The geochemistry of the Turriff metavolcanics, Grenville Province, southeastern Ontario

1985 ◽  
Vol 22 (3) ◽  
pp. 435-441 ◽  
Author(s):  
P. E. Holm ◽  
T. E. Smith ◽  
B. D. Grant ◽  
C. H. Huang
Keyword(s):  
Trace Element ◽  
Continental Crust ◽  
Major Element ◽  
Geochemical Data ◽  
Grenville Province ◽  
Oceanic Ridge ◽  
X Ray ◽  
Fluorescence Techniques ◽  
Marginal Sea ◽  
The Many

Fifty-seven samples of the Turriff metavolcanic sequence from the Hastings region of the Grenville Province have been chemically analyzed. Ten major-element oxides and ten trace-element values for each sample were determined by standard X-ray fluorescence techniques. The sampled sections consist predominantly of mafic flows, subordinate intermediate flows, and minor felsic flows and pyroclastics. The sequence has been regionally metamorphosed to lower amphibolite facies. The geochemical data indicate that the metavolcanics represent a tholeiitic mafic–silicic bimodal sequence. Immobile-element discriminant diagrams indicate that the Turriff metabasalts are most similar to recent oceanic ridge basalts, whereas the metabasalts from other published studies of Grenville metavolcanics have an island-arc tholeiite affinity. However, because of the many chemical similarities between continental and oceanic ridge tholeiites, the bimodal nature of the sequence, and the field relationships, it is most likely that the eruption of the Turriff metavolcanics was associated with the rifting of continental crust, perhaps leading to the development of a marginal sea.

Grenville metagabbro complexes of the Otter Lake area, Quebec

1989 ◽  
Vol 26 (2) ◽  
pp. 215-230 ◽  
Author(s):  
Ralph Kretz ◽  
Peter Jones ◽  
Ron Hartree
Keyword(s):  
Trace Element ◽  
Major Element ◽  
Lake Area ◽  
High Grade ◽  
Grenville Province ◽  
Reaction Zones ◽  
Select Trace Element ◽  
Mineral Analyses

Metagabbro complexes in a portion of the Grenville Province lying northwest of Ottawa occur as sheets, cylinders, and irregular bodies within a medium- to high-grade marble–gneiss–amphibolite terrane. The largest bodies (0.5–10 km in greatest dimension) consist principally of felsic metagabbro, mafic metagabbro, and minor metapyroxenite. Major-element and select trace-element analyses show that different complexes contain distinctly different amounts of K and other elements resulting in different interelement trends.Microstructure and microprobe mineral analyses provide evidence that the following metamorphic changes have occurred: (i) recrystallization of Ca pyroxene, orthopyroxene, and plagioclase; (ii) reaction of Mg-rich olivine with plagioclase to produce reaction zones consisting of orthopyroxene and a hornblende–spinel intergrowth; (iii) reaction of Mg–Fe olivine with plagioclase to produce garnet and hornblende; (iv) production of anthophyllite and hornblende from orthopyroxene and plagioclase; (v) production of hornblende (locally as rims about Ca pyroxene) from Ca pyroxene and plagioclase; (vi) crystallization of biotite, possibly by reaction between orthopyroxene and K-feldspar; and (vii) crystallization of small inclusions of spinel and ilmenite in Ca pyroxene and of spinel and biotite in plagioclase.With regard to the reaction olivine + plagioclase = orthopyroxene + hornblende + spinel, the anorthite and locally the forsterite components were extracted preferentially from plagioclase and olivine; K and Ti (for hornblende) and Zn (for spinel) were evidently obtained from the surrounding minerals; and H, F, and Cl (for hornblende) were obtained from beyond the gabbro bobies. Locally the reaction occurred within large crystals of Ca pyroxene where embedded olivine and plagioclase crystals were in contact.The production of hornblende rims about Ca pyroxene evidently involved plagioclase as a reactant, but the rims formed regardless of the contacting minerals. For example, rims were locally produced where Ca-pyroxene crystals were embedded in large crystals of orthopyroxene.Application of five geothermometers to crystals of both igneous and metamorphic origin yield temperatures of about 700 °C, similar to temperatures recorded for the enclosing marble and gneiss.

The retrograde hydration of the continental granitoid crust as seen from epidote-bearing veins: Trace elements and microstructures

2020 ◽  
Author(s):  
Veronica Peverelli ◽  
Alfons Berger ◽  
Thomas Pettke ◽  
Holger Stunitz ◽  
Pierre Lanari ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Continental Crust ◽  
Host Rock ◽  
Geochemical Characteristics ◽  
Geochemical Data ◽  
Massif Central ◽  
Eu Anomaly ◽  
Aar Massif ◽  
Ree Patterns

<p>The widespread presence of epidote-bearing veins and hydrous minerals such as micas in meta-granitoid rocks attests to the large extent of hydration of the exhuming continental crust. The ability of epidote (Ca<sub>2</sub>Al<sub>3</sub>Si<sub>3</sub>O<sub>12</sub>(OH) – Ca<sub>2</sub>Al<sub>2</sub>Fe<sup>3+</sup>Si<sub>3</sub>O<sub>12</sub>(OH)) to incorporate a wide variety of trace elements renders this mineral a promising geochemical tracer of circulating fluid(s).</p><p>We report trace element and microstructural data on epidote-bearing veins from the Aar Massif (Central Alps) and from the Albula Pass (Eastern Alps). We characterized and classified the epidote-bearing veins based on their extent of deformation, shape and size of the epidote grains, coexisting minerals, and degree of dynamic recrystallization of associated quartz. Laser ablation ICP-MS data of individual epidote crystals reveal prominent zoning, confirmed by electron probe maps for Sr and Mn. Overall, low to very low Th/U ratios (down to 0.0005 in the Aar Massif veins and 0.001 in the Albula ones) with Th often below limits of detection (< 0.1 µg/g at 16 µm beam size) go along with variably LREE-depleted patterns (and CI Chondrite-normalized La<sub>N</sub>/Yb<sub>N</sub> ~0.35 in the Aar Massif veins and ~0.60 in the Albula Pass veins). Strontium contents are variable (hundreds to thousands of µg/g) and mostly high (up to 10100 µg/g in the Aar Massif samples and 12800 µg/g in the Albula Pass samples). The in-situ geochemical data are linked to the microstructures in order to assess whether microstructures can be related to variations in trace elements, also considering the role of coexisting phases. Moreover, trace element data of samples from the Aar Massif are compared to metamorphic host-rock epidotes and cleft epidotes from the same massif.</p><p>We find that REE patterns of Aar Massif vein epidotes are clearly different than those of metamorphic host-rock epidotes and of cleft epidotes. In addition, REE patterns vary based on the microstructural characteristics of veins. Overall REE patterns of the Albula Pass vein epidotes resemble those from the Aar Massif. Different veins and microstructures define clusters in Sr vs. Y, Eu anomaly vs. Th/U ratios, and Eu anomaly vs. U values. Geochemical heterogeneities are observed among sampling localities within the Aar Massif.</p><p>The fact that the geochemical characteristics of retrograde hydrothermal vein epidotes are clearly different than those of high-grade metamorphic and metamorphic host-rock epidotes, and the relationship between geochemical characteristics and microstructures support the hypothesis that the deformation did not alter the original geochemical record through neomineralization. Our data argue for the potential of epidote as a powerful fluid tracer in the granitoid continental crust.</p>

Cordierite-gedrite rocks from the Central Metasedimentary Belt boundary thrust zone (Grenville Province, Ontario): Mesoproterozoic metavolcanic rocks with affinities to the Composite Arc Belt

2005 ◽  
Vol 42 (10) ◽  
pp. 1815-1828 ◽  
Author(s):  
William H Peck ◽  
Michael S Smith
Keyword(s):  
Trace Element ◽  
Major Element ◽  
Grenville Province ◽  
Melt Extraction ◽  
Oxygen Isotope Ratios ◽  
Metavolcanic Rocks ◽  
Thrust Zone ◽  
Ree Patterns ◽  
Isotope Systematics ◽  
Igneous Protoliths

Cordierite–gedrite rocks in the southern Grenville Province occur near the base of the Central Metasedimentary Belt boundary thrust zone, interpreted by some as a crustal suture between the 1.29–1.24 Ga Composite Arc Belt and >1.4 Ga rocks of Laurentia. Major and trace-element compositions of these rocks are consistent with volcanic protoliths that range in composition from basalt to dacite. These cordierite–gedrite rocks have low CaO (average 1.2 wt.%) and major element and oxygen-isotope ratios suggestive of hydrothermal alteration before metamorphism. Rare-earth element (REE) compositions also indicate igneous protoliths, although some REE patterns have been modified by local melt extraction. The trace-element compositions of cordierite–gedrite rocks, and neodymium-isotope systematics, are similar to those of metavolcanic rocks in the Composite Arc Belt and are consistent with the extension of the Composite Arc Belt to the base of the boundary thrust zone.

Reply to ‘Geochemistry and original nature of Precambrian khondalites in the Eastern Ghats, Orissa: a discussion’

1991 ◽  
Vol 82 (1) ◽  
pp. 89-90 ◽  
Author(s):  
B. Dash ◽  
D. R. Bowes
Keyword(s):  
Sri Lanka ◽  
Trace Element ◽  
Soil Profile ◽  
Major Element ◽  
Major Elements ◽  
Eastern Ghats ◽  
Geochemical Data ◽  
Weathered Soil ◽  
Considerable Body

(1) The interpretation of Dash et al. (1987) that the quartz–sillimanite–garnet (khondalite) assemblage of Orissa represents a metamorphosed deeply weathered soil profile(s) is based on a considerable body of new geochemical data: 59 new major and trace element rock analyses and 9 new major element rock analyses(ca. 1800 determinations) compared with the previous basis of 2 rock analyses for major elements only from Orissa supported by 3 for major elements only from other parts of India and 4 from Sri Lanka (ca 90 determinations—table 4).

scholarly journals Trace element limitation of lymph nodes structure according to the x-ray fluorescent analysis with synchrotron radiation (SR XRF)

2020 ◽  
Author(s):  
O. V. Gorchakova ◽  
Yu. P. Kolmogorov ◽  
V. N. Gorchakov ◽  
G. A. Demchenko ◽  
S. N. Abdreshov
Keyword(s):  
Synchrotron Radiation ◽  
Lymph Nodes ◽  
Trace Element ◽  
X Ray ◽  
Fluorescent Analysis ◽  
Sr Xrf

scholarly journals Major and trace element analyses of igneous rocks by polarizing energy dispersive X-ray fluorescence spectrometry (EDXRF)

2014 ◽  
Vol 43 (2) ◽  
pp. 47-53 ◽  
Author(s):  
Toshio MIYAZAKI ◽  
Shin-ichi YAMASAKI ◽  
Noriyoshi TSUCHIYA ◽  
Satoshi OKUMURA ◽  
Ryoichi YAMADA ◽  
...  
Keyword(s):  
Trace Element ◽  
Igneous Rocks ◽  
Energy Dispersive ◽  
Fluorescence Spectrometry ◽  
X Ray

Applications of Non-Dispersive X-Ray Fluorescence Techniques for in Vitro Studies

1973 ◽  
Vol 20 (1) ◽  
pp. 379-388 ◽  
Author(s):  
R. J. Baglan ◽  
A. B. Brill ◽  
J. A. Patton
Keyword(s):  
In Vitro Studies ◽  
X Ray ◽  
Fluorescence Techniques
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