Unravelling tectonic and climate signatures in the Quaternary of SE
Spain
Director of Research: Dr. Anne E. Mather
Second Supervisor: Professor Neil Roberts,
Advisor: Dr Martin Stokes
RATIONALE
Tectonics and climate are important environmental controls on the
behaviour of geomorphic systems, particularly in systems sensitive to
change such as those close to an internal geomorphic threshold or in a
marginal climate setting such as the semi-arid zone. Geomorphic
systems will be particularly susceptible to changes in sediment input
(calibre and discharge), water input (amount of effective runoff
determining discharge) and changes in the water to sediment ratio. All
these factors will determine whether the geomorphic system is in a
state of net aggradation or net incision. Over time scales such as the
Quaternary both climate and tectonics can drive these changes which
are typically documented by river terrace sequences in fluvial systems
and trenching and backfilling in alluvial fans. When both tectonics
and climate combine to drive a directional change other geomorphic
systems may coevally exist such as lake systems or active springs and
associated travertines. Where preserved, these landforms store data on
past climate (e.g through palaeoecology, stable isotope analysis and
sedimentology) and tectonic activity (e.g. through deformation of
sediments and geomorphic surfaces). Where the record is particularly
well exposed and complete it may be possible to ascertain the relative
significance of tectonics versus climate in the long term evolution
of the landscape.
Current research by the Director of Study and collaborators has
highlighted the development of an apparently contemporaneous lake and
extensive travertine system within the Almeria/Tabernas Basin (Harvey
& Mather, 1996; Mather et al, 1997; Harvey et al in press; Mather et
al in press). These deposits have been dated relatively, using rat
teeth stratigraphy to ca. 150 ka. Absolute dates (U/Th) are awaited
for some of the travertine sequence. The lake and travertine system is
intercalated with alluvial fan and river terraces. The terrace,
travertine and lake record appears to span most of the Quaternary. The
sequence offers exciting possibilities in unraveling 1) past climate
change (sedimentology, pollen, palaeontology); 2) tectonic activity
(terraces are locally back tilted and lake sediments display syn and
post depositional deformation) and 3) assessing rates of change (using
U/Th dates from travertine which caps former fluvial levels). This
research could thus provide 1) low altitude climate data for this area
of the western Mediterranean, which is currently lacking; 2) the
extent and timing of tectonic activity in the Tabernas Basin over the
Quaternary, consolidating the regional tectonic geomorphology and
relative stratigraphic framework currently being established for the
Almeria Province by the DOS and coworkers and 3) enhance
understanding of rates of change in aggradation and incision over
Quaternary timescales in tectonically active, semi-arid areas.
CONTEXT OF THE RESEARCH
The research will form part of a wider regional study into the
long-term landscape development of SE Spain linked with the
Universities of Liverpool, Reading (PRIS), Cambridge and Exeter
(Camborne School of Mines). The student will benefit from joining an
active Quaternary Environments research team in Plymouth Geographical
Sciences, part of which comprises current postgraduate students
working in the same region of SE Spain, on related topics.
Enquiries can be made to Dr Anne Mather (e-mail
[log in to unmask]; tel. 01752 233056)
Anne Mather
Quaternary Environments Research Group
Department of Geographical Sciences
University of Plymouth
Drake Circus
Plymouth Devon
PL4 8AA
Tel: 01752 233056
Fax: 01752 233054
Email: [log in to unmask]
http://www.science.plymouth.ac.uk/departments/geography/
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