| 1996 - 98
Research Publications (1996-1998)
Patterson, R.T., Burbidge, S.M.
and Luternaur, J.L. 1998. An atlas of common Quaternary shelf benthic
foraminiferal species from off the coast of British Columbia. Geological
Survey of Canada Bulletin 503, 92 p.
Guilbault, J.-P., and Patterson, R.T.
1998 Rudoloculina hooperi N. Gen. N. Sp., A new miliolid with an
agglutinated outer surface from the northeastern Pacific Ocean.
Journal of Foraminiferal Research, 28: 306-311.
Blais-Stevens, A., and Patterson, R.T.,
1998 Foraminiferal biofacies of Saanich Inlet, Vancouver Island,
British Columbia: valuable environmental indicators. Journal of
Foraminiferal Research, 28:201-219.
Reinhardt, E.G., Patterson, R.T.,
Blenkinsop, J. and Raban, A., 1998 Paleoenvironmental Evolution
of the Inner Basin of the Ancient Harbor at Caesarea Maritima, Israel;
Foraminiferal and Sr Isotopic Evidence. Revue de Paleobiologie,
Reinhardt, E.G., Stanley, D., and Patterson,
R.T., 1998 Strontium isotopic-paleontological method as a high-resolution
paleosalinity tool for lagoonal environments. Geology, 26 (11):1003-1006.
Hutchinson, I., Patterson, R.T.,
Mathewes, R.W. 1998. Plant macrofossil, pollen, diatom, and foraminiferal
biofacies of the Fraser delta. Geology of the Fraser River Delta.
Geological Survey of Canada Bulletin 525: 161-175.
Reinhardt, E.G., Dalby, A., Kumar, A.,
and Patterson, R.T. 1998. Utility of arcellacean morphotypic
variants as pollution indicators in mine tailing contaminated lakes
near Cobalt, Ontario, Canada. Micropaleontology, 44: 131-148.
Patterson, R.T., McKillop, W.B.,
Kroker, S., Nielson, E., and Reinhardt, E.G. 1997. Evidence for
rapid avian-mediated foraminiferal colonization of Lake Winnipegosis,
Manitoba, during the Holocene Hypsithermal. Paleolimnology. 18:
Patterson, R.T., 1997. Assignment
of World Wide Web Virtual Museum Projects in Undergraduate Geoscience
Courses. Computers and Geosciences. 23: 581-585.
Guilbault, J.-P., Patterson, R.T
, Barrie, J.V., and Conway, K.W., Thomson, R.E. 1997. Late Quaternary
paleoceanographic changes in Dixon Entrance, British Columbia shelf:
evidence from the foraminiferal faunal succession. Journal of Foraminiferal
Ozarko, D.L., Patterson, R.T., and
Williams, H.F.L. 1997. Marsh foraminifera from Nanaimo, British
Columbia: infauanl habitat and taphonomic implications. Journal
of Foraminiferal Research. 27:51-68.
Cavazza, W., Blenkinsop, J., DeCelles,
P.G., Patterson, R.T., and Reinhardt, E.D., 1997, Stratigrafia
e sedimentologia della sequenza sedimentaria oligocenico-quaternaria
del bacino calabro-ionico: Bollettino della Societa Geologica Italiana,
Blais-Stevens, A., Clague, J.J., Bobrowsky,
P.T., and Patterson, R.T 1997. Paleoseismic evidence in late Holocene sediments, Saanich Inlet, British Columbia.
Canadian Journal of Earth Sciences, 34: 1295-1420.
Patterson, R.T., and Fowler, A.D.,
1996, Evidence of self-organization in planktic foraminiferal evolution:
implications for interconnectedness of paleoecosystems. Geology.
Patterson, R.T., Barker, T., and
Burbidge, S.M.,1996, Arcellaceans (Thecamoebians) as Proxies of
Arsenic and Mercury Contamination in Northeastern Ontario Lakes.
Journal of Foraminiferal Research. 26:172-183.
Asioli, A., Medioli, F.S., and Patterson,
R.T.,1996, Thecamoebians as the tool for reconstruction of paleoenvironments
in some southern Alpine Lakes (Orta, Varese and Candia). Journal
of Foraminiferal Research. 26:248-263
Reinhardt, E.G., Easton, N., Patterson,
R.T., 1996, Foraminiferal evidence of late Holocene sea-level
change on Amerindian site distribution at Montagu Harbour, British
Columbia. Géographie Physique et Quaternaire. 50:35-46
Rudoloculina hooperi N. Gen. N. Sp.,
A new miliolid with an agglutinated outer surface from the northeastern
Guilbault, J.-P., and Patterson, R.T.,
Journal of Foraminiferal Research (1998) 28:306-311.
Rudoloculina hooperi n. gen., n. sp., a new miliolid from
Holocene and modern shelf sediments of the northeastern Pacific
Ocean, is characterized by chambers that are quadrate in cross-section
and by a test wall with embedded agglutinated grains, some of
which consist of miliolid-type shell material (subparallel calcite
laths). The agglutinated grains are either calcareous and low
in magnesium (Mg/Ca less than or equal to 0.01) or silicic. Rudoloculina
hooperi has previously been mistakenly reported from the same
region as Quinqueloculina agglutinata Cushman. The morphologically
similar genus Cycloforina has been reported mostly from warmer
waters, suggesting that R. hooperi is near the northern limit
of its range in the Gulf of Alaska.
An atlas of common Quaternary shelf benthic
foraminiferal species from off the coast of British Columbia.
Geological Survey of Canada Bulletin 503, 92 p.
Patterson, R.T., Burbidge, S.M. and Luternaur, J.L.
Geological Survey of Canada Bulletin 503 (1998) 92 p.
Taxonomic notes and scanning electron micrograph illustrations
have been provided for 103 species of the more abundant and ecologically
diagnostic benthic foraminifera commonly found in the coastal
waters off British Columbia - marsh species have been treated
elsewhere and are not included herein. This monograph, the first
major systematic treatment of foraminifera in the area, will ease
identification problems for future paleoceanographically and biostratigraphically
oriented foraminiferal workers.
Foraminiferal biofacies of Saanich Inlet,
Vancouver Island, British Columbia: valuable environmental indicators.
Blais-Stevens, A., and R.T. Patterson,
Journal of Foraminiferal Research (1998) 28:201-219.
Foraminiferal biofacies identified in Saanich Inlet appear
to be closely linked to a variety of environmental parameters,
including water quality. Five biofaceis are defined based on Q-mode
cluster analysis and on faunal distribution profiles of foraminiferal-bearing
surface sediment samples. Biofacies 1 (Eggerella advena Biofacies),
which occurs in near shore environments near two basys with densely
populated shorelines, appears to have an affinity for areas contaminated
by sewage outfall and septic system drainage. Biofacies 2 (Eggerella
advena-Spiroplectammina biformis Biofacies) and 3 ( Miliammina
fusca Biofacies) characterizes shallow, brackish water, and are
distributed in shallow bays adjacent to Biofacies 1. Biofacies
4 (Lobatula fletcheri Biofacies), the only biofacies dominated
by a calcareous fauna, has been subdivided into two sub-biofacies:
Sub-biofacies 4A occurs in deep water, low oxygen environments,
whereas Sub-biofacies 4B characterizes shallow water, normal marine
environments. The patchy distribution of sub-biofacies 4B sampes
is probably due to vagaries of water circulation in the restricted
basins. Biopfacies 5 ( Leptyohalysis catella - Spiroplectammin
biformis Biofacies) occupies a relatively deeper muddy environemnt
with a high proportion plan debris and probably relatively lower
owygen levels. Hence, the main environemtnal control defining
the biofacies is water circulation (or lack therof), which is
influences by the shape of the fiord (presence of the sill).
method as a high-resolution paleosalinity tool for lagoonal environments.
Reinhardt, E.G., Stanley, D., and Patterson, R.T.,
Geology (1998) 26:1003-1006.
A combined strontium isotopic (87Sr/86Sr) - paleontological
method is newly applied to a modern lagoon in Egypt's Nile delta
to test its applicability as a paleosalinity proxy. Analyses of
22 surficial samples collected throughout the lagoon include 81
Sr isotopic analyses of molluscs, foraminifera, ostracods, barnacles,
bryozoans, serpulid worm tubes, pore water and gypsum crystals.
Two distinct salinity groups are distinguished in each sample:
a lower salinity group (~1 ppt) mixed with a higher salinity group
(~ 3-10 ppt) that, respectively, are interpreted as the modern
biocoenosis and an older relict fauna. The relict fauna denotes
higher salinity conditions in the lagoon prior to closure of the
Aswan High Dam (1964), while the modern fauna records freshening
of the lagoon. Recent decreased salinity is a response to regulated
River Nile flow and increased discharge into Manzala of fresh
water via canals and drains. Quantification of this short-term
salinity change holds promise for study of modern lagoons in other
world settings, and may provide paleoclimatic information for
older lagoon sequences in the Nile delta and the geologic record.
Paleoenvironmental Evolution of
the Inner Basin of the Ancient Harbor at Caesarea Maritima, Israel;
Foraminiferal and Sr Isotopic Evidence.
Reinhardt, E.G., Patterson, R.T., Blenkinsop, J. and Raban,
Revue de Paleobiologie (1998) 17:1-21.
Archaeological excavations within the inner harbor at Caesarea
Maritima, Israel have been conducted to understand the history
of the ancient harbor built by Herod the Great at the end of the
1st c. BC. An integrated foraminiferal and strontium isotope analysis
(87Sr/86Sr) of three stratigraphic sections (Areas, I9, I14,
TN1) from the inner harbor has greatly enhanced the archaeological
interpretation. The foraminiferal analysis of forty-two sediment
samples and forty-two 87Sr/86Sr measurements of six fossil taxa
have indicated temporal paleosalinities that can be related to
the form and function of the inner harbor. The recognition of
three predominantly salinity controlled biofacies was based on
the diversity and distribution of hyaline, agglutinated, and porcelaneous
Areas I9 and I14 in the inner harbor were situated in a restricted
but relatively well circulated brackish water environment in at
least the 1st c. AD and probably up to the 3rd c. AD, with periods
of higher salinity. A highly restricted lagoon was created, probably
by the formation of a sand bar, sometime during the 3rd c. AD.
The lagoon remained restricted and brackish and began to shoal
by the 5th c. AD. Continued infilling of the brackish water lagoon
with sand overwash deposits continued into at least the 7th c.
Area TN1, which was further seaward in the inner harbor was a
quiet restricted brackish water environment in the 6th -7th c.
AD and may have been the center of harbor activity during this
time. The restriction of this area was likely due to a renovation
in the form of a seawall or a sandbar. The area was deliberately
infilled with rubble, probably in the 7th c. AD, to prevent seaborn
This paleoenvironmental study using an integrated micropaleontological/strontium
isotope approach emphasizes the potential of the methodology for
the study of salinity changes in coastal lagoon environments.
Utility of arcellacean morphotypic
variants as pollution indicators in mine tailing contaminated
lakes near Cobalt, Ontario, Canada.
Reinhardt, E.G., Dalby, A., Kumar, A., and Patterson, R.T.
Micropaleontology. (1998) 44: 1-18
Six assemblages resulting from Q-mode cluster analysis
of 27 arcellacean taxa in thirty-nine sediment-water interface
samples collected from two small lakes heavily polluted by mine
tailings near the town of Cobalt, northeastern Ontario, Canada,
correlated well with various distinct polluted and remediated
environments. Results of R-mode cluster analysis indicated that
arcellacean morphs within the same species often discriminate
among environments, thus utilization of infraspecific categories
increases resolution when studying lake microenvironments, pollutants,
and rates of lake remediation. Results of this study suggest that
successful lake remediation in these and similarly polluted lakes
is best achieved by leaving the tailings undisturbed to be buried
naturally, or to speed the process by addition of an allochthonous
Plant macrofossil, pollen, diatom, and
foraminiferal biofacies of the Fraser delta. Geology of the Fraser
River Delta. 592:
Hutchinson, I., Patterson, R.T., Mathewes, R.W.
Geological Survey of Canada Bulletin. (1998) 525: 161-175.
Small-scale variations in relief across the 1000 km2 Fraser
River delta platform and associated variations in tidal submergence,
water-table depth, substrate salinity, sediment accumulations
rate and sediment mobility support a diverse array of marine and
terrestrial ecological communities. This mosaic of wet meadows
and shrubland, bogs and riparian woodlands above the high tide
mark, and marshes, sandflats and mudflats in the intertidal zone
(often greatly modified by agricultural activity and urban development)
can be linked by a successional model that relates the nature
of the ecological community to the elevations of the deltaic platform
and the character of the substrate. Palaeoecological investigations
of plant microfossil, pollen, diatom and foraminiferal biofacies
have proven useful in: 1) reconstructing the late glacial and
early Holocene oceanic conditions in the Strait of Georgia; 2)
reconstructing small-scale eustatic and coseismically generated
relative sea-level changes; 3) assessing flooding frequency in
interdisciplinary areas; and 4) developing models to explain autogenic
changes associated with fire occurrence in raised bogs, which
may lead to improved bog conservation measures.
Evidence for rapid avian-mediated foraminiferal
colonization of Lake Winnipegosis, Manitoba, during the Holocene
Patterson, R.T., McKillop, W.B., Kroker, S., Nielson, E.,
and Reinhardt, E.G.
Paleolimnology. (1997) 18: 131-143.
A Holocene ecological succession was documented using palynological,
foraminiferal, and molluscan faunas sampled from an excavated trench
on the margin of Bell River Bay, Lake Winnipegosis, Manitoba. The
palynological data record the known gradually isostatically-induced
shift from aquatic to terrestrial conditions at the site, and clearly
delineates the Holocene Hypsithermal maximal warm interval (commencing
here about 5500 years BP). Concurrent with this warming the site
became occupied by the extinct salt tolerant gastropod Marstonia
gelida and the marine foraminifer Cribroelphidium gunteri
by at least 5430 years BP. Water fowl-assisted colonization
of non-marine habitats by foraminifera has previously been suggested
as a dispersal mechanism for other non-marine foraminiferal occurrences.
However, as this relatively warm-water foraminifer (presently found
as far north as Cape Cod, MA on the Atlantic USA coast, and Vancouver,
BC on the Canadian Pacific coast but also found in Canadian Maritime
provinces during the Hypsithermal) did not inhabit the area either
prior to or following the Hypsithermal warm interval, this occurrence
indicates the efficiency with which foraminifera can utilize non-selective
avian transport to colonize new non-marine and marine habitats.
It may be that only a few years were required for colonization of
the site to occur (2000-3000 km distant from native populations);
this suggests that avian transport is a much more important foraminiferal
dispersal mechanism than previously realized. The appearance of
foraminifera at this site may also constrain models designed to
determine the time required for hydraulically injected glacial freshwater
to be flushed from normally brine producing aquifers in the region.
Marsh foraminifera from Nanaimo, British
Columbia: infauanl habitat and taphonomic implications
Ozarko, D.L., Patterson, R.T., and Williams, H.F.L.
Journal of Foraminiferal Research. (1997) 27:51-68.
Marsh foraminiferal faunas from nine cores in two transects in
and around Nanaimo inlet were examined to assess the implications
of infaunal habitat and taphonomic processes for biofacies formation.
High marsh faunas live slightly deeper infaunally compared to those
in the low marsh, reflecting harsher conditions in the high marsh.
Most living Jadammina macrescens occur from 0-20 cm in the
high marsh and from 0-11 cm in the low marsh; the main depth preference
is from 2-8 cm. Most living Trochammina inflata occur between
0-25 cm in the high marsh and from 0-20 cm in the low marsh.
Haplophragmoides wilberti is most abundant overall between
3-7 cm, being almost absent at the surface in all cores. H. wilberti
is found primarily between 0-15 cm in the high marsh, and from 0-12
cm in the low marsh. Most living Miliammina fusca occur from
0-10 cm, with maximum abundance in the top 3 cm.
Five cluster analyses of the foraminiferal data using a sample
base of 0-1, 0-3, 0-5, 0-7 and 0-10 cm, respectively, discriminated
five biofacies in each case which were then used to determine which
near-surface aliquot is most analogous to deeper subsurface biofacies.
Results show near-surface sediment sampling should be done through
the 0-10 cm interval. This aliquot allows the main infaunal species
characteristics to be observed, yet is thin enough that epifaunal
species are also accurately represented.
These results indicate that at least in coastal British Columbia
traditional sampling strategies that assess modern marsh foraminiferal
occurrence based only on examination of the uppermost 0-1 cm will
not give an accurate representation of actual marsh species distribution.
Modern marsh foraminiferal distribution assessment based on the
thicker surface aliquot that we propose will permit researchers
to delineate both subtle and dramatic sea level changes more precisely.
This precision is critical in studies designed to differentiate
the magnitude of seismic events and also to recognize subtle eustatic
events as well.
Assignment of World Wide Web Virtual
Museum Projects in Undergraduate Geoscience Courses.
Computers and Geosciences (1997). 23: 581-585.
Internet World Wide Web virtual museum projects are viable
alternatives to the traditional term paper in undergraduate geoscience
courses. Hyper Text Markup Language is so easy to use that students
are not overly distracted from adequately researching their topic,
and are thus able to gather sufficient background data. In fact,
the intelligent and creative integration of text and accompanying
digital artifacts requires a level of understanding of the material
that is not often achieved during the writing of traditional term
papers. Most significantly, the students are motivated to create
high-calibre documents by the knowledge that their projects will
be exposed to a global audience.
Stratigrafia e sedimentologia della
sequenza sedimentaria oligocenico-quaternaria del bacino calabro-ionico
(Stratigraphy and sedimentology of the Oligocent-Quaternary sedimentary
sequence of the Calabrian-Ionian Basin)
Cavazza, W., Blenkinsop, J., DeCelles, P.G., Patterson, R.T.,
and Reinhardt, E.D.
Bollettino della Societa Geologica Italiana (1997) 116:51-77
The substantial Quaternary uplift of the Calabrian peninsula (southern
Italy) has extensively exposed a thick sedimentary sequence of Oligocene
to Quaternary age. This sequence covers nonconformably the crystalline
basement complex of the Calabrian microplate and represents the
proximal portion of the fill of the Calabrina forarc basin, still
active between the Ionian subduction zone to the southeast and the
calcalkaline Aeolian volcanic arc to the northwest.
Analysis of sedimentological facies and paleocurrents as well as
the petrological study of sandsones and conglomerates indicate that
the terrigenous detritus contained in the clastic units of the basin-fill
sequence was derived either directly from the erosion of the nearby
crysalline basement or - for the younger units of the basin fill
- from the partial cannibalization of the older sedimentary units.
The only exceptions are the varicolored clays, derived from the
Ionian accretionary prism.
Late Quaternary paleoceanographic
changes in Dixon Entrance, British Columbia shelf: evidence from
the foraminiferal faunal succession.
Guilbault, J.-P., Patterson, R.T , Barrie, J.V., Conway,
K.W., and Thomson, R.E.
Journal of Foraminiferal Research. (1997) 27:151-174.
Late glacial and Holocene foraminiferal stratigraphy of 7 piston
cores from Dixon Entrance on the Pacific coast of Canada yielded
11 biofacies defined in part by cluster analysis and in part by
the percentage of temperate species. Temperate species are defined
as those that are not reported north of the southern Bering Sea.
It is possible to define three phases in the deglaciation based
on the percentage of temperate species: the glacial phase with 0
to 5% temperate species, the transitional phase with 5 to 20% and
the temperate phase, with more than 20%. Epistominella vitrea and
Cassidulina reniforme- dominated assemblages characterize the oldest,
"glacial" deposits (14,000-12,900 BP). Younger sediments have substrate-influenced
assemblages. Muddy "transitional" deposits (12,900-10,500 BP) are
dominated by the same species as the glacial material, but the coarser
sediments are dominated by the attached form Lobatula fletcheri.
The most abundant species in muddy "temperate" deposits (<10,500
BP) are either Epistominella pacifica or Nonionella stella. Coarse
sediments of the same age contain mostly L. fletcheri, but also
temperate species of the genus Islandiella. Compared to Queen Charlotte
Sound further south, Dixon Entrance enjoyed generally more open
marine conditions thanks in part to the greater depth that facilitated
upwelling of warmer and more saline deep Californian Undercurrent
Paleoseismic evidence in late Holocene sediments, Saanich Inlet, British Columbia.
Blais-Stevens, A., Clague, J.J., Bobrowsky, P.T., and Patterson,
Canadian Journal of Earth Sciences (1997) 34: 1295-1420.
Eight piston cores of sediment spanning the last 1500 years
were collected from Saanich Inlet, an anoxic fiord on southern Vancouver
Island, to obtain information on sedimentation and prehistoric earthquake
activity. The cores consist mainly of fine-grained varved sediments,
but include massive layers deposited by subaqueous debris flows.
The debris flows may have been triggered by earthquakes or by the
buildup of fine sediment on the walls of the inlet. Cesium-137 and
210Pb data, 14C ages, and varve counts were
used to date and correlate massive layers in the eight cores. The
uppermost massive layer in two cores may record a magnitude 7.2
earthquake which occurred in 1946 near Comox, British Columbia,
200 km north-northwest of Saanich Inlet. Seven older layers are
found in two of more cores and are about 200, 440, 550, 800-850,
1050-1100, 1100-1150, and 1450-1500 years old. Two of these older
layers may correlate with previously documented earthquakes in the
region. There is an average of one massive layer per 116 varves
in the core with the greatest number of such layers, which is broadly
consistent with the expected periodicity of moderate to large earthquakes
in the region -- on average, one earthquake producing local Modified
Mercalli Intensity VII or VIII per century. Saanich Inlet may contain
a proxy record of all moderate and large earthquakes that have affected
southwestern British Columbia during Holocene time, but some of
the massive layers undoubtedly are nonseismically generated deposits
because many do not appear to correlate from one core to then next.
Evidence of self-organization in planktic
foraminiferal evolution: implications for interconnectedness of
Patterson, R.T., and Fowler, A.D.
Geology. (1996) 24:215-218.
We analyzed planktic foraminiferal evolutionary data using
techniques of nonlinear dynamics, a methodology new to paleontology.
The data set comprises 196 extinction and speciation horizons derived
from biostratigraphic ranges of 662 reliably defined species. Both
extinction and speciation data sets are well characterized by power-law
models. However, return maps and a predictor technique indicate
that the extinction data are more highly deterministic than speciation
data. We interpret the analysis, particularly extinction data, to
be consistent with planktic foraminiferal evolution being organized,
and not randomly driven. Our results preclude neither periodic large
extinction events driven by external forces as predetermined by
another system (e.g., large-body impact); nor internally driven
extinction processes where spontaneously derived interdependencies
cascade through the ecosystem; or some combination thereof. Our
data support a model whereby the internal organization of an ecosystem
regulates the response to changes in a deterministic manner, the
relative scales of disturbances and extinctions depending on the
degree of interdependency within the system. Thus any contention
that species interactions are not sufficiently intense to generate
mass extinctions can be dismissed. Random walks generated by genetic
drift and the transitory nature of n-dimensional niche space may
explain why speciation is less deterministic than extinction.
Arcellaceans (Thecamoebians) as Proxies
of Arsenic and Mercury Contamination in Northeastern Ontario Lakes.
R.T. Patterson,T. Barker, and S.M. Burbidge
Journal of Foraminiferal Research (1996) 26:172-183.
Q-mode cluster analysis of arcellacean populations in three
small lakes (two heavily polluted by mine tailings) near the town
of Cobalt in northeastern Ontario permitted five distinct faunal
assemblages to be recognized and related to ecologic tolerance.
Mine waste and mill tailings were dumped into Crosswise Lake until
1970, and a leaking tailings dam continues to pollute Peterson Lake.
Natural sedimentation is slowly burying the tailings in these lakes
but areas of highly toxic sediments remain exposed in several areas.
Levels of arsenic and mercury contamination in the substrate are
as high as 7110 ppm and 2.54 ppm, respectively, in Crosswise Lake;
and 8330 ppm and 0.77 ppm, respectively, in Peterson Lake (maximum
acceptable concentrations for aquatic life are 50 ppm and 0.100
ppm, respectively). A Contaminated Substrate Assemblage (1), dominated
by Centropyxis aculeata (x=27.5%), Centropyxis constricta
(x=13.5%), and Arcella vulgaris (x=9.7%), characterizes
the most heavily polluted parts of the lakes. Centropyxids, known
to be opportunistic and capable of withstanding hostile conditions,
become less dominant in biofacies found in substrates characterized
by progressively less mine tailing contamination (Mine Tailings
Assemblage , Muddy Substrate Assemblage , and Diatom Mud Assemblage
Unpolluted Gillies Lake was not comparable with Crosswise or Peterson
lakes as a pronounced thermocline results in significantly different
limnological conditions (i.e., very low bottom temperatures and
oxygen concentrations) in that lake. The presence of a Cucurbitella
tricuspis (x=90.3%) dominated fauna (Transported Fauna Assemblage
) in most Gillies Lake samples is enigmatic as no significant
populations of Spirogyra spp., the algae with which the partially
planktic Cucurbitella tricuspis has a symbiotic relationship,
have been observed. We suspect that Assemblage 5 is allochthonous.
The results of this pilot study indicate that arcellaceans are
useful not only to monitor environmental pollutants but to assess
rates of lake remediation.
Thecamoebians as the tool for reconstruction
of paleoenvironments in some southern Alpine Lakes (Orta, Varese
A. Asioli, F.S. Medioli, and R.T. Patterson,
Journal of Foraminiferal Research (1996) 26:248-263
A study of Thecamoebians was carried out on three sediment
cores collected in three Northern Italian lakes (Orta, Varese, Candia).
The recognition of distinct morphotypical populations ("morphs ")
within three species of thecamoebians in varying paleolomnological
settings has resulted in a refined understanding of the environmental
parameters controlling their distribution. For example: D. proteiformis
morph "proteiformis" is well adapted to environments rich in organic
matter and sulphides while D. proteiformis morph "rapa" tolerates
polluted and acidified waters (presence of: copper sulfates, ammonium
sulfates, high content of ammonium and nitrite nitrogen, and water
with pH values between 3.9 and 4.5).
Although most questions about the ecology of thecamoebians are
still unresolved, this study strongly suggests that with further
research these Protozoa can be used as a valuable tool for paleoenvironmental
reconstructions and detection of environmental deterioration.
Foraminiferal evidence of late Holocene
sea-level change on Amerindian site distribution at Montagu Harbour,
E.G. Reinhardt, N. Easton, R.T. Patterson
Geographie Physique et Quaternaire. (1996) 50:35-46
Foraminiferal and sedimentological analysis of an underwater
stratigraphic section from an Amerindian habitation site at Montague
Harbour, British Columbia has further documented late Holocene sea
level changes. It appears that part of the documented transgression
was caused by tectonic subsidence of the area (Event 1 at approx.
3500 calendar years BP and Event 2 sometime before 1100 calendar
years BP) and was recognized in the stratigraphic record by rapid
environmental changes. The environmental changes caused by rapid
shifts in water depth were recognized through sedimentological and
foraminiferal evidence. The tectonic subsidence events, coupled
with gentle late Holocene transgression, caused the breaching of
Montague Harbour's northwestern channel. The breaching of the channel
improved water circulation and increased salinity within the harbour.
The salinity changes are reflected in the shift from a low salinity
Cribroelphidium excavatum (Terquem, 1876) phenotype "clavata"
dominated biofacies (1) at the base of the section to a higher salinity
Buccella tenerrima (Bandy, 1950) and Elphidiella hannai
(Cushman and Grant, 1927) dominated biofacies (2) at the top. These
sea-level changes would have eventually forced local Amerindian
settlements inland. The 14C dating of wood and shell, indicates
that the recovery of archaeological remains of the Charles culture
(ca.6500-3200 years BP) requires investigation in deeper waters.