Silicified plant megafossils from the upper Turonian of Vienne, western France. (29th November 2018)

• Record Type: Journal Article
• Authors: Gomez, Bernard; Daviero-Gomez, Véronique; Garcia, Géraldine; Caner, Laurent; Boura, Anaïs; Barral, Abel; Cantinolle, Patrice; Valentin, Xavier
• Is Part Of: Earth and environmental science transactions of the Royal Society of Edinburgh. Volume 108:Number 4(2018)
• Page Start: 449
• Page End: 457
• Publication Date: 2018-11-29
• Subjects: early silification, -- Geinitzia reichenbachii, -- 'Lomatopteris' superstes, -- silex, -- upper Cretaceous; Earth sciences -- Periodicals; Earth sciences -- Scotland -- Periodicals; 550.5
• DOI: 10.1017/S1755691018000105
• Languages: English
• ISSNs: 1755-6910

Abstract

ABSTRACT: A new locality with silicified permineralised plant megafossils is reported from the upper Turonian of Colombiers, Vienne, western France. The plant fossil assemblage consists of Geinitzia reichenbachii (Geinitz) Hollick et Jeffrey and ' Lomatopteris ' superstes Saporta. Whilst G. reichenbachii is a worldwide widespread Cretaceous conifer, ' L. ' superstes is reported in western France for the first time. The latter fossil shows bipinnately compound leaf, marginal teeth, one thick primary vein, pinnate secondary veins and faint, reticulate, narrower veins. Besides its fern-like gross morphology, these characters indicate that it most likely belongs to angiosperms and eudicots. The formation of silicified nodules bearing such fossils from the Cenomanian to the Coniacian of western France was previously attributed to the secondary silicification of limestones during Cenozoic climatic weathering episodes. However, based on both petrography and preservation evidence, we demonstrate that it was an endogenic process contemporaneous to the earliest stages of fossil diagenesis created by palaeoenvironmental and climatic conditions.