PRIDEAUX PLACE, PADSTOW
THE GROUNDS, GEOLOGY and
SOIL
MATERIALS USED
in the construction of
PRIDEAUX PLACE
Padstow
sits on the edge of the Camel Estuary, being on the "back" of Gunver
Head. a rise of upper Devonian rock, having areas of greenstone/dolerite, the
nearest granite is to be found on Bodmin Moor. The Original Grange Manor house
appears to have been built of a different slate from that used for the
remainder of the house (1588-1592), but inspection of samples taken, merely
show that they were removed from different parts of the same quarry. It seems
that the quarry was first worked when the Priory Tithe Barns and local cottages
were being built.
The
base soil is clay and silt, generally acid and damp. The ground is a rich mass
of leaf compost, offering perfect conditions for plant propagation and growth.
The
house is built of slate taken from the same quarry on the opposite side of the
road from Place, a very distinctive stone, which has proved almost impossible
to match, due to the peculiar range of discolouration in aging, which takes
place. The greatest difficulty arises when masonry is removed and the stone
expands when loads are removed, it is therefore impossible to repair the wall
as it existed. Any stone removed MUST be stored under load pressure.
Granite
was used to form opening frames for doors and windows, this granite appears to
be a moor stone, Metamorphic, showing signs of China Clay.
Upper
Devonian rock includes Purple, Green, Delabole Slate for this stretch of
Cornwall. Ostracod slate occurs in the Padstow area, with the banded slates (
purple and green ) lying in the St. Minver synclinorium and are at least 400
feet thick. This is mentioned here in that these were used to form the top of
the Dairy rear wall, grotesque work, assumed to be in 1770, when the long Green
Walk was extended to it's present form from being an access to the Bowling
Green. The purple variety is also used in featured garden walling around the
grounds.
Besides
the general Slate, there are "grotesque" works, of crystal based
granites and other "imported" stone, presumably selected at the
assistance of Dr.Borlase, by Humphrey Prideaux, around 1770. The entrance steps
of the Library are flanked with "pool" rocks, which are the same
slate from the local quarry, which have been shaped by the flow of water, where
the water used to flow in a stream from the rock face, prior to the quarry
being depleted.
The
other stone in use at Prideaux, is Cataclews ( Carrack Loos, as it used to be
), a blue-grey Greenstone from a proterobase sill near Trevose Head : similar
to this is the more durable Polyphant picrite or the Duporth picrite. Some of
the features, used in the building or found in the grounds, are probably
retrieved from the demolished Chapel of St.Samson ( see notes elsewhere ).
The
granite, as before 1800, was largely removed from surface blocks or debris,
generally known as Moor Stone. It seems likely that the granite used for
Prideaux Place came from the St. Austell region, perhaps Roche being broken
clitters, worked and dressed where they lay. In any event it is sure that the
Grange Manor was built of local Slate, the remainder of the house being built
of the same Slate with later alterations and additions using a mixture of the
remnants of the quarry and the tunnel excavation, together with Slate from St.
Minver and Trevose Head being a black Slate. Features of the external walling
of the Grounds are built of the Metamorphic Granites of Savath/Helman Tor
region.
A
final note, of particular importance, is that The Temple, Seat and Obelisk (
refer to notes elsewhere ) are made of "Bath Stone", the first use of
this stone in Cornwall. When the Obelisk was demolished to form the access
drive at the South Entrance, parts of it were used to form the base feature
strip, matching the granite strip of the East Entrance off the front terrace.