scholarly journals Pedothem carbonates reveal anomalous North American atmospheric circulation 70,000–55,000 years ago

2016 ◽  
Vol 113 (4) ◽  
pp. 919-924 ◽  
Author(s):  
Erik J. Oerter ◽  
Warren D. Sharp ◽  
Jessica L. Oster ◽  
Angela Ebeling ◽  
John W. Valley ◽  
...  
Keyword(s):  
North American ◽  
Inductively Coupled Plasma ◽  
Climatic Conditions ◽  
Uranium Isotopes ◽  
Glacial Cycles ◽  
Inductively Coupled ◽  
Wind River Basin ◽  
The North ◽  
Before And After ◽  
Paleoclimate Records

Our understanding of climatic conditions, and therefore forcing factors, in North America during the past two glacial cycles is limited in part by the scarcity of long, well-dated, continuous paleoclimate records. Here, we present the first, to our knowledge, continuous, millennial-resolution paleoclimate proxy record derived from millimeter-thick pedogenic carbonate clast coatings (pedothems), which are widely distributed in semiarid to arid regions worldwide. Our new multiisotope pedothem record from the Wind River Basin in Wyoming confirms a previously hypothesized period of increased transport of Gulf of Mexico moisture northward into the continental interior from 70,000 to 55,000 years ago based on oxygen and carbon isotopes determined by ion microprobe and uranium isotopes and U-Th dating by laser ablation inductively coupled plasma mass spectrometry. This pronounced meridional moisture transport, which contrasts with the dominant zonal transport of Pacific moisture into the North American interior by westerly winds before and after 70,000–55,000 years ago, may have resulted from a persistent anticyclone developed above the North American ice sheet during Marine Isotope Stage 4. We conclude that pedothems, when analyzed using microanalytical techniques, can provide high-resolution paleoclimate records that may open new avenues into understanding past terrestrial climates in regions where paleoclimate records are not otherwise available. When pedothem paleoclimate records are combined with existing records they will add complimentary soil-based perspectives on paleoclimate conditions.

Detrital zircon geochronology of the Aycross Formation (Eocene) near Togwotee Pass, western Wind River Basin, Wyoming

2017 ◽  
Vol 54 (2) ◽  
pp. 69-85 ◽  
Author(s):  
David Malone ◽  
John Craddock ◽  
Kacey Garber ◽  
Jarek Trela
Keyword(s):  
Late Cretaceous ◽  
Detrital Zircon ◽  
Inductively Coupled Plasma ◽  
Middle Eocene ◽  
Detrital Zircons ◽  
Zircon Age ◽  
Detrital Zircon Geochronology ◽  
Inductively Coupled ◽  
Wind River Basin ◽  
The North

The Aycross Formation is the basal unit of the Absaroka Volcanic Supergroup in the southern Absaroka Range and consists of volcanic sandstone, mudstone, breccia, tuff and conglomerate. The Aycross was deposited during the waning stages of the Laramide Orogeny and the earliest phases of volcanism in the Absaroka Range. U-Pb geo-chronology using laser ablation multicollector inductively coupled plasma mass spectrometry LA-ICP-MS was performed on detrital zircons collected from an Aycross sandstone bed at Falls Campground east of Togwotee Pass. The detrital zircon age spectrum ranged fom ca 47 to 2856 Ma. Peak ages, as indicated by the zircon age probability density plot are ca. 51, 61, and 72 Ma. Tertiary zircons were the most numerous (n = 32), accounting for 42% of the zircon ages spectrum. Of these 19 are Eocene, and 13 are Paleocene, which are unusual ages in the Wyoming-Idaho-Montana area. Mesozoic zircons (n = 21) comprise 27% of the age spectrum and range in age from 68–126 Ma; all but one being late Cretaceous in age. No Paleozoic zircons are present. Proterozoic zircons range in age from 1196–2483 Ma, and also consist of 27% of the age spectrum. The maximum depositional age of the Aycross Formation is estimated to be 50.05 +/− 0.65 Ma based on weighted mean of the eight youngest grains. The Aycross Formation detrital zircon age spectrum is distinct from that of other 49–50 Ma rocks in northwest Wyoming, which include the Hominy Peak and Wapiti Formations and Crandall Conglomerate. The Aycross must have been derived largely from distal westerly source areas, which include the late Cretaceous and Paleocene Bitteroot Lobe of the Idaho Batholith. In contrast, the middle Eocene units further to the north must have been derived from erosion of the Archean basement-cored uplift of the Laramide Foreland in southwest Montana.

scholarly journals Effect of wood biomass components on self-heating

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Nozomi Miyawaki ◽  
Takashi Fukushima ◽  
Takafumi Mizuno ◽  
Miyao Inoue ◽  
Kenji Takisawa
Keyword(s):  
Moisture Content ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Chemical Oxidation ◽  
Spontaneous Ignition ◽  
Emission Spectrometry ◽  
Inductively Coupled ◽  
Self Heating ◽  
Inorganic Substances ◽  
Before And After

AbstractBiomass may ignite due to biological oxidation and chemical oxidation. If this phenomenon (spontaneous ignition) is controlled, it would be possible to produce biochar at a lower cost without the need for an external heat resource. We investigated if self-heating could be controlled by using sawdust and bark chips. When sawdust and bark chips were used under controlled conditions, the bark chips temperature increased to the torrefaction temperature. The ash content of bark chips was ~ 2%d.b. higher than that of sawdust; consequently, the inorganic substances contained in the bark chips might affect the self-heating. Self-heating was suppressed when inorganic substances were removed by washing with water. Therefore, the inorganic substances in the biomass might have affected self-heating. The inorganic element contents of the bark chips were measured by inductively coupled plasma optical emission spectrometry before and after washing. The potassium content of the bark chips was reduced remarkably by washing, and there was a possible influence of potassium on self-heating. Finally, the effect of moisture content on self-heating was investigated to obtain stable reactivity. Thus, at a moisture content of 40%w.b., a steady self-heating behavior may be realized.

Provenance of basaltic tephra from Vatnajökull subglacial volcanoes, Iceland, as determined by major- and trace-element analyses

The Holocene ◽  
2011 ◽  
Vol 21 (7) ◽  
pp. 1037-1048 ◽  
Author(s):  
Bergrún Arna Óladóttir ◽  
Olgeir Sigmarsson ◽  
Gudrún Larsen ◽  
Jean-Luc Devidal
Keyword(s):  
Trace Element ◽  
Inductively Coupled Plasma ◽  
Major Element ◽  
Element Composition ◽  
Major Element Composition ◽  
Volcanic System ◽  
The Holocene ◽  
Inductively Coupled ◽  
Ice Cap ◽  
The North

The Holocene eruption history of subglacial volcanoes in Iceland is largely recorded by their tephra deposits. The numerous basaltic tephra offer the possibility to make the tephrochronology in the North Atlantic area more detailed and, therefore, more useful as a tool not only in volcanology but also in environmental and archaeological studies. The source of a tephra is established by mapping its distribution or inferred via compositional fingerprinting, mainly based on major-element analyses. In order to improve the provenance determinations for basaltic tephra produced at Grímsvötn, Bárdarbunga and Kverkfjöll volcanic systems in Iceland, 921 samples from soil profiles around the Vatnajökull ice-cap were analysed for major-element concentrations by electron probe microanalysis. These samples are shown to represent 747 primary tephra units. The tephra erupted within each of these volcanic system has similar chemical characteristics. The major-element results fall into three distinctive compositional groups, all of which show regular decrease of MgO with increasing K2O concentrations. The new analyses presented here considerably improve the compositional distinction between products of the three volcanic systems. Nevertheless, slight overlap of the compositional groups for each system still remains. In situ trace-element analyses by laser-ablation-inductively-coupled-plasma-mass-spectrometry were applied for better provenance identification for those tephra having similar major-element composition. Three trace-element ratios, Rb/Y, La/Yb and Sr/Th, proved particularly useful. Significantly higher La/Yb distinguishes the Grímsvötn basalts from those of Bárdarbunga and Rb/Y values differentiate the basalts of Grímsvötn and Kverkfjöll. Additionally, the products of Bárdarbunga, Grímsvötn and Kverkfjöll form distinct compositional fields on a Sr/Th versus Th plot. Taken together, the combined use of major- and trace-element analyses in delineating the provenance of basaltic tephra having similar major-element composition significantly improves the Holocene tephra record as well as the potential for correlations with tephra from outside Iceland.

Otolith microchemistry of Nezumia aequalis (Pisces: Macrouridae) from widely different habitats in the Atlantic and Mediterranean

2003 ◽  
Vol 83 (4) ◽  
pp. 883-886 ◽  
Author(s):  
Sarah C. Swan ◽  
John D.M. Gordon ◽  
Beatriz Morales-Nin ◽  
Tracy Shimmield ◽  
Terrie Sawyer ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Fish Populations ◽  
Reykjanes Ridge ◽  
Inductively Coupled ◽  
The North ◽  
Microchemical Analysis ◽  
Physical Environments ◽  
Eastern Atlantic Ocean ◽  
North Eastern ◽  
Plasma Mass Spectrometry

Otoliths were obtained from Nezumia aequalis, a small macrourid that is widely distributed throughout the Atlantic and Mediterranean—two very different physical environments. Microchemical analysis of the otoliths was carried out using solution-based inductively coupled plasma mass spectrometry of whole otoliths. Significant differences between fish populations were found for concentrations of the elements Li and Sr. Only 54% of the samples were correctly classified by area using discriminant analysis. Otolith samples from the Reykjanes Ridge were most easily distinguished. The results are discussed in relation to trace element concentrations in the waters of the north-eastern Atlantic Ocean and the Mediterranean Sea.

Understanding pre- and syn-orogenic tectonic evolution in western Himalaya through age and petrogenesis of Palaeozoic and Cenozoic granites from upper structural levels of Bhagirathi Valley, NW India

2021 ◽  
pp. 1-27
Author(s):  
Aranya Sen ◽  
Koushik Sen ◽  
Amitava Chatterjee ◽  
Shubham Choudhary ◽  
Alosree Dey
Keyword(s):  
Inductively Coupled Plasma ◽  
Age Distribution ◽  
Normal Fault ◽  
Western Himalaya ◽  
Indian Plate ◽  
Low Grade ◽  
Inductively Coupled ◽  
The North ◽  
Plasma Mass Spectrometry ◽  
Structural Levels

Abstract The Himalaya is characterized by the presence of both pre-Himalayan Palaeozoic and syn-Himalayan Cenozoic granitic bodies, which can help unravel the pre- to syn-collisional geodynamics of this orogen. In the Bhagirathi Valley of Western Himalaya, such granites and the Tethyan Himalayan Sequence (THS) hosting them are bound to the south by the top-to-the-N extensional Jhala Normal Fault (JNF) and low-grade metapelite of the THS to its north. The THS is intruded by a set of leucocratic dykes concordant to the JNF. Zircon U–Pb laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) geochronology of the THS and one leucocratic dyke reveals that the two rocks have a strikingly similar age distribution, with a common and most prominent age peak at ~1000 Ma. To the north of the THS lies Bhaironghati Granite, a Palaeozoic two-mica granite, which shows a crystallization age of 512.28 ± 1.58 Ma. Our geochemical analysis indicates that it is a product of pre-Himalayan Palaeozoic magmatism owing to extensional tectonics in a back-arc or rift setting following the assembly of Gondwana (500–530 Ma). The Cenozoic Gangotri Leucogranite lies to the north of Bhaironghati Granite, and U–Pb dating of zircon from this leucogranite gives a crystallization age of 21.73 ± 0.11 Ma. Our geochemical studies suggest that the Gangotri Leucogranite is a product of muscovite-dehydration melting of the lower crust owing to flexural bending in relation to steepening of the subducted Indian plate. The leucocratic dykes are highly refracted parts of the Gangotri Leucogranite that migrated and emplaced along extensional fault zones related to the JNF and scavenged zircon from the host THS during crystallization.

scholarly journals Patterns of millennial variability over the last 500 ka

2010 ◽  
Vol 6 (3) ◽  
pp. 295-303 ◽  
Author(s):  
M. Siddall ◽  
E. J. Rohling ◽  
T. Blunier ◽  
R. Spahni
Keyword(s):  
Atmospheric Circulation ◽  
North Atlantic ◽  
Glacial Cycles ◽  
The North ◽  
The North Atlantic ◽  
Paleoclimate Records ◽  
Temperature Proxy ◽  
Freshwater Release ◽  
Glacial Periods ◽  
Climate Events

Abstract. Millennial variability is a robust feature of many paleoclimate records, at least throughout the last several glacial cycles. Here we use the mean signal from Antarctic climate events 1 to 4 to probe the EPICA Dome C temperature proxy reconstruction through the last 500 ka for similar millennial-scale events. We find that clusters of millennial events occurred in a regular fashion over half of the time during this with a mean recurrence interval of 21 kyr. We find that there is no consistent link between ice-rafted debris deposition and millennial variability. Instead we speculate that changes in the zonality of atmospheric circulation over the North Atlantic form a viable alternative to freshwater release from icebergs as a trigger for millennial variability. We suggest that millennial changes in the zonality of atmospheric circulation over the North Atlantic are linked to precession via sea-ice feedbacks and that this relationship is modified by the presence of the large, Northern Hemisphere ice sheets during glacial periods.

scholarly journals Assessment of Albumin ECM Accumulation and Inflammation as Novel In Vivo Diagnostic Targets for Multi-Target MR Imaging

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 964
Author(s):  
Jana Möckel ◽  
Julia Brangsch ◽  
Carolin Reimann ◽  
Jan O. Kaufmann ◽  
Ingolf Sack ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Endothelial Damage ◽  
Plaque Burden ◽  
Signal Loss ◽  
Inductively Coupled ◽  
Before And After ◽  
Plasma Mass Spectrometry ◽  
Magnetic Resonance Imaging Mri ◽  
Mri Study

Atherosclerosis is a progressive inflammatory vascular disease characterized by endothelial dysfunction and plaque burden. Extracellular matrix (ECM)-associated plasma proteins play an important role in disease development. Our magnetic resonance imaging (MRI) study investigates the feasibility of using two different molecular MRI probes for the simultaneous assessment of ECM-associated intraplaque albumin deposits caused by endothelial damage and progressive inflammation in atherosclerosis. Male apolipoprotein E-deficient (ApoE-/-)-mice were fed a high-fat diet (HFD) for 2 or 4 months. Another ApoE-/--group was treated with pravastatin and received a HFD for 4 months. T1- and T2*-weighted MRI was performed before and after albumin-specific MRI probe (gadofosveset) administration and a macrophage-specific contrast agent (ferumoxytol). Thereafter, laser ablation inductively coupled plasma mass spectrometry and histology were performed. With advancing atherosclerosis, albumin-based MRI signal enhancement and ferumoxytol-induced signal loss areas in T2*-weighted MRI increased. Significant correlations between contrast-to-noise-ratio (CNR) post-gadofosveset and albumin stain (R2 = 0.78, p < 0.05), and signal loss areas in T2*-weighted MRI with Perls’ Prussian blue stain (R2 = 0.83, p < 0.05) were observed. No interference of ferumoxytol with gadofosveset enhancement was detectable. Pravastatin led to decreased inflammation and intraplaque albumin. Multi-target MRI combining ferumoxytol and gadofosveset is a promising method to improve diagnosis and treatment monitoring in atherosclerosis.

scholarly journals Anti-Microbial, Anti-Oxidant, and α-Amylase Inhibitory Activity of Traditionally-Used Medicinal Herbs: A Comparative Analyses of Pharmacology, and Phytoconstituents of Regional Halophytic Plants’ Diaspora

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5457
Author(s):  
Mohsen Al-Omar ◽  
Hamdoon Mohammed ◽  
Salman Mohammed ◽  
Essam Abd-Elmoniem ◽  
Yasser Kandil ◽  
...  
Keyword(s):  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Inhibition Zone ◽  
Climatic Conditions ◽  
Inductively Coupled ◽  
Long Time ◽  
Iron And Zinc ◽  
Anti Oxidant ◽  
Halophytic Plants

Halophytes are the category of plants growing under harsh conditions of super-salinity, and are wide-spread in the coastal Mediterranean climatic conditions and desert oasis. They are adept at surviving through maintaining excessive production of enzymatic, and non-enzymatic secondary metabolites, especially phenolics and flavonoids that primarily work as anti-oxidants and phytoalexins. Five major halophyte species growing in the kingdom’s Qassim’s high-salted desert regions were investigated for confirming their traditionally used biological activity of sugar-control and anti-infectious properties. In this context, the comparative presence of phenolics, and flavonoids together with anti-microbial, anti-oxidants, and the anti-diabetic potentials of the plants’ extracts were investigated through the α-amylase inhibition method. The highest concentrations of phenolics and flavonoids were detected in Salsola imbricata (360 mg/g of the extract as Gallic-Acid-Equivalents/GAE, and 70.5 mg/g of the extract as Rutin-Equivalents/RE). In contrast, the lowest concentrations of phenolics and flavonoids were detected in Salsola cyclophylla (126.6 mg/g GAE, and 20.5 mg/g RE). The halophytes were found rich in trace elements, a factor for water-retention in high-salinity plants, wherein iron and zinc elements were found comparatively in higher concentrations in Aeluropus lagopoides (4113 µg/kg, and 40.1 µg/kg, respectively), while the copper was detected in higher concentration (11.1 µg/kg) in S. imbricata, analyzed through Inductively Coupled Plasma Optical Emission Spectrometric (ICP-OES) analysis. The anti-oxidant potentials and α-amylase enzyme inhibition-based anti-diabetic activity of S. imbricata was significantly higher than the other halophytes under study, wherein S. cyclophylla exhibited the lowest level of α-amylase inhibition. The maximum DPPH radicals’ (52.47 mg/mL), and α-amylase inhibitions (IC50 22.98 µg/mL) were detected in A.lagopoides. The anti-microbial activity against the Methicillin-Resistant Staphylococcus aureus was strongly exhibited by Zygophyllum simplex (33 mm Inhibition Zone-Diameter, 50 µg/mL Minimum-Inhibitory-Concentration), while Escherichia coli, Enterococcus faecalis, and Candida albicans growths were moderately inhibited by Tamarix aphylla. The current findings exhibited significant differences among the locally distributed halophytic plants species with regards to their bioactivity levels, anti-oxidant potentials, and the presence of trace elements. The ongoing data corroborated the plants’ traditional uses in infections and diabetic conditions. The enhanced local distribution of the plants’ diaspora and higher density of occurrence of these plants species in this region, in comparison to their normal climatic condition’s counterparts, seemed to be affected by humans’ use of the species as part of the traditional and alternative medicine over a period of long time.

Using Mineral Chemistry to Aid Exploration: A Case Study from the Resolution Porphyry Cu-Mo Deposit, Arizona

2020 ◽  
Vol 115 (4) ◽  
pp. 813-840 ◽  
Author(s):  
David R. Cooke ◽  
Jamie J. Wilkinson ◽  
Mike Baker ◽  
Paul Agnew ◽  
Josh Phillips ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Mineral Chemistry ◽  
Three Dimensions ◽  
Temperature Sensitive ◽  
Blind Test ◽  
Inductively Coupled ◽  
Porphyry Cu ◽  
The North ◽  
Icp Ms ◽  
Volcaniclastic Rocks

Abstract The giant, high-grade Resolution porphyry Cu-Mo deposit in the Superior district of Arizona is hosted in Proterozoic and Paleozoic basement and in an overlying Cretaceous volcaniclastic breccia and sandstone package. Resolution has a central domain of potassic alteration that extends more than 1 km outboard of the ore zone, overlapping with a propylitic halo characterized by epidote, chlorite, and pyrite that is particularly well developed in the Laramide volcaniclastic rocks and Proterozoic dolerite sills. The potassic and propylitic assemblages were overprinted in the upper parts of the deposit by intense phyllic and advanced argillic alteration. The district was disrupted by Tertiary Basin and Range extension, and the fault block containing Resolution and its Cretaceous host succession was buried under thick mid-Miocene dacitic volcanic cover, obscuring the geologic, geophysical, and geochemical footprint of the deposit. To test the potential of propylitic mineral chemistry analyses to aid in the detection of concealed porphyry deposits, a blind test was conducted using a suite of epidote-chlorite ± pyrite-altered Laramide volcaniclastic rocks and Proterozoic dolerites collected from the propylitic halo, with samples taken from two domains located to the north and south and above the Resolution ore zone. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data of epidote provided indications of deposit fertility and proximity. Competition for chalcophile elements (As, Sb, Pb) between coexisting pyrite and epidote grains led to a subdued As-Sb fertility response in epidote, consistent with epidote collected between 0.7 and 1.5 km from the center of a large porphyry deposit. Temperature-sensitive trace elements in chlorite provided coherent spatial zonation patterns, implying a heat source centered at depth between the two sample clusters, and application of chlorite proximitor calculations based on LA-ICP-MS analyses provided a precisely defined drill target in this location in three dimensions. Drilling of this target would have resulted in the discovery of Resolution, confirming that epidote and chlorite mineral chemistry can potentially add value to porphyry exploration under cover.

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