Organised by:
North West Regional Group, North Wales Geology Association
Venue:
University of Chester Department of Biological Sciences, Parkgate Campus, Binks Building, Room CBK011, Chester CH1 4AR
Event status:
EVENT CLOSED
A joint meeting of the North West Regional Group and the North Wales Geology Association.
The Fossil Forest at Brymbo is of national and
international importance because of its unique
assemblage of plant fossils. About 14 m of Coal
Measures of middle Duckmantian age are exposed at
Brymbo including two coal seams; the Crank and 2-
Yard Coals. There are laminated mudstones crowded
by fragments of pteridosperms, ferns, Calamites and
lycophytes. A thin layer of ironstone nodules has
yielded a similar range of plant remains. Preservation
of the two are different but both contain stems that
have yielded cuticles and reproductive organs that
yielded spores. Careful recording of the plant fossils
has shown different assemblages to be recognised
from the various strata enabling tentative ecological
interpretations to be made.
About 20 erect arborescent lycophyte stems have been
found at several horizons. Some are rooted in a coal
parting where there are no recognizable Stigmaria
bases. The stem casts are formed either in sandstone
or less durable mudstone. One Stigmaria is complete
spreading over nearly 5 metres and has a 1.7 m tall
trunk.
Such well-preserved Stigmaria are uncommon. There
are also large numbers of erect Calamites stems still in
their original growth positions. The precipitation of an
iron-bearing oxide mineral within the pith cavity of the
partially buried stems formed a rigid layer allowing
sediments to fill it. Kernel density map and nearest
neighbour analysis of clusters of cross sections of
Calamites suggests that each small patch of these pith
casts represents an individual plant spread by
rhizomatous growth.
About the Speaker: Professor Barry Thomas (Aberystwyth University)
Professor Thomas is an honorary professor within the
Institute of Biological, Environmental & Rural Sciences
(IBERS) at Aberystwyth University. His main area of
research is in Carboniferous palaeobotany especially the
taxonomy, geographic and stratigraphic distribution
and ecology of the lycophytes and calamites. His other
research interests are geoconservation and living sporebearing
plants.
CPD
These events may be considered for contributing to
a recognised Continuing Professional Development
(CPD) scheme as part of personal development. Delegates
should check their individual scheme requirements.
Time
Lecture start promptly at 7:00pm with teas and coffees available at 6:30pm in room opposite.