evolution of the earth or into the history of earth science,
or that can be used for research, teaching, or reference
(Brocx, 2008). It encompasses the variety of rocks types,
stratigraphy, structural geology, geomorphology, and
hydrology and covers a large variety of processes and
products across a wide range of scales, from global tectonics, mountain building, landscape evolution to local surface processes and products such as weathering, erosion
and sedimentation, cliff faces, fossils sites and mineral
localities, and, at the microscale, diagenesis and
deformation.
Geoconservation. This term refers to an action that
works toward the preservation of sites of geoheritage significance for heritage, science, or education purposes. It
can encompass all important geological features from the
regional scale to the individual crystal, involving specific
sites (special sites), or ensembles of geological sites.
A “specific site” is where a significant geological feature
occurs in isolation or may have historical or cultural
significance; these have been formally identified in the
British Isles as (geological) site(s) of special scientific
interest (SSSI) or regionally important geological/
geomorphologic sites (RIGS) (Ellis et al., 1996).
Geodiversity. Geodiversity is the natural variety of geological, geomorphological, pedological, and hydrological
features of a given area and geological processes forming
them (Brocx and Semeniuk, 2007). Use of the term, which
etymologically means “the diversity of geological features,” should be applied only in a region-specific or
site-specific sense, i.e., not as a synonym for geology.
Geosite. This is a term used to denote small sites of
geoheritage significance used for education, science,
geotours, and reference.
Geopark. Geopark is used to denote large sites of
geoheritage significance, usually an ensemble of geosites
used for education, science, geotours, and reference.
Introduction
Estuaries stand as a distinct environment along the coast in
that they bridge the aquatic hydrochemical environmental
gap between freshwater and seawater. They can bring
another aspect in addition to this hydrochemical setting
because the landscape and geomorphic/sedimentologic
setting of an estuary provide variability to the “mixing
bowl” where freshwater and seawater interact. The
emphasis on the landscape and geomorphic/sedimentologic settings of estuaries has resulted in their being classified according to a geomorphic framework or according to
their origin (Fairbridge, 1980; Nichols and Biggs, 1985;
Perillo, 1995). In this context, with their geologic, geomorphic, and sedimentologic characteristics and variability, they fall into the realm of geodiversity and
geoheritage. As such, estuaries, in addition to the complexities and variability of styles of hydrochemical
mixing, which is their first tier criterion of identification,
provide a rich assortment of geologic, geomorphic,
sedimentologic, mineralogic, and biogenic attributes such
as shell deposits and bioturbation structures, not only in
regard to the features within the estuaries themselves but
also in the geology, geomorphology, and hydrology of
the immediately surrounding landscape that frames or that
has built them. Consequently, they hold potential to contain features and sites of geological significance or
geoheritage value and lend themselves to qualifying as
sites of geoheritage significance. This is especially the
case in that estuaries, as sedimentary repositories, reside
in various types of geologic and geomorphic settings,
from rias to coastal plains to structural controlled
(Fairbridge, 1980; Perillo, 1995), which results in
a variety of geomorphic and sedimentologic estuarine
types, and occur in a wide range of climates from tropical
to temperate and from humid to arid, which also results in
a variety of geologic/geomorphic, sedimentologic, and
geochemical/mineralogic expressions. A large diversity
(or geodiversity) of estuary types can be expected therefore from the perspective of the earth sciences.
Before a description is provided of the procedure to
determine geoheritage values, the terms “geoheritage,”
“geoconservation,” “geodiversity,” “geosite,” and
“geoparks” are defined. They are associated with the concept of geoheritage, the enactment of geoconservation,
and the inscription of geosites/geoparks.
Identifying and assessing sites of geoheritage
value using the geoheritage tool kit
Identifying estuaries in different geological regions and
the geoheritage essentials (i.e., the geological features that
characterize an area) of these estuaries provides the first
step in identifying sites for geoheritage. Clearly not all
aspects of estuaries on earth are present in the one region,
and not all aspects of an estuary in a region may be of
geoheritage significance – the former recognizes the
uniqueness, rarity, or representativeness of some estuarine
features, and the latter requires some measure of assessment of significance. There are a number of ways that sites
of geoheritage significance may be identified, and the
British and European literature provides a history of how
this has been achieved, with the final outcome being an
inventory-based approach (Doyle et al., 1994; Wimbledon
et al., 1995; Wimbledon, 1996; ProGEO, 2002; for discussion see Brocx, 2008).
The British and European approach to compiling an
inventory of features of significance in the realm of geology has been successful in that numerous and varied
aspects of geology have been identified and secured, but
the approach has been thematic within a context of known
geology and nationally specific geology. This is largely
because the geology of European countries is reasonably
well known, and these countries are relatively small
(compared to, say, Australia, an island continent with
a surface are of $7.7 million km
2
, and Africa with a surface area of $30 million km
2
). Australia has its own
188
DETERMINING GEOHERITAGE VALUES
or that can be used for research, teaching, or reference
(Brocx, 2008). It encompasses the variety of rocks types,
stratigraphy, structural geology, geomorphology, and
hydrology and covers a large variety of processes and
products across a wide range of scales, from global tectonics, mountain building, landscape evolution to local surface processes and products such as weathering, erosion
and sedimentation, cliff faces, fossils sites and mineral
localities, and, at the microscale, diagenesis and
deformation.
Geoconservation. This term refers to an action that
works toward the preservation of sites of geoheritage significance for heritage, science, or education purposes. It
can encompass all important geological features from the
regional scale to the individual crystal, involving specific
sites (special sites), or ensembles of geological sites.
A “specific site” is where a significant geological feature
occurs in isolation or may have historical or cultural
significance; these have been formally identified in the
British Isles as (geological) site(s) of special scientific
interest (SSSI) or regionally important geological/
geomorphologic sites (RIGS) (Ellis et al., 1996).
Geodiversity. Geodiversity is the natural variety of geological, geomorphological, pedological, and hydrological
features of a given area and geological processes forming
them (Brocx and Semeniuk, 2007). Use of the term, which
etymologically means “the diversity of geological features,” should be applied only in a region-specific or
site-specific sense, i.e., not as a synonym for geology.
Geosite. This is a term used to denote small sites of
geoheritage significance used for education, science,
geotours, and reference.
Geopark. Geopark is used to denote large sites of
geoheritage significance, usually an ensemble of geosites
used for education, science, geotours, and reference.
Introduction
Estuaries stand as a distinct environment along the coast in
that they bridge the aquatic hydrochemical environmental
gap between freshwater and seawater. They can bring
another aspect in addition to this hydrochemical setting
because the landscape and geomorphic/sedimentologic
setting of an estuary provide variability to the “mixing
bowl” where freshwater and seawater interact. The
emphasis on the landscape and geomorphic/sedimentologic settings of estuaries has resulted in their being classified according to a geomorphic framework or according to
their origin (Fairbridge, 1980; Nichols and Biggs, 1985;
Perillo, 1995). In this context, with their geologic, geomorphic, and sedimentologic characteristics and variability, they fall into the realm of geodiversity and
geoheritage. As such, estuaries, in addition to the complexities and variability of styles of hydrochemical
mixing, which is their first tier criterion of identification,
provide a rich assortment of geologic, geomorphic,
sedimentologic, mineralogic, and biogenic attributes such
as shell deposits and bioturbation structures, not only in
regard to the features within the estuaries themselves but
also in the geology, geomorphology, and hydrology of
the immediately surrounding landscape that frames or that
has built them. Consequently, they hold potential to contain features and sites of geological significance or
geoheritage value and lend themselves to qualifying as
sites of geoheritage significance. This is especially the
case in that estuaries, as sedimentary repositories, reside
in various types of geologic and geomorphic settings,
from rias to coastal plains to structural controlled
(Fairbridge, 1980; Perillo, 1995), which results in
a variety of geomorphic and sedimentologic estuarine
types, and occur in a wide range of climates from tropical
to temperate and from humid to arid, which also results in
a variety of geologic/geomorphic, sedimentologic, and
geochemical/mineralogic expressions. A large diversity
(or geodiversity) of estuary types can be expected therefore from the perspective of the earth sciences.
Before a description is provided of the procedure to
determine geoheritage values, the terms “geoheritage,”
“geoconservation,” “geodiversity,” “geosite,” and
“geoparks” are defined. They are associated with the concept of geoheritage, the enactment of geoconservation,
and the inscription of geosites/geoparks.
Identifying and assessing sites of geoheritage
value using the geoheritage tool kit
Identifying estuaries in different geological regions and
the geoheritage essentials (i.e., the geological features that
characterize an area) of these estuaries provides the first
step in identifying sites for geoheritage. Clearly not all
aspects of estuaries on earth are present in the one region,
and not all aspects of an estuary in a region may be of
geoheritage significance – the former recognizes the
uniqueness, rarity, or representativeness of some estuarine
features, and the latter requires some measure of assessment of significance. There are a number of ways that sites
of geoheritage significance may be identified, and the
British and European literature provides a history of how
this has been achieved, with the final outcome being an
inventory-based approach (Doyle et al., 1994; Wimbledon
et al., 1995; Wimbledon, 1996; ProGEO, 2002; for discussion see Brocx, 2008).
The British and European approach to compiling an
inventory of features of significance in the realm of geology has been successful in that numerous and varied
aspects of geology have been identified and secured, but
the approach has been thematic within a context of known
geology and nationally specific geology. This is largely
because the geology of European countries is reasonably
well known, and these countries are relatively small
(compared to, say, Australia, an island continent with
a surface are of $7.7 million km
2
, and Africa with a surface area of $30 million km
2
). Australia has its own
188
DETERMINING GEOHERITAGE VALUES