11.1 Introduction
The interpretation of sedimentary structures on marine shelves, continental slopes
and deep-sea basins progressed enormously due to an improved interdisciplinary
research between oceanographers and marine geologists. A thorough in-depth
analysis was recently published by Herna ´ndez-Molina et al. (2016), in which they
demonstrate the impact of oceanographic processes of different time scales on
morphosedimentary structures of various spatial scales. Although actuogeology as
a tool is known since Johannes Walther (1888), this discipline becomes more and
more important for the evaluation of recent global change. The deep sea was looked
at as a quiet and low energy environment throughout most of the twentieth century.
During the last decade it became more and more accepted that different oceanographic processes form and shape deep sea sedimentary environments
(e.g. Hübscher et al. 2010; Rebesco et al. 2014).
The rediscovery of cold water non zooxanthellate coral reefs along the NW
European continental margin (Dons 1932; Le Danois 1948; Henriet et al. 1998) has
stimulated marine geological and oceanographic research of these systems to better
understand the processes behind their formation and distribution. Cold-water coral
(CWC) reefs are widespread along the continental margins of all ocean basins
(Roberts et al. 2006). Since these classical studies (l.c.) many more reef sites have
been identified worldwide, predominantly in the North Atlantic. Indeed, the presence of Lophelia pertusa as a main frame-builder of CWC reefs is today known
from, for example, the Norwegian margin (e.g. Freiwald 2002; Fossa ˚ et al. 2002;
Hovland et al. 2012), the Porcupine, Rockall and Hatton banks (e.g. White et al.
2007; Mazzini et al. 2012), the Celtic margin (e.g. Wheeler et al. 2007), the
Mediterranean Sea (e.g. Taviani et al. 2005, 2011; Fink et al. 2012; Savini et al.
2014), the Gulf of Cadiz (GoC; e.g. van Rensbergen et al. 2005; van Rooij et al.
2011), off Morocco (e.g. Foubert et al. 2008; Glogowski et al. 2015), off Mauritania
(e.g. Eisele et al. 2011, 2014), the Angola margin (e.g. Le Guilloux et al. 2009), the
Gulf of Mexico (e.g. Hübscher et al. 2010; Hebbeln et al. 2014), and around the
Bahamas (e.g. Reed et al. 2006; Correa et al. 2012).
The major frame builder of these modern carbonate mounds is Lophelia pertusa
(Linnaeus 1758). This species was first observed in the open waters of the Atlantic
during the Challenger Expedition by Thomson (1878). This species also dominates
modern CWC growth in the Bay of Biscay. The Bay of Biscay can be subdivided
into five geographic regions (Fig. 11.1) beginning in the north with the French
Celtic and the Armorican margins, the French Aquitaine margin in the southeast,
and the Iberian Cantabrian and Galician margins in the south. The Celtic and
Armorican margins display a relatively broad shelf from the coast to the shelf
break wider than 200 km and a steep slope (Lallemand and Sibuet 1986) which
extends from a depth of about 200–4000 mbsl towards the abyssal plain. CWCs
occur predominantly in canyons and on the slopes of the Amorican margin
(e.g. Reveillaud et al. 2008). They do not exhibit large scale coral mound structures
such as those known form the Porcupine Seabight, but are well-developed reef
182
W.-C. Dullo et al.
The interpretation of sedimentary structures on marine shelves, continental slopes
and deep-sea basins progressed enormously due to an improved interdisciplinary
research between oceanographers and marine geologists. A thorough in-depth
analysis was recently published by Herna ´ndez-Molina et al. (2016), in which they
demonstrate the impact of oceanographic processes of different time scales on
morphosedimentary structures of various spatial scales. Although actuogeology as
a tool is known since Johannes Walther (1888), this discipline becomes more and
more important for the evaluation of recent global change. The deep sea was looked
at as a quiet and low energy environment throughout most of the twentieth century.
During the last decade it became more and more accepted that different oceanographic processes form and shape deep sea sedimentary environments
(e.g. Hübscher et al. 2010; Rebesco et al. 2014).
The rediscovery of cold water non zooxanthellate coral reefs along the NW
European continental margin (Dons 1932; Le Danois 1948; Henriet et al. 1998) has
stimulated marine geological and oceanographic research of these systems to better
understand the processes behind their formation and distribution. Cold-water coral
(CWC) reefs are widespread along the continental margins of all ocean basins
(Roberts et al. 2006). Since these classical studies (l.c.) many more reef sites have
been identified worldwide, predominantly in the North Atlantic. Indeed, the presence of Lophelia pertusa as a main frame-builder of CWC reefs is today known
from, for example, the Norwegian margin (e.g. Freiwald 2002; Fossa ˚ et al. 2002;
Hovland et al. 2012), the Porcupine, Rockall and Hatton banks (e.g. White et al.
2007; Mazzini et al. 2012), the Celtic margin (e.g. Wheeler et al. 2007), the
Mediterranean Sea (e.g. Taviani et al. 2005, 2011; Fink et al. 2012; Savini et al.
2014), the Gulf of Cadiz (GoC; e.g. van Rensbergen et al. 2005; van Rooij et al.
2011), off Morocco (e.g. Foubert et al. 2008; Glogowski et al. 2015), off Mauritania
(e.g. Eisele et al. 2011, 2014), the Angola margin (e.g. Le Guilloux et al. 2009), the
Gulf of Mexico (e.g. Hübscher et al. 2010; Hebbeln et al. 2014), and around the
Bahamas (e.g. Reed et al. 2006; Correa et al. 2012).
The major frame builder of these modern carbonate mounds is Lophelia pertusa
(Linnaeus 1758). This species was first observed in the open waters of the Atlantic
during the Challenger Expedition by Thomson (1878). This species also dominates
modern CWC growth in the Bay of Biscay. The Bay of Biscay can be subdivided
into five geographic regions (Fig. 11.1) beginning in the north with the French
Celtic and the Armorican margins, the French Aquitaine margin in the southeast,
and the Iberian Cantabrian and Galician margins in the south. The Celtic and
Armorican margins display a relatively broad shelf from the coast to the shelf
break wider than 200 km and a steep slope (Lallemand and Sibuet 1986) which
extends from a depth of about 200–4000 mbsl towards the abyssal plain. CWCs
occur predominantly in canyons and on the slopes of the Amorican margin
(e.g. Reveillaud et al. 2008). They do not exhibit large scale coral mound structures
such as those known form the Porcupine Seabight, but are well-developed reef
182
W.-C. Dullo et al.