杏吧原创

Jonasson, K.E., Schr枚der-Adams, C.J. and聽Patterson, R.T.,1995,Benthic foraminiferal distribution at Middle Valley, Juan de Fuca Ridge: a Northeast Pacific hydrothermal venting site. Marine Micropaleontology, 25: 151-167. https://doi.org/10.1016/0377-8398(95)00012-p

Fourteen benthic foraminiferal bearing surface samples collected from the Area of Active Venting (AAV) in Middle Valley at a depth of 2430 m at the northern end of Juan de Fuca Ridge, northeast Pacific Ocean, yielded 156 identifiable taxa. Sample sites were selected near active or recently active vents, where temperatures up to 274 degrees C have been measured. Agglutinated foraminifera dominate within the AAV. However, like the macrofauna observed near hydrothermal vents, foraminfiera do not venture into the extreme habitats where temperatures are greater than 20 degrees C. Where clam beds are found in association with active hydrogen sulphide venting, benthic foraminifera occur rarely. Low foraminiferal abundance and species diversity at the immediate site of active venting is attributed to rapid changes in physical and chemical conditions caused by circulating hydrothermal vent waters.

Patterson, R.T., and Burbidge, S.M., 1995, New Late Oligocene to Pleistocene hyaline calcareous unilocular foraminifera from DSDP Site 357 (Leg 39) on the Rio grande Rise, southwest Atlantic Ocean. Journal of Paleontology, 69: 635-655. https://doi.org/10.1017/s0022336000035174

Thirty-two new species of unilocular benthic foraminifera were described from 50 Late Oligocene to Pleistocene samples from DSDP Site 357 (Leg 39) on the Rio Grande Rise in the southwest Atlantic Ocean. These new species make up nearly one-third of the 112 species of unilocular foraminifers identified in the core. Such a high proportion of new taxa is not unexpected as the group has been ignored by most researchers.

New taxa described include聽Lagena praemeridionalis, Lagena rotundocostatina, Exsculptina sicula, Exsculptina umbelliforma聽Patterson and Cavazza,聽Favulina prolatella, Favulina quasiperthensis, Galwayella copiosotubula, Galwayella oscula, Galwayella spherula, Homalohedra anastomocostata, Homalohedra goniachrados, Homalohedra gothicofenestella, Homalohedra polykamptarion, Lagnea congestacolla, Lagnea derbiosa, Oolina curvella, Vasicostella lecythella, Vasicostella spinulafunda, Fissurina anapetebasilaris, Fissurina binaroculella, Fissurina favobasella, Fissurina fissuroscula, Fissurina labeona, Lagenosolenia angula, Lagenosolenia penna, Palliolatella anfracta, Palliolatella hadrocheilos, Pseudoolina becella, Pseudoolina oscillum, Parafissurina kladerorhektis, Parafissurina prolatolonga, and聽Pseudofissurina plastica.聽The new name,聽Lagenosolenia incompta,a聽is proposed for聽Lagena bicarinata聽(Terquem) var.聽politaMatthes, 1939.

Patterson, R.T., Cavazza, W., and Blenkinsop, J., 1995, Planktic foraminiferal biostratigraphy and 87Sr/86Sr Isotopic stratigraphy of the Oligocene-to Quaternary sedimentary sequence in the southern Calabrian-Peloritani Arc, southern Italy: Journal of Paleontology, 69: 7-20. https://doi.org/10.1017/s0022336000026871

Integration of foraminiferal biostratigraphy, 87Sr/86Sr isotope stratigraphy and traditional physical stratigraphy has provided a refined age control of a poorly known Oligocene-to-Pleistocene sedimentary sequence covering nonconformably the crystalline basement complex of the Calabria-Peloritani arc (CPA), a continental block which rifted off the southern margin of the European plate during Neogene time. In spite of the fossil poor content of the sequence, the simultaneous use of paleontological and geochemical techniques have resulted in the following conclusions. 1) The age of an unnamed, thin calcarenite unit locally present at the base of the sequence, previously considered Rupelian to early Aquitanian in age, has been refined to Chattian (27-26 Ma). This calcarenite was considered a basal, conformable member of the overlying Stilo 鈥� Capo d鈥橭rlando Formation (SCO Fm). However, this study indicates that it is separated from the SCO Fm either by an angular unconformity or by a disconformity representing a significant time interval. 2) The SCO Fm has a latest Chattian/ earliest Aquitanian-Burdigalian age. Previously published reports suggested deposition over a much longer time span, ranging from late Rupelian to Langhian. 3) An unnamed deep-marine siliciclastic unit mostly composed of conglomerate and sandstone and previously considered Tortonian in age is, in fact, Serravallian to Tortonian. 4) The depositional interval of the 鈥渢rubi鈥�, fine grained marine deposits, has been independently confirmed to span the Pliocene?Pleistocene.

The results of this study provide a framework for future sequence-stratigraphic and paleotectonic studies in the area, and prove the effectiveness of an integrated paleontological/geochemical (⁸⁷Sr/⁸⁶Sr ) approach in the study of fossil-poor sedimentary sequences.

Patterson, R.T., Guilbault, J.-P., Thomson, R.E., and Luternauer, J.L. 1995, Foraminiferal Evidence of Younger Dryas isochronous cooling on the British Columbia shelf, west coast of Canada. Geographie Physique et Quaternaire. 49: 409-428/ https://doi.org/10.7202/033063ar

Foraminiferal analysis was carried out on a 12,000 鈥� 9,000 years old piston core from Goose Island Trough, Queen Charlotte Sound, on the British Columbia shelf. Cluster analysis of the data resulted in the recognition of five separate faunas related to distinct paleoceanographic phases. These results provide detailed information on the paleoceanographic conditions that prevailed during passage of a late Quaternary glacial isostatic forebulge across the region, and during a cool interval correlatable with the Younger Dryas cold stadial.

Passage of the glacial forebulge (beginning 11,470-11,260 years BP and terminating prior to 10,000 years BP) resulted in a gradual decrease in water depth to ~75-90 m at the core site, based on sedimentological data and increasing proportions of shallow-water benthic foraminifera. In the early聽stages of the regression, circulation remained open and salinity at near normal marine levels, as indicated by the high Shannon diversity indexes (up to 2.5) and the high proportion of planktic foraminifera. The fall in the proportion of planktic foraminifera from 11.8 to 2.6% suggests that the area became more isolated from the open ocean late in the regression. Near glacial conditions between ~11,100 ? 10,000 years BP at this locality are unrelated to passage of the glacial forebulge. The presence of very cold low-salinity water in the area is shown by high proportions of聽Cassidulina reniforme聽and聽Islandiella helenae.聽The depressed salinity and temperature may have resulted from a modification of regional weather patterns during the Younger Dryas cold phase. Decreased mean continental summer temperatures could have reduced the seasonal influence of the North Pacific High and lengthened that of the Aleutian Low. This would have resulted in a near continuous surface onshore Ekman transport, which combined with enhanced coastal runoff, would have effectively blocked the movement onto the shelf of deep, saline and less cold water of the California Undercurrent. The resultant isolated inshore basin comprised of the present-day Hecate Strait and Queen Charlotte Sound is tentatively named the 鈥淗ecate Sea鈥�.

By ~10,000 years BP the Younger Dryas?like cooling event had terminated and weather and oceanographic circulation had returned to near modern patterns as indicated by the near replacement of聽Islandiella helenae聽产测听Nonionellina labradorica聽and by the development of a modern聽Epistominella vitrea聽dominated biofacies. Paleoceaonographic details associated with the termination of the cooling event are difficult to determine precisely due to the rapid increase in water depth at this locality after 10,000 years BP. Once water depth reached 100 m the site may once again have been influenced by upwelling, resulting in the climate signal blending with a water depth signal.

Reinhardt, E.G., Easton, N.,聽Patterson, R.T., 1996, Foraminiferal evidence of late Holocene sea-level change on Amerindian site distribution at Montagu Harbour, British Columbia. Geographie Physique et Quaternaire. https://doi.org/10.7202/033073ar

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鈥檚 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聽Cribroelphidium excavatum聽(Terquem, 1876) phenotype 鈥渃lavata鈥� dominated biofacies (1) at the base of the section to a higher salinity聽Buccella tenerrima聽(Bandy, 1950) and聽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.

Asioli, A., Medioli, F.S., and聽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. https://doi.org/10.2113/gsjfr.26.3.248

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 (鈥渕辞谤辫丑蝉”) within three species of thecamoebians in varying paleolomnological settings has resulted in a refined understanding of the environmental parameters controlling their distribution. For example:聽D. proteiformis聽morph 鈥減roteiformis鈥� is well adapted to environments rich in organic matter and sulphides while聽D. proteiformis聽morph 鈥渞apa鈥� 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.

McKillop,W.B.,聽Patterson, R.T.,聽Delorme, L.D., Nogrady, T. 1992 (published in 1994). The origin, physico-chemistry and biotics of sodium chloride dominated saline waters on the western shore of Lake Winnepegosis, Manitoba. Canadian Field-Naturalist, 106:454-473.

Twenty-three sodium chloride dominated saline sites clustered along the western shore of Lake Winnipegosis were studied over a three year period. Sites were classified into four habitat categories based in part on salinity, which frequently exceeded that of oceanic environments. The source of the saline waters together with associated physico-chemical factors and unique biological communities are described. In addition to an unique flora, members of five animal phyla; Chordata, Protozoa, Rotifera, Arthropoda, and Mollusca, were present. Of these only the Mollusca lacked marine representation. Transport of the marine species by birds from coastal areas is suggested.

Reinhardt, E.G.,聽Patterson, R.T., and Schr枚der-Adams, C.J. 1994, Geoarchaeology of the ancient harbor site of Caesarea Maritima, Israel: evidence from sedimentology and paleoecology of benthic foraminifera. Journal of Foraminiferal Research, 24:37-48. https://doi.org/10.2113/gsjfr.24.1.37

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 (鈥渕辞谤辫丑蝉”) within three species of thecamoebians in varying paleolomnological settings has resulted in a refined understanding of the environmental parameters controlling their distribution. For example:聽D. proteiformis聽morph 鈥減roteiformis鈥� is well adapted to environments rich in organic matter and sulphides while聽D. proteiformis聽morph 鈥渞apa鈥� 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.

Clark, F.,聽Patterson, R.T., and Fishbein, E, 1994, Distribution of Holocene benthic foraminifera from the tropical southwest Pacific Ocean. Journal of Foraminiferal Research, 24: 241-267. https://doi.org/10.2113/gsjfr.24.4.241

A suite of 62 surface and near surface samples has been examined for its benthic foraminiferal faunas. The cores sampled ranged from 110 to 8900 m water depth, and are distributed across the tropical southwest Pacific Ocean, north and east of Australia. A total of 606 species were identified. Census data was obtained for each sample, and species found in statistically significant fractional abundances (88 in all) were analyzed using a new Q-mode clustering algorithm (Error Weighted Maximum Likelihood [EWML]). Both the full data set, and an edited data set comprising 44 samples and 39 species, were analyzed. With the aid of these analyses ten benthic foraminiferal assemblages were identified. Three manually constrained assemblages, each represented by a single sample, were recognized. Five statistically constrained assemblages were recognized, each having a water depth range coincident with the range of known water masses of the region. The聽Astrononion echolsi-Cassidulina teretisAssemblage and the聽Nuttalites bradyanus聽Assemblage were developed in samples from depths bathed by waters of the Deep Oxygen Minimum, the聽Epistominella exigua-Globocassidulina rarilocula聽Assemblage was developed in samples from depths bathed by Deep Water, a derivative Antarctic Bottom Water, and both the聽Globocassidulina subglobosa-Pseudoparrella parca聽Assemblage and the聽Nuttalides umboniferusAssemblage were developed in samples from depths bathed by Antarctic Bottom Water proper. From depths very near the calcite compensation depth (CCD), a Mixed Calcareous/Agglutinated Abyssal Assemblage was developed in a pair of samples, whereas below the CCD, the tenth assemblage, the Abyssal Agglutinated Assemblage, was developed, with only a few corroded calcareous specimens accompanying the agglutinated benthic faunas. These latter two assemblages were also manually constrained.

Patterson, R.T., and Luternauer, J.L. 1993. Holocene foraminiferal faunas from cores collected on the Fraser River delta, British Columbia: a paleoecological Interpretation: Current Research, Paper 93-1A:245-254. https://doi.org/10.4095/134211

Interpretation of sedimentary environments are made based on the foraminiferal faunas recovered from four cores (FD90-A, FD90-B, FD91-1, and FD91-2) collected on the Fraser delta. These relatively short cores (<55 m) are primarily comprised of prodelta sands overlying ancetral Strait of Georgia mud and silt. The muds and silts are characterized by a low diversity foraminifera fauna, dominated by Buccella frigida, Cribroelphidium excavatum, and Elphidiella hannai. This fauna is typical of low salinity, neritic depth conditions. Foraminifera are virtually absent from the prodelta sands as the winnowing conditions prevalent during deposition of this unit made colonization difficult.

Josenhans, H.W., Barrie, J.V., Conway, C.,聽Patterson, R.T., Mathewes, R.W. and Woodsworth, G.J. 1993. Surficial geology of the Queen Charlotte Basin: evidence of submerged proglacial lakes at 170 m on the continental shelf of western Canada. Current Research, Paper 93-1A: 186?192. https://doi.org/10.4095/134198

A high resolution marine seismic and sampling program in the region was carried out during a 12 day cruise aboard the research vessel CFAV Endeavour. Preliminary results indicate that grounded glaciers deposited sediments in the deep troughs which indent the continental shelf as far west as the shelf break. Offlapping till tongues found in the troughs indicate that ice retreated stepwise from Queen Charlotte Sound at the closed of the last (Late Wisconsinan) glaciation. Detailed studies of submerged shoreline deposits define the volume and frequency of failure of steeply dipping prograde sand and gravel deposits.

Clark, F., and聽Patterson, R.T., 1993. A taxonomic key to the unilocular genera of calcareous foraminifera. Journal of Paleontology, 67:20-28. https://doi.org/10.1017/s0022336000021132

Taxonomic keys are rarely used as an aid to the identification of foraminifera. Such keys become increasingly attractive, however, as the number of taxa which must be distinguished becomes large. The proliferation of known genera over the last 25 years is nowhere more apparent than in the unilouclar foraminifera, where the number of genera has risen from five to 46. We present herein a dichotomous key in which any species may be assigned to its proper genus by progressing through a series of steps, consisting of paired statements, in which only one choice is made at a time.

Mathewes, R.W., Heusser, L.E., and聽Patterson, R.T., 1993.Evidence for a Younger Dryas-like cooling event on the British Columbia coast. Geology, 21:101-104. https://doi.org/10.1130/0091-7613(1993)021<0101:efaydl>2.3.co;2

Two independent paleoclimatic records from the Pacific coast of Canada indicate that a late-glacial warming trend was interrupted by a return to colder conditions between about 11,000 and 10,200 radiocarbon yr. B.P., correlative with the classical Younger Dryas chronozone of the North Atlantic region. Fossil benthic foraminifera from three cores from the continental shelf dated by accelerator mass spectrometry show peak abundances of the cold-water indicator species聽Cassidulina reniforme聽at this time. Fossil-pollen spectra from two sites on the Queen Charlotte Islands record a shift from forest to open, herb-rich vegetation after 11,100 year B.P., probably in response to colder and wetter conditions identified by pollen-climate transfer functions. These preliminary data for a cold oscillation between ca. 11,000 and 10,000 yr ago in the northeast Pacific argue that this deglacial phenomenon was not restricted to the North Atlantic, but was a hemispheric 鈥� and possibly global 鈥� event.

Fishbein, E., and聽Patterson, R.T., 1993. 鈥淓rror weighted maximum likelihood (EWML)鈥� a new statistically valid method to cluster quantitative micropaleontological data. Journal of Paleontology, 67:475-486. https://doi.org/10.1017/s0022336000036921

The advent of readily-available computer-based clustering packages has created some controversy in the micropaleontological community concerning the use and interpretation of computer based biofacies discrimination. This is because dramatically different results can be obtained depending on methodology. The analysis of various clustering techniques reveals that in most instances, no statistical hypothesis is contained in the clustering model and that no basis exists for accepting one biofacies partitioning over another. Furthermore most techniques do not consider standard error in species abundances and generate results that are not statistically relevant. When many rare species are present, accumulated statistically insignificant differences in rare species can overshadow the significant differences in the major species leading to biofacies containing members having little in common.

A statistically-based 鈥渆rror-weighted maximum likelihood鈥� (EWML) clustering method is described that determines biofacies by assuming samples from a common biofacies are normally distributed. This method also weights species variability to be inversely proportional to measurement uncertainty. The method has been applied to samples collected from the Fraser River Delta marsh and shows that five distinct biofacies can be resolved in the data. Similar results were obtained from readily available packages when the data set was preprocessed to reduce the number of degrees of freedom. Based on the sample results from the new algorithm, and on tests using a representative micropaleonotological data set, a more conventional iterative processing method is recommended. This method, although not statistical in nature, produces similar results to EWML (not commercially available yet) with readily available analysis packages. Finally, some of the more common clustering techniques are discussed and strategies for their proper utilization are recommended.

Evoy, R.W., Moslow, T.F.,聽Patterson, R.T., and Luternauer, J.L. 1993. Patterns and variability in sediment accumulation rates, Fraser River delta foreslope, British Columbia, Canada. Geo-Marine Letters, 13:212-218. https://doi.org/10.1007/bf01207750

Minimum sediment accumulation rates on the Fraser River delta foreslope exhibit a high degree of spatial variation, with accumulation rates ranging from 0.50 to 3.0 cm/yr. Accumulation rates generally increase towards Sand Heads channel, the active foreslope depocenter. Sedimentation rates and patterns and micropaleontological assemblages are interpreted to reflect reintroduction of older sediment from upslope via slumping and sediment-gravity flow processes. Such processes account for the bulk of sedimentiton in much of the subaquaeous delta. These processes provide a mechanism for sand bypassing of the delta plain and foreslope and for deliver of coarse-grained sediment directly to prodelta and basinal environments.

Patterson, R.T., Cavazza, W., and Blenkinsop, J. 1993.Tortaguttus stiloensis,聽a new species of foraminifera from the Plio-Pleistocene of Calabria, Italy: Transactions of the American Microscopical Society, 112:168?171. https://doi.org/10.2307/3226831

Tortaguttus stiloensis,聽a new species of benthic foraminifera is described from Middle Pleistocene sediments of Calabria, Italy. This species is characterized by radiating elevated costae on the surface of a double marginal carinae connected by numerous crosstruts.

Patterson, R.T., 1993. Late Quaternary benthic foraminiferal biofacies and paleoceanography of Queen Charlotte sound and southern Hecate Strait, British Columbia. Journal of Foraminiferal Research, 23:1-18. https://doi.org/10.2113/gsjfr.23.1.1

Analysis of Late Quaternary benthic foraminifera in cores from Queen Charlotte Sound and Hecate Strait yields new information on the paleoceanographic history of the region. Q-mode cluster analysis grouped samples
into seven associations reflecting benthic foraminiferal biofacies: the Gyroidina-Bolivina Biofacies and Gyroidina-Seabrookia Biofacies are relict lower to middle bathyal faunas introduced to shallower depths when cooler water masses influenced the area; the Cribroelphidium Biofacies, I slandiella Biofacies, Epistominella Biofacies, and Bucella Biofacies are similar to each other in faunal makeup and characterize varying depositional conditions at neritic depths; the Lobatuln-Gavelinopsis Biofacies characterizes shallow, high energy, shelly banks. Repetition of many of these biofacies in the cores indicates an overall instability, or cyclic nature, of the water masses affecting the region through the Late Quaternary.

A gradual increase in the proportion of Buliminelln elegantissima, a foraminifer associated with terriginous plant debris suggests a gradual decrease in sea level during deposition of the Bl lithologic unit (~= 12,000 years BP in the cores presented here) deposited at most sites. A population maximum of Buliminella elegantissima in diachronous lag deposits of the B2 lithologic unit (=11,600-10,000 years BP) indicates a maximum lowstand. The almost complete absence of this species in superjacent B3 lithologic unit sediments indicates subsequent rapid subsidence and termination of terrestrial organic input, probably due to the collapse of the Fraser Glaciation forebulge. Deposition of the B3 unit had terminated everywhere in the region by =9,000 years BP. A Cassidulina reniforme population maximum occurs in sediments dated between about 10,100 and 11,300 years B.P. The presence of high proportions of this species, associated with very cold water (glacial or near-glacial) regimes, indicates a brief interval of cooler conditions during deglaciation, isochronous with the Younger Dryas event of Europe and eastern North America. This suggests that this event is not restricted to the North Atlantic but represents a much more widespread phenomenon.