Environmental geological research in the Lake Balaton region
C 14 dating ; Eutrophication ; Holocene ; Human impact ; Hungary ; Lacustrine sediment ; Lake ; Lake level ; Palaeo-ecology ; Pollution ; Quaternary ; Recreation area ; Stratigraphy
The research was focused mainly on surveying lake deposits, as well as the morphology and structure of the Pre-Quaternary lake deposits and the morphology and structure of the Pre-Quaternary basement of Lake Balaton. Paleontological investigations
(pollen, diatoms, ostracods) in the 4 subbasins of the lake allowed the reconstruction of the ecological history of the area as well providing detailed stratigraphic information. Radiocarbon dating of peat helps to date the beginning of lake formation
. In the Holocene increasing temperature and precipitation brought about a progressive rise in lake level.
Late Pleistocene marine chronology of the Gippsland Lakes region, Australia
Australia ; Coastal dune ; Coastal dynamics ; Coastal environment ; Coastal sedimentation ; Dating ; Lake ; New South Wales ; Pleistocene ; Thermoluminescence ; Tsunami
The aim of this paper is to assess, using mainly thermoluminescence dating, the chronology of the Gippsland Lakes barriers between Lake Tyers in the east and Wilson Promontory in the west, and to present a revised model for the coastal evolution
Holocene fluctuations of a meromictic lake in southern British Columbia
British Columbia ; C 14 dating ; Canada ; Climatic variation ; Holocene ; Lacustrine sedimentation ; Lake ; Lake level ; Palaeoclimatology ; Palaeogeography ; Precipitation ; Salt lake ; Semi-arid area ; Stratigraphy ; Tephrochronology
The AA. describe the stratigraphy of a 5.45-m-long sediment core from Mahoney Lake, a meromictic lake in southern British Columbia. Using changes in sediment alone, the AA. infer changes in lake levels from which they deduce changes in climate
. They infer many sharp oscillations in lake level, and they ascribe these to climate fluctuations throughout the Holocene.
AMS radiocarbon dating of Lake Michigan beach-ridge and dune development
C 14 dating ; Dune ; Lake ; Lake level ; Michigan ; Palaeo-environment ; Palaeoclimate ; Regression analysis ; United States of America
Strandplains of shore-parallel beach ridges bordering the Great Lakes are valuable for reconstructing histories of climate-related lake-level fluctuations. The resolution and imprecision of radiocarbon chronologies can be improved with AMS C 14
dates of roots and rhizomes of plant species associated with the formation and growth of the sand -dune caps of beach ridges. An AMS radiocarbon chronology of beach-ridge formation in northern Lake Michigan shows that information about variation
Biogenic silica record in Lake Biwa of central Japan over the past 145,000 years
Biogenic process ; Diatom ; Geochronology ; Glacial features ; Honshu ; Interglacial ; Japan ; Lacustrine sedimentation ; Lake ; Palaeoclimatology ; Palynology ; Quaternary ; Silica
The record of the biogenic silica flux (BSF) in Lake Biwa reflects changes in diatom productivity in the lake and provides information regarding changes in paleoclimatic conditions. The BSF record of Lake Biwa demonstrates 5 periods over the past ca
. 145,000 yr and 5 intervals. Time series of the BSF record can be correlated with the record of biogenic silica content in Lake Baikal and the marine oxygen isotopes stages 1 through 6. Furthermore, the BSF values varied with much higher amplitude during
A high-resolution 11,400-yr diatom record from Lake Victoria, East Africa
Afrique ; Afrique de l'Est ; Diagramme pollinique ; Diatomée ; Holocène ; Lake Victoria ; Niveau lacustre ; Palynologie ; Paléo-environnement ; Paléo-écologie ; Quaternaire ; Sédiment lacustre ; Variation climatique ; Zone intertropicale
Africa ; Climatic variation ; Diatom ; Eastern Africa ; Holocene ; Lacustrine sediment ; Lake level ; Palaeo-ecology ; Palaeo-environment ; Palynology ; Pollen diagram ; Quaternary ; Tropical zone
Fine-interval (30-45 yr) sampling of a core from Lake Victoria's Damba Channel shows that numerous abrupt changes in the lake's diatom assemblages have occurred in response to climatic fluctuations over the past 11,400 C 14 yr. 4 distinct climatic
phases bounded by sudden transitions are inferred. The diatom-inferred paleoclimatic history for northern Lake Victoria closely resembles that inferred from a well-dated pollen record from Pilkington Bay.
Late Quaternary temporal and event classifications, Great Lakes region, North America
Amérique du Nord ; Canada ; Chronostratigraphie ; Classification ; Etats-Unis ; Glaciaire ; Great Lakes ; Interglaciaire ; Quaternaire ; Stratigraphie
Canada ; Chronostratigraphy ; Classification ; Glacial features ; Great Lakes ; Interglacial ; North America ; Quaternary ; Stratigraphy ; United States of America
In this paper, diachronic and event classifications are proposed for the Great Lakes region. Well-established names, including Wisconsin, Sangamon, and Illinois, are used at the episode (or glaciation/interglaciation) rank without significant
redefinition. The Hudson Episode (Interglaciation) is introduced for postglacial time, the current interglacial interval. The Wisconsin Episode is divided into the Ontario, Elgin, and Michigan Subepisodes in the eastern and northern parts of the Great Lakes
region and into the Athens and Michigan Subepisodes in the southern and western parts of the Great Lakes region.
Climatic oscillations 10,000-155,000 yr B.P. at Owens Lake, California reflected in glacial rock flour abundance and lake salinity in core OL-92
California ; Carbonate ; Clay mineral ; Climatic variation ; Core sampling ; Geochemistry ; Glacier advance ; Lacustrine sediment ; Lake ; Quaternary ; Salinity ; United States of America
Chemical analyses of the acid-soluble and clay-size fractions of sediment samples (1500-yr resolution) reveal oscillations of lake salinity and of glacial advances in core OL-92 back to 155,000 yr B.P. The AA. found that the mineralogy and chemistry
of the clay fraction provide indices of glacial rock flour. They also report on the composition of the acid-soluble carbonate fraction which gives further detail on closed-lake conditions.
Radiocarbon ages and environments of deposition of the Wono and Trego hot springs tephra layers in the Pyramid Lake subbasin, Nevada
C 14 dating ; Lacustrine sedimentation ; Lake level ; Nevada ; Oxygen 18 ; Palaeogeography ; Pleistocene ; Quaternary ; Sedimentary structure ; Tephrochronology ; United States of America ; Volcanic ash ; Watershed
This paper presents new information on the age and environment of deposition of the Trego Hot Springs (THS) and Wono layers that indicate the surface of Pyramid Lake lay well below the Sqaw Creek site when the Trego tephra layer was deposited
. The studies indicate that the surface elevation of Pyramid Lake was at or below its spill point to Winnemucca Lake subbasin (1177 m) when the THS layer was deposited and was at its spill point to the Smoke Creek-Black Rock Desert subbasin (1207 m) when
Paleomagnetic investigation of lake Lahontan sediments and its application for dating pluvial events in the Northwestern Great Basin
A comparison of paleomagnetic secular variation in sediment of Pleistocene Lake lahontan in the northwestern Great basin with secular variation in lake sediment in the Mono Basin, California, indicates that Lake Lahontan was in the valley
of the Truckee River between Pyramid Lake and Wadsworth, Nevada, from about 19,000 to 13,000 yr B.P. On the basis of field mapping and tephrochronology, the sections of older lacustrine sediments are not coeval. The apparent, but erroneous, correlation of those
Dynamic variations of water quality in Taihu Lake and multivariate analysis of its influential factors
Beijing ; China ; Eutrophication ; Lake ; Pollution ; Principal components analysis ; Seasonal variation ; Spatial variation ; Suspended load ; Water quality
Dynamic variation of water quality in Meiliang Bay and part of West Taihu Lake has been analysed based on data from 1991 to 1992. Principal component analysis is used to reveal the mutual relationships of various factors.
A 3500 14C yr high-resolution record of water-level changes in lake Titicaca, Bolivia/Peru
Bolivia ; C 14 dating ; Climatic variation ; Core sampling ; Geochemistry ; Geochronology ; Holocene ; Lacustrine sedimentation ; Lake ; Lake level ; Lithology ; Peru ; Quaternary ; South America ; Watershed
Sediment cores collected from the southern basin of Lake Titicaca, on a transect from 4.6 m above overflow level to 15.1 m below overflow level are used to identify a new century-scale chronology of Holocene lake-level variations. The results
indicate that lithologic and geochemical analyses on a transect of cores can be used to identify and date century-scale lake-level changes. Detailed sedimentary analyses of subfacies and radiocarbon dating were conducted on 4 representative cores. Several
of the low lake levels coincided with cultural changes in the region, including the collapse of the Tiwanaku civilization.
Water balance and sediment yield in Lake Balaton catchment, Hungary
Ecosystem ; Eutrophication ; Fertilizer ; Hungary ; Lake ; Pollution ; Recreation area ; Sediment budget ; Suspended load ; Water balance ; Watershed
Lake Balaton being a recreation area of international significance, research on the influx of sediments and solutes as well as on pollution and eutrophication is very important. Methods include a detailed analysis of a test area typical for the N
. characterize the role of the N catchment from the aspect of the lake ecosystem.
Aerial photography ; British Columbia ; Canada ; Flood ; Glacial features ; Glacial lake ; Ice breakup ; Meltwater ; Photointerpretation
This paper documents a previously unreported jökulhlaup from an unnamed lake at the margin of Goddard Glacier in the southern Coast Mountains of British Columbia. This event is of interest because Goddard Lake probably first formed in the middle
in the hydrogeological system of the Hévíz lake. The paleogeographical reconstruction was based on large-scale geological models. A special attention was paid to the geomorphological control on sedimentation and karstification. The consequences of differential erosion
Eolian quartz flux to Lake Biwa, central Japan, over the past 145,000 years
In this study, the AA. isolated monomineralic quartz from lacustrine sediments of Lake Biwa, central Japan, identified atmospherically transported quartz grains in the sediments, and inferred variations in the intensity of East Asian winter monsoon
during the past 145,000 yr based on fluctuations in the influx of eolian quartz to the lake.
Andes ; Archaeology ; Aridity ; Bolivia ; Civilization ; Climatic variation ; Holocene ; Lake level ; Palaeogeography ; Palaeolimnology ; Peru ; Quaternary ; South America
Paleolimnological and archaeological records that span 3500 years from Lake Titicaca and the surrounding Bolivian-Peruvian altiplano demonstrate that the emergence of agriculture (ca. 1500 B.C.) and the collapse of the Tiwanaku civilization (ca. A.D
. 1100) coincided with periods of abrupt, profound climate change. The timing and magnitude of climate changes are inferred from stratigraphic evidence of lake-level variation recorded in 14C-dated lake-sediments cores. A prolonged drier period (ca. A.D
Genetically complex and morphologically diverse pingos in the Fish Lake area of South West Banks Island, N.W.T., Canada
Banks Island ; Canada ; Classification ; Frost action ; Geomorphogenesis ; Lake level ; Northwest Territories ; Palaeogeography ; Periglacial features ; Permafrost ; Pingo ; Thermokarst
, active and collapsed/collapsing features. The presence of deep kettle lakes in the area probably creates a dynamic system of interlinked taliks which influence the groundwater supply to centres of ground ice growth. All the pingos post-date the Last