scholarly journals PRIMELT3 MEGA.XLSM software for primary magma calculation: Peridotite primary magma MgO contents from the liquidus to the solidus

2015 ◽  
Vol 16 (2) ◽  
pp. 563-578 ◽  
Author(s):  
C. Herzberg ◽  
P. D. Asimow
Keyword(s):  
Primary Magma

scholarly journals Carbon Fluxes and Primary Magma CO2Contents Along the Global Mid‐Ocean Ridge System

2019 ◽  
Vol 20 (3) ◽  
pp. 1387-1424 ◽  
Author(s):  
Marion Le Voyer ◽  
Erik H. Hauri ◽  
Elizabeth Cottrell ◽  
Katherine A. Kelley ◽  
Vincent J. M. Salters ◽  
...  
Keyword(s):  
Carbon Fluxes ◽  
Primary Magma ◽  
Mid Ocean Ridge ◽  
Ocean Ridge ◽  
Ridge System

scholarly journals The Metallogeny of the Lubei Ni–Cu–Co Sulfide Deposit in Eastern Tianshan, NW China: Insights From Petrology and Sr–Nd–Hf Isotopes

2021 ◽  
Vol 9 ◽  
Author(s):  
Ping Li ◽  
Ting Liang ◽  
Yonggang Feng ◽  
Tongyang Zhao ◽  
Jiangtao Tian ◽  
...  
Keyword(s):  
Lithospheric Mantle ◽  
Crustal Contamination ◽  
Primary Magma ◽  
Phase Iii ◽  
Hf Isotopes ◽  
Cobalt Sulfide ◽  
Geodynamic Setting ◽  
Sulfide Deposit ◽  
Eastern Tianshan ◽  
Clastic Rocks

The Lubei Ni–Cu–Co deposit situated in western segment of the Huangshan-Jing’erquan mafic–ultramafic rock belt in eastern Tianshan of the Central Asian Orogenic Belt (CAOB). The estimated reserve is approximately 9.11 million tons of ore resources with average grades of 0.82 wt% Ni, 0.52 wt% Cu, and 0.03 wt% Co. The Lubei intrusion is mainly composed of gabbro (phase I), peridotite (phase II), pyroxene peridotite (phase III), olivine pyroxenite (phase IV), and diorite (phase V), which intruded into the early Carboniferous tuffaceous clastic rocks. Zircon Laser Ablation–Inductively Coupled Plasma–Mass Spectrometry (LA–ICP–MS) U–Pb age of the diorite (phase V) from the edge of the intrusion is interpreted as the top-limit metallogenic age, which is consistent with the formation ages of the Huangshan and Xiangshan Ni–Cu deposits in eastern Tianshan. The roughly parallel rare earth element (REE) curves of the Lubei intrusion indicate the magma originated from a homologous source. The slightly enriched large ion lithophile elements (LILE) are compared to high field strength elements (HFSE) with negative Nb and Ta anomalies show that the Lubei intrusion has arc-affiliate geochemical characteristics. The Sr–Nd–Hf isotopes show that the magma was derived from depleted lithospheric mantle, while suffering 4–10% lower crustal contamination with slight contamination of the upper crust. Based on a comprehensive conservation of regional geological, geochemical, and geochronological evidence, the primary magma of the Lubei intrusion was identified that it was derived from the partial melting of metasomatized lithospheric mantle previously modified by subduction events. The Lubei nickel–copper–cobalt sulfide deposit was formed after the primary magma experienced fractional crystallization, crustal contamination, and sulfide segregation in a post-collisional extensional geodynamic setting after the closure of the Kanggur ocean basin in the early Permian.

scholarly journals Oxygen isotope composition of zircons from the Talnakh economic intrusion of the Noril’sk province: first data

2019 ◽  
Vol 489 (2) ◽  
pp. 170-173
Author(s):  
I. Yu. Badanina ◽  
E. A. Belousova ◽  
K. N. Malitch ◽  
S. F. Sluzhenikin
Keyword(s):  
Oxygen Isotope ◽  
Isotope Composition ◽  
Oxygen Isotope Composition ◽  
Primary Magma ◽  
Crustal Component ◽  
Layered Series ◽  
Isotope Data ◽  
Oxygen Isotope Data ◽  
First Results ◽  
Isotope Analyses

This study presents the first results of oxygen isotope analyses (18O) collected on zircons from the Talnakh economic intrusion within the Norilsk province. Zircons from gabbro-diorite, gabbroic rocks of the layered series and plagioclase-bearing wehrlite have similar mantle-like mean 18O values (5,39 0,49; 5,64 0,48 and of 5,28 0,34, respectively), which differ from 18O in zircons from sulfide-bearing melanocratic troctolite with a taxitic texture in the lower part of the intrusion (mean 18O = 6,50 0,98). These new oxygen isotope data support (i) the mantle-derived origin of the primary magma(s), parental to the Talnakh intrusion, and (ii) possible involvement of a crustal component during the formation of sulfide-bearing taxitic-textured rocks.

A new locality for primary xenolith-bearing nephelinites in northwestern British Columbia

1985 ◽  
Vol 22 (10) ◽  
pp. 1556-1559 ◽  
Author(s):  
Michael D. Higgins ◽  
John M. Allen
Keyword(s):  
British Columbia ◽  
Trace Element ◽  
Volcanic Belt ◽  
Primary Magma ◽  
Similar Composition ◽  
Element Abundances ◽  
Late Tertiary

High Ni abundances (420–500 ppm) and Mg* values (100 × Mg/(Mg + Fe2+) = 69–71) and the presence of mantle-derived xenoliths indicate that a subvolcanic nephelinite intrusion in northwestern British Columbia represents an unmodified primary magma. A separate, closely associated nephelinite intrusion shows evidence of minor olivine fractionation from a similar composition. Only three other occurrences of primary nephelinite have been described. This new occurrence suggests that these magmas may not be so rare as previously supposed. The trace-element abundances closely resemble those of primary nephelinites of similar La content from Freemans Cove, Canada. Such compositions are usually taken as evidence of intraplate rifting and doming. Therefore, these rocks are further evidence of late Tertiary or Quaternary rifting in the Stikine volcanic belt.

The Petrogenesis of a Spilitic Rock Series from New Zealand

1956 ◽  
Vol 93 (2) ◽  
pp. 89-110 ◽  
Author(s):  
M. H. Battey
Keyword(s):  
New Zealand ◽  
Large Scale ◽  
Primary Magma ◽  
Rock Series ◽  
Tholeiitic Magma ◽  
Influence Of Water ◽  
Differentiation Trend

AbstractWell-preserved examples of spilites show marked affinities with certain tholeiites in texture, chemistry, differentiation trend, and in some aspects of their mineralogy. The presence in them of albite and apparently primary chlorite, in association with unaltered augite, is ascribed to the influence of water as a component of the magma, and the high content of alkali in the basic members to retention of volatile oxides present in tholeiitic magma. Evidence is lacking of large-scale metasomatism by external agencies and the postulate of a special primary magma seems unwarranted. A series may be traced, in rocks of different environments, from “dry tholeiite” to “wet tholeiite” to spilite.Four new rock analyses and one of chlorite are given.

Permian volcanism in the Mongolian orogenic zone, northeast China: geochemistry, magma sources and petrogenesis

2001 ◽  
Vol 138 (2) ◽  
pp. 101-115 ◽  
Author(s):  
YONGFENG ZHU ◽  
SHIHUA SUN ◽  
LIBING GU ◽  
YOSHIHIDE OGASAWARA ◽  
NENG JIANG ◽  
...  
Keyword(s):  
Fractional Crystallization ◽  
Volcanic Rocks ◽  
Major Elements ◽  
Mantle Metasomatism ◽  
Primary Magma ◽  
Lower Permian ◽  
Depleted Mantle ◽  
Incompatible Trace Elements ◽  
Basic Rocks ◽  
Orogenic Zone

Lower Permian volcanism was the first magmatic activity to occur after the collision events in the Mongolian orogenic zone, east China. The Permian volcanic rocks are therefore a key to understanding the dynamics of the unified continental lithosphere. The volcanic rocks consist of basic and intermediate rocks. The intermediate rocks with high initial 87Sr/86Sr ratios (0.7051 to 0.7052) and low εNd values (−0.73 to −3.57) generally overlie the basic rocks in the field. The basic rocks have relatively low initial 87Sr/86Sr ratios (0.7034 to 0.7051) and high εNd values (2.72 to −0.10). Two parallel Rb–Sr isochrons give almost the same age, about 270 Ma. One consists of the basic rocks giving an initial isochron 87Sr/86Sr ratio of 0.7035. The other consists of the intermediate rocks and one sample of basalt, which give an initial isochron 87Sr/86Sr value of 0.7051. The strong correlations between SiO2 and other major elements suggest that fractional crystallization played an important role in the magmatic processes. However, fractional crystallization cannot explain the geochemistry of most incompatible trace elements and Sr–Nd isotope characteristics. The positive correlation between Th/Nb and (La/Sm)N ratios demonstrates the direct relation between the enrichment of the light rare earth elements and the contamination of continental sediments. The high contents of large ion lithosphere elements (LILE) in the Permian volcanic rocks may suggest an additional ‘crust + fluid’ component, especially in the intermediate rocks, which are highly enriched in Ba (> 400 ppm) relative to the basic rocks (> 200 ppm). We propose that the subduction slab dropped into depleted mantle and released fluid, which induced the mantle metasomatism and LILE enrichment. The metasomatized mantle partially melted and formed the ‘primary’ magma. This primary magma assimilated with the Proterozoic biotite–quartz schist during its rise, and finally formed the Permian volcanic rocks. Magma assimilated with the Proterozoic biotite–quartz schist in small amounts could have produced the basic rocks, while assimilation of larger amounts of magma (because of longer assimilation time) would generate intermediate rocks.

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