[en] This paper describes a rare occurrence of a rich and diverse palynological assemblage from a controversial stratigraphic unit in well EW8 in northwestern Saudi Arabia. The composition of this assemblage strongly suggests a Pridoli age and therefore it is referred here to the Tawil Formation. The assemblage encountered contains very characteristic chitinozoans, acritarchs, tasmanities, scolecodontsm, eurypterid cuticle and common land-derived miospores and hilate cryptospores. Chitinozoans such as Margachitina elegans, Ancyrochitina fragilis brevis, Ancyrochitina fragilis, Sphaerochitina sphaerocephala, Urnochitina urna, Pseudochlathrochitina carmenchui and Lagenochitina brevicollis confer the Pridoli age assignment. This assemblage of chitinozoans correlates very well with Assemblage D from the Alternances Gréso-Argileuses Formation of the A1-61 well in northwestern Libya. Among the acritarchs present are: Cymbosphaeridium pilar, Leoniella carminae,Diexallophasis spp., Tunisphaeridium cf caudatum, Leiofusa estrecha and Eupoikilofusa striatifera.
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<br />Furthermore, the join occurrence of U. urna, P. carmenchui and M. elegans is clearly indicative of the middle part of the Pridoli as in the Libyan well A1-61, and in many wells in Algeria. This corresponds to what is considered to be a transgressive mid Pridoli event in the Algerian Sahara, with non marine intervals bracketing this brief marine sea level rise. This event is likely to have extended into all of north Gondwana including Arabia.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Al-Hajri, S.
Verniers, J.
Paris, F.
Al-Ruwaili, M.
Steemans, Philippe ; Université de Liège - ULiège > Département de géologie > Paléobiogéologie - Paléobotanique - Paléopalynologie (PPP)
Le Hérissé, A.
Language :
English
Title :
A distinctive marginal marine palynological assemblage from the Pridoli of Northwestern Saudi Arabia