TY - JOUR
T1 - The seabed geomorphology and geological structure of the Firth of Lorn, western Scotland, UK
AU - Howe, John
AU - Arosio, Riccardo
AU - Dove, Dayton
AU - Anderton, Roger
AU - Bradwell, Tom
PY - 2014/5/1
Y1 - 2014/5/1
N2 - We present recently collected swath bathymetry from the Firth of Lorn.
553km2 of data were collected during 2012-2013 as part of the INIS Hydro
project (Ireland, Northern Ireland and Scotland Hydrographic Survey).
The inshore waters covered by this survey represent a priority area for
the renewable industry, shipping and tourism and encompass a number of
Special Areas of Conservation (SAC) including for rocky reef habitat.
Surprisingly, given this interest, this project is the first
comprehensive bathymetric survey of the area. This region of near shore
continental shelf is revealed as a predominantly bedrock-dominated
seabed, characterised by a series of narrow, stratigraphically
constrained basins eroded into the Proterozoic and Palaeozoic-age
bedrock. The principal basement of the region is composed of deformed
Dalradian-age metasediments overlain unconformably by ?Silurian-age Old
Red Sandstones and lavas. The resistant, uneroded igneous extrusives
have formed raised rock platforms. Most strikingly the central region of
the Firth of Lorn is dominated by an up to 150m high vertical cliff
extending for approximately 20km. The origin of this prominent feature,
here termed the Insh Fault, is not well understood however it may have
resulted from a combination of Dalradian-age faulting and erosion of
exposed softer metasediments in the central basin. Extensive seabed
faulting also occurs; possibly as Dalradian-age syn-sedimentary faults.
Carboniferous and Tertiary-age minor intrusives are common throughout
the region in particular the Tertiary-age dolerite dyke swarms can be
traced for many kilometres, exposed on the sediment-free bedrock
surfaces. The survey region includes the Corryvreckan Whirlpool and
Great Race, beneath the tidal flows of which there are active submarine
sand dunes. Evidence for past glaciation is widespread and well
preserved in the Firth of Lorn with preserved moraines and over-deepened
basins common across the area. Initial geological and geomorphological
mapping shows that our understanding of the offshore outcrop geology can
be greatly improved by the collection of these new high-resolution
bathymetric datasets.
AB - We present recently collected swath bathymetry from the Firth of Lorn.
553km2 of data were collected during 2012-2013 as part of the INIS Hydro
project (Ireland, Northern Ireland and Scotland Hydrographic Survey).
The inshore waters covered by this survey represent a priority area for
the renewable industry, shipping and tourism and encompass a number of
Special Areas of Conservation (SAC) including for rocky reef habitat.
Surprisingly, given this interest, this project is the first
comprehensive bathymetric survey of the area. This region of near shore
continental shelf is revealed as a predominantly bedrock-dominated
seabed, characterised by a series of narrow, stratigraphically
constrained basins eroded into the Proterozoic and Palaeozoic-age
bedrock. The principal basement of the region is composed of deformed
Dalradian-age metasediments overlain unconformably by ?Silurian-age Old
Red Sandstones and lavas. The resistant, uneroded igneous extrusives
have formed raised rock platforms. Most strikingly the central region of
the Firth of Lorn is dominated by an up to 150m high vertical cliff
extending for approximately 20km. The origin of this prominent feature,
here termed the Insh Fault, is not well understood however it may have
resulted from a combination of Dalradian-age faulting and erosion of
exposed softer metasediments in the central basin. Extensive seabed
faulting also occurs; possibly as Dalradian-age syn-sedimentary faults.
Carboniferous and Tertiary-age minor intrusives are common throughout
the region in particular the Tertiary-age dolerite dyke swarms can be
traced for many kilometres, exposed on the sediment-free bedrock
surfaces. The survey region includes the Corryvreckan Whirlpool and
Great Race, beneath the tidal flows of which there are active submarine
sand dunes. Evidence for past glaciation is widespread and well
preserved in the Firth of Lorn with preserved moraines and over-deepened
basins common across the area. Initial geological and geomorphological
mapping shows that our understanding of the offshore outcrop geology can
be greatly improved by the collection of these new high-resolution
bathymetric datasets.
M3 - Article
VL - 16
SP - 3048
JO - EGU General Assembly 2014, held 27 April - 2 May, 2014 in Vienna, Austria, id.3048
JF - EGU General Assembly 2014, held 27 April - 2 May, 2014 in Vienna, Austria, id.3048
ER -