonian deposits is also determined by the fact that the first subdivision of the Devonian in the type sections of ...
openaire +1 more source
Famennian crinoids and blastoids (Echinodermata) from Mongolia
Palaeobiodiversity and Palaeoenvironments, 2020Herein we report on the most abundant and diverse fauna of Palaeozoic crinoids and blastoids collected from Mongolia to date. The fauna is from the Late Devonian (Famennian) Samnuuruul Formation in western Mongolia. The fauna consists of two genera of blastoids and twelve genera of crinoids—four genera of camerates, three genera of flexibles, one ...
J. A. Waters +4 more
openaire +1 more source
The global Frasnian-Famennian »Kellwasser Event«
Geologische Rundschau, 1991During the UppermostP. gigas conodont zone (P. linguiformis zone) the stepwise Frasnian extinction culminates in the global transgressive-regressive Frasnian-Famennian »Kellwasser event«. Most pelagic organisms of the tropical marine environment are more or less affected by this mass extinction.
openaire +1 more source
Effect of the Frasnian-Famennian extinction event on the stromatoporoids
Geology, 1987Although Paleozoic stromatoporoids were drastically reduced in abundance and diversity by the Frasnian-Famennian (F/F) mass extinction event, at least 20 genera (mostly labechiids and clathrodictyids) are known from latest Devonian rocks. Some typical Frasnian genera survived the F/F crisis to die out in early Famennian time, and others took part in ...
openaire +1 more source
Biostratigraphy of Famennian in Hainan Island, South China
Science in China Series D: Earth Sciences, 2001On the basis of the faunas including conodonts Palmatolepis gracilis sigmoidalis, P. gracilis gracilis, Polygnathus germanus, which are found for the first time, and corals Cystophrentis kalaohoensis it is confirmed that the Changjiang Formation refers to the Famennian, and may correlate with the Shaodong Formation and Menggongao Formation of central ...
Renjie Zhang +3 more
openaire +1 more source
A new phyllocarid crustacean from the Famennian of Belgium
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2009A single carapace of an echinocaridid phyllocarid found in the uppermost part of the Evieux Formation at Arbre near Namur of late (latest ?) Famennian age lacks both the posterocentral and posterodorsal ridges, both characters considered to be derived ones. This makes it a member of the E. punctata group.
Racheboeuf, Patrick R., Clement, G.
openaire +2 more sources