Short, A. D., 1982. Wave-cut bench and wave-cut platform; Erosion
ramp, wave ramp. In Schwartz, M. L., (ed.), The Encyclopedia of
Beaches and Coastal Environments. Stroudsburg: Hutchinson
and Ross, pp. 856–857; 393.
Short, A. D., 1999. Handbook of Beach and Shoreface
Morphodynamics. Chichester: Wiley. 379 p.
Short, A. D., and Farmer, B., 2012. 101 Best Australian Beaches.
Sydney, Australia: NewSouth Publishing. 222 p.
Simon, S., 2012. Seymour Simon’s Extreme Earth Records. San
Francisco, CA: Chronic Books. 56 p.
Soluri, E. A., and Woodson, V. A., 1990. World vector shoreline.
International Hydrographic Review, LXVII(1), 27–36.
Spagnolo, M., Llopis, A., Pappalardo, M., and Feferici, P. R., 2008.
A new approach for the study of the coast indentation index.
Journal of Coastal Research, 24(6), 1459–1468.
Stoddart, D. R., and Steers, J. A., 1978. The nature and origin of
coral reef islands. In Jones, O. A., and Endean, R., (eds.), Biology and Geology of Coral Reefs. Geology II, Vol. IV, New York:
Academic Press, pp. 59–105.
Suess, E., 1888. The Face of the Earth (Das Antlitz der Erde), Vol.
2. London: Oxford University Press (English translation 1906 by
Sollas, H. B.), 5 Vols.
Trenhaile, A. S., 1987. The Geomorphology of Rock Coasts.
Oxford: Clarendon Press. 384 p.
Valentin, H., 1952. Die Küsten der Erde. Petermanns
Geographisches Mitteilungen Ergänzsungheft, 246, 118 p.
Voigt, B., 1998. Glossary of Coastal Terminology. Olympia, WA:
Washington Department of Ecology, Publication, pp. 98–105
(Modified 2012).
Walker, H. J., 2005. Ice-bordered coasts. In Schwartz, M. L. (ed.),
The Encyclopedia of Coastal Science. Dordrecht, The Netherlands: Springer, pp. 542–545.
Wang, Y., and Healy, T., 2002. Definition, properties, and classification of muddy coasts. In Healy, T., Wang, Y., and Healy, J.-A.
(eds.), Muddy Coasts of the World: Processes, Deposits and
Function. Amsterdam: Elsevier, pp. 9–18.
Wang, C., Zhang, J., and Ma, Y., 2010. Coastline interpretation from
multispectral remote sensing images using an association rule
algorithm. International Journal of Remote Sensing, 31(24), 6409.
Woodroffe, C. D., 2002. Coasts: Form, Process and Evolution.
Cambridge, UK: Cambridge University Press. 623 p.
Zenkovich, V. P., 1967. Processes of Coastal Development. Edinburgh: Oliver and Boyd. 73 p.
Cross-references
Beach
Beach Processes
Coastal Engineering
Engineered Coasts
Reef Coasts
COBALT-RICH MANGANESE CRUSTS
James R. Hein
U.S. Geological Survey, Santa Cruz, CA, USA
Synonyms
Cobalt crusts; Cobalt-rich crusts; Cobalt-rich ferromanganese crusts; Fe–Mn crusts; Ferromanganese crusts; Iron–
manganese crusts; Polymetallic crusts
Definition
Layered manganese oxide and iron oxyhydroxide
(ferromanganese) deposits formed from direct and very
slow precipitation of minerals from seawater onto hard
substrates; crusts contain minor but significant concentrations of cobalt, titanium, nickel, platinum, molybdenum,
tellurium, zirconium, and other metallic and rare-earth elements sorbed from seawater by the particulate manganese
and iron minerals.
Introduction
The existence of iron (Fe)–manganese (Mn) crusts
(Figure 1) has been known for more than a century; however, during early explorations, crusts were not distinguished from manganese nodules. It was not until the
early 1980s that a research cruise was dedicated to the
investigation of Fe–Mn crusts and their resource potential
for cobalt (Halbach et al., 1982). From then until the end
of the twentieth century, many research cruises were
undertaken to study crusts; Hein et al. (2000) summarized
much of that work. Although the initial attraction for
crusts was their high cobalt (Co) content, they have also
been considered to be a potential ore for nickel (Ni) and
Mn. Subsequent work has shown that crusts host large
quantities of many critical metals needed for high-tech,
green-tech, and energy applications (Hein et al., 2013;
Hein and Koschinsky, 2014). In addition, because crusts
precipitate from seawater layer by layer over millions of
years, and therefore represent condensed stratigraphic sections, they have been used to study changes in the global
ocean and climates that occurred over the past 70 Ma
(e.g., Frank et al., 1999).
Occurrence and distribution
Fe–Mn crusts form pavements on rock surfaces and coat
talus (pebbles and cobbles) throughout the global ocean
(from Antarctica to the North Pole) where the seabed
was kept clear of sediment for millions of years. The crusts
obtain thicknesses up to 260 millimeter (mm) and grow
(accrete) at rates of generally 1–5 mm per million years.
The maximum thickness of crusts on seamounts increases
with increasing age of the seamount. Fe–Mn crusts form
at water depths of 400–7,000 meters (m) on the flanks of
extinct submarine volcanoes (seamounts, guyots), ridges,
and plateaus, although crusts of more economic interest
occur at depths of about 800–2,500 m because Ni, Co,
and Mo contents are higher and crusts are thicker. More
than 100,000 seamounts occur in the global ocean, many
within the Exclusive Economic Zone (EEZ) of Pacific
Island nations (Figure 2). The same volcanism that formed
the islands or volcanic edifices below carbonate islands
and atolls also formed the submerged seamounts on which
crusts grow. Abundant seamounts also occur in many
areas beyond national jurisdictions (Figure 2). Fewer seamounts occur in the Atlantic and Indian Oceans, and Fe–
Mn crusts there are commonly associated with oceanic
spreading centers. Those crusts commonly obtain
COBALT-RICH MANGANESE CRUSTS
113
ramp, wave ramp. In Schwartz, M. L., (ed.), The Encyclopedia of
Beaches and Coastal Environments. Stroudsburg: Hutchinson
and Ross, pp. 856–857; 393.
Short, A. D., 1999. Handbook of Beach and Shoreface
Morphodynamics. Chichester: Wiley. 379 p.
Short, A. D., and Farmer, B., 2012. 101 Best Australian Beaches.
Sydney, Australia: NewSouth Publishing. 222 p.
Simon, S., 2012. Seymour Simon’s Extreme Earth Records. San
Francisco, CA: Chronic Books. 56 p.
Soluri, E. A., and Woodson, V. A., 1990. World vector shoreline.
International Hydrographic Review, LXVII(1), 27–36.
Spagnolo, M., Llopis, A., Pappalardo, M., and Feferici, P. R., 2008.
A new approach for the study of the coast indentation index.
Journal of Coastal Research, 24(6), 1459–1468.
Stoddart, D. R., and Steers, J. A., 1978. The nature and origin of
coral reef islands. In Jones, O. A., and Endean, R., (eds.), Biology and Geology of Coral Reefs. Geology II, Vol. IV, New York:
Academic Press, pp. 59–105.
Suess, E., 1888. The Face of the Earth (Das Antlitz der Erde), Vol.
2. London: Oxford University Press (English translation 1906 by
Sollas, H. B.), 5 Vols.
Trenhaile, A. S., 1987. The Geomorphology of Rock Coasts.
Oxford: Clarendon Press. 384 p.
Valentin, H., 1952. Die Küsten der Erde. Petermanns
Geographisches Mitteilungen Ergänzsungheft, 246, 118 p.
Voigt, B., 1998. Glossary of Coastal Terminology. Olympia, WA:
Washington Department of Ecology, Publication, pp. 98–105
(Modified 2012).
Walker, H. J., 2005. Ice-bordered coasts. In Schwartz, M. L. (ed.),
The Encyclopedia of Coastal Science. Dordrecht, The Netherlands: Springer, pp. 542–545.
Wang, Y., and Healy, T., 2002. Definition, properties, and classification of muddy coasts. In Healy, T., Wang, Y., and Healy, J.-A.
(eds.), Muddy Coasts of the World: Processes, Deposits and
Function. Amsterdam: Elsevier, pp. 9–18.
Wang, C., Zhang, J., and Ma, Y., 2010. Coastline interpretation from
multispectral remote sensing images using an association rule
algorithm. International Journal of Remote Sensing, 31(24), 6409.
Woodroffe, C. D., 2002. Coasts: Form, Process and Evolution.
Cambridge, UK: Cambridge University Press. 623 p.
Zenkovich, V. P., 1967. Processes of Coastal Development. Edinburgh: Oliver and Boyd. 73 p.
Cross-references
Beach
Beach Processes
Coastal Engineering
Engineered Coasts
Reef Coasts
COBALT-RICH MANGANESE CRUSTS
James R. Hein
U.S. Geological Survey, Santa Cruz, CA, USA
Synonyms
Cobalt crusts; Cobalt-rich crusts; Cobalt-rich ferromanganese crusts; Fe–Mn crusts; Ferromanganese crusts; Iron–
manganese crusts; Polymetallic crusts
Definition
Layered manganese oxide and iron oxyhydroxide
(ferromanganese) deposits formed from direct and very
slow precipitation of minerals from seawater onto hard
substrates; crusts contain minor but significant concentrations of cobalt, titanium, nickel, platinum, molybdenum,
tellurium, zirconium, and other metallic and rare-earth elements sorbed from seawater by the particulate manganese
and iron minerals.
Introduction
The existence of iron (Fe)–manganese (Mn) crusts
(Figure 1) has been known for more than a century; however, during early explorations, crusts were not distinguished from manganese nodules. It was not until the
early 1980s that a research cruise was dedicated to the
investigation of Fe–Mn crusts and their resource potential
for cobalt (Halbach et al., 1982). From then until the end
of the twentieth century, many research cruises were
undertaken to study crusts; Hein et al. (2000) summarized
much of that work. Although the initial attraction for
crusts was their high cobalt (Co) content, they have also
been considered to be a potential ore for nickel (Ni) and
Mn. Subsequent work has shown that crusts host large
quantities of many critical metals needed for high-tech,
green-tech, and energy applications (Hein et al., 2013;
Hein and Koschinsky, 2014). In addition, because crusts
precipitate from seawater layer by layer over millions of
years, and therefore represent condensed stratigraphic sections, they have been used to study changes in the global
ocean and climates that occurred over the past 70 Ma
(e.g., Frank et al., 1999).
Occurrence and distribution
Fe–Mn crusts form pavements on rock surfaces and coat
talus (pebbles and cobbles) throughout the global ocean
(from Antarctica to the North Pole) where the seabed
was kept clear of sediment for millions of years. The crusts
obtain thicknesses up to 260 millimeter (mm) and grow
(accrete) at rates of generally 1–5 mm per million years.
The maximum thickness of crusts on seamounts increases
with increasing age of the seamount. Fe–Mn crusts form
at water depths of 400–7,000 meters (m) on the flanks of
extinct submarine volcanoes (seamounts, guyots), ridges,
and plateaus, although crusts of more economic interest
occur at depths of about 800–2,500 m because Ni, Co,
and Mo contents are higher and crusts are thicker. More
than 100,000 seamounts occur in the global ocean, many
within the Exclusive Economic Zone (EEZ) of Pacific
Island nations (Figure 2). The same volcanism that formed
the islands or volcanic edifices below carbonate islands
and atolls also formed the submerged seamounts on which
crusts grow. Abundant seamounts also occur in many
areas beyond national jurisdictions (Figure 2). Fewer seamounts occur in the Atlantic and Indian Oceans, and Fe–
Mn crusts there are commonly associated with oceanic
spreading centers. Those crusts commonly obtain
COBALT-RICH MANGANESE CRUSTS
113