This huge capstone rests 5 feet (1.5 metres) above the bottom of
a natural fissure in the limestone beneath. The presence of
seismically unresolvable sediment-filled fissures in supposedly
rigid fault blocks can lead to a significant underestimate of
regional extension based on the restoration of motion on normal
faults on seismic-reflection profiles The supporting stones were
placed along the edge of the hole like a wall to support the
capstone. The low supporting stones give it a squat appearance.
When excavated in 1908 bones of several men, women and children
were found. There were also remains of animal bones, shells, flint
tools, pottery and a bone pin in the chamber. The pottery style
indicates it was in use from the late Neolithic to the Early Bronze
Age. Limestone Fissures In Anglesey the Carboniferous limestone is
cut by numerous fissures that are filled with Mesozoic sediments
(sedimentary dykes, neptunian dykes).
The fissures contain a record of Triassic–Lower Jurassic
sediments that are only sparingly preserved in their normal
stratigraphical position between the Carboniferous Limestone and
the unconformably overlying Upper Inferior Oolite of Bajocian age.
Most fissures were clearly formed by rapid influx of unlithified
sediment from the land surface or sea floor.
Some smaller cavities, or larger cavities with restricted access
to the unconformity, were apparently filled by sediment that
trickled down into the fissure system. The vast majority of
fissures are interpreted as having formed as a response of the
Carboniferous Limestone. Such patterns of extension are thought
likely to be characteristic of the subsurface geology in much of
southern England and Wales.
To log this earthcache please upload a photo of you or your GPSr
with the burial chamber in the photo and E-Mail me the answer the
following questions
1) What is the weight of the capstone
2) Estimate the circumference of the capstone.
Any logs with no photograph may be deleted,