The rocks of the Haltwhistle burn were laid down over a period of about 10 million
years around 330 million years ago during the Carboniferous Period.
Northumberland, at the time, lay closer to the equator and the area was subject to
repeated changes in sea level. Vast areas of marine deposits can be seen at the top
of the Burn as deep layers of limestone interspersed with thinner bands of mudstone/shale.
These have yielded a range of fossils and are easily accessed. Further down the burn
the freshwater sequence of sandstone, coal and mudstone/shale are highly visible.
These are the remains of tropical forests which were inundated by wide braided rivers
which deposited sand, weathered from the mountains further north.
Limestone was quarried and burnt to produce lime for mortar and field improvement.
(The remains of lime kilns can be explored at the top of the Burn.) Sandstone was
quarried from various cliffs all up the Burn. The workings can still be seen clearly
and the stone found in the buildings of the town. Whinstone, from the Whin Sill
north of the Military Road, was quarried until the 1950s and carried down a little
railway alongside the Burn by a small steam train. The track bed is now the footpath.
This is an exceptionally hard, igneous stone which is used for road stone.
One sandstone exposure at the northern end of the burn has been extensively weathered
by the wind, exposing the thin layers of different coloured and sized sand grains
from which it is formed. These exposures are accessible and give an excellent experience
of both the processes of sedimentary rock formation and erosion.
As well as visiting the rocks in the field, a sample of the various rock types will
be available for hardness or porosity testing which can be carried out in the Woodland
Rocks and Soils
Child- friendly information of coal measure formation.
Photographs illustrating various rock formations of the Burn
Practical activities to explore coal and sandstone formation (available in classroom
or in field)
Field trip with guide
Facilities of Woodland Classroom for “lab” work, teaching or wet weather lunch
Rock samples for testing (can be carried out in field)