4 Sediments of Adjacent Seas
and Estuaries
4.1 Introduction
4.2 Water Circu1ation and Sediments
4.2.1 Estuaries
4.2.2 Adjacent Seas with Estuarine Water Circu1ation
4.2.3 Adjacent Seas with Anti-Estuarine Water
Circulation
4.2.4 A Composite Basin: the Mediterranean Sea
4.2.5 Basins with Horizontally Separated Inflow
and Outflow
4.2.6 Estuarine and Anti-Estuarine Large
Ocean Basins
4.3 Sedimentary History of Some Modem Adjacent Seas
4.3.1 The B1ack Sea
Miocene-Pliocene Deve10pment
The Holocene Black Sea
4.3.2 The Gu1f ofCalifomia
General Setting
Hydrographyand Sediments
4.3.3 The Red Sea and Gulf of Aden
Tectonic Setting
Pre-Rift and Syn-Rift Sediments
with Evaporites
Post-Evaporite Sediments
Quatemary Sediments in the Red Sea
Controlled by Sea-Level Changes
4.3.4 The Persian (Arabian) Gulf
General Setting
Quatemary and Holocene Sediments
4.4 Summary (Adjacent Seas)
4.1 Introduction
Adjacent seas are shallow or deep water-filled basins
of limited extent which are connected with the world
oceans by a gateway or strait. Such basins may develop on both continental and oceanic crust, as well
as in diverse tectonic settings. Prominent present-day
examples are the Red Sea, representing an ocean in
its initial stage, the Persian Gulf, a foreland basin,
and the Black Sea, a kind of remnant basin. The Gulf
of Califomia originated mainly from strike-slip
movements along a plate boundary. Wide river estuaries, although usually covering only limited areas,
also show some features characteristic of adjacent
basins.
The depositional environment of adjacent seas is
largely determined by the mechanism controlling the
connection with the neighboring ocean. The opening
may be wide and deep (as that of an estuary) or characterized bya narrow sill protecting the adjacent basin from the direct influence of the open sea. Depending on the dimension of this opening and the
climate, adjacen~ basins may have a more or less normal salinity, or they tend to become brackish
(hyposaline) or more saline (hypersaline) than average sea water. Because such systems react sensitively
to small changes in the entrance area, the sedimentary facies of adjacent basins may vary significantly
with time, definitely more so than normal marine deposits. Furthermore, river inflow and the climate of
the neighboring land are important factors.
Some adjacent seas represent immature ocean basins (e.g., the Red Sea) which evolve into wider ocean
basins. Then the sediments of the adjacent sea stage
may become buried deeply under younger, fully marine shelf and slope sediments of continental margins
(e.g. Thiede 1978; cf. Sect. 12.2). Then, only subsequent uplift and erosion, providing land exposures,
or drillholes in such sequences can reveal the early
climatic-oceanic history of such a basin development.
To understand the highly variable facies of adjacent basin sediments, some general mIes conceming
the water circulation of such basins have to be introduced.
For further information see, e.g., Seibold (1970), Grasshoff
(1975), Pickard and Emery (1982), Seibold and Berger
(1996). Some general mIes for thermohaline circulation in
the oceans (Chap. 5.2) also apply for circulation in estuaries and adjacent basins.
4.2 Water Circulation and Sediments
4.2.1 Estuaries
The wide mouth of a river, i.e., an estuary, may be
regarded as a comparatively small, specific, frequently occurring type of an adjacent sea. Such a
semi-closed elongate basin has a relatively wide connection to the open sea and on the landward end a
and Estuaries
4.1 Introduction
4.2 Water Circu1ation and Sediments
4.2.1 Estuaries
4.2.2 Adjacent Seas with Estuarine Water Circu1ation
4.2.3 Adjacent Seas with Anti-Estuarine Water
Circulation
4.2.4 A Composite Basin: the Mediterranean Sea
4.2.5 Basins with Horizontally Separated Inflow
and Outflow
4.2.6 Estuarine and Anti-Estuarine Large
Ocean Basins
4.3 Sedimentary History of Some Modem Adjacent Seas
4.3.1 The B1ack Sea
Miocene-Pliocene Deve10pment
The Holocene Black Sea
4.3.2 The Gu1f ofCalifomia
General Setting
Hydrographyand Sediments
4.3.3 The Red Sea and Gulf of Aden
Tectonic Setting
Pre-Rift and Syn-Rift Sediments
with Evaporites
Post-Evaporite Sediments
Quatemary Sediments in the Red Sea
Controlled by Sea-Level Changes
4.3.4 The Persian (Arabian) Gulf
General Setting
Quatemary and Holocene Sediments
4.4 Summary (Adjacent Seas)
4.1 Introduction
Adjacent seas are shallow or deep water-filled basins
of limited extent which are connected with the world
oceans by a gateway or strait. Such basins may develop on both continental and oceanic crust, as well
as in diverse tectonic settings. Prominent present-day
examples are the Red Sea, representing an ocean in
its initial stage, the Persian Gulf, a foreland basin,
and the Black Sea, a kind of remnant basin. The Gulf
of Califomia originated mainly from strike-slip
movements along a plate boundary. Wide river estuaries, although usually covering only limited areas,
also show some features characteristic of adjacent
basins.
The depositional environment of adjacent seas is
largely determined by the mechanism controlling the
connection with the neighboring ocean. The opening
may be wide and deep (as that of an estuary) or characterized bya narrow sill protecting the adjacent basin from the direct influence of the open sea. Depending on the dimension of this opening and the
climate, adjacen~ basins may have a more or less normal salinity, or they tend to become brackish
(hyposaline) or more saline (hypersaline) than average sea water. Because such systems react sensitively
to small changes in the entrance area, the sedimentary facies of adjacent basins may vary significantly
with time, definitely more so than normal marine deposits. Furthermore, river inflow and the climate of
the neighboring land are important factors.
Some adjacent seas represent immature ocean basins (e.g., the Red Sea) which evolve into wider ocean
basins. Then the sediments of the adjacent sea stage
may become buried deeply under younger, fully marine shelf and slope sediments of continental margins
(e.g. Thiede 1978; cf. Sect. 12.2). Then, only subsequent uplift and erosion, providing land exposures,
or drillholes in such sequences can reveal the early
climatic-oceanic history of such a basin development.
To understand the highly variable facies of adjacent basin sediments, some general mIes conceming
the water circulation of such basins have to be introduced.
For further information see, e.g., Seibold (1970), Grasshoff
(1975), Pickard and Emery (1982), Seibold and Berger
(1996). Some general mIes for thermohaline circulation in
the oceans (Chap. 5.2) also apply for circulation in estuaries and adjacent basins.
4.2 Water Circulation and Sediments
4.2.1 Estuaries
The wide mouth of a river, i.e., an estuary, may be
regarded as a comparatively small, specific, frequently occurring type of an adjacent sea. Such a
semi-closed elongate basin has a relatively wide connection to the open sea and on the landward end a