Insights into the redox history of the NWA 1068/1110 martian basalt from mineral equilibria and vanadium oxybarometry

2006 ◽  
Vol 91 (10) ◽  
pp. 1616-1627 ◽  
Author(s):  
C. D.K. Herd
Keyword(s):  
Mineral Equilibria ◽  
History Of ◽  
Redox History

scholarly journals On the thermal and redox history of the Yamato diogenite Y-74013

1986 ◽  
Vol 95 (3) ◽  
pp. 381-395
Author(s):  
Amalbikash Mukherjee ◽  
T. A. Viswanath
Keyword(s):  
History Of ◽  
Redox History

scholarly journals Redox history of the Three Gorges region during the Ediacaran and Early Cambrian as indicated by the Fe isotope

2018 ◽  
Vol 9 (1) ◽  
pp. 155-172 ◽  
Author(s):  
Yusuke Sawaki ◽  
Miyuki Tahata ◽  
Tsuyoshi Komiya ◽  
Takafumi Hirata ◽  
Jian Han ◽  
...  
Keyword(s):  
Early Cambrian ◽  
Three Gorges ◽  
The Three Gorges ◽  
Three Gorges Region ◽  
History Of ◽  
Redox History

Regional geothermobarometry in the granulite facies terrane of South India

1983 ◽  
Vol 73 (4) ◽  
pp. 221-244 ◽  
Author(s):  
M. Raith ◽  
P. Raase ◽  
D. Ackermand ◽  
R. K. Lal
Keyword(s):  
South India ◽  
Analytical Data ◽  
Granulite Facies ◽  
Critical Discussion ◽  
Granulite Facies Metamorphism ◽  
Northern Margin ◽  
Mineral Equilibria ◽  
Metamorphic History ◽  
Facies Metamorphism ◽  
History Of

ABSTRACTIn the southern part of the Archaean craton of South India, an approximately 3.4–2.9 b.y. old migmatite–gneiss terrane (Peninsular gneiss complex) has been subjected to granulite facies metamorphism about 2.6 b.y. ago. During this event, the extensive charnockite-khondalite zone of southern India developed. A younger metamorphism (Proterozoic?) led to retrogression of the charnockites and khondalites, mainly under the conditions of the amphibolite facies.The physical conditions of metamorphism have been evaluated by applying methods of geothermobarometry to the widespread charnockitic assemblages with garnet, orthopyroxene, clinopyroxene, plagioclase, and quartz. The interpretation of the P–T estimates includes a critical discussion of potential error sources, e.g. errors of the analytical data and the calibrations of the models, and takes into account the complex metamorphic history of the rocks and the kinetics of the mineral equilibria.P-T estimates were obtained for seven subareas from the rim compositions of the coexisting minerals: Shevaroy Hills 680±55°C—7·4±1 kb; Kollaimalai area 680±40°C—8·6± 1 kb; Nilgiri Hills 680±90°C—6·6±0.8kb (upland massif) and 705±60°C—9·3±0.8 kb (northern margin); Bhavani Sagar area 650±50°C—7·2± 1 kb; Sargur-Mysore area 690±60°C—7·6 kb; Bangalore-Kunigal-Satnur area 760±50°C—6 kb. Except for the last subarea, the P-T model data reflect the conditions of a late annealing stage probably related to the retrogressive metamorphism. Conditions near the peak of granulite facies metamorphism (730–800°C—6·5–9·5 kb) are recorded by the core compositions of the minerals. Although a rather uniform cooling history of the main part of the charnockite-khondalite terrane is suggested from the temperature data, differential uplift of smaller blocks is indicated by the regional variation of the pressure data.

Crystallization, melt inclusion, and redox history of a Martian meteorite: Olivine-phyric shergottite Larkman Nunatak 06319

2010 ◽  
Vol 74 (15) ◽  
pp. 4543-4576 ◽  
Author(s):  
A.H. Peslier ◽  
D. Hnatyshin ◽  
C.D.K. Herd ◽  
E.L. Walton ◽  
A.D. Brandon ◽  
...  
Keyword(s):  
Melt Inclusion ◽  
Martian Meteorite ◽  
History Of ◽  
Redox History

ECOLOGY AND EVOLUTION OF MANGANESE MINERALS: IMPLICATIONS FOR THE REDOX HISTORY OF EARTH AND LIFE

2018 ◽  
Author(s):  
Daniel R. Hummer ◽  
◽  
Robert M. Hazen ◽  
Ahmed Eleish ◽  
Chao Liu ◽  
...  
Keyword(s):  
History Of ◽  
Manganese Minerals ◽  
Redox History

scholarly journals Seasonal and Spatial Variation of Mo Isotope Compositions in Headwater Stream of Xijiang River Draining the Carbonate Terrain, Southwest China

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1076 ◽  
Author(s):  
Jie Zeng ◽  
Guilin Han ◽  
Jian-Ming Zhu
Keyword(s):  
Southwest China ◽  
Isotopic Fractionation ◽  
Dilution Effect ◽  
Dry Season ◽  
Wet Season ◽  
Xijiang River ◽  
Seasonal And Spatial Variations ◽  
History Of ◽  
River Reach ◽  
Redox History

The dissolved molybdenum (Mo) contents and Mo isotope in water samples from the upper Xijiang River (XJR), draining the carbonate terrain, southwest China, are reported to investigate the seasonal and spatial variations, sources, ion budget, and isotopic fractionation of dissolved Mo. The results show that the Mo concentrations (5.3–18.9 nmol/L) exhibit an extensive variation along the mainstream without significant spatial pattern, but the Mo concentrations are slightly higher in the dry season than in the wet season caused by the dilution effect. There is a slight spatial tendency for δ98/95Mo to become higher along the mainstream (0.51–1.78%), while the seasonal variations in δ98/95Mo values of NPR (Nanpanjiang River) reach and BPR (Beipanjiang River) reach can be identified higher in the dry season but lower in the wet season. Based on the hydro-geochemical analysis, the sources of dissolved Mo are identified as the carbonates and sulfide/sulfate minerals weathering with a seasonal contribution. Moreover, our results suggest there is no significant Mo isotopic fractionation during weathering and riverine transportation. The calculation of Mo budget demonstrates that the dissolved δ98/95Mo of river draining the carbonate terrain is underestimated, which could significantly influence the redox history of oceans by Mo isotope model.

Evolution of P–T conditions during a high-grade metamorphic event in the Maniwaki area (Grenville Province)

1984 ◽  
Vol 21 (7) ◽  
pp. 853-863 ◽  
Author(s):  
A. Indares ◽  
J. Martignole
Keyword(s):  
Granulite Facies ◽  
Grenville Province ◽  
Mineral Equilibria ◽  
Metamorphic History ◽  
Average Slope ◽  
History Of ◽  
Mineral Compositions ◽  
Uplift And Erosion ◽  
Peak Pressures ◽  
Basic Rocks

Pelitic and basic rocks of the Grenville Supergroup in the Maniwaki area (100 km north of Ottawa) were selected for a detailed investigation of the metamorphic history of the Central Metasedimentary Belt of the Grenville Province.Mineral assemblages suggest metamorphic conditions of the granulite facies with local and irregular persistence of the amphibolite facies. Chemical analysis of minerals reveals a lack of equilibrium on the thin section scale. Systematic variation of mineral compositions is explained as the net result of several mineral equilibria established at different stages during the metamorphic evolution of the area. Peak temperatures obtained by biotite–garnet thermometry (cores of isolated grains) are between 760 and 860 °C, whereas clinopyroxene–garnet thermometry gives 740–820 °C. Retrograde temperatures as estimated by various thermometers range between 550 and 750 °C (biotite–garnet), 498 and 670 °C (cordierite–garnet), and 690 and 720 °C (clinopyroxene–garnet). Peak pressures were 6.5–8.5 kbar (650–850 MPa) based upon the ga–pl–sil–qtz barometer and the cpx–ga–pl–qtz barometer. Retrograde pressures of 3.5–5.5 kbar (350–550 MPa) (ga–pl–sil–qtz), 4.1–5.2 kbar (410–520 MPa) (cd–ga), and 5.7–7 kbar (570–700 MPa) (cpx–ga–pl–qtz) were determined.A compilation of results in a P–T diagram allows us to construct a retrograde gradient convex towards the T axis, with an average slope of 12 bar/°C (1.2 MPa/°C). This curve suggests fast uplift and erosion just after the peak of metamorphism followed by a long cooling stage accompanied by minor uplift.

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