ELSEVIER
Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
Natural dissolution of modern shallow water benthic foraminifera:
taphonomic effects on the palaeoecological record
John W. Murray a,Ł , Elisabeth Alve b
a
School of Ocean and Earth Science, Southampton Oceanography Centre, European Way, Southampton SO14 3ZH, UK
b Department of Geology, University of Oslo, P.O. Box 1047 Blindern, N-0316 Oslo, Norway
Received 15 October 1997; revised version received 5 May 1998; accepted 29 May 1998
Abstract
Comparison of the living and dead assemblages of benthic foraminifera from the coastal areas of the Skagerrak–
Kattegat reveals that, although there are considerable similarities in terms of the presence=absence of species, there are
major differences in relative abundance at species level. Furthermore, the relative abundance of calcareous tests in the
living assemblages is considerably higher than that of the dead assemblages (average values of 67 and 30%, respectively).
Since the environments are microtidal, there is little transport of foraminiferal tests due to tidal currents so there are no
introduced exotic species although there is local transport caused by waves and wave-induced currents. However, the major
taphonomic process appears to be dissolution, of calcareous tests. This is manifested through etching and breakage of
test walls, leading to complete decalcification which leaves a residue of organic linings of certain taxa (e.g., Ammonia
beccarii), and a marked increase in abundance of agglutinated tests in the dead assemblages. Although dissolution is
normal in marsh settings throughout the world, the Skagerrak–Kattegat area is unusual in the intensity of dissolution in the
subtidal zone. Whereas most of the calcareous species occur throughout the investigated depth range (except marsh), two
of the subtidal agglutinate species (Eggerelloides scaber and Ammotium cassis) show upper depth limits. Consequently, the
agglutinated foraminifera are better indicators than calcareous foraminifera of upper depth limits in these shallow subtidal
environments.  1999 Elsevier Science B.V. All rights reserved.
Keywords: taphonomy; carbonate dissolution; shallow water foraminifera; marsh; sea level; Skagerrak–Kattegat
1. Introduction
Over a three year period, a baseline ecological
study of shallow water (6 m) benthic foraminifera
along the Skagerrak–Kattegat coasts has been carried
out. A principal aim has been to provide data necessary to enhance climatic and environmental interpretations of past (particularly Quaternary) marginal
Ł Corresponding
author. Tel.: C44-1703-592617; Fax: C44-170359052; E-mail: jwm1@mail.soc.soton.ac.uk
marine successions. In order to do this, it is essential to investigate the ecology and distribution of the
living assemblages and to determine the taphonomic
changes during fossilization. The results for the living assemblages are discussed in Alve and Murray
(1999). In the present paper we present detailed results for the dead assemblages and focus particularly
on taphonomy and sea level=water depth indicators.
A more complete description of the environment
is given in Alve and Murray (1999) and only a
summary is given here. The Skagerrak–Kattegat area
0031-0182/99/$ – see front matter  1999 Elsevier Science B.V. All rights reserved.
PII: S 0 0 3 1 - 0 1 8 2 ( 9 8 ) 0 0 1 3 2 - 1
196
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
is characterized by a very small tidal range (<40
cm, but occasionally higher due to variations in atmospheric pressure and temporal wind directions),
and thermohaline water stratification, at least in the
summer, with little diurnal variation in salinity or
temperature. There is ice cover along the Norwegian
and Swedish coasts, and sometimes along that of
Denmark, during the winter, and a wide annual range
of temperature from about 0 to >20ºC. The Swedish
and southern coasts of the Kattegat are partly influenced by the brackish surface water outflow from the
Baltic whereas the Skagerrak and western Kattegat
shorelines are more influenced by water from the
North Sea (salinity 30–33‰). The transparency of
the water, due to the low supply of sediment (at least
during the summer months) and lack of tidal mixing,
allows the development of seagrass meadows which
stabilise the sediment surface and provide both food
and protection for the benthos. The remains of these
plants also contribute to the total organic carbon
(TOC) content of the fine-grained sediments.
Previous work on the living, dead and=or total
foraminiferal assemblages from the shallow inshore
has been confined to various parts of Oslo Fjord
(Goës, 1894; Kiær, 1900; Christiansen, 1958; Risdal,
1964; Thiede et al., 1981; Alve and Nagy, 1986,
1990; Alve, 1990, 1995) and Swedish estuaries (Olsson, 1973, 1976; Nyholm et al., 1977). There have
been no previous foraminiferal studies of the Skagerrak coast of Norway or the Danish Kattegat coast
and Limfjord except for a study of the Øresund at the
entrance to the Baltic (Hansen, 1965). Baltic shallow water faunas have been studied by Lutze (1965,
1968a,b, 1974), Grabert (1971), Wefer (1976) and
Brönnimann et al. (1989).
2. Material and methods
From 1994 to 1996, 171 samples were collected
from 27 localities along the Skagerrak–Kattegat
coast from the intertidal zone to a water depth of
6 m (Fig. 1) but two (162, 163) were not used in this
study. The majority of samples were collected in the
month of July in successive years. The exceptions
were samples 84–89 (Aug.) and 152–159 (Oct.).
The depths recorded are those at the time of sampling. Because of the irregular tidal pattern, it was
difficult to know the exact position of average sea
level in the investigated areas. However, it was clear
that the water level was never very high or very low
because it was always within the range of intertidal
algal cover on rocks or jetties, i.e., the maximum
deviation from mean sea level was in the range of
about 20–30 cm at most stations. For a number of
stations from water depths of less than around 0.5
m at the time of sampling, it has not been possible
to be certain whether they are normally subtidal or
intertidal. Further details of the sampling areas are
given in Alve and Murray (1999, table 1).
The subtidal foraminiferal samples were collected
with a small grab, each with a volume of about
100 cm3 . The grab was carefully operated so that
negligible loss of surface sediment took place. On
removal from the water, it was gently opened in
a bowl. The surface oxidized sediment layer was
scooped off and placed in a container. In areas
exposed at the time of collection, samples were
scraped from the sediment surface (to a depth of 1–2
cm). All samples were preserved in 70% ethanol.
In the laboratory, the foraminiferal samples were
washed on a 63 µm sieve (large fragments of organic material were removed on a 1 mm sieve),
stained for 1 h in rose Bengal (1 g=l), and washed
again to remove the surplus stain. Those samples
not rich in organic material were dried at 40ºC
and the foraminifera were concentrated using tetrachloroethylene or carbon tetrachloride. Organic-rich
samples were spread out over a large area in a pan
and allowed to dry at 40ºC to avoid forming a hard
block. The dry material was then gently brushed off
into a container. It was not necessary to float such
samples in a heavy liquid.
For each sample separate assemblages of living
and dead individuals were picked (ideally 250–300
individuals in each, although some were too small to
yield this number).
Most Reophax moniliformis tests were fragmented so it was impossible to decide exactly how
many individuals were present. In order to reduce
over-representation, we decided to count only those
specimens with three or more chambers. Another
problem is that individuals of Goesella waddensis
lacking their initial chambers are impossible to distinguish from R. moniliformis. Consequently, all G.
waddensis have been counted together with R. monil-
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
197
Fig. 1. Map of the Skagerrak–Kattegat with investigated areas shown by numbers from 1 to 27. 1 D Isefjærfjord; 2 D Kvastadkilen; 3 D
Dype Holla (Lyngør); 4 D Tøkersfjord (Lyngør); 5 D Hasdalen; 6 D Kilsfjord; 7 D Tjøme; 8 D Borre; 9 D Horten; 10 D Sandebukta;
11 D Bunnefjord; 12 D Hunnebotn; 13 D Hålkedalskilen; 14 D Tjärnö; 15 D Finnsbobukten; 16 D Gullmarsvik; 17 D Hafstensfjord; 18
D Kungsbackafjord; 19 D Jonstorp; 20 D Kildehuse; 21 D Kalundborg; 22 D Vejle Fjord; 23 D Havhuse (Kalø Vig); 24 D Vosnæs Pynt
(Kalø Vig); 25 D Løgstør; 26 D Valsted; 27 D Frederikshavn. Long arrows show general surface water circulation in the Skagerrak (after
Svansson, 1975). JCW D Jutland Coastal Water; BW D Baltic Water; NCC D Norwegian Coastal Current.
iformis and the few instances where we are confident
that the former is present are noted below. Ammotium
cassis and Ammobaculites balkwilli were also commonly fragmented. We therefore counted only those
fragments which included the initial part.
Species diversity was calculated for samples
with ½100 individuals using the Fisher alpha index (Fisher et al., 1943) and the information function
H .S/ (see Murray, 1991, for formula and application). Variants of agglutinated taxa are illustrated in
Plate I. The full range of agglutinated taxa are illus-
trated in Murray and Alve (1999) and the calcareous
forms in Alve and Murray (1999).
At most stations, additional samples were taken
for grain size and total organic carbon (TOC) analysis. Sediment size analysis was carried out using
standard sieving techniques, sieved on 63, 125, 250,
500, and 1000 µm meshes. TOC analyses were made
using the Leco combustion method.
Water temperature and salinity were measured using either a Salinity Temperature Bridge, type M.C.5,
or a thermometer and Atago salinity refractometer.
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J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
PLATE I
PLATE I
SEM photographs of selected agglutinated taxa. # refers to the sample number (area number; see Fig. 1).
1–5. Variants of Ammobaculites balkwilli Haynes.
1, 2. Typical forms, #98 (24).
3–5. Compressed form, #122 (21).
6–14. Variants of Reophax moniliformis Siddall.
6–8. Normal form, 6, 7, #64 (17), 8. #122 (21).
9–13. Irregular form, #31 (1).
14.
Deformed individual, #31 (1).
15, 16. Typical Goesella waddensis Van Voorthuysen, showing triserial initial portion, uniserial main part, and terminal circular
aperture, #120 (21).
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
3. Results
The foraminiferal data are given in Appendix A,
table A1 (this table has been placed on the WWW
as an Online Background Dataset 1 ); fourteen samples yielded fewer than 50 dead individuals and are
marked with a star. The living foraminifera were
divided into 6 ecological categories by Alve and
Murray (1999) and the same pattern is followed here
(see Table 1 for a summary). Marshes are treated
separately from other intertidal=subtidal areas because of their distinctive faunas.
3.1. Marsh environments
Six marsh areas were sampled — Borre (area 8),
Horten (9), Bunnefjord (11), Hunnebotn (12), Hålkedalskilen (13), and Kalundborg (21) (Fig. 1). With
the exception of Borre and Hålkedalskilen, samples
were collected from dense Carex acuta marsh with
some Salicornia, and the sediment between the plants
was covered with green filamentous algae. At Borre
(8), there was some green algal cover between the
sparse Carex acuta but no Salicornia was present. In
addition, at Hunnebotn (12) and Horten (9), samples
were also collected from the damp sediment surface
beneath a litter layer (dry leaf debris several centimetres thick) among Phragmites australis landward of
the Carex acuta marsh. At Hålkedalskilen (13) there
were only scattered Salicornia plants with no Phragmites australis or Carex acuta.
The marsh sediment median diameter shows a
wide range (from phi 0.2 to C4.2; gravel=coarse
sand to fine sandy mud). The TOC content of 6 of
the 14 marsh samples was analysed and the values
vary from 0.4 to 14.8%.
The marsh assemblage agglutinated foraminifera
are exclusively organo- and ferro-agglutinated (i.e.,
none with a calcareous cement). The most widely distributed and abundant species are Jadammina macrescens and Miliammina fusca (categories 2 and 3, respectively) and these are dominant in most of the samples (table A1 1 ). They are accompanied by Tiphotrocha comprimata (category 1) or, more rarely, by
Trochammina inflata (category 2), and by calcareous
1
To be reached via: http:==www.elsevier.nl=locate=palaeo; mirror site: http:==www.elsevier.com=locate=palaeo.
199
Ammonia beccarii or Elphidium williamsoni (category 3). However, on the highest marsh at Hunnebotn
(area 12, samples 159, 170), the dominant form is
Balticammina pseudomacrescens (category 1) which
was not found elsewhere. At Kalundborg (area 21)
the dominant form was Haplophragmoides wilberti
(category 2) and this was rare elsewhere.
The unvegetated sediment areas bordering the
marsh also sometimes have common marsh taxa.
For instance, J. macrescens at Bunnefjord (11) and
Hålkedalskilen (13) while at Kalundborg (21) there
is H. wilberti, J. macrescens, and T. inflata. At
Horten (9), two stations (44, 45) from 0.1 to 1 m
have >50% J. macrescens even though there is no
marsh immediately adjacent (table A1 1 ).
3.2. Intertidal–subtidal
The majority of samples are dominated by agglutinated taxa. Most assemblages are M. fusca dominated (found in 19 of the 27 sample areas). Eggerelloides scaber assemblages (category 5) are restricted
to the Skagerrak coast of Norway. Ammoscalaria
runiana assemblages (category 4) are found mainly
along the Kattegat coast of Denmark. Reophax moniliformis assemblages (category 4) are sparsely present
throughout the region. Ammotium cassis assemblages
(category 5) are confined to Horten (9).
Calcareous assemblages include those of A. beccarii (category 3) which is widely distributed and E.
williamsoni which is especially common along the
Danish Kattegat coast. Assemblages rarely present
are those of Elphidium excavatum (category 4, areas
4, 19, 21), Haynesina germanica (category 3, areas
16, 17), and Cibicides lobatulus (category 6, area 3,
particularly associated with bioclastic sands).
Most of the assemblages are found from the intertidal zone down to the limits of sampling.
However, the A. cassis, A. runiana, E. scaber,
E. excavatum, and H. germanica assemblages are
all found only subtidally. The E. williamsoni assemblage is restricted to depths of 0–1 m with the
exception of one occurrence at 4.5 m.
3.3. Species diversity
The marsh Fisher alpha species diversity values
are generally less than 1.2 except at Hålkedalskilen
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J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
Table 1
Comparison of living and dead depth distributions for principal species (data on living from Alve and Murray, 1999)
Species
B. pseudomacrescens
T. comprimata
Category
Live,
dead
Depth range
(m)
Makes up
½5% of ass.
Makes up
½10% of ass.
As dominant
species
1
L, D
L
D
IT a
IT a
IT a –1
IT a
IT a
IT a
IT a
IT a
IT a
IT a
IT a
ND
2
L
D
L
D
L
D
IT–0.5
IT–3
IT–1
IT–6
IT–4
IT–4
IT a
IT a –1
IT–0.3
IT–3
IT–2
IT–0.5
IT a
IT a –0.5
IT
IT–1.5
IT a
IT a –0.5
ND
ND
IT a
IT a –1
IT a
IT a
3
L
D
L
D
L
D
L
D
L
D
L
D
IT–1
IT–5
IT–4
IT–5.5
IT–6
IT–6
IT–5
IT–6
IT–6
IT–5
IT–6
IT–6
IT–1
0.15–1
IT–2
IT–0.1
IT–5
IT–6
IT–5
IT–6
IT–6
0.15–6
IT–6
IT–6
IT
–
IT–0.5
IT–0.2
IT–5
IT–4.5
IT–5
IT–4.5
IT–4.5
0.15–6
IT–6
IT–6
ND
ND
IT
0.1
IT–3.5
IT–5
IT–5
IT–4.5
1–4.5
2–4
IT–6
IT–5.5
4
L
D
L
D
L
D
L
D
L
D
L
D
L
D
IT–4
0.5–2
IT–6
IT–6
IT–5.5
IT–6
IT–2
IT–2
IT–6
IT–6
IT–5
0.1–6
IT–6
IT–6
IT–4
–
IT–5
IT–6
IT–5
IT–5
1–2
1
0.2–6
IT–6
2
0.5
0.2–6
IT–6
IT–4
–
IT–3
IT–6
IT–4
IT–5
1–2
–
0.4–6
0–6
2
–
2–5
IT–6
IT–4
–
0.2–3
IT–6
0.5
ND
1–2
ND
0.4–4.5
0.4–6
ND
–
2–2.5
1–5
5
L
D
L
D
L
D
1–5
3.5
2–4.5
IT–6
3–6
2–6
3.5
–
–
IT–6
3–6
4–6
–
–
–
IT–6
3–6
3–6
ND
ND
ND
3–6
ND
3–4.5
6
L
D
L
D
L
D
L
D
IT–4
IT–5
IT–5
IT–5
IT–5
IT–5
1–5
0.5–5
IT–2
IT–5
IT
IT–5
2
1–5
4–5
–
2
IT–5
–
5
–
2–5
4–5
–
2
IT–5
ND
ND
ND
ND
5
–
T. inflata
J. macrescens
H. wilberti
E. albiumbilicatum
A. salsum
M. fusca
E. williamsoni
H. germanica
A. beccarii
E. pulchella
R. moniliformis
A. balkwilli
E. oceanensis
E. excavatum
P. (L.) haynesi
A. runiana
O. kilianensis
E. scaber
A. cassis
C. lobatulus
E. margaritaceum
R. anomala
N. depressulus
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
201
where they range up to 1.5. The intertidal–subtidal
values range from alpha 0.6–3.6 with most between
1.0 and 2.9 and only 6 values ½3.0. With one exception of H(S) 2.11 (sample 13, area 3), all the H(S)
values are less than 2.0.
In particular, this applies to some juvenile individuals of M. fusca and occasionally to A. runiana.
3.4. Species distributions
A comparison of live and dead distributions based
solely on presence=absence shows good overall
agreement (Table 2) but there are major differences
in abundance, as discussed below.
The majority of species are widely distributed.
It was noted above that broken individuals of G.
waddensis cannot be distinguished from R. moniliformis. However, complete individuals of G. waddensis (Plate I, 15, 16) were found in Oslo Fjord
(areas 7–10), along the Swedish coast (areas 13, 16,
17) and in Denmark (21, 24) over a depth range from
0–5 m.
3.5. Destruction of tests
Many dead assemblages contain the organic linings of calcareous foraminifera (principally of A.
beccarii, Plate II, 3). Some individuals of A. beccarii, E. excavatum, E. williamsoni, and H. germanica
show partial decalcification (in some instances, the
organic lining is exposed, Plate II, 5, 6; or test wall
layers peeling off, Plate II, 1, 2, 4, 8, 9, 12) or the
test is so fragile that when touched with a moist
paintbrush it disintegrates. In addition, the amount
of dissolution can be gauged by comparing the living and dead assemblages from the same samples,
accepting that there may be some differences caused
by seasonal variability in the living assemblages. The
percentages of calcareous tests are markedly lower
in the dead (Figs. 2 and 3). Dissolution appears to be
more severe along the Skagerrak coast of Norway,
the Kattegat coasts of Sweden and southern Denmark
(areas 1–21 but excluding the shell sands of area 3),
and much less conspicuous along the Kattegat coast
of Denmark and the Limfjord (areas 22–27).
Some agglutinated tests are very fragile and, although they have survived sample preparation, they
collapse when wetted with a moistened paintbrush.
4. Discussion
4.1. Taphonomy
The relationships between living assemblages and
the dead ones drawn from them have been discussed
by several authors and most recently by Murray
(1991) and Martin et al. (1995). The dead assemblages represent the time-averaged input from the
death of living individuals and the effects of postmortem modifying processes, namely, transport (loss
or gain of tests) and destruction of tests (dissolution
of calcareous and disaggregation of fragile agglutinated forms; see also De Rijk and Troelstra, 1999).
It must be stressed that only by making comparative
studies of the living (ideally studied over a period of
more than a year) and dead assemblages is it possible to identify the taphonomic processes operating
and to properly determine the pathways to fossilization (see Murray and Alve, 1999). As an example,
Fig. 2 illustrates the differences between the living
and dead assemblages in area 9 (Horten, Norway).
It clearly shows that calcareous taxa are much more
common in the living assemblages and agglutinated
taxa dominate the dead assemblages. This pattern
would not have been so obvious if the comparison
had been made between live and total (live plus
dead) assemblages. This applies even though there is
seasonality of the living assemblage composition.
4.1.1. Transport of tests
Transport due to tidal action is not considered
to be a significant process in introducing exotic
IT D intertidal (including marsh); ND D not dominant.
Categories: 1 D associated only with marsh plants; 2 D basically, but not entirely, associated with marsh plants; 3 D basically, but not
entirely, restricted to non-marsh areas, 4 D solely recorded in non-marsh intertidal to subtidal environments; 5 D restricted to subtidal
areas; 6 D basically living in the most open marine areas.
a Instances where the species is associated with marsh plants.
202
PLATE II
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
species in the microtidal areas of the Skagerrak and
Kattegat. This is evident from the fact that nearly all
dead species are represented by living individuals;
thus, there is no gain of exotic forms. This is in
marked contrast with more tidally influenced areas
such as the southern North Sea (e.g., Haake, 1962).
However, there is some local transport of tests due
to waves and wave induced currents. The depth
ranges of some species, for example, J. macrescens
and T. inflata, which live solely in association with
marsh plants (Alve and Murray, 1999) have their
dead ranges extended into the subtidal zone but
their presence still indicates close proximity to a
marsh. Also, the depth ranges of certain subtidal
species are extended both shallower (E. scaber) and
deeper (E. albiumbilicatum, A. salsum). However,
the majority of the non-marsh species show a living
depth distribution covering most of the investigated
depth interval.
4.1.2. Abundance of agglutinated tests and
syndepositional carbonate dissolution
Based on the relative abundance of calcareous
tests in the live and dead assemblages, it seems
that little postmortem change is taking place in
the intertidal–shallow subtidal areas of Dype Holla
(area 3), Tøkersfjord (4), Borre (8), Vejle Fjord (22),
Kalø Vig (23, 24), Løgstør (25), and Valsted (26).
However, overall there are pronounced differences
between the living and dead assemblages (Fig. 3).
Possible explanations for this include patchiness and
seasonal changes in living assemblage composition
203
as well as postmortem changes such as transport and
carbonate dissolution. Of these, dissolution of calcareous tests is clearly active because in each sample
the dead assemblage is generally enriched in agglutinated tests compared to the living and there are
severely etched calcareous tests present. There are
even live individuals with etched tests (illustrated in
Alve and Murray, 1999), for example at Kvastadkilen
and Kilsfjord (areas 2 and 6). The pathways from
live calcareous-dominated to completely dissolved
(non-calcareous) dead agglutinated assemblages are
described in Murray and Alve (1999).
Both living and dead assemblages (of >100 individuals) show a wide range of abundance of agglutinated tests (0–100%) with a mean value of 30% for
the living and 67% for the dead. This indicates that
overall syndepositional dissolution is very active.
Carbonate dissolution is complex and may be
caused by several processes including corrosive
bottom or sediment pore waters (which may be
brought about by the metabolization of organic matter, Reaves, 1986) and bacterial destruction (Freiwald, 1995).
Following the postglacial rise of sea level, seawater entered the Baltic Sea via the Kattegat around
8000 years ago. The foraminiferal record in the
straits between the two seas is calcareous throughout
the past 8000 years (Lukashina, 1995). The development of corrosive bottom waters in the Baltic Sea is
a relatively recent phenomenon. The deposits formed
between 8000 and 4500 yr B.P. were calcareous
but after that carbonate preservation was much re-
PLATE II
Dissolution features of calcareous tests as observed under the scanning electron microscope. # refers to the sample number (area number;
see Fig. 1).
1–6. Ammonia beccarii (Linné), #4 (3).
1.
Detail of third chamber from most recent: loss of chamber walls and microcrystalline unit outlines emphasised through etching.
2.
Wall layers peeling away.
3.
Organic lining.
4.
Detail of NE quadrant of fig. 5.
5.
Organic lining exposed in the lower part and wall layering in the centre of the image.
6.
Loss of wall layers and exposure of organic lining in the final chamber.
7–11. Elphidium excavatum (Terquem), #120 (21).
8.
Loss of wall layers especially in the final chamber (fig. 9).
10.
Etched surface showing enlarged pores and rough crystal units.
11.
Severely corroded specimen showing chamber damage.
12.
Haynesina germanica (Ehrenberg) showing etched surface, #4 (3).
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J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
Table 2
Comparison of the biogeographic distributions of living and dead representatives (data on living from Alve and Murray, 1999)
Area
Norway
1
A. balkwilli
A. balkwilli
A. runiana
A. runiana
A. cassis
A. cassis
A. salsum
A. salsum
B. pseudomacr.
B. pseudomacr.
E. scaber
E. scaber
H. wilberti
H. wilberti
J. macrescens
J. macrescens
M. fusca
M. fusca
P. (L) haynesi
P. (L) haynesi
R. moniliformis
R. moniliformis
T. comprimata
T. comprimata
T. inflata
T. inflata
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
A. beccarii
A. beccarii
C. lobatulus
C. lobatulus
E. albiumb.
E. albiumb.
E. excavatum
E. excavatum
E. macellum
E. macellum
E. margarit.
E. margarit.
E. oceanensis
E. oceanensis
E. williamsoni
E. williamsoni
E. pulchella
E. pulchella
H. germanica
H. germanica
N. depressulus
N. depressulus
O. kilianensis
O. kilianensis
R. anomala
R. anomala
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
L
D
2
3
Sweden
4
5
6
ð ð ð
ð ð
ð ð ð
ð ð
ð ð ð
ð ð
ð ð ð
ð ð
ð ð
ð
ð ð ð
ð ð
ð ð ð
ð ð ð
ð
ð
ð ð
ð ð
ð
ð
ð
ð
ð
ð
ð
ð
ð
ð
ð ð ð
ð ð ð
ð
ð
ð
ð
ð ð
ð ð
ð
ð
ð
ð
ð ð
ð ð
ð ð
ð ð
ð
ð
ð ð
ð ð
ð ð
ð
ð
ð
7
8
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
ð
ð
ð
ð ð ð
ð ð
ð
ð
ð
ð
ð
ð ð ð
ð
ð
ð
ð
ð ð
ð ð
ð ð ð ð
ð ð
ð
ð
ð
ð
ð
ð
ð
ð
ð
ð ð
ð
ð
ð ð ð
ð ð ð ð ð ð ð
ð ð ð ð ð ð ð
ð ð ð ð ð ð ð
ð
ð
ð ð
ð ð ð
ð
ð ð ð
ð
ð
ð
ð ð
ð
ð ð
ð
ð ð ð
ð
ð
ð
ð ð ð ð ð
ð ð ð ð ð
ð
ð
ð
ð
ð
ð
ð
ð ð
ð
ð ð ð
ð
9
Denmark
ð ð
ð ð
ð
ð
ð
ð
ð
ð
ð
ð
ð
ð ð
ð ð ð ð
ð ð ð
ð ð ð ð
ð ð ð ð ð
ð ð ð ð ð
ð
ð ð ð
ð ð ð ð ð
ð
ð
ð
ð
ð
ð ð ð ð ð ð ð
ð
ð ð ð ð ð ð ð ð ð
ð
ð ð ð
ð
ð
ð
ð ð
ð
ð ð ð ð ð
ð ð ð ð ð
ð ð ð ð ð
ð
ð
ð ð ð ð ð
ð ð ð ð ð
ð ð ð
ð ð ð
ð
ð ð
ð ð ð
ð ð ð
ð ð ð ð ð ð
ð ð ð ð ð ð
ð
ð ð
ð
ð ð ð ð ð ð ð
ð ð ð ð ð ð ð
ð
ð
ð ð
ð ð
ð
ð
ð ð
ð ð
ð
ð
ð ð ð ð
ð
ð
ð ð
ð ð ð
ð ð ð
ð
ð
ð ð ð
ð ð ð
ð
ð ð
ð ð
ð
ð
ð
ð
ð
ð ð ð ð ð ð ð ð ð ð ð ð ð ð ð ð ð ð ð
ð ð ð ð ð ð ð ð
ð ð ð ð ð ð ð ð ð
ð ð
ð
ð
ð
ð ð ð ð ð ð ð ð ð ð
ð ð ð ð
ð ð
ð ð
ð ð
ð ð
ð ð
ð ð
ð ð
ð
ð ð
ð
ð
ð
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ð
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ð
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ð
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ð
ð
ð
ð
ð
ð
No.
areas
16
ð 22
18
22
3
4
14
16
1
1
6
ð 13
7
15
11
23
25
25
7
6
19
ð 22
3
3
5
9
ð ð ð ð ð ð 24
ð ð ð ð ð ð 23
2
4
ð
4
ð
ð
5
ð ð ð ð ð ð 19
ð
ð ð ð ð 19
1
1
ð
2
ð ð ð 6
ð
ð
7
ð ð ð ð ð
9
ð ð ð ð ð ð 27
ð ð ð ð ð ð 25
ð
4
ð
3
ð ð ð ð ð ð 24
ð ð ð ð ð ð 18
2
ð
ð 3
ð
ð ð
9
ð ð ð
4
1
2
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
205
Fig. 3. Comparison of the % calcareous tests between live and
dead assemblages averaged for 1 m intervals and plotted at the
0.5 m depth points.
Fig. 2. Distribution of living (as % living assemblage) and dead
(as % dead assemblage) foraminifera in relation to environmental parameters at Horten, Norway. Abbreviations: A. ba D A.
balkwilli; A. ru D A. runiana; A. ca D A. cassis; M. fus D M.
fusca; R. mo D R. moniliformis; T. co D T. comprimata; A. becc
D A. beccarii; E. ex D E. excavatum; H. ge D H. germanica. Bar
widths: widest to narrowest >50%, 30–50%, 10–30%, <10%,
respectively.
duced. At present, dissolution is particularly severe
at depths >20 m in Flensburg Fjord (Exon, 1972).
The outflowing Baltic surface water moves along
the Swedish coast towards the Skagerrak. In addition, the inflowing freshwater from Sweden and
Norway is from a region of mainly acid igneous and
metamorphic rocks overlain by peaty soils. Along
this coast and into Oslo Fjord, Alexandersson (1972,
1974, 1978, 1979) observed that bioclastic calcareous grains from sublittoral sands show signs of dissolution: dull etched surfaces, and increased fragility
leading ultimately to disintegration (which he termed
maceration). He considered that the seawater was
undersaturated with respect to CaCO3 for long periods of time and probably constantly. Furthermore,
he believed that much of the dissolution took place
in seawater rather than in the sediment. This may
be true for the macrofauna but is perhaps less likely
for the foraminifera which mainly live below the
sediment–water interface.
Reaves (1986) noted that carbonate dissolution in
muds may be controlled by the consumption of organic matter. In the summer, microbial activity leads
to destruction of organic matter causing anoxic-sulphidic conditions at the sediment–water interface
and the formation of ferrous sulphide minerals with
carbonate saturation of the pore waters. In the winter,
the cool temperatures slow down microbial activity,
the ferrous sulphide minerals become oxidized, and
the pH is lowered causing carbonate dissolution. The
process takes place in the top few centimetres of the
sediment (Walter and Burton, 1990). In the study
area, although the presence of decaying seagrass
might be a possible cause of increased dissolution,
there is no obvious link to this because both high
and low degrees of dissolution are present within
sediments with a dense cover of Zostera. Elsewhere,
dissolution is most intense in highly bioturbated ar-
206
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
eas (often of slow sediment accumulation, Martin et
al., 1995) where the build-up of alkalinity is inhibited
by water-flushing in burrows and oxidation of solid
phase sulphides during particle reworking. Thus,
the best mollusc shell preservation occurs in those
regions least affected by biological physical disturbance (Aller, 1982). It has commonly been observed
that calcareous foraminifera are poorly preserved in
marsh sediments (for example, Jonasson and Patterson, 1992; De Rijk and Troelstra, 1999). Severe dissolution of calcareous foraminifera has been reported
from subtidal sediments in Long Island Sound, USA,
where the irrigated burrows and tubes of the macrofauna prevented the build-up of carbonate alkalinity
(Green et al., 1993). The foraminifera disappeared
within the course of a year.
Even in areas of tropical carbonate sediment accumulation carbonate dissolution takes place. In Florida
Bay most pore fluids have excess [Ca2C ] relative to
the overlying seawater and this is a measure of active
dissolution. Unlike terrigenous sediments, carbonate
dissolution may extend to a depth of a metre below
the sediment surface (Walter and Burton, 1990).
The dissolution of foraminiferal carbonate by bacteria leads to pitting and then disintegration of chamber walls (Freiwald, 1995). This type of destruction
is not commonly observed in our material. As noted
above, in the Skagerrak–Kattegat foraminifera the
calcareous walls become so fragile that they are
chalky and disintegrate en masse.
In conclusion, carbonate dissolution is known to
be a widespread phenomenon affecting both terrigenous and carbonate sedimentary environments.
However, not all environments with terrigenous sediments experience severe dissolution (for example
those of the southern North Sea coast, Haake, 1962)
otherwise there would be a poor fossil record of calcareous foraminifera. The Norwegian and Swedish
coastal areas of the Skagerrak and Kattegat are unusual in having such severe dissolution.
4.1.3. Destruction of agglutinated tests
Some agglutinated tests are poorly held together
with cement and may be fragile (e.g., Schröder,
1988; Murray, 1991; De Rijk and Troelstra, 1999).
Douglas et al. (1980) suggested that, in the deep
sea, the organic cement may be oxidized within the
surface layer of sediment, whereas loss of agglu-
tinated tests may be reduced in coastal areas with
higher rates of sedimentation (Alve, 1996). Culver
et al. (1996) recorded loss of M. fusca in the subsurface coastal barrier deposits of Virginia, USA. As
already noted, some M. fusca disaggregated when
being picked although this was relatively rare. It
does mean that there is potentially some loss of agglutinated taxa from assemblages but it has not been
possible to quantify this.
4.2. Indicators of sea level and water depth
The living assemblages from this area were divided into six categories based on presence or absence of marsh plants, whether they were intertidal
or subtidal, and salinity. Categories 1–5 comprise
euryhaline and category 6 are essentially stenohaline species (Alve and Murray, 1999). Category 1
includes taxa found living only in association with
marsh plants and, with the exception of some rare
occurrences down to 1 m, this is true of the dead
too (Table 1). Category 2 includes forms normally
found living in association with marsh plants but also
found in unvegetated areas. Local transport has been
responsible for extending the depth ranges of some
of the dead occurrences. Categories 3 and 4 include
living species which are intertidal to subtidal, those
in 3 sometimes occurring in marshes whereas those
in 4 do not. Category 5 includes living euryhaline,
subtidal taxa while category 6 includes essentially
stenohaline forms found in both intertidal and subtidal settings. In general, there is some extension
of the overall depth range for the dead occurrences.
Some minor calcareous species which were locally
abundant living are much less abundant dead due to
the taphonomic processes discussed above (e.g., E.
pulchella, E. oceanensis). On the other hand, some
minor agglutinated live taxa become dominant dead
species (e.g., E. scaber, A. cassis).
There is considerable interest in defining past sea
levels using microfossils. Marsh taxa have been especially used (e.g., D.B. Scott and Medioli, 1978, California and Nova Scotia; D.K. Scott and Leckie, 1990,
Massachusetts) and specific assemblages have been
correlated with elevation above mean sea level. However, De Rijk (1995) and De Rijk and Troelstra (1997)
have suggested that in Massachusetts marshes salinity
is more important than elevation in controlling distri-
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
butions. Patterson (1990) invoked a combination of
both elevation and salinity to explain the patterns observed on high marshes in British Columbia.
The Skagerrak–Kattegat area is not well suited to
test these rival hypotheses because the tides are very
small or non-existent and water level changes due to
barometric pressure and wind stress are more significant. Also, the difference in elevation between the
marsh front and the landward limit is often only a few
tens of cm at the most. The typical marsh taxa found
here (J. macrescens, T. comprimata, and T. inflata)
are normally associated with high marshes elsewhere
(for instance 60–120 cm above mean sea level in California and Nova Scotia, Scott and Medioli, 1978).
De Rijk (1995) and De Rijk and Troelstra (1997)
found a positive correlation between the abundance of
J. macrescens and T. comprimata and mean salinity.
Likewise, they found a negative correlation between
the abundance of Haplophragmoides manilaensis and
salinity. Our records of salinity were taken only on the
day of sampling. Nevertheless, we see the same general relationships. Balticammina pseudomacrescens
was found only on the most landward and higher parts
of the marsh and the cover of dry leaf litter indicates
that this part of the marsh is not often flooded. In
conclusion, it can be said that the marsh assemblages
of the Skagerrak–Kattegat are very reliable indicators
of the upper limit of sea level and probably also of
salinity (Alve and Murray, 1999).
As regards indicators of water depth, the calcareous species do not show any pronounced upper or
lower depth limits although ½10% living or dead
E. williamsoni are confined to depths of <5 m in
this area. On the other hand, the agglutinated taxa
A. cassis and E. scaber are found in abundances
>10% only deeper than 3 m. Thus the agglutinated
foraminifera may be the better indicators than calcareous foraminifera of upper depth limits in these
shallow sublittoral environments as well as better
indicators of sea level in marsh deposits.
4.3. Application to palaeoenvironmental
interpretation
Data on modern ecology form the basis for interpreting fossil assemblages to reconstruct past
environments. The living assemblages record the
picture at the time of sampling. In the absence
207
of postmortem change, the dead assemblages give
the time-averaged record of successive living assemblages (the ideal dead assemblages of Murray,
1991). Severe dissolution has affected the preservation of many of the dead assemblages in this
area but they nevertheless contain useful ecological
data which can be used to interpret fossil agglutinated assemblages. Similar dissolution loss of calcareous forms was reported by Culver et al. (1996)
from coastal barrier deposits of Virginia, USA, and
they urged caution in interpreting fossil assemblages.
In the present study area, the living assemblages
and those dead assemblages which have not undergone significant postmortem dissolution provide
good analogues for the interpretation of fossil calcareous assemblages such as those found in the
Quaternary (Knudsen and Nordberg, 1987; Knudsen,
1994).
5. Conclusions
The dead assemblages of the Skagerrak–Kattegat
area show a good overall agreement in terms of
presence=absence of species but often major differences of abundance from the living; the latter is
primarily attributed to postmortem modification.
The most significant taphonomic process in the
Skagerrak–Kattegat area is dissolution of calcareous
tests.
Many of the living assemblages are dominated by
calcareous taxa but, for those affected by dissolution,
the dead assemblages are dominated by non-calcareous agglutinated forms.
The depth distribution patterns of living and dead
taxa are similar.
Marsh dead assemblages extend down to about
half a metre water depth and individual taxa occur
as dead tests down to 4–6 m due to local transport.
Nevertheless, abundant marsh species are reliable
indicators of local sea level. The composition of the
assemblages seems to vary with salinity.
In this region, agglutinated foraminifera are better
indicators of water depth than calcareous forms. Ammotium cassis and Eggerelloides scaber are reliable
indicators of water depths greater than about 3 and 2
m, respectively. Marsh agglutinated taxa are the best
indicators of sea level.
208
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
Like the living assemblages, calcareous dead assemblages which are not much altered through dissolution serve as good analogues for the interpretation
of Quaternary assemblages.
Polysaccammina hyperhalina Medioli, Scott and Petrucci (in
Petrucci et al., 1983) is the same as R. moniliformis (D.B. Scott,
pers. commun., 1997) and their illustrations show a similar range
of variability. They did not record G. waddensis van Voorthuysen
in their samples.
Acknowledgements
References
We are pleased to acknowledge the Natural Environment Research Council for grant GR9=1591‘A’
and the Industrial Liaison fund (Oslo University)
for financial support. We are grateful to Pål Glad
for help with sampling in Norway, to Eva Larsen,
Siggurd Gausdal, Arne M. Svendsen, Bent Åsnes,
Trond Smith, John Ingebrigtsen, and Tjärnö marinbiologiska laboratorium for kindly letting us use their
boats, to Inger-Ann Hansen for performing the TOC
analyses, and to Daphne Woods for carrying out the
grain size analyses. Karen Luise Knudsen, MaritSolveig Seidenkrantz, Sacha De Rijk, Dave Scott,
and John E. Whittaker are thanked for their discussions on taxonomy. The manuscript was reviewed
by Karen Luise Knudsen and Sacha De Rijk and
by referees Bill Berggren, Jean-Pierre Debenay and
Ron Martin; we thank them for their constructive
comments.
Alexandersson, E.T., 1972. Shallow-marine carbonate diagenesis as related to the carbonate saturation level of seawater.
Palaeontol. Inst. Univ. Uppsala Publ. 125, 1–10.
Alexandersson, E.T., 1974. Carbonate cementation in coralline
algal nodules in the Skagerrak, North Sea: biochemical precipitation in undersaturated waters. J. Sediment. Petrol. 44,
7–26.
Alexandersson, E.T., 1978. Destructive diagenesis of carbonate
sediments in the eastern Skagerrak, North Sea. Geology 6,
324–327.
Alexandersson, E.T., 1979. Marine maceration of skeletal carbonates in the Skagerrak, North Sea. Sedimentology 26, 845–
852.
Aller, R.C., 1982. Carbonate dissolution in nearshore terrigenous
muds: the role of physical and biological reworking. J. Geol.
90, 79–95.
Alve, E., 1990. Variation is estuarine foraminiferal biofacies with
diminishing oxygen conditions in Drammensfjord, SE Norway. In: Hemleben, C., Kaminski, M.A., Kuhnt, W., Scott,
D.B. (Eds.), Paleoecology, Biostratigraphy, Paleoceanography
and Taxonomy of Agglutinated Foraminifera. Kluwer, Dordrecht, pp. 661–694.
Alve, E., 1995. Benthic foraminiferal distribution and recolonization of formerly anoxic environments in Drammesfjord,
southern Norway. Mar. Micropaleontol. 25, 169–186.
Alve, E., 1996. Benthic foraminiferal evidence of environmental
change in the Skagerrak over the past six decades. Nor. Geol.
Unders. Bull. 430, 85–93.
Alve, E., Murray, J.W., 1999. Marginal marine environments of
the Skagerrak and Kattegat: a baseline study of living (stained)
benthic foraminiferal ecology. Palaeogeogr., Palaeoclimatol.,
Palaeoecol. 146, 171–193.
Alve, E., Nagy, J., 1986. Estuarine foraminiferal distribution in
Sandebukta, a branch of the Oslo Fjord. J. Foraminiferal Res.
16, 261–284.
Alve, E., Nagy, J., 1990. Main features of foraminiferal distribution reflecting estuarine hydrography in Oslo Fjord. Mar.
Micropaleontol. 16, 181–206.
Brönnimann, P., Lutze, G.F., Whittaker, J.E., 1989. Balticammina
pseudomacrescens, a new brackish water trochamminid from
the western Baltic Sea, with remarks on the wall structure.
Meyniana 41, 167–177.
Christiansen, B., 1958. The foraminifer fauna in the Dröbak
Sound in the Oslo Fjord (Norway). Nytt Mag. Zool. 6, 5–91.
Culver, S.J., Woo, H.J., Oertel, G.F., Buzas, M.A., 1996.
Foraminifera of coastal depositional environments, Virginia,
U.S.A.: distribution and taphonomy. Palaios 11, 459–486.
De Rijk, S., 1995. Salinity control on the distribution of
Appendix A. Comments on morphological
variation in selected agglutinated species
The following species show variability in their form:
Ammobaculites balkwilli Haynes occurs as two variants (Plate
I, 1–5). The typical form has an inflated test and when fully developed a length of around 670 µm. The second is somewhat
smaller and is compressed in the plane of the planispiral (maximum length around 360 µm). Typical forms occur throughout
the study area. Compressed forms occur in Oslo Fjord (area 8),
along the Swedish (area 18) and Denmark (area 21) coasts from
intertidal to 2 m.
Haplophragmoides wilberti Anderson is very variable and
includes forms regarded by D.B. Scott as H. manilaensis (pers.
commun., 1997).
Reophax moniliformis Siddall in its typical development has
a near-cylindrical test with parallel sides and almost flush sutures
(Plate I, 6–8). Some tests are more irregular, with recessed
chambers and depressed sutures in parts (Plate I, 9–13). Whereas
the normal variant occurs throughout the study area, the irregular
form is present mainly around the Skagerrak (areas 1, 2, 4, 6, 8,
14–16) with only 2 occurrences in the Kattegat (21, 22); depth
range 0–5 m.
J.W. Murray, E. Alve / Palaeogeography, Palaeoclimatology, Palaeoecology 146 (1999) 195–209
salt marsh foraminifera (Great Marshes, Massachusetts). J.
Foraminiferal Res. 25, 156–166.
De Rijk, S., Troelstra, S.R., 1997. Salt marsh foraminifera from
the Great Marshes, Massachusetts: environmental controls.
Palaeogeogr., Palaeoclimatol., Palaeoecol. 130, 81–112.
De Rijk, S., Troelstra, S.R., 1999. The application of a
foraminiferal actuo-facies model to salt-marsh cores. Palaeogeogr., Palaeoclimatol., Palaeoecol. (in press).
Douglas, R.G., Liestman, J., Walch, C., Blake, C., Cotton, M.L.,
1980. The transition from live to sediment assemblage in
benthic foraminifera from the southern California borderland.
In: Field, M., Bouma, A., Coulburn, I., Douglas, R.C., Ingle, J.
(Eds.), Pacific Coast Paleogeogr. Symp. Pac. Sect. 4, 256–280.
Exon, N., 1972. Sedimentation in the outer Flensburg Fjord area
(Baltic Sea) since the last glaciation. Meyniana 22, 5–62.
Fisher, R.A., Corbet, A.S., Williams, C.B., 1943. The relationship between the number of species and the number of individuals in a random sample of an animal population. J. Anim.
Ecol. 12, 42–58.
Freiwald, A., 1995. Bacteria-induced carbonate degradation: a
taphonomic case study of Cibicides lobatulus from a highboreal carbonate setting. Palaios 10, 337–346.
Goës, A.T., 1894. A synopsis of the Arctic and Scandinavian
recent marine foraminifera hitherto discovered. K. Sven. Vet.
Akad. Handl. 25, 1–127.
Grabert, B., 1971. Zur Eignung von Foraminiferen als Indikatoren für Sandwanderung. Sonderdr. Dtsch. Hydrogr. Z. 24,
1–14.
Green, M.A., Aller, R.C., Aller, J.Y., 1993. Carbonate dissolution and temporal abundances of foraminifera in Long Island
Sound sediments. Limnol. Oceanogr. 38, 331–345.
Haake, F.W., 1962. Untersuchungen an der Foraminiferen-fauna
im Wattgebiet zwischen Langeoog und dem Festland. Meyniana 17, 13–27.
Hansen, H.J., 1965. On the sedimentology and the quantitative
distribution of living foraminifera in the norther part of the
Øresund. Ophelia 2, 323–331.
Jonasson, K.E., Patterson, R.T., 1992. Preservation potential of
salt marsh foraminifera from the Fraser River delta, British
Columbia. Micropaleontology 38, 289–301.
Kiær, H., 1900. Synopsis of the Norwegian marine Thalamophorae. Nor. Fish. Mar. Invest. Rep. 1 (7), 1–59.
Knudsen, K.L., 1994. The marine Quaternary in Denmark: a
review from glacial–interglacial studies. Bull. Geol. Soc. Den.
41, 203–218.
Knudsen, K.L., Nordberg, K., 1987. Late Weichselian and
Holocene biostratigraphy in borings southeast of Frederikshavn, Denmark. Bull. Geol. Soc. Den. 36, 289–303.
Lukashina, N.P., 1995. Foraminifera as indicators of water
masses in the Baltic Sea and the Strait of Kattegat. Oceanology 35, 261–265.
Lutze, G.F., 1965. Zur Foraminiferen-fauna der Ostsee. Meyniana 15, 75–142.
Lutze, G.F., 1968a. Jahresgang der Foraminiferen-fauna in der
Bottsand Lagune (Westliche Ostsee). Meyniana 18, 13–30.
Lutze, G.F., 1968b. Siedlungs-Strukturen rezenter Foraminiferen.
Meyniana 18, 31–34.
209
Lutze, G.F., 1974. Foraminiferen der Kieler Bucht (Westliche
Ostsee): 1 ‘Hausgartengebiet’ des Sondersforchungsbereiches
95 der Universität Kiel. Meyniana 26, 9–22.
Martin, R.E., Harris, M.S., Liddell, W.D., 1995. Taphonomy and
time-averaging of foraminiferal assemblages in Holocene tidal
flat sediments, Bahia la Choya, Sonora, Mexico (northen Gulf
of California). Mar. Micropaleontol. 26, 187–206.
Murray, J.W., 1991. Ecology and Palaeoecology of Benthic
Foraminifera. Longman, Harlow, Essex, 397 pp.
Murray, J.W., Alve, E., 1999. Taphonomic experiments on
marginal marine foraminiferal assemblages: how much ecological information is preserved? Palaeogeogr., Palaeoclimatol., Palaeoecol. (in press).
Nyholm, K.G., Olsson, I., Andren, L., 1977. Quantitative investigations on the macro- and meiobenthic faunas in the Göta
River estuary. Zoon 5, 15–28.
Olsson, I., 1973. Benthic fauna and zooplankton in some polluted
Swedish estuaries. Ambio 2, 158–163.
Olsson, I., 1976. Distribution and ecology of the foraminiferan
Ammotium cassis (Parker) in some Swedish estuaries. Zoon 4,
137–147.
Patterson, R.T., 1990. Intertidal benthic foraminiferal biofacies
on the Fraser River Delta, British Columbia: modern distribution and paleocological importance. Micropaleontology 36,
229–244.
Petrucci, F., Medioli, F.S., Scott, D.B., Pianetti, F.A., Cavazzini
a, R., 1983. Evaluation of the usefulness of foraminifera (sic.)
as sea level indicators in the Venice lagoon (N. Italy). Acta
Nat. Ateneo Parmense 19, 63–77.
Reaves, C.M., 1986. Organic matter metabolizability and calcium
carbonate dissolution in nearshore marine muds. J. Sediment.
Petrol. 56, 486–494.
Risdal, D., 1964. Foraminiferfaunaens relasjon til dybdeforholdene i Oslofjorden, med en diskusjon av de senkvartære
foraminifersoner. Nor. Geol. Unders. 226, 1–142.
Schröder, C.J., 1988. Subsurface preservation of agglutinated
foraminifera in the northwest Atlantic Ocean. Abh. Geol.
B.-A. 41, 325–336.
Scott, D.B., Medioli, F.S., 1978. Vertical zonations of marsh
foraminifera as accurate indicators of former sea-levels. Nature
272, 528–531.
Scott, D.K., Leckie, R.M., 1990. Foraminiferal zonation of
Great Sippewissett salt marsh (Falmouth, Massachusetts). J.
Foraminiferal Res. 20, 248–266.
Svansson, A., 1975. Physical and chemical oceanography in the
Skagerrak and Kattegat, 1. Open sea conditions. Fish. Board
Swed. Inst. Mar. Res. Rep. 1, 1–88.
Thiede, J., Qvale, G., Skarboe, O., Strand, J.E., 1981. Benthonic
foraminiferal distributions in a southern Norwegian fjord system: a re-evaluation of Oslo Fjord data. Spec. Publ. Int. Assoc.
Sedimentol. 5, 469–495.
Walter, L.M., Burton, E.A., 1990. Dissolution of recent platform
carbonate sediments in marine pore fluids. Am. J. Sci. 290,
601–643.
Wefer, G., 1976. Umwelt, Produktion und Sedimentation benthischer Foraminiferen in der Westlichen Ostee. Rep. Sondersforschungsbereich 95 Kiel 14, 1–103.