Broken Beds, but better science; using multiple hypotheses to interpret geological data

• Published in: Terra nova (Oxford, England) Vol. 35; no. 1; pp. 73 - 82
• Main Authors: Gallois, Arnaud, Burgess, Peter, Bosence, Dan, Hollis, Cathy
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01-02-2023
• Subjects: Cretaceous; Data collection; Diagenesis; Evaporites; Geological data; Hypotheses; Jurassic; Limestone; Outcrops; Sedimentology
• ISSN: 0954-4879; 1365-3121
• DOI: 10.1111/ter.12631

In this study, we propose a multiple hypotheses approach to improve interpretations of limited remotely sensed datasets, such as sparsely exposed outcrops, subsurface datasets, or planetary objects using semi‐quantitative scoring and ranking of observable features. This method is demonstrated using an outcrop example from the Broken Beds of the Upper Jurassic–Lower Cretaceous Purbeck Limestone Group exposed along Britain's Jurassic Coast. Four published hypotheses regarding their origin are refined, represented in matrix form, scored and ranked based on carefully selected outcrop features. Semi‐quantitative scoring utilises knowledge of likely processes governing the occurrence of a range of features, some of which might be ignored or down‐played to favour a single hypothesis. Furthermore, by integrating expertise from different sub‐disciplines (e.g. basin analysis, sedimentology, diagenesis), we also consider the combined evidence of multiple features. This new method results in an interpretation that favours a multi‐process origin for the Broken Beds due to evaporite dissolution, overpressure release and tectonic folding, with identified uncertainty, all useful to guide further data collection.