Mixed Clastic–Carbonate Cycles and Sequences: Quaternary of Egypt and Carboniferous of England

• Main Author: Maurice E. Tucker
• Format: Article
• Language: English
• Published: Croatian Geological Survey 2003-06-01
• Series: Geologia Croatica
• Subjects: Clastic–carbonate interaction; Sequences; Cycles; Quaternary Red Sea; Egypt; Yoredale cycles; Carboniferous cycles; England
• Online Access: http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/228
• ISSN: 1330-030X; 1333-4875

<div>There are various types of mixed clastic–carbonate sequences and</div><div>parasequences in the geological record and sea-level change is one</div><div>of the major controls on their development, as well as the obvious</div><div>availability of terrigenous material. Mixed-lithology sequences are</div><div>especially well-developed in icehouse times, as in the Permo–Carboniferous and Quaternary. The two major types, lower carbonate – upper clastic and lower clastic – upper carbonate sequences, reflect the rates of sea-level change and the source of clastic sediment – whether it</div><div>is brought across the carbonate platform from the adjacent landmass</div><div>or supplied axially to the basin. Two examples of carbonate–clastic</div><div>high-frequency sequences are discussed: 1) from the Red Sea coast</div><div>of Egypt, Quaternary transgressive/highstand shallow-water carbonates</div><div>and late highstand/falling-stage/lowstand clastics deposited in</div><div>incised-valley fills and fan deltas, and 2) from northern England,</div><div>mid-Carboniferous ‘Yoredale’ cycles of transgressive shelf carbonates</div><div>passing up into highstand coarsening-up deltaic and shoreline clastics,</div><div>capped by palaeosoils and coal. Locally, falling-stage incised-valleys</div><div>supplied sediments to the adjoining basin. One significant difference</div><div>between these two examples is the palaeoclimate: arid in the Red Sea</div><div>leading to the episodic supply of sand and gravel, and humid in the</div><div>Carboniferous resulting in the more continuous supply of mud and</div><div>sand, each having a different effect on carbonate deposition.</div>