ECOLOGICAL STUDIES AT LOUOH I N E
20 1
11. THE TOPOGRAPHY OF LOUGH INE
Lough Ine is situated on the south coast of Ireland about four miles
east of Baltimore Harbour, which is near the extreme south-west corner
of that country. It is about 1 km long and a little less than 2 km wide,
and is divided unequally into north and south basins by a ridge which
extends, a t a depth of less than 10 m, from the east bank to within a
$ km of the west bank (Fig. 1). The central part of the ridge rises above
water as Castle Island, separated from the eastern shores of the lough
by narrows only about 1 m deep at low water. West of the ridge the
bottom drops steeply to a depth of about 45 m, forming a trough more
than half a kilometre long and running north and south close to the
western shore. Apart from the Western Trough, which is shared between the two basins, considerable areas lie a t 20 to 25 m, and at even
greater depths in the North Basin.
At its south-east corner, Lough Ine is joined by a narrow channel,
known as the Rapids, to Barloge Creek, which in turn opens into the
Atlantic about 1 km south of the lough (Fig. 2). At their narrowest part
the Rapids are only about 20 m wide between high water marks (12 m
between low water marks) and in this region the tide flows in and out
over a shallow sill, only about a m deep at the lowest tide. Further
particulars are given by Renouf (1931).
Evidence concerning the origin of Lough Ine has been supplied to us
by Dr. K. Coe and Dr. E. B. Selwood of the University of Exeter, who
have examined the area. The following is taken almost verbatim from
the report which they have supplied to us.
“The rocky shores of Lough Ine are made of massive cross-bedded
sandstones which form the lowest unit recognized within the Old Red
Sandstone of West Cork. To north and south are outcrops of an overlying
slate series.
“The distribution of rock types and structures are shown on the map
[Fig. 31, which indicates an overturned anticline with limbs dipping to
the north-north-west a t high angles. The form of the anticline is continuous across the lake, showing an absence of significant faulting.
Minor irregularities in the shore are controlled by joints and the distribution of hard and soft bands.
“It is clear that the origin of Lough Ine cannot be ascribed purely to
marine erosion. A clue is contained in the topographic profile drawn
parallel to the tectonic trend, which is strongly reminiscent of iceplucked corrie lakes showing a steep back wall with a deepened foot
and a rock bar. It seems certain that the over-deepened part is due to
ice-scouring, and that a glacier was locally moving west to east along a
pre-existing valley. The valley appears to have been interrupted by an
20 1
11. THE TOPOGRAPHY OF LOUGH INE
Lough Ine is situated on the south coast of Ireland about four miles
east of Baltimore Harbour, which is near the extreme south-west corner
of that country. It is about 1 km long and a little less than 2 km wide,
and is divided unequally into north and south basins by a ridge which
extends, a t a depth of less than 10 m, from the east bank to within a
$ km of the west bank (Fig. 1). The central part of the ridge rises above
water as Castle Island, separated from the eastern shores of the lough
by narrows only about 1 m deep at low water. West of the ridge the
bottom drops steeply to a depth of about 45 m, forming a trough more
than half a kilometre long and running north and south close to the
western shore. Apart from the Western Trough, which is shared between the two basins, considerable areas lie a t 20 to 25 m, and at even
greater depths in the North Basin.
At its south-east corner, Lough Ine is joined by a narrow channel,
known as the Rapids, to Barloge Creek, which in turn opens into the
Atlantic about 1 km south of the lough (Fig. 2). At their narrowest part
the Rapids are only about 20 m wide between high water marks (12 m
between low water marks) and in this region the tide flows in and out
over a shallow sill, only about a m deep at the lowest tide. Further
particulars are given by Renouf (1931).
Evidence concerning the origin of Lough Ine has been supplied to us
by Dr. K. Coe and Dr. E. B. Selwood of the University of Exeter, who
have examined the area. The following is taken almost verbatim from
the report which they have supplied to us.
“The rocky shores of Lough Ine are made of massive cross-bedded
sandstones which form the lowest unit recognized within the Old Red
Sandstone of West Cork. To north and south are outcrops of an overlying
slate series.
“The distribution of rock types and structures are shown on the map
[Fig. 31, which indicates an overturned anticline with limbs dipping to
the north-north-west a t high angles. The form of the anticline is continuous across the lake, showing an absence of significant faulting.
Minor irregularities in the shore are controlled by joints and the distribution of hard and soft bands.
“It is clear that the origin of Lough Ine cannot be ascribed purely to
marine erosion. A clue is contained in the topographic profile drawn
parallel to the tectonic trend, which is strongly reminiscent of iceplucked corrie lakes showing a steep back wall with a deepened foot
and a rock bar. It seems certain that the over-deepened part is due to
ice-scouring, and that a glacier was locally moving west to east along a
pre-existing valley. The valley appears to have been interrupted by an