|Graphic correlation of Frasnian sections (Upper Devonian) in the Ardennes, Belgium|
Gouwy, S.; Bultynck, P. (2000). Graphic correlation of Frasnian sections (Upper Devonian) in the Ardennes, Belgium. Bull. Kon. Belg. Inst. Natuurwet. Aardwet. = Bull. - Inst. r. sci. nat. Belg., Sci. Terre 70: 25-52
In: Bulletin van het Koninklijk Belgisch Instituut voor Natuurwetenschappen. Aardwetenschappen = Bulletin de l'Institut Royal des Sciences Naturelles de Belgique. Sciences de la Terre. KBIN: Brussel. ISSN 0374-6291, more
Frasnian, Ardennes, graphic correlation, T-R-cycles, conodonts
A high-resolution correlation of 10 Frasnian sections in the Belgian Ardennes is made using the graphic correlation method. The measured ranges of 85 conodont taxa, 48 coral taxa. 29 brachiopod taxa and one stromatoporoid taxon have been assembled into a chronostratigraphic framework. The Ardennes Frasnian Regional Composite developed in this study provides a higher stratigraphic resolution than the traditionally used conodont zonation. It allows a subdivision of the Frasnian into 532 composite standard units derived from the standard reference section in the southern part of the Dinant Synclinorium, completed with a section in the Philippeville Massif for the uppermost part of the Frasnian that is not exposed in the southern part of the Dinant Synclinorium, units 332-532. By correlating the sections using time-equivalent lines, the diachronous pattern of the deposits becomes clearly visible. The combination of this pattern and the conodont biofacies changes in the sections were used to recognise four major third order (500.000y-5m.y.) transgression-regression cycles. The first one, starting in the latest Givetian (Early falsiovalis Zone), continues through the transitans Zone and ends in the lower part of the punctata Zone. The second and third T-R cycles cover the punctata and hassi sl Zones, the jamieae Zone and the major part of the Early rhenana Zone. The fourth cycle (superimposed by a few minor cycles) starts in the early rhenana Zone and continues till the triangularis Zone. The first, second and fourth cycles are considered eustatic. Through graphic correlation of the Composite Standard (CS) of the Frasnian (KLAPPER, 1997) with the regional composite of the Ardennes, new data are added to the CS of the Frasnian and some already incorporated ranges are extended.