Prehistoric sites
with decorated stones and possible Winter solstice alignments
by Martin J. Powell
In the
Northern hemisphere, the winter solstice
occurs when the sun reaches its most southerly point along the ecliptic (the sun's
apparent path through the constellations). This is
the shortest day of the year and the official commencement of winter (in the Southern
hemisphere this is the summer solstice, i.e. its longest day and the official
commencement of summer).
Due to an effect called precession of the equinoxes,
whereby the Earth's axis 'wobbles' in space, in prehistoric times the sun's
declination had a slightly greater value at midwinter (and midsummer) than it
does today. The sites listed here are thought to date from the later Neolithic
and Bronze Age periods in Britain and Ireland, at which time the sun's declination
at midwinter was around -23º.91.
In the current Gregorian calendar, the winter solstice in the Northern
hemisphere takes place
on 21st or 22nd December.
Whilst the interpretation of decorated stones remains under
debate, the following sites, together with those containing alignments to other
significant calendar dates, provide some evidence to support the theory
that in certain instances they may have held an astronomical symbolism.
The book references shown in the 'Source' column are listed
in the 'Bibliography' section below.
IF
- Indicated Foresight (i.e. notch or cleft on horizon)
A3 - Alignment
with 3 stones
In addition to the above sites, the following stone circle
variants, known as 'Four-Posters', also contain cupmarked stones in their South-easterly
or South-westerly quadrant, which may have served as indicators of the midwinter
sunrise or sunset. However, the astronomy of these sites has
not yet been fully assessed (Ruggles, 1999, pg. 157). Because of the small sizes of these sites,
the precision level of the proposed astronomical alignments is likely to be considerably less
than the majority of those listed above.
1. The central pillar
of this three-stone alignment has two large cupmarks on its SW face.
2. Alignment is
from geometrical centre to the outlying standing stone known as Long Meg.
On one face of Long Meg are three carvings; a cup-and-ring mark with a
gutter, a spiral and some incomplete concentric circles.
3. Five stones remain
of an original circle of eight. The cupmarks are on the inner face of
a stone at the SW.
4. The recumbent
stone is positioned at the SW and has 119 cupmarks. Unlike Rothiemay,
the majority of recumbent stone circles in Aberdeenshire appear to have their
recumbent slabs orientated towards the major southern moonset (see Note 5).
5. Alignment is
from the circle centre to a cupmarked stone positioned to the East of the
recumbent slab. The recumbent slab itself is positioned at the SSW of the circle,
in line with the major southern moonset.
6. This peculiar site
was discovered and examined in the mid-1970s and mid-1980s. It comprises
man-made platforms, standing stones, cupmarked slabs and other features. The
alignment in question is from the so-called 'Oak Bank' stone, a recumbent slab
situated on a ridge, to a natural outcrop with a single cupmark some 35 metres
to the SW.
7. Alignment is
to the rising midwinter sun to the SE. The two inner stones of the four-stone
alignment are cupmarked on alternate faces. Burl also suggests that the
builders may have intended the rays of the midwinter setting sun to fall on
the SW face of one of the cupmarked stones. The alignment to the NW is
to the most northerly moonset.
8. The site comprises
a NE-SW line of three Clava cairns. Two passage-grave entrances face the
midwinter setting sun, which would have shone into their chambers. There
are cupmarks in the chamber of the SW tomb and on its Western kerbstone.
9. Alignment is
to a 1.8 metre long boulder positioned some 3 metres to the South-west of the
kerb. The boulder is decorated with cupmarks, cup-and-ring marks and grooves.
A crude causeway connects the boulder to the cairn. A kerbstone
on the Eastern side of the cairn is also cupmarked.
10. Alignment is through
the recumbent slab at the SW, which has a cupmark carved inside the apparent
outline of an axe. Opposite the recumbent are two tall portal stones,
which define the axis of the circle along the same alignment.
11. The South-western
stone of the Four
Stones has three cupmarks on its sloping upper surface, each about 7cm in
diameter (see site
plan).
12. These four stones may originally have surrounded a
cairn.
13. The site is
also referred to by the names 'Dull' and 'Weem'.
14. Alignment is
to a fallen stone SE of the circle, which has numerous cupmarks.
1976
The Stone Circles of the British Isles,
Yale University Press (New Haven & London).
1993
From Carnac to Callanish: The Prehistoric Stone Rows
and Avenues of Britain, Ireland and Brittany, Yale University Press
(New Haven & London).
MILLIGAN, Max & BURL, Aubrey
1999
Circles of Stone: The Prehistoric Rings of Britain
and Ireland, The Harvill Press (London).
POWELL, Martin J.
1995
'Astronomical Indications at a Bell-barrow in South
Wales' in the journal Archaeoastronomy,
Vol. 26, No. 20, Science History Publications (Cambridge).
RUGGLES, Clive
1999
Astronomy in Prehistoric Britain and Ireland,
Yale University Press (New Haven & London).
THOM, Alexander
1967
Megalithic Sites in Britain,
Oxford University Press (Oxford).
