Geochemical Appraisal on History and Evolution of Barail Sandstones of Zote-Ngur, Champhai District, Mizoram, India

Mizoram is part of Surma basin which later evolved into the present state of geological terrain due to Indo- Myanmar tectonic collision during the Oligocene period. The present work deals with geochemical characteristics of Barail sandstones exposed in Champhai area of eastern region in Mizoram. The major/minor oxides, trace elements and rare earth elements data are used to infer the geological history and evolution of the sandstone in the study area of Champhai. The petrographic study shows the presence of various detrital grains like quartz, lithic fragments, feldspar, chertz, mica, etc., which are cemented by siliceous and ferruginous materials. Geochemically, the sandstones indicate high wt% of SiO2, Al2O3 and MgO compared to Upper Continental Crust (UCC) while rest of the major oxides indicate low concentrations. The geochemical classification indicated the sandstones as litharenite and wacke. The chondrite normalised REE pattern shows the enrichment of HREE and depletion of LREE with negative Eu anomaly. The value of Eu/Eu*, La/Lu, La/Co, Th/Sc, Th/Co, Cr/Th and high ratio of LREE/HREE of Barail sandstone suggest felsic source rock. The analysis of paleoweathering history indicated moderate to intensive weathering in the provenance. Various tectonic discriminant function diagrams suggested Active Continental Margin settings.

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Geological Guide to Selected Areas of the Kruger National Park

Koedoe ◽

10.4102/koedoe.v29i1.530 ◽

1986 ◽

Vol 29 (1) ◽

Cited By ~ 2

Author(s):

J.W. Bristow ◽

R. Sweeney ◽

F.J. Venter

Keyword(s):

National Park ◽

Kruger National Park ◽

Eastern Region ◽

Geological History ◽

Sedimentary Deposits ◽

Rock Types ◽

Southern Area ◽

Granitoid Rocks ◽

Western Half ◽

East West

The Kruger National Park (KNP) contains a considerable variety of rock types, ranging from Archaean granitoids to Recent sedimentary deposits. Some 3 500 million years of geological history is represented in an approximately 85 km east-west section at the southern area of the Kruger National Park. Older rocks are typically found in the western half of the KNP and to the east rock units become progressively younger. Some of the more important rock types found in the KNP include greenstones of the Barberton Mountain Land (approximately 3 500 million years old), granitoid rocks of the Nelspruit Batholith (approximately 3 200 million years old), syenitic intrusions associated with the Phalaborwa Complex (approximately 2 050 million years old), Soutpansberg volcanics and sediments (approximately 1 750 million years old), Timbavati Gabbros (approximately 1 450 million years old?), Karoo sediments and Lebombo volcanics (approximately 200 - 170 million years old) and Cretaceous to Recent sedimentary deposits which are best developed in the eastern region of the park.

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Prostaglandins (PG) Inhibit Human Platelet Aggregation by PG Receptor Antagonism as well as Adenylate Cyclase Stimulation

10.1055/s-0039-1684546 ◽

1979 ◽

Author(s):

D.E. MacIntyre ◽

E.W. Salzman

Keyword(s):

Platelet Aggregation ◽

Adenylate Cyclase ◽

Human Platelet ◽

High Ratio ◽

Receptor Antagonism ◽

Human Platelet Aggregation ◽

Alkyl Groups ◽

Low Concentrations ◽

Alkyl Substitution ◽

Adenylate Cyclase Stimulation

11-Deoxy and/or 15 or 16 alkyl substitution confer platelet aggregating activity to bis-enoic PG's: e.g., 11-deoxy-PGE2 (threshold (T)-5μM); ll-deoxy-15(S)-15-methyl-PGE2 (T=0.1μM);ll-deoxy-15(S)-16-methyl-PGE2(T=0.1μM). Responses induced by such PG’s mimic those induced by PGH2 and PGH2 analogues (e.g., U44069). N0164 competitively inhibits aggregation induced by PG’s and suppresses “secondary” responses induced by low concentrations of ADP or arachidonic acid, suggesting involvement of a specific PG stimulatory receptor in platelet aggregation. We compared non-aggregatory PG’s as inhibitors of pri mary aggregation induced by ADP or U44069. PG’s containing 11-deoxy and/or 16-alkyl groups selectively inhibited aggregation induced by U44069. Mean I50 values (n-4) against ADP and U44069 respectively were PGA2 (>100μM; 0.3μM); PGB2 (>100μM; 5μM); PGD2 (6nM; 2nM); PGE1(10nM; 5nM); 11-deoxy PGE1 (60μM; 2μM); ll-deoxy-15-(R)-16-methyl (100μM; 2μM); 13,14-dihydro-16-methyl-PGE2 methyl ester(750nM; 15nM). A low ADP: 406 I50 ratio (e.g., PGD2) indicates that inhibition is mainly due to adenylate cyclase stim ulation, and a high ratio (e.g., PGA2) that inhibition is mainly due to PG receptor antagonism. We have demonstrated a PG stimulatory receptor on the platelet, and its involvement in “secondary” aggregation. PG’s inhibit aggregation by combining with this receptor and/or by stimulating adenylate cyclase.

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Garnet Geochemistry of Reduced Skarn System: Implications for Fluid Evolution and Skarn Formation of the Zhuxiling W (Mo) Deposit, China

Minerals ◽

10.3390/min10111024 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1024

Author(s):

Xiao-Xia Duan ◽

Ying-Fu Ju ◽

Bin Chen ◽

Zhi-Qiang Wang

Keyword(s):

Major And Trace Elements ◽

Oscillatory Zoning ◽

Extrinsic Factors ◽

Rock Interaction ◽

Eu Anomaly ◽

Two Generations ◽

Formation Conditions ◽

In Suit ◽

Grossular Garnet ◽

Ree Pattern

A newly discovered tungsten ore district containing more than 300,000 tons of WO3 in southern Anhui Province has attracted great attention. The Zhuxiling W (Mo) deposit in the district is dominated by skarn tungsten mineralization. This paper conducted in suit EPMA and LA-ICPMS spot and mapping analysis of the skarn mineral garnet to reveal the evolution of fluids, metasomatic dynamics, and formation conditions of skarn. Two generations of garnet have been identified for Zhuxiling W (Mo) skarn: 1) Gt-I generation garnet is isotropic, Al-rich grossular without zoning. As a further subdivision, Gt-IB garnet (Adr19-46Grs49-77 (Sps+Pyr+Alm)4-5) contains significantly high content of Ti and Mn compared with Gt-IA garnet (Adr3-42Grs53-96 (Sps+Pyr+Alm)1-5). 2) Gt-II generation garnet is anisotropic, Fe-rich andradite with oscillatory zoning. Gt-II garnet displays compositional changes with a decrease of Fe and an increase of Mn from proximal skarn (Gt-IIA) to distal skarn (Gt-IIB) with the presence of subcalcic garnet for Gt-IIB type (Sps+Pyr+Alm = 56–68). The presence of pyrrhotite associated with subcalcic garnet indicates a relatively reduced skarn system. Gt-I grossular is overall enriched in Cr, Zr, Y, Nb, and Ta compared with the Gt-II andradite, and both W and Sn strongly favor Fe-rich garnet compared with Al-rich garnet. Gt-IA grossular garnet presents a REE trend with an upward-facing parabola peaking at Pr and Nd in contrast to low and flat HREE, and Gt-IB grossular garnet has a distinct REE pattern with enriched HREE. Gt-IIA andradite garnet displays a right-dipping REE pattern (enriched LREE and depleted HREE) with a prominent positive Eu anomaly (Eu/Eu* = 3.6–15.3). In contrast, Gt-IIB andradite garnet shows depleted LREE and enriched HREE with a weak positive Eu anomaly (Eu/Eu* = 0–6.0). The incorporation and fractionation of REE in garnet are collectively controlled by crystal chemistry and extrinsic factors, such as P–T–X conditions of fluids, fluid/rock ratios, and mineral growth kinetics. Major and trace elements of two generations of garnet combined with optical and textural characteristics suggest that Gt-I Al-rich grossular garnets grow slowly through diffusive metasomatism under a closed system, whereas Gt-II Fe-rich andradite represent rapid growth garnet formed by the infiltration metasomatism of magmatic fluids in an open system. The Mn-rich garnet implies active fluid–rock interaction with Mn-rich dolomitic limestone of the Lantian Group in the district.

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The ‘europium anomaly’ in plants: facts and fiction

10.31223/x5kg8j ◽

2021 ◽

Author(s):

Olivier Pourret ◽

Antony van der Ent ◽

Andrew Hursthouse ◽

Dasapta Irawan ◽

Haiyan Liu ◽

...

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Data Availability ◽

Soil Systems ◽

Eu Anomaly ◽

Interference Correction ◽

Icp Ms ◽

Fair Principles ◽

Preferential Uptake ◽

Ree Pattern

Rare earth elements (REEs) and normalized REE pattern determined in plant and soil samples represent powerful tools to trace biogeochemical processes during weathering, soil genesis and processes in the rhizosphere, and thus publications reporting rare earth elements and normalized REE pattern in soil systems and plants are increasing rapidly. Generally, a normalized REE pattern allow for the recognition of an anomalous concentrations of an individual REE. In the literature anomalies are predominantly reported/focused for/on the redox-sensitive elements cerium (Ce) and europium (Eu) that can shift their oxidation state during interactions with organic and inorganic soil phases and biological processes affecting the elements’ mobility in soil and uptake by plants. Thus positive Eu anomalies in plants are often interpreted as a consequence of reduction of Eu3+ to Eu2+ in the rhizosphere followed by a preferential uptake of Eu2+. However, due to an analytical artefact in ICP-MS analysis, a false Eu anomaly may be reported. This can be avoided by using a barium (Ba) interference correction. We draw attention to the possibility of this problem and to being aware of potential occurrence when Eu anomalies are reported. Finally, we recommend (i) including information on how this potential problem was dealt with in the Materials and Methods section of articles and (ii) how to implement FAIR principles in the section (including data availability on an open repository).

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Geochemical behavior of REE associated with Laterization process in Daklak Province, Southern Viet Nam

Science and Technology Development Journal ◽

10.32508/stdj.v17i3.1477 ◽

2014 ◽

Vol 17 (3) ◽

pp. 69-75

Author(s):

K. Okamura ◽

K. Watanabe ◽

K. Yonezu ◽

Huyen Thuong Dang ◽

Du Cong Do ◽

...

Keyword(s):

Noble Metals ◽

Xrd Analysis ◽

The Other ◽

High Demand ◽

Basaltic Rocks ◽

Southern Vietnam ◽

Ce Anomaly ◽

Eu Anomaly ◽

Other Hand ◽

Ree Pattern

The importance of REE for modern industries is proved by the high demand. The abundance of REE is richer than that of noble metals like gold or silver. However, supply sources are concentrated in China. The share of the product of REE was highest in 2009 (over 90%) and that is used as a national strategy.Mining industry in Vietnam is mainly developed in northern part. Deposits of principle metals are located around Hanoi, and REE deposits (Dong Pao) is also explored in Lai Chau Province. On the other hand, few bauxite mine is in southern Vietnam and the REE exploration is not conducted enough. Therefore, the study about REE in southern Vietnam is significant. Samples are from mainly basalt and granite. REE pattern, which is normalized by the abundance of chondrite, of basaltic rocks and laterites shows that is decreases monotony. That amount of REE is low (50-180ppm). REE pattern of magnetite rocks and laterites has no Eu and Ce anomaly. On the other hand, illuminate rocks and laterites have strong negative Eu anomaly. Clay minerals were observed by XRD analysis using hydraulic elutriation. The result of REE pattern and sequential extraction, it is indicated that the form of HREE is changed and adsorbed to clay and LREE is leached out. In tailing in Stop 16, it is observed that the concentration of HREE (about 3 times to 5 times than that of before washing). Eu anomaly is affected by reductive environment of the cooling of magma, and it is considered that Ce anomaly is occurred by the change of Ce form (Ce3+ to Ce4+). CeO2 is insoluble to water in the soil. From the XRD analysis, the cause of HREE concentration in water treatment is considered by the clay mineral

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Eu anomaly- reliability of the proxy in inferring source composition of clastic Sedimentary rocks: A case study from western Dharwar craton, Karnataka, India

10.5194/egusphere-egu2020-21526 ◽

2020 ◽

Author(s):

Anirban Mitra ◽

Sukanta Dey

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Earth Element ◽

Sedimentary Rocks ◽

Dharwar Craton ◽

Source Rocks ◽

Granitic Rocks ◽

Negative Anomaly ◽

Eu Anomaly ◽

Ree Pattern

Use of trace and rare earth element concentration of terrigenous sedimentary rocks to deduce the composition of their source rocks in the hinterland is a very common and efficient practice. The results of geochemical analysis of the metaquartzarenites located at the basal part of Bababudan and Sigegudda belt, late Archean greenstone sequences of western Dharwar craton show that the sediments were most possibly supplied from Paleo to Mesoarchean granitoids of western Dharwar Craton. Rare earth element patterns of these basal quartzites display fractionated REE pattern in variable degree (LaN/YbN =1.47-10.63) with moderate to highly fractionated LREE (LaN/SmN=2.67-8.93) and nearly flat to slighly elevated HREE (GdN/ YbN=0.62-1.29) and a significant Eu negative anomaly (avg. Eu/Eu*=0.67). In general, presence of negative Eu anomaly in clastic rocks reflect the widespread occurrence of granitic rocks in the source area, which possess negative Eu anomaly. On the other hand, mechanical enrichment of zircon (having negative Eu anomaly, high HREE concentration and low LaN/YbN), if present, will hamper the whole REE pattern of the sediments and necessarily, do not actually mimic the source composition. Here, in our study, the Th/Sc vs Zr/Sc diagram show mineral Zircon has been concentrated by mechanical concentration in the sedimentary rocks. Few quartzite samples which have high Zr content typically exhibit low LaN/YbN values, reflecting pivotal role of mineral zircon in controlling the REE pattern of the sediments. Hence, in this case, we should be cautious in interpreting of the Eu negative anomaly of the basal quartzites for meticulously identifying their source rock composition. More geochemical and other analytical approaches are required in this regard.

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Prostaglandins (PG) Inhibit Human Platelet Aggregation By PG Receptor Antagonism as well as Adenylate Cyclase Stimulation

10.1055/s-0038-1665818 ◽

1979 ◽

Author(s):

D. E. Macfarlane ◽

E. W. Salzman

Keyword(s):

Platelet Aggregation ◽

Adenylate Cyclase ◽

Human Platelet ◽

High Ratio ◽

Receptor Antagonism ◽

Human Platelet Aggregation ◽

Alkyl Groups ◽

Low Concentrations ◽

Alkyl Substitution ◽

Adenylate Cyclase Stimulation

11-Deoxy and/or 15 or 16 alkyl substitution confer platelet aggregating activity to bis-enoic PG’s: e.g., ll-deoxy-PGE2(threshold (T)-5μM); ll-deoxy-15(S)-15-methyl-PGE2(T= O.lμM); ll-deoxy-15(S)-16-methyl-PGE2(T=0.1μM). Responses induced by such PG’s mimic those induced by PGH2 and PGH2 analogues (e.g., U44069). N0164 competitively inhibits aggregation induced by PG’s and suppresses “secondary” responses induced by low concentrations of ADP or arachidonic acid, suggesting involvement of a specific PG stimulatory receptor in platelet aggregation. We compared non-aggregatory PG’s as inhibitors of primary aggregation induced by ADP or U44069. PG’s containing 11-deoxy and/or 16-alkyl groups selectively inhibited aggregation induced by U44069. Mean I50 values (n=4) against ADP and U44069 respectively were PGA2(>100μM; 0.3μM); PGB2(>100μM; 5μM). PGE1(60μM; 2μM); PGE1(10nM; 5nM); 11-deoxy PGEX (60μM; 2μM); ll-deoxy-15-(R)-16-methyl PGE1(lOOμM; 2μM); 13,14-dihydro-16-methyl-PGE2 methyl ester (750nM; 15nM). A low ADP: U4406 I50 ratio (e.g., PGD2) indicates that inhibition is mainly due to adenylate cyclase stim ulation, and a high ratio (e.g., PGA2) that inhibition is mainly due to PG receptor antagonism. We have demonstrated a PG stimulatory receptor on the platelet, and its involvement in “secondary”aggregation. PG’s inhibit aggregation by combining with this receptor and/or by stimulating adenylate cyclase.

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Contrasting settings of serpentinite bodies in the northwestern Zagros Suture Zone, Kurdistan Region, Iraq

Geological Magazine ◽

10.1017/s0016756811000409 ◽

2011 ◽

Vol 148 (5-6) ◽

pp. 819-837 ◽

Cited By ~ 18

Author(s):

NABAZ R. H. AZIZ ◽

KHALID J. A. ASWAD ◽

HEMIN A. KOYI

Keyword(s):

Trace Element ◽

Suture Zone ◽

Carbonate Sediments ◽

Thrust Sheet ◽

Eu Anomaly ◽

Lree Content ◽

Hemipelagic Sediment ◽

Ree Patterns ◽

Ree Pattern ◽

Arabian Platform

AbstractProtrusions and lenses of serpentinite–matrix mélanges occur at several places along the thrust faults of the Zagros Suture Zone. They separate the lower allochthonous thrust sheet, the ‘Lower Allochthon’ (i.e. Walash–Naopurdan nappe), of Paleocene–Eocene age from sediments of the Arabian platform and the upper thrust sheet of Mesozoic, ophiolite-bearing terranes termed the ‘Upper Allochthon’ (i.e. Gemo–Qandil nappe). The serpentinite–matrix mélanges occur mostly as stretched bodies (slices) on both sides of the Lower Allochthon (Hero, Halsho and Pushtashan (HHP) and Galalah, Qalander and Rayat (GQR)). Their overall chondrite-normalized rare earth element (REE) patterns form two main groups. Group One exhibits enrichment in the total REEs (> 1 × chondrite) whereas the Group Two pattern shows depletion (i.e. < 1 × chondrite). Bulk-rock MORB-normalized profiles of Group Two are almost flat in the MREE–HREE region with flattening profiles in the Gd–Lu range (> 3 times the MORB composition). In comparison with Group One, Group Two has extremely high REE content and displays variable depletions in the moderately incompatible high-field-strength elements (HFSEs) (Zr, Hf, Y) relative to their adjacent REEs. The REEs in the GQR serpentinite–matrix mélanges have a noticeably high LREE content, and a positive Eu anomaly, and their HREE content never reaches more than 1 × chondrite (i.e. < 0.01 to 1 × chondrite). The latter indicates that the hemipelagic sedimentary, melt-like components (i.e. high LREE, U/La, La/Sm and low Ba/Th) control the geochemical peculiarities of this type of serpentinite. The HHP serpentinite–matrix mélanges, however, are either equally divided between the two REE pattern groups (e.g. Hero, Halsho) or inclined towards Group One (e.g. Pushtashan). Contrary to GQR serpentinites, the variation in HHP serpentinite–matrix mélanges spans a compositional spectrum from U/La-rich to more Ba/Th-rich. Such ratio variations reflect the large variation in these two subducted sedimentary components (i.e. carbonate and hemipelagic sediment mix). The obvious differences in the trace element signatures of the GQR and HHP serpentinite–matrix mélanges might be related to plate tectonic parameters such as convergence rate, subduction age and thickness and type of subducted slab. It is more likely that the influx of subducted components to the mantle wedge relied heavily on the composition of the sedimentary inputs. These vary considerably with time from the relatively deepwater hemipelagic sediments (Qulqula Radiolarite Formation) to platform carbonate sediments (Balambo limestone). The trace element signatures of the GQR and HHP serpentinite–matrix mélanges might suggest multi-staging of the allochthonous sheet emplacement on the Arabian platform sediments.

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PLASMA AND PHAGOSOME MEMBRANES OF ACANTHAMOEBA CASTELLANII

The Journal of Cell Biology ◽

10.1083/jcb.51.1.193 ◽

1971 ◽

Vol 51 (1) ◽

pp. 193-215 ◽

Cited By ~ 82

Author(s):

Andrew G. Ulsamer ◽

Paddy L. Wright ◽

Mary G. Wetzel ◽

Edward D. Korn

Keyword(s):

Plasma Membranes ◽

Unsaturated Fatty Acids ◽

Acanthamoeba Castellanii ◽

High Ratio ◽

Polystyrene Latex ◽

Whole Cells ◽

Low Concentrations ◽

Cell Fractions ◽

Equilibrium Centrifugation ◽

Fatty Acid Compositions

Plasma membranes were isolated from the ameba Acanthamoeba castellanii by low-speed velocity centrifugation followed by equilibrium centrifugation in a sucrose gradient. The isolated membranes had a high ratio of sterol to phospholipid (0.98 moles/mole) and of phospholipid to protein (0.43 mg/mg). The plasma membranes had very low concentrations of DNA, RNA, lipid inositol, and glycerides. Glycolipids and glycoproteins were enriched in the plasma membranes relative to their concentrations in the whole cell. The plasma membranes were also judged to be of high purity by the absence, or very low level, of enzymatic activities considered to be indicative of other cell membranes, and by electron microscope examination. Alkaline phosphatase and 5'-nucleotidase activities were enriched in the plasma membranes 13-fold relative to the whole homogenate and had higher specific activities in the plasma membranes than in any other cell fractions. A Mg++ adenosine triphosphatase (ATPase) was enriched sixfold in the plasma membranes relative to the whole homogenate. The phospholipids of the plasma membranes contained more phosphatidylethanolamine and phosphatidylserine and less phosphatidylcholine than did the phospholipids of the whole cells. There were differences in the fatty acid compositions of corresponding phospholipids in the plasma membranes and whole cells but no difference in the ratios of total saturated to unsaturated fatty acids. The membranes of phagosomes isolated from amebae that had ingested polystyrene latex had essentially the same phospholipid, sterol, and enzymatic composition as plasma membranes.

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The REE-Induced Absorption and Luminescence in Yellow Gem-Quality Durango-Type Hydroxylapatite from Muránska Dlhá Lúka, Slovakia

Minerals ◽

10.3390/min10111001 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1001

Author(s):

Peter Bačík ◽

Jana Fridrichová ◽

Ján Štubňa ◽

Tomáš Bancík ◽

Ľudmila Illášová ◽

...

Keyword(s):

Photoluminescence Spectrum ◽

Trace Element Composition ◽

Element Composition ◽

Granitic Rocks ◽

Eu Anomaly ◽

Yellow Color ◽

Ree Patterns ◽

Ree Pattern ◽

Oh Content ◽

Ftir And Raman Spectroscopy

In talc-magnesite veins in serpentinite near Muránska Dlhá Lúka (MDL), Slovakia, yellow euhedral to subhedral crystals apatite of a gem quality occur. It has a composition of hydroxylapatite with F− varying between 0.29 and 0.34 apfu, Cl− in range of 0.02–0.05 apfu and calculated OH− content between 0.62–0.68 apfu. Moreover, [CO3]2− molecules were identified by FTIR and Raman spectroscopy. MDL apatite contains only up to 0.003 apfu As5+ and Si4+ substituting for P5+; Ca is substituted by small amount of Na, Fe2+, Mn2+ (all up to 0.006 apfu), and Rare Earth Elements (REE—in total up to 0.017 apfu). Compared to trace-element composition of similar apatites from Durango, Mexico, the REE content in MDL apatite is around ten times lower with Nd > Ce >> La, its chondrite-normalized REE pattern has almost a horizontal slope and larger negative Eu anomaly. The MDL apatite is richer in Mn, Pb and Li, but poorer in As, V, Th and U. The concentrations of Sr and Y are similar. In the optical absorption spectra, the most prominent bands are at 585–590 nm (Nd3+) and between 600 and 800 nm (Mn2+, Ce3+-SiO3− photochromic center and Nd3+). The photoluminescence spectrum of MDL apatite shows bands between 550 and 620 nm (Dy3+, Sm3+, Pr3+ and also Mn2+) which likely enhance its yellow color. MDL hydroxylapatite likely formed from fluids derived from granitic rocks as evidenced by the chondrite-normalized REE patterns, Li, Mn and Y concentrations. The Sr content reflects the host-rock serpentinite composition. Fluids for its crystallization were likely derived from Muráň complex orthogneisses by the Alpine deformation and recrystallization in greenschist to lower amphibolite facies.

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