| At first sight, Bingham
appears to offer nothing of interest to the geologist. There
are no spectacular rocky crags or mountainous peaks and fossils
are hard to find. However, despite being hidden from view,
Bingham's rocks document a fascinating record of life and
landscapes extending back hundreds of millions of years into
geological time.
The sedimentary rocks below Bingham consist
of particles of clay, sand or lime that were first deposited
in layers and then - over millions of years of geological
time - compressed and cemented together to form rock. The
composition, layering and fossil content of sedimentary rocks
enable geologists to reconstruct ancient environments with
amazing accuracy and detail. They also help us to predict
where valuable resources of coal, oil and gas can be found.
IPR/24-3C Fossilized
salt crystals preserved on this 250 million year-old slab
of siltstone from the Bingham area indicate that this rock
was originally deposited on mudflats next to a salt lake.
Geological
Map
The rocks beneath Bingham
Why Bingham is where it is |
Since the early 1960s, numerous boreholes
have been sunk near Bingham to explore for oil, gas and coal
resources several hundred metres below the surface. As these
boreholes penetrated deeper into the ground, they encountered
progressively older layers of sedimentary rocks. Samples from
each of these layers have enabled geologists to piece together
a history of events stretching back over 300 million years
before the present day, long before the time of the dinosaurs.
The rocks immediately below the soil
in Bingham are around 220 million years old, deposited in
the Triassic geological period. The present landscape, however,
has been shaped in the past few tens of thousands of years
during the Ice Age. What happened during this enormous time
gap? Younger Jurassic and Cretaceous rocks were formerly deposited
on top of these Triassic rocks, but have been removed by steady
erosion over the past few million years. These younger rocks,
including the Lincolnshire Limestone and the Chalk, are still
preserved in Lincolnshire. The effect of the Ice Age in the
last 2 million years was to sculpt the present landscape and
lay over it a thin veneer of different kinds of sedimentary
deposit that characterize Ice Ages.
Geological processes of deposition and
erosion are continuing today, but operate so slowly that their
effects are almost undetectable over a single human lifespan.
In terms of geological time, traces of Man occur in only the
most recent deposits. The peat and clay deposits of Bingham
Moor contain pre-historic human artefacts, together with the
remains of freshwater mollusc shells that may be several thousand
years old. Bingham Moor is a former marsh with seasonal ponds
and meres, formed since the end of the last Ice Age 10,000
years ago. Other sand and gravel deposits in the Bingham area
can be related to earlier Ice Ages that have occurred over
the last 500,000 years. These deposits preserve a record of
past climatic and environmental variations that can be used
to predict future changes - vital if we are to understand
Man's own impact on the environment. |