Influence of Climatic Trends and Cycles on Varve Deposition in Crawford Lake, Ontario, Canada
نویسندگان
چکیده
Varves accumulating below the chemocline of meromictic Crawford Lake, Milton, Ontario, Canada, consist dark-colored organic matter laminations that are primarily deposited during fall plankton die-off, alternating with light-colored comprising calcite crystals precipitated a relatively narrow water temperature and pH-controlled depositional window in summer. A novel high-resolution imaging protocol was used to photograph varve record 87 cm-long freeze core CRA19-2FT-B2, collected from deepest part (~23 m) lake February 2019. High-resolution images were to: (1) characterize couplets between AD 1870 2000 (chronology verified through 137Cs/210Pb analysis CRA22-1FRA-3, consistent historic nuclear fallout other proxies Great Acceleration); (2) document distinctive varves permit correlation cores throughout deep basin Lake; (3) measure thickness individual dark light- colored laminations, which found vary 0.04 mm 3.76 mm; (4) carry out wavelet spectral time series analyses based on data can be correlated climatic trends cycles. Time identified cycles statistically significant periodicities attributed Quasi-biennial Oscillation (2.3 years), El Niño Southern (2–7 11-year Schwabe Sunspot cycle possible Pacific Decadal (50–70 years). This research not only provides baseline chronostratigraphic allow subsampled for various proxies, but also documents dynamics climate drivers influence deposition both inorganically calcite. Lake is currently candidate site under consideration Global boundary Stratotype Section Point (GSSP) define Anthropocene series/epoch.
منابع مشابه
A Bayesian assessment of the mercury and PCB temporal trends in lake trout (Salvelinus namaycush) and walleye (Sander vitreus) from lake Ontario, Ontario, Canada.
Polychlorinated biphenyls (PCBs) and total mercury (THg) are two of the most prevalent contaminants, resulting in restrictive advisories on consuming fish from the Laurentian Great Lakes. The goal of this study is to examine the temporal trends of the two contaminants in walleye (Sander vitreus) and lake trout (Salvelinus namaycush) for Lake Ontario. We employed Bayesian inference techniques to...
متن کاملLimnological and sedimentary processes at Sawtooth Lake, Canadian High Arctic, and their influence on varve formation
This paper synthesizes data collected to document the modern limnological and sedimentary processes in South Sawtooth Lake located on northern Ellesmere Island, Nunavut, Canada. Field observations show that the finely laminated sediments deposited in the distal basin are formed by the settling of overflows and interflows, and in rare occasions, by non-erosive hyperconcentrated density flows. Th...
متن کاملcritical period effects in foreign language learning:the influence of maturational state on the acquisition of reading,writing, and grammar in english as a foreign language
since the 1960s the age effects on learning both first and second language have been explored by many linguists and applied linguists (e.g lennerberg, 1967; schachter, 1996; long, 1990) and the existence of critical period for language acquisition was found to be a common ground of all these studies. in spite of some common findings, some issues about the impacts of age on acquiring a second or...
15 صفحه اولImpacts of hydrodynamics and benthic communities on phytoplankton distributions in a large, dreissenid-colonized lake (Lake Simcoe, Ontario, Canada)
We quantified the vertical and horizontal variation of chlorophyll a (Chl-a) to test how benthic filter feeders (dreissenid mussels), rooted macrophytes, and hydrodynamics influence phytoplankton distributions in a large lake (Lake Simcoe, Canada). Water column Chl-a did not differ significantly among sites of different depth, distance offshore, or rooted macrophyte biomass, but among the nears...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Geosciences
سال: 2023
ISSN: ['2076-3263']
DOI: https://doi.org/10.3390/geosciences13030087