Lateral variability of ichnofabrics in marine cores : Improving sedimentary basin analysis using Computed Tomography images and high-resolution digital treatment. / Rodríguez-Tovar, Francisco J.; Dorador, Javier; Mena, Anxo; Hernández-Molina, F. Javier.

In: Marine Geology, Vol. 397, 01.03.2018, p. 72-78.

Research output: Contribution to journalArticlepeer-review

Published

Abstract

Major ichnofabric attributes may be related to a number of limiting marine parameters for tracemakers with paleoenvironmental significance, including ocean/atmosphere dynamics. This is why ichnofabric analysis has proven to be a very useful tool in sedimentary basin analysis — as well as in other Earth Science disciplines — although it is a comparatively recent approach in ichnological research. Ichnofabric characterization is usually based on 2D visual observations of a single view in both outcrops and cores. Yet ichnofabric features can vary vertically and laterally within a very short-distance, which may lead to misinterpretations. Here, a new methodological approach is presented, allowing for a more objective evaluation of ichnofabric features, based on the high-resolution digital treatment of Computed Tomography images on marine sediments cores. The method evaluates variations in ichnoassemblages, cross-cutting relationships, and the degree of bioturbation structures in nearby selected images pertaining to several sections of the same interval of a core. Average values of the obtained data imply a significant improvement of the resolution than 2D observations, and therefore a more precise and objective characterization of ichnofabrics. The usefulness of the method and its differences with respect to traditional ichnofabric analysis are exemplified by a study of the gravity core FSG09-10 (Galicia Bank domain, NW Iberian Peninsula), showing as a very significant tool to interpret paleoenvironmental changes (i.e., sedimentation rate, nutrient availability, and bottom water oxygenation) from the Last Glacial Maximum (LGM) to Heinrich Event 1 (HE1). This example reveals the importance of proposed methods in order to characterize the ichnofabrics, including their lateral variability, with clear implications for future research on basin analysis.

Original languageEnglish
Pages (from-to)72-78
Number of pages7
JournalMarine Geology
Volume397
Early online date24 Dec 2017
DOIs
Publication statusPublished - 1 Mar 2018
This open access research output is licenced under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

ID: 29561113