The fingerprint of environmental change in the fluvial-aeolian sedimentary record

Desert aeolian sedimentary systems are sensitive to changes in a wide range of environmental variables, including climate, sea level, sediment supply and tectonic factors. As such, the preserved sedimentary deposits of desert dune fields record a fingerprint of past environmental change. This research project will use a combined field-based, remote-sensing and modelling approach to characterise a variety of different types of aeolian sedimentary system, and will develop a suite models that will enable regional palaeoenvironmental reconstruction for desert systems that evolved during several different periods in earth history and in different geographic settings in response to dramatically changing environmental conditions.

Developed models will be used as predictors of the sediment system response to future environmental change, especially desertification arising from on-going climate change.

The aim of this research project is to develop a model to account for the response of preserved desert aeolian sedimentary systems to global drivers of environmental change, including climate, sea level, sediment supply and tectonics. Work will involve field-based data collection from world-class outcrops in the SW United States, analysis of remotely sensed data of modern systems, and lab-based modelling of sedimentary system evolution.

Specific research objectives of this research are: (i) to collect field-derived and remotely sensed data sets describing a range of sedimentary styles from both modern and ancient examples of major aeolian systems for which external controls can be shown to have played a key role in determining the preserved system state; (ii) to demonstrate evidence to show that primary allogenic and autogenic controls on preserved aeolian sedimentary systems are interdependent and interrelated via a series of complex feedback mechanisms; (iii) to develop a novel and innovative "next-generation" sequence stratigraphic model with which to explain how a range of interlinked environmental factors act to govern the nature of the preserved aeolian sedimentary record; (iv) to apply the model to account for the sedimentology of a range of aeolian successions.

The project will involve three principal research methods: (i) field-based data collection from a well-exposed aeolian study succession located in the SW United States, involving sedimentary lithofacies analysis to reconstruct aeolian dune type and the nature of autogenic bed-form behaviour (e.g. migration style), architectural-element analysis to reconstruct how the aeolian dunes accumulated and became preserved, and sequence stratigraphic analysis to determine how the aeolian succession is divided into separate sequences, each representing a distinct phase of dune-field accumulation under a specific set of palaeoenvironmental conditions; (ii) establishment of a database to account for the global distribution of preserved aeolian desert successions through geologic time. This aspect of the project will relate different types of aeolian succession to a range of global environmental controls that are known to have operated at certain times in Earth history; (iii) the application of forward numerical modelling software (already developed by FRG-ERG at Leeds) to show how different configurations of environmental controls can give rise to aeolian dune-field successions with predictable sedimentary features.