Age of the Cutler Dam Alloformation (Late Pleistocene), Bonneville Basin, Utah

2001 ◽  
Vol 56 (3) ◽  
pp. 322-334 ◽  
Author(s):  
Darrell S. Kaufman ◽  
Steve L. Forman ◽  
Jordon Bright
Keyword(s):  
Amino Acid ◽  
Cold Climate ◽  
Deep Lake ◽  
Oxygen Isotope Stage ◽  
Infrared Stimulated Luminescence ◽  
Stage 4 ◽  
Show Evidence ◽  
Glacial Stage ◽  
Glacier Ice ◽  
Bonneville Basin

AbstractLuminescence geochronology, especially infrared stimulated luminescence analyses on marsh mud, shows that a relatively deep lake reached its peak (∼1340 m above sea level) in the Bonneville basin 59,000±5000 yr ago. The age is consistent with nonfinite 14C ages and with amino acid geochronology on ostracodes. The Cutler Dam Alloformation was deposited during this lake cycle, which, like the subsequent Bonneville lake cycle, appears to have reached its maximum highstand following the peak of a global glacial stage (marine oxygen-isotope stage 4) but at a time when other records from North America show evidence for cold climate and expanded glacier ice.

scholarly journals Discovery of the skull ofStephanorhinus kirchbergensis(Jäger, 1839) above the Arctic Circle

2017 ◽  
Vol 88 (3) ◽  
pp. 537-550 ◽  
Author(s):  
Irina V. Kirillova ◽  
Olga F. Chernova ◽  
Jan van der Made ◽  
Vladimir V. Kukarskih ◽  
Beth Shapiro ◽  
...  
Keyword(s):  
Complete Mitochondrial Genome ◽  
Cold Climate ◽  
The Arctic ◽  
Arctic Circle ◽  
Climate Conditions ◽  
Oxygen Isotope Stage ◽  
Microwear Analysis ◽  
Stage 4 ◽  
History Of ◽  
Open Woodland

AbstractThe skull of the extinct rhinocerosStephanorhinus kirchbergensis(Jäger, 1839) was discovered in the Chondon River valley (Arctic Yakutia, Russia) during the summer of 2014. This is the first find ofStephanorhinusabove the Arctic Circle, expanding significantly the known geographic range of the genus.14C dating and geologic evidence indicate that the skull dates to between 48,000 and 70,000 yr, corresponding to Marine Oxygen Isotope Stage 4/3. It is thus among the latest records of this species. To explore the evolutionary and natural history of this relatively unknown animal, we performed morphological, dietary, and genetic analyses. Phylogenetic inference based on a complete mitochondrial genome sequence confirms the systematic placement ofStephanorhinusas most closely related to the extinct woolly rhinoceros,Coelodonta. Food remains in the fossas of the cheek teeth, identified asLarix,Vaccinium,Betulasp.,Aulacomnium, and dicotyledonous herbs and grasses, suggest a mixed feeder’s diet. Microwear analysis suggests that, during the last months of its life, this individual fed predominantly on leaves and twigs. The habitat ofStephanorhinuscomprised grassland and open woodland that were characterized by moist and cold climate conditions, similar to those in the region today.

Palynology of Oxygen Isotope Stage 6 and Substage 5e from the Cover Beds of a Marine Terrace, Taranaki, New Zealand

1990 ◽  
Vol 34 (1) ◽  
pp. 86-100 ◽  
Author(s):  
M. Royd Bussell
Keyword(s):  
New Zealand ◽  
Oxygen Isotope ◽  
Major Change ◽  
Oxygen Isotope Stage ◽  
Long Period ◽  
Marine Terraces ◽  
Tree Ferns ◽  
Glacial Stage ◽  
Marine Platform ◽  
Organic Deposits

AbstractCover beds on uplifted Quaternary marine terraces in the Taranaki-Wanganui area of New Zealand include organic deposits which yield abundant pollen. In the west at Ohawe, marine shore platform deposits are overlain by laterally extensive lignites and laharic breccia, interbedded with alluvium and capped by tephra-rich loess. Following a time of presumably interglacial marine deposition on the platform, a long period of glacial climate is suggested by pollen floras dominated by grass and shrubland taxa. Trees were sparse, but the abundance of podocarps, Nothofagus, and tree ferns increased during at least one interval, suggesting minor climatic amelioration. Near the top of the section, a major change in regional vegetation is recorded by a dominance of pollen derived from podocarp-hardwood forest taxa, including Ascarina, interpreted as indicating a fully interglacial climate. The marine platform, previously assigned to oxygen isotope substage 5e, is now placed in stage 7. The overlying deposits were deposited during glacial stage 6, while interglacial substage 5e is recorded by sediment and pollen assemblages near the top of the section.

scholarly journals Vocabulaire périglaciaire bilingue

2005 ◽  
Vol 6 (12) ◽  
pp. 201-226 ◽  
Author(s):  
Louis-Edmond Hamelin ◽  
Peter Clibbon
Keyword(s):  
Systematic Study ◽  
Cold Climate ◽  
Frozen Ground ◽  
Patterned Ground ◽  
Chemical Erosion ◽  
Action Effect ◽  
Climate Action ◽  
French And English ◽  
Glacier Ice ◽  
English Speaking

A considerable lack of agreement exists, particularly between French and English-speaking geomorphologists, on the precise use of many periglacial terms, and up to the presenty there bas been little correlation of the periglacial terminology of these two languages. Accordingly, the authors have prepared a bilingual glossary of 900 periglacial terms in an attempt to eliminate some of this confusion. Many of the problems encountered in the preparation of this glossary result from different conceptions of the terms « periglacial » and « périglaciaire ». Periglacial studies are generally considered to involve analyses of permanently frozen ground, patterned ground and frost-shattering, whereas the term « périglaciaire »refers to the systematic study of all « cold »processes (except those associated with glacier ice) and their resultant phenomena. The term thus includes, amongst other things, gelifraction, gelifluction, geliturbation, fluvioperiglacial action, effect of sea, lake, river and ground ice, windwork in areas of cold climate, action of snow, and chemical erosion by meltwater.

Geochronology of Middle and Upper Pleistocene Loess Sections in Hungary

1997 ◽  
Vol 48 (3) ◽  
pp. 291-312 ◽  
Author(s):  
Manfred Frechen ◽  
Erzsébet Horváth ◽  
Gyula Gábris
Keyword(s):  
Accumulation Rate ◽  
Luminescence Dating ◽  
Glacial Cycle ◽  
Last Interglacial ◽  
High Accumulation ◽  
Oxygen Isotope Stage ◽  
Infrared Stimulated Luminescence ◽  
Derivatives Of ◽  
Very High ◽  
The Last Glacial

The application of both thermoluminescence and infrared stimulated luminescence dating to the extensively studied “classical” Hungarian loess/paleosol sequences from Basaharc, Mende, and Paks provides a reliable chronological framework and climatostratigraphic reconstruction for the last interglacial/glacial cycle. Based on this combined luminescence dating study a new chronology is proposed for the “Young Loess” in Hungary. Luminescence dating suggests that the loess below the MF2 horizon formed during the penultimate glaciation. The MF1 horizon probably formed during an interstade within oxygen isotope stage 3. For the youngest loess, overlying MF1, a very high accumulation rate was determined. Large time gaps occur above MF2 and MF1, indicating that most of the record of the last glaciation is missing in the standard sections at Basaharc, Mende, and Paks. Either large discontinuities or a very low accumulation rate occurred in all three type sections during the soil-forming periods. High-resolution studies of climatic proxies using this combined luminescence dating approach provide a reliable chronological framework for loess and loess derivatives of the last glacial cycle in Hungary, although a precise and complete chronostratigraphic reconstruction cannot be achieved from the incomplete records found at these sites.

scholarly journals An evaluation of climate, crustal movement and base level controls on the Middle-Late Pleistocene development of the River Severn, U.K.

2002 ◽  
Vol 81 (3-4) ◽  
pp. 329-338 ◽  
Author(s):  
D. Maddy
Keyword(s):  
Sea Level ◽  
Late Glacial ◽  
High Energy ◽  
Cold Climate ◽  
Faunal Remains ◽  
Sea Level Changes ◽  
Climate Conditions ◽  
Oxygen Isotope Stage ◽  
Base Level

AbstractThe Pleistocene development of the lower Severn valley is recorded in the fluvial sediments of the Mathon and Severn Valley Formations and their relationship to the glacigenic Wolston (Oxygen Isotope Stage 12), Ridgacre (OIS 6) and Stockport (OIS 2) Formations. The most complete stratigraphical record is that of the Severn Valley Formation, which post-dates the Anglian Wolston Formation and comprises a flight of river terraces, the highest of which is c.50 m above the present river. The terrace staircase indicates that the Severn has progressively incised its valley during the post-Anglian period. The terrace sediments are predominantly composed of fluvially deposited sands and gravels, largely the result of deposition in high-energy rivers under cold-climate conditions. Occasionally towards the base of these terrace deposits low-energy fluvial facies are preserved which contain faunal remains and yield geochronology which support their correlation with interglacial conditions. This simple stratigraphy supports a climate-driven model for the timing of terrace aggradation and incision, with the incision mode at its most effective during the cold-warm transitions and the aggradational mode at its most effective during warm-cold climate transitions. The chronology of terrace aggradation in the lower Severn seems to correspond with the Milankovitch lOOka climate cycles. The timing of incision events suggests that base level (eustatic sea-level) changes do not play a significant role i.e. incision occurs as sea-level is rising.Although climate change is significant in governing the timing of incision, the long-term incision of the River Severn appears to be driven by crustal uplift. A long-term incision rate of 0.15 m ka1, calculated using the base of the terrace deposits, is believed to closely equate with the long-term uplift rate. Superimposed on this long-term uplift are periods of complex terrace sequence development resulting from rapid incision during periods of glacio-isostatic rebound, with large incision events reflecting the rebound adjustment to late glacial stage isostatic depression. However, in no case in the Severn valley has glacial encroachment led to enhanced incision, suggesting that there has been no additional uplift resulting from isostatic compensation for glacial erosion.

scholarly journals Genome Shrinkage and Loss of Nutrient-Providing Potential in the Obligate Symbiont of the Primitive Termite Mastotermes darwiniensis

2011 ◽  
Vol 78 (1) ◽  
pp. 204-210 ◽  
Author(s):  
Zakee L. Sabree ◽  
Charlie Ye Huang ◽  
Gaku Arakawa ◽  
Gaku Tokuda ◽  
Nathan Lo ◽  
...  
Keyword(s):  
Amino Acid ◽  
Gut Microbiome ◽  
Essential Amino Acid ◽  
Diet Shift ◽  
Evolutionary Divergence ◽  
Relaxed Selection ◽  
Content Type ◽  
Gut Microbes ◽  
Termite Gut ◽  
Show Evidence

ABSTRACTBeneficial microbial associations with insects are common and are classified as either one or a few intracellular species that are vertically transmitted and reside intracellularly within specialized organs or as microbial assemblages in the gut. Cockroaches and termites maintain at least one if not both beneficial associations.Blattabacteriumis a flavobacterial endosymbiont of nearly all cockroaches and the termiteMastotermes darwiniensisand can use nitrogenous wastes in essential amino acid and vitamin biosynthesis. Key changes during the evolutionary divergence of termites from cockroaches are loss ofBlattabacterium, diet shift to wood, acquisition of a specialized hindgut microbiota, and establishment of advanced social behavior. Termite gut microbes collaborate to fix nitrogen, degrade lignocellulose, and produce nutrients, and the absence ofBlattabacteriumin nearly all termites suggests that its nutrient-provisioning role has been replaced by gut microbes.M. darwiniensisis a basal, extant termite that solely retainsBlattabacterium, which would show evidence of relaxed selection if it is being supplanted by the gut microbiome. This termite-associatedBlattabacteriumgenome is ∼8% smaller than cockroach-associatedBlattabacteriumgenomes and lacks genes underlying vitamin and essential amino acid biosynthesis. Furthermore, theM. darwiniensisgut microbiome membership is more consistent between individuals and includes specialized termite gut-associated bacteria, unlike the more variable membership of cockroach gut microbiomes. TheM. darwiniensis Blattabacteriumgenome may reflect relaxed selection for some of its encoded functions, and the loss of this endosymbiont in all remaining termite genera may result from its replacement by a functionally complementary gut microbiota.

Radiocarbon and Cation-Radio Ages for Rock Varnish on Tioga and Tahoe Marainal Boulders of Pine Creek, Eastern Sierra Nevada, California, and their Paleoclimatic Implications

1987 ◽  
Vol 28 (1) ◽  
pp. 38-49 ◽  
Author(s):  
Ronald I. Dorn ◽  
Brent D. Turrin ◽  
A. J. Timothy Jull ◽  
Timothy W. Linick ◽  
Douglas J. Donahue
Keyword(s):  
Mass Spectrometry ◽  
Sierra Nevada ◽  
Lake Level ◽  
Oxygen Isotope Stage ◽  
Effective Period ◽  
Stage 4 ◽  
Rock Varnish ◽  
Pine Creek ◽  
Cation Ratio ◽  
Eastern Sierra Nevada

AbstractAccelerator mass spectrometry 14C analyses of organic matter extracted from rock varnishes on morainal boulders yield limiting minimum ages for three crests of the Tioga glaciation. At Pine Creek in the eastern Sierra Nevada, varnish started to form on boulders of the outermost Tioga moraine before 19,000 yr B.P., and varnish originated on the innermost Tioga moraine before 13,200 yr B.P. Comparisons with lake-level, paleohydrological, paleoecological, colluvial, and rock varnish micromorphological data indicate that central-eastern California and western Nevada experienced a moisture-effective period during the late Pleistocene but after the Tioga maximum, and perhaps as Tioga glaciers receded from the mouth of Pine Creek canyon. Varnishes on Tahoeage morainal boulders at Pine Creek have cation-ratio ages of about 143,000–156,000 yr B.P., suggesting that the Tahoe glaciation should not be correlated with oxygen-isotope stage 4 in the early Wisconsin, but rather with stage 6. Varnishes on morainal boulders of an older glaciation at Pine Creek are dated by cation ratio at about 182,000–187,000 yr B.P.

Glutathione transferase isoenzymes from Bufo bufo embryos at an early developmental stage

1992 ◽  
Vol 283 (1) ◽  
pp. 217-222 ◽  
Author(s):  
C Di Ilio ◽  
A Aceto ◽  
T Bucciarelli ◽  
B Dragani ◽  
S Angelucci ◽  
...  
Keyword(s):  
Amino Acid ◽  
Developmental Stage ◽  
Glutathione Transferase ◽  
Bufo Bufo ◽  
Amino Acid Sequences ◽  
Early Developmental Stage ◽  
Terminal Amino Acid ◽  
Stage 4 ◽  
Terminal Amino ◽  
Ph Range

Six forms of glutathione transferase (GST) were resolved from the cytosolic fraction of Bufo bufo embryos at developmental stage 4 by GSH-Sepharose affinity chromatography followed by f.p.l.c. chromatofocusing in the 9-6 pH range. They have apparent isoelectric points at pH 8.37 (GST I), 8.22 (GST II), 8.10 (GST III), 7.84 (GST IV), 7.37 (GST V) and 7.12 (GST VI), and each displayed an apparent subunit molecular mass of 23 kDa by SDS/PAGE. The Bufo bufo embryo enzymes showed very similar structural, catalytic and immunological properties, as indicated by their substrate-specificities, inhibition characteristics, c.d. spectra, h.p.l.c. elution profiles and immunological reactivities, as well as by their N-terminal amino acid sequences. Although Bufo bufo embryo GSTs do not correspond to any other known GSTs, the results of our experiments indicate that amphibian GSTs could be included in the Pi family of GSTs. This conclusion is supported by the analysis of c.d. spectra, and by the fact that mammalian Pi class GSTs and amphibian GSTs showed about 80% identity in their N-terminal amino acid sequences. Furthermore, antisera prepared against Bufo bufo GST III cross-reacted in immunoblotting analysis with Pi class GSTs, and vice versa.

Cosmogenic nuclide chronology of pre-last glacial maximum moraines at Lago Buenos Aires, 46�S, Argentina

2005 ◽  
Vol 63 (3) ◽  
pp. 301-315 ◽  
Author(s):  
Michael R. Kaplan ◽  
Daniel C. Douglass ◽  
Bradley S. Singer ◽  
Robert P. Ackert ◽  
Marc W. Caffee
Keyword(s):  
Northern Hemisphere ◽  
Erosion Rate ◽  
Buenos Aires ◽  
Glacial Cycles ◽  
Rate Estimate ◽  
Oxygen Isotope Stage ◽  
Erosion Rates ◽  
Cosmogenic Nuclide ◽  
Stage 4 ◽  
Glacial Advance

At Lago Buenos Aires, Argentina, 10Be, 26Al, and 40Ar/39Ar ages range from 190,000 to 109,000 yr for two moraines deposited prior to the last glaciation, 23,000�16,000 yr ago. Two approaches, maximum boulder ages assuming no erosion, and the average age of all boulders and an erosion rate of 1.4 mm/103 yr, both yield a common estimate age of 150,000�140,000 yr for the two moraines. The erosion rate estimate derives from 10Be and 26Al concentrations in old erratics, deposited on moraines that are >760,000 yr old on the basis of interbedded 40Ar/39Ar dated lavas. The new cosmogenic ages indicate that a major glaciation during marine oxygen isotope stage 6 occurred in the mid-latitude Andes. The next five youngest moraines correspond to stage 2. There is no preserved record of a glacial advance during stage 4. The distribution of dated boulders and their ages suggest that at least one major glaciation occurred between 760,000 and >200,000 yr ago. The mid-latitude Patagonian glacial record, which is well preserved because of low erosion rates, indicates that during the last two glacial cycles major glaciations in the southern Andes have been in phase with growth and decay of Northern Hemisphere ice sheets, especially at the 100,000 yr periodicity. Thus, glacial maxima are global in nature and are ultimately paced by small changes in Northern Hemisphere insolation.

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