A high-elevation MIS 5 hydrologic record using mollusks and ostracodes from Snowmass Village, Colorado, USA

2014 ◽  
Vol 82 (3) ◽  
pp. 604-617 ◽  
Author(s):  
Saxon E. Sharpe ◽  
Jordon Bright
Keyword(s):  
Stable Isotopes ◽  
Water Temperature ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
High Elevation ◽  
Total Dissolved Solids ◽  
Water Based ◽  
Fossil Site ◽  
Mis 5E ◽  
Mis 5

AbstractSediments containing terrestrial and aquatic mollusks and ostracodes from the Ziegler Reservoir fossil site (2705 m elevation) near Snowmass Village, Colorado, span ~130–87 ka (MIS 5e through 5b). The southeastern area of the site where taxa were recovered was a relatively fresh, shallow, well-vegetated wetland during MIS 5e through 5c time, approximately 2 m deep, with a total dissolved solids value of ~200–1000 mg L− 1. The wetland was seasonally or annually variable and groundwater discharged along the margins of the bounding moraine. Groundwater likely contributed solutes to the system and may have contributed 18O-enriched water. Based on stable isotopes from ostracode calcite (δ18OOST and δ13COST), seasonal evaporation occurred and the dissolved inorganic carbon pool was unexpectedly enriched in 13C. The mollusk and ostracode faunas changed little across the MIS 5e/5d/5c boundaries, whereas a distinct change in the ostracode fauna occurred between the deposition of Unit 11 and Unit 13, which corresponds in time to the MIS 5c/5b boundary, indicating some combination of increased surface and/or groundwater flow, a decrease in water temperature, and a freshening and a possible deepening of the wetland.

A quantitative midge-based reconstruction of mean July air temperature from a high-elevation site in central Colorado, USA, for MIS 6 and 5

2014 ◽  
Vol 82 (3) ◽  
pp. 580-591 ◽  
Author(s):  
Danielle R. Haskett ◽  
David F. Porinchu
Keyword(s):  
Sierra Nevada ◽  
Air Temperature ◽  
High Elevation ◽  
Oxygen Isotope Stage ◽  
Subfossil Chironomids ◽  
Air Temperatures ◽  
Fossil Site ◽  
Colorado Rockies ◽  
Mis 5E ◽  
Mis 5

AbstractSediments recovered from the Ziegler Reservoir fossil site (ZRFS) in Snowmass Village, Colorado (USA) were analyzed for subfossil chironomids (or midges). The midge stratigraphy spans ~140–77 ka, which includes the end of Marine Oxygen Isotope Stage (MIS) 6 and all of MIS 5. Notable shifts in midge assemblages occurred during two discrete intervals: the transition from MIS 6 to MIS 5e and midway through MIS 5a. A regional calibration set, incorporating lakes from the Colorado Rockies, Sierra Nevada, and Uinta Mountains, was used to develop a midge-based mean July air temperature (MJAT) inference model (r2jack = 0.61, RMSEP = 0.97°C). Model results indicate that the transition from MIS 6 to MIS 5e at the ZRFS was characterized by an increase in MJAT from ~9.0 to 10.5°C. The results also indicate that temperatures gradually increased through MIS 5 before reaching a maximum of 13.3°C during MIS 5a. This study represents the first set of quantitative, midge-based MJAT estimates in the continental U.S. that spans the entirety of MIS 5. Overall, our results suggest that conditions in the Colorado Rockies throughout MIS 5 were cooler than today, as the upper limit of the reconstructed temperatures is ~2°C below modern July air temperatures.

Taxonomic overview and tusk growth analyses of Ziegler Reservoir proboscideans

2014 ◽  
Vol 82 (3) ◽  
pp. 518-532 ◽  
Author(s):  
Daniel C. Fisher ◽  
Michael D. Cherney ◽  
Cody Newton ◽  
Adam N. Rountrey ◽  
Zachary T. Calamari ◽  
...  
Keyword(s):  
High Elevation ◽  
Environmental Pressures ◽  
Terminal Pleistocene ◽  
Fossil Site ◽  
Males And Females ◽  
Low Levels ◽  
Colorado Rockies ◽  
Mammut Americanum ◽  
Source Of Information ◽  
Mis 5

AbstractAt an altitude of 2705 m in the Colorado Rockies (USA), the Ziegler Reservoir fossil site gives a rare look at a high-elevation ecosystem from the late Pleistocene (especially MIS 5) of North America. Remains of more than four mammoths and about 35 mastodons dominate the macrofossil assemblage. Mammoth remains are attributed to Mammuthus columbi, and mastodon remains are referred to the well-known, continent-wide Mammut americanum. Mastodon remains occur within and between several lake-margin slump deposits. Their deposition must therefore have occurred as events that were to some degree separate in time. We treat the mastodon assemblage in each stratigraphic unit as a source of information on environmental conditions during the lives of these individuals. Mastodon mandibular tusks are abundant at the site and represent both males and females, from calves to full-grown adults. This study presents the first attempt to use microCT, thin-section, and isotope records from mandibular tusks to reconstruct features of life-history. We recognize an up-section trend in δ18O profiles toward higher values, suggestive of warmer temperatures. Throughout this sequence, mastodon growth histories show low mean sensitivities suggestive of low levels of environmental stress. This work helps frame expectations for assessing environmental pressures on terminal Pleistocene populations.

Diel behavior of stable isotopes of dissolved oxygen and dissolved inorganic carbon in rivers over a range of trophic conditions, and in a mesocosm experiment

2010 ◽  
Vol 269 (1-2) ◽  
pp. 22-32 ◽  
Author(s):  
Stephen R. Parker ◽  
Christopher H. Gammons ◽  
Simon R. Poulson ◽  
Michael D. DeGrandpre ◽  
Charmaine L. Weyer ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Dissolved Oxygen ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Mesocosm Experiment ◽  
Trophic Conditions

Growth characteristics of bloom-forming filamentous green algae in the littoral zone of an experimentally acidified lake

1995 ◽  
Vol 52 (10) ◽  
pp. 2251-2263 ◽  
Author(s):  
Michael A. Turner ◽  
Leif J. Sigurdson ◽  
David L. Findlay ◽  
E. Todd Howell ◽  
Gordon G. C. Robinson ◽  
...  
Keyword(s):  
Water Temperature ◽  
Green Algae ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Benthic Algae ◽  
Growth Characteristics ◽  
Experimental Lakes Area ◽  
Filamentous Green Algae ◽  
High Photosynthetic Capacity ◽  
Major Factors

Filamentous green algae, predominantly Mougeotia and Zygogonium, bloom frequently in the littoral zones of acidified lakes. Growth characteristics of Zygogonium-dominated filamentous green algae were studied for 4 yr in an experimentally acidified (pH 4.5) lake at the Experimental Lakes Area of northwestern Ontario. They were present in low abundance as periphyton (algal associations attached to surfaces) during spring, and as blooms of metaphyton (benthic algae unconstrained by surfaces) beginning in midsummer and reaching a maximum in early fall. Metaphytic filamentous green algae displayed high photosynthetic capacity in summer despite the oligotrophic nature of the acidified lake. The major factors controlling photosynthetic rates of Zygogonium were similar to those controlling Mougeotia, and included algal crowding, irradiance, dissolved inorganic carbon, and water temperature. Rates of photosynthesis were negatively dependent upon algal crowding, so that highest rates were associated with minimum algal crowding. Light requirements for photosynthesis were higher than those of the epilithon, which were dominant prior to acidification. The dependence of photosynthesis on ambient concentrations of dissolved inorganic carbon was partly regulated by water temperature. Anthropogenically caused releases from growth limitations (e.g., increased availability of limiting nutrients, increased water temperature, and extension of the growing season) may cause proliferation of filamentous green algae in the future.

scholarly journals Effect of Rainfall and pH on Musty Odor Produced in the Sanbe Reservoir

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3600
Author(s):  
Sangyeob Kim ◽  
Shohei Hayashi ◽  
Shingo Masuki ◽  
Kazuhiro Ayukawa ◽  
Shuji Ohtani ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Temperature ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Water Systems ◽  
Cyanobacterial Blooms ◽  
Field Observations ◽  
The World ◽  
Musty Odor ◽  
Harmful Cyanobacterial Blooms

Harmful cyanobacterial blooms are continuously formed in water systems such as reservoirs and lakes around the world. Geosmin and 2-methylisoborneol (2-MIB) produced by some species of cyanobacteria have caused odor problems in the drinking water of the Sanbe Reservoir in Japan. Field observations were conducted for four years (2015–2019) to investigate the cause of this musty odor. It was found that geosmin was produced by Dolichospermum crassum and Dolichospermum planctonicum (cyanobacteria), and 2-MIB was due to Pseudanabaena sp. and Aphanizomenon cf. flos-aquae (cyanobacteria). Changes in water temperature and pH caused by rainfall were correlated with changes in the concentration of geosmin and 2-MIB. In particular, geosmin and 2-MIB tended to occur under low rainfall conditions. When there was low rainfall, the reservoir changed to an alkaline state because the phytoplankton consumed CO2 for photosynthesis. In an alkaline reservoir, dissolved inorganic carbon mainly existed in the form of bicarbonate (HCO3−). Thus, the results suggest that under such conditions in reservoirs, cyanobacteria grew easily because they could use both CO2 and HCO3− for photosynthesis. Specifically, our study suggests that in order for the musty odor problem in the reservoir to be solved, it is important that the pH of the reservoir be controlled.

scholarly journals PHYSICOCHEMICAL AND ISOTOPIC CHARACTERIZATION OF FORMATION WATERS FROM OIL FIELDS IN THE SERGIPE BASIN, BRAZIL

2014 ◽  
Vol 32 (3) ◽  
pp. 531
Author(s):  
Danilo R. Sá Teles ◽  
Antônio Expedito G. de Azevedo ◽  
Alexandre B. Costa ◽  
Maria R. Zucchi ◽  
Alexandre A. Ferreira
Keyword(s):  
Stable Isotopes ◽  
Isotopic Exchange ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Oil Fields ◽  
Northeastern Brazil ◽  
Formation Water ◽  
Water Formation ◽  
Isotopic Characterization

ABSTRACT. This paper presents a study of the physicochemical and isotopic characteristics of formation waters from the Castanhal, Siririzinho and Aguilhadafields in the Sergipe Basin, northeastern Brazil. In each of the samples, pH, conductivity, concentration of dissolved inorganic carbon (DIC), δ18O, δ2H, and δ13C weremeasured. These measurements are used to identify isotopic similarities among waters from local aquifers, which can be used as a proxy for groundwater connectivitywith formation water. Formation waters from the Castanhal and Siririzinho fields are enriched in deuterium, as evidenced by their δ2H values above the Global MeteoricWater Line (GMWL), which may be a result of significant isotopic exchange between water and H2S. These measurements are in accordance with the large enrichment in13C of DIC resulting from biodegradation, with the formation of methane depleted in 13C and CO2 enriched in 13C. These results indicate interaction between formationwater with rocks and other fluids.Keywords: stable isotopes, dissolved inorganic carbon, biodegradation. RESUMO. Este trabalho apresenta um estudo das características físico-químicas e isotópicas de águas de formação dos campos Castanhal, Siririzinho e Aguilhada, localizados na Bacia de Sergipe, nordeste do Brasil. Em cada uma das amostras foram medidos os parâmetros pH, condutividade elétrica, concentração de carbonoinorgânico dissolvido (CID), δ18O, δ2H e δ13C. A partir dos resultados obtidos, foi possível identificar a similaridade isotópica com as águas de aquíferos locais,indicando conexão de água subterrânea com água de formação. As águas de formação dos campos Castanhal e Siririzinho apresentaram um enriquecimento em deutério,resultado da troca isotópica entre a água e o H2S. Também foi verificado, um grande enriquecimento no δ13C do CID, resultado dos processos de biodegradação coma formação de metano empobrecido em 13C e CO2 enriquecido neste isótopo. Os resultados encontrados indicam interação entre a água de formação com as rochas ecom outros fluidos.Palavras-chave: isótopos estáveis, carbono inorgânico dissolvido, biodegradação.

The interplay of glacial/interglacial climate-CO2 and productivity effects on coccolith calcification and vital effects across the MIS 12 to MIS 9 in the western tropical Atlantic

2020 ◽  
Author(s):  
Alba González-Lanchas ◽  
Heather M. Stoll ◽  
José-Abel Flores ◽  
Francisco J. Sierro ◽  
Ivan Hernandez-Almeida ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Isotopic Fractionation ◽  
Tropical Atlantic ◽  
Physiological Mechanisms ◽  
Carbon Isotopic ◽  
Acquisition Strategies ◽  
Climatic Period ◽  
Vital Effects

<p>Coccolithophores play an important dual role in ocean biogeochemistry: they use dissolved inorganic carbon (DIC) in the surface for both photosynthesis and coccolith calcification. Stable isotopes in coccoliths are the result of various effects, including different vital effects, allowing hypotheses about the varying active carbon acquisition strategies in response to changing environmental conditions. Understanding the physiological mechanisms that cause these changes remains challenging.</p><p>The MIS 12 to MIS 9 interval is a crucial climatic period encompassing changing glacial-interglacial cyclicity and pronounced variations in atmospheric CO<sub>2</sub> concentration. Different paleorecords indicate that coccoliths were an important component of the carbonate fraction during this interval, with the outstanding worldwide dominance of the highly calcified coccolithophore species <em>Gephyrocapsa caribbeanica</em>.</p><p>The carbon isotopic fractionation during photosynthesis (εp) in alkenones, biomarkers produced by coccolithophores, is a proxy to reconstruct past aqueous CO<sub>2</sub> concentration. Here we present a new εp reconstruction spanning this glacial/interglacial interval (460 to 330 kyr) at ODP Site 925 in the western tropical Atlantic. We aim to evaluate the interplay of CO<sub>2 </sub>and productivity effects on coccolith calcification and stable isotopes (δ<sup>18</sup>O and δ<sup>13</sup>C) in coccolith calcite integrating these data with the size and thickness of coccolith platelets and the geochemical Sr/Ca record.</p><p>The comparison of mean coccolith size with coeval samples from the deeper ODP Site 929 allows the evaluation of the degree of nannofossil dissolution across the interval.</p>

scholarly journals Comparison of temperature and humidity during MIS 11 and MIS 5e interglacials with the Holocene using stable isotopes in tufa deposits from northern France

2021 ◽  
pp. 1-12
Author(s):  
Julie Dabkowski ◽  
Nicole Limondin-Lozouet
Keyword(s):  
Stable Isotopes ◽  
Paris Basin ◽  
The Holocene ◽  
Calcareous Tufa ◽  
Continental Area ◽  
Molluscan Diversity ◽  
Moisture Conditions ◽  
Mis 5E ◽  
Mis 5 ◽  
Almost Continuous

Abstract Many recent palaeoclimatic studies have focused on Pleistocene interglacials, especially Marine Isotopic Stages (MIS) 5e and 11, as analogs to our modern interglacial (MIS 1). In continental area, archives allowing comparison between interglacials remain scarce. Calcareous tufa deposits, as they are characteristic of these periods and can provide long, almost continuous, palaeoclimatic records through their isotopic content, appear highly suitable for such investigation. In this paper, δ18O and δ13C values from the three well-dated tufas of Saint-Germain-le-Vasson, Caours, and La Celle are combined to compare temperature and moisture conditions prevailing during MIS 1, 5e, and 11, in the Paris Basin. Both Pleistocene interglacials, and especially their optima, appear stronger than the Holocene: MIS 11 was wetter and warmer than both the Holocene and MIS 5e, which itself experienced wetter conditions than the Holocene. These observations are consistent with palaeontological data from the studied sites, especially malacological assemblages, which record, as at other European tufa sites, a relative depletion of molluscan diversity during the Holocene compared with the Pleistocene (MIS 5 and 11) interglacials.

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