Journal•ISSN: 0096-1191
Journal of Foraminiferal Research
Cushman Foundation for Foraminiferal Research
About: Journal of Foraminiferal Research is an academic journal published by Cushman Foundation for Foraminiferal Research. The journal publishes majorly in the area(s): Foraminifera & Benthic zone. It has an ISSN identifier of 0096-1191. Over the lifetime, 1388 publications have been published receiving 42963 citations. The journal is also known as: JFR.
Topics: Foraminifera, Benthic zone, Genus, Geology, Cretaceous
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this paper, Pearson et al. provide an alphanumeric notation for Paleo-Eocene gene zones using the prefix "P" (for Paleocene), "E' (for Eocene) and "0"(for Oligocene) to achieve consistency with recent short-hand notation for other Cenozoic zones (Miocene ['M'], Pliocene [PL] and Pleistocene [PTD]).
Abstract: New biostratigraphic investigations on deep sea cores and outcrop sections have revealed several shortcomings in currently used tropical to subtropical Eocene plank tonic foraminiferal zonal schemes in the form of: 1) mod ified taxonomic concepts, 2) modifiel:l/different ranges of taxa, and 3) improved calibrations with magnetostratig raphy. This new information provides us with an op portunity to make some necessary improvements to ex isting Eocene biostratigraphic schemes. At the same time, we provide an alphanumeric notation for Paleo gene zones using the prefix 'P' (for Paleocene), 'E' (for Eocene) and '0' (for Oligocene) to achieve consistency with recent short-hand notation for other Cenozoic zones (Miocene ['M'], Pliocene [PL] and Pleistocene [PTD. Sixteen Eocene (E) zones are introduced (or nomen claturally emended) to replace the 13 zones and subzones of Berggren and others (1995). This new zonation serves as a template for the taxonomic and phylogenetic studies in the forthcoming Atlas of Eocene Planktonic Forami nifera (Pearson and others, in press). The 10 zones and subzones of the Paleocene (Berggren and others, 1995) are retained and renamed and/or emended to reflect im proved taxonomy and an updated chronologic calibra tion to the Global Polarity Time Scale (GPTS) (Berggren and others, 2000).' The PaleocenelEocene boundary is correlated with the lowest occurrence (LO) of Acarinina sibaiyaensis (base of Zone El), at the top of the trun cated and redefined (former) Zone P5. The five-fold zonation of the Oligocene (Berggren and others, 1995) is modified to a six-fold zonation with the elevation of (former) Subzones P21a and P21b to zonal status. The Oligocene (0) zomil' components are re named and/or nomenclaturally emended.
557 citations
••
TL;DR: Benthic foraminiferal distributions in polluted marine areas have been investigated over the last three to four decades, and several workers have pointed out that they provide one of the most sensitive and inexpensive markers available for indicating deterioration of marginal marine environments as mentioned in this paper.
Abstract: Benthic foraminiferal distributions in polluted marine areas have been investigated over the last three to four decades, and several workers have pointed out that they provide one of the most sensitive and inexpensive markers available for indicating deterioration of marginal marine environments. Most investigations have been carried out in temperate regions, in areas exposed to several pollution sources. However, environments characterized by organic waste contamination (e.g., sewage or paper and pulp mills) have been addressed more frequently than areas exposed to oil, thermal and various other kinds of pollution. Among the most abundant species close to many outfall areas in temperate regions are Elphidium excavatum and/or Eggerella advena (NW At1antic)lEggerelloides scabrus (NE Atlantic). The dominant tolerant or opportunistic species seems to depend on local hydrographical properties rather than type of effluent. Increased abundance, due to increased nutrient concentrations and reduced predation and competition, is often recorded in areas having high organic inputs. Such abundance aureoles may be separated from outfall centers by an area of strongly reduced abundance or, in severe cases, by a dead zone. Characteristic features of proximal areas include decreased diversity and increased dominance of tolerant or opportunistic species compared to distal areas. Whether agglutinated or calcareous forms dominate seems to depend on the local hydrography, acidity of the sediment porewater and whether living, dead or total (living + dead) assemblages are considered. Test deformation in foraminifera is known from the geological record. In modern environments, deformation occurs more frequently in polluted than in non-polluted areas. Whether different kinds of test deformation develop under pollution- versus naturally-induced stress and what kind of stress properties cause deformations have not yet been established. Differential adaptions to the complex, and in many cases unique, hydrographical and physical conditions that characterize estuarine environments often make it difficult to separate natural faunal properties from pollution effects, especially in a temporal context. Consequently, pollution effects on the biota in estuaries can best be evaluated by comparing the natural, pre-pollution assemblages with those of the present day. The presence of empty foraminiferal tests in sediment cores penetrating through contaminated intervals provides this kind of information, but possible diagenetic alterations of the original assemblages must always be considered. The fossil record can also provide a comparative baseline for evaluating to what extent legislation, intending to cause environmental improvements, has had a positive effect.
550 citations
••
370 citations
••
TL;DR: The in vitro experiments explain the changes that occurred in the Pleistocene foraminiferal assemblages from the Red Sea around 18 thousand years ago and earlier and support the conclusion that salinity is the driving mechanism behind this phenomenon.
Abstract: The biological response to extreme temperatures and
salinities is investigated in the laboratory for seven
species of planktonic foraminifera: Globigerinoides
sacculi/er (Brady), Globigerinoides ruber (d'Orbigny),
Globigerinoides conglobatus (Brady), Globigerine/la siphonifera
(d'Orbigny), Orbulina universa d'Orbigny,
Neogloboquadrina dutertrei (d'Orbigny) and Globorotalia
menardii (d'Orbigny). When one of the vital processes,
food acceptance, growth or reproduction is inhibited
by a culture variable, the absolute survival limit
is reached. The measured in vitro temperature ranges
compare well with the global temperature distribution
patterns of these species, suggesting that this parameter
plays a major role in their biogeographical distribution.
The salinity ranges that are tolerated in laboratory
cultures exceed the range encountered in modern oceans.
Thus salinity does not limit the distribution of the
species investigated herein.
In general, larger mean final shell sizes are attained
and the total shell length increase is larger at optimum
temperatures and salinities than at extreme culture conditions,
but the differences were not always statistically
significant. Marginal temperature and salinity conditions
do not induce contained growth in expatriated
specimens.
Under extreme culture conditions, the relative frequency
of the different shell morphologies is altered
relative to normal conditions. "Abnormal" phenotypes
are more frequent under normal conditions and the
"normal" morphology is found more often under extreme
conditions. As opposed to previous reports, the
frequency of kummerform chambers generally decreases
toward extreme temperature and salinity culture
conditions, indicating that kummerform phenotypes
are not indicative of environmental stress. The
incidence of sac-like chambers in G. sacculi/er and the
formation of spherical chambers in adult 0. universa
decrease toward extreme temperature and salinity culture
conditions, demonstrating that maturation is suppressed
in stress situations.
SEM investigations show that changes in shell porosity
are correlated with treatment variables in culture.
The highest porosities are attained at higher temperatures
and lower salinities. Generally, an increase
in total porosity is achieved by an increase of the pore
area accompanied by a reduction of the pore density.
The in vitro experiments explain the changes that
occurred in the Pleistocene foraminiferal assemblages
from the Red Sea around 18 thousand years ago and
earlier. During glacial periods, salinity approximated
or even exceeded the upper thresholds that were tolerated
under laboratory conditions. Under these circumstances,
species disappeared from the water column.
The order of disappearance as recorded in the
sediments may be explained with the upper salinity
limits found in this study. Also, the recurrent shifts of
dominance between G. sacculi/er and G. ruber are well
documented for this fossil assemblage. The present experiments
support the conclusion that salinity is the
driving mechanism behind this phenomenon. Observations
in modern oceans suggest that the fertility of
the water mass is probably also an important factor
behind the shifts of dominance between G. sacculi/er
and G. ruber.
333 citations
••
293 citations