La pedra en sec. Materials, eines i tècniques tradicionals a les illes ...

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:* * *: 6 6.4.1 DRYSTONE MASONRY STRUCTURES
Description
Temporary watercourse channelled
between drystone walls.
Uses
Channelling and removal of surface
runoff from cultivated fields and
excess water from springs (font
Coberta, example 2). Example 2 was
commissioned by Archduke Llu!s Salvador
of Austria prior to 1884, possibly
in 1876 (Canyelles, 1997).
Site
Terraced slopes originally used to
grow vineyards (example 2) and olive
trees (examples 1 and 3).
Materials
Limestone (example 1); sandstone
(example 2); rough rock, breccia,
compacted clay, silicic rock (example
3).
Torrent profile
Sloping (examples 1 and 2); stepped
with a steep slope from the front part
of each step (example 3).
Bed
Cobbled.
Channel walls
In example 1, the most common, just
the two sides of the torrent were waIled
to stop the water carrying away
soil from the fields. The walls of the
channels in examples 2 and 3 are part
of the crop land terrace walls that they
go through.
Bridging structures
There is a small sandstone bridge in
each terraced field to cross the torrent
in example 2 and at each side of the
channel there are some steps running
parallel to the torrent which also make
it possible to access the terraced
fields.
Bridging structures at the torrent in
example 3 are very basic. Next to
each terrace wall the channel is less
deep to make crossing easier as if it
were a ford. Where the torrent meets
the cam! de sa Ca/a it runs through a
3.30 m long culvert so as not to damage
the road.
Location
Font Garrover, Mancor de la Vall
(example 1); Miramar, Valldemossa
(example 2); cam! de sa Ca/a, Deia
(example 3).