Formation of authigenic monazite-(Ce) to monazite-(Nd) from Upper Carboniferous graywackes of the Drahany Upland: Roles of the chemical composition of host rock and burial temperature

Lithos ◽  
2011 ◽  
Vol 127 (1-2) ◽  
pp. 373-385 ◽  
Author(s):  
Renata Čopjaková ◽  
Milan Novák ◽  
Eva Franců
Keyword(s):  
Chemical Composition ◽  
Host Rock ◽  
Upper Carboniferous

The chemical composition of Upper Carboniferous pteridosperm cuticles

1994 ◽  
Vol 21 (1) ◽  
pp. 107-112 ◽  
Author(s):  
Pim F. van Bergen ◽  
Andrew C. Scott ◽  
Patrick J. Barrie ◽  
Jan W. de Leeuw ◽  
Margaret E. Collinson
Keyword(s):  
Chemical Composition ◽  
Upper Carboniferous

New data on chemical composition of lithium mica from granitic pegmatites of Murzinka pluton (Central Urals)

2020 ◽  
pp. 81-88
Author(s):  
T. A. Gvozdenko ◽  
I. A. Baksheev ◽  
E. I. Gerasimova ◽  
D. A. Khanin ◽  
M. V. Chervyakovskya ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Host Rock ◽  
Granitic Pegmatites ◽  
High Degree ◽  
Central Urals ◽  
Very High

Mica samples from granitic pegmatites of Mokrusha and Ministerskaya mines, Murzinka pluton, Central Urals are polylithionite, sokolovaite, trilithionite, Li-bearing muscovite, and annite–phlogopite series. Chromium and magnesium, uncommon elements for light mica are detected in samples from both mines, indicates host-rock contamination of pegmatites. The low values K/Rb ratio and Ta/Nb ratio define a very high degree of pegmatite differentiation of both mines.

Sur la notion de "types" de gisements metalliferes

1958 ◽  
Vol S6-VIII (3) ◽  
pp. 237-244
Author(s):  
Pierre Routhier
Keyword(s):  
Chemical Composition ◽  
Host Rock ◽  
Country Rock ◽  
Ore Deposits ◽  
Igneous Rocks ◽  
Ore Deposit ◽  
Ore Body ◽  
Enclosing Rocks

Abstract Limitations of existing classifications of ore deposits are examined, and a new "natural" classificationis proposed, based on "types." The types are based on the mineralogic and geologic characteristics of the ore deposit itself and of the host rock. Among the characteristics to be determined for the ore deposit itself are its hypogene paragenesis, superficial alteration, and the chemical composition and ore content of both the hypogene and supergene ore. The characteristics to be determined for the host rock relate to the lithology and stratigraphy of the enclosing rocks and the presence of contact alteration, if any; the form of the ore body in relation to the structure of the country rock; the nearby presence of igneous rocks; and age, if determinable. Descriptions can be completed by giving a list of examples of similar deposits with their age, if known, and pertinent genetic hypotheses.

scholarly journals NGUỒN GỐC VÀ ĐIỀU KIỆN THÀNH TẠO CỦA CORINDON TRONG ĐÁ GNEIS MỎ TRÚC LÂU, HUYỆN LỤC YÊN, TỈNH YÊN BÁI

2011 ◽  
Vol 33 (1) ◽  
pp. 55-62
Author(s):  
Nguyễn Thị Minh Thuyết ◽  
Ngụy Tuyết Nhung ◽  
Nguyễn Ngọc Khôi
Keyword(s):  
Crystal Structure ◽  
Absorption Spectrum ◽  
Chemical Composition ◽  
Host Rock ◽  
Mineral Assemblage ◽  
Mining Area ◽  
Red River ◽  
Assemblage Analysis

Origin and forming conditions of corundums in gneiss in Truc Lau mine, Luc Yen District, Yen Bai ProvinceTruc Lau gem mining area, belonged to Truc Lau, Phuc Loi commune of Luc Yen district, Yen Bai province, islocated in the Red River zone. Here, corundums (ruby, sapphire) have been exploited in placer since the late 80s of the last century. In recent years, they have been found in gneiss host rock. Based on the results of chemical composition, crystal structure, inclusion, color, absorption spectrum of corundum as well as mineral assemblage analysis and thermobarometer confirmed that corundums from Truc Lau gneiss are the production of metapelite and formed by breaking down of muscovite at 650-769oC, 7.6-5.2kbar.

An anorthite-epidote-garnet-hornfels from Namaqualand, South Africa

1941 ◽  
Vol 26 (175) ◽  
pp. 134-139
Author(s):  
C. B. Coetzee
Keyword(s):  
South Africa ◽  
Chemical Composition ◽  
Host Rock ◽  
Analytical Data ◽  
Present Communication ◽  
Northern Boundary ◽  
The North ◽  
North Eastern ◽  
Geological Map ◽  
North Eastern Part

The present communication deals with a calc-silicate hornfels of uncommon mineralogical and chemical composition. It may be tentatively referred to the deep-seated metamorphism of a marl, and on account of the shortage of analytical data pertaining to metamorphosed sediments of the calcareo-argillaceous type, a detailed investigation of a variety of this group seems justified.Intercalated bands of anorthite-epidote-garnet-hornfels bordered bilaterally by pyroxene-bearing gneisses occur on the farms Zandfontein, Pella, and Klein Pella in the north-eastern part of the division of Namaqualand, South Africa (cf. geological map), On Klein Pella small exposures also extend intermittingly for approximately 1·5 miles due WNW.-ESE. of the amphibolite koppie situated on the northern boundary of the farm area. The bands exhibit a gentle pinch and swell structure with maximum widths of 15 to 41 inches, and the contact with the host rock is commonly marked by an epidotic fringe ¾ inch in thickness. In some cases the anorthite-epidote-garnet-rock is penetrated by parallel lenticles of pure quartz which may attain maximum breadths of 0·8 inch.

Generation of anorthositic magma by H2O-fluxed anatexis of silica-undersaturated gabbro: an example from the north Norwegian Caledonides

2000 ◽  
Vol 137 (6) ◽  
pp. 609-621 ◽  
Author(s):  
R. S. SELBEKK ◽  
K. P. SKJERLIE ◽  
R. B. PEDERSEN
Keyword(s):  
Chemical Composition ◽  
Host Rock ◽  
Average Chemical Composition ◽  
The North ◽  
Melting Experiments ◽  
Norwegian Caledonides

The Skattøra migmatite complex in the north Norwegian Caledonides consists of migmatized slightly nepheline-normative metagabbros that are net-veined by numerous (up to 90%) anorthositic and leucodioritic dykes. The average chemical composition of 17 anorthosite dykes is (wt %) 58.4% SiO2, 0.2% TiO2, 23% Al2O3, 1.8% FeOt, 0.7% MgO, 6.3% CaO, 7.8% Na2O, 0.2% K2O. A migmatite leucosome and a dyke have been dated by the U/Pb method on titanite to 456±4 Ma. In low melt fraction areas minor leucosomes are orientated parallel to the foliation. More intense anatexis formed stromatic to schlieric migmatites. The leucosomes are commonly connected to dykes, suggesting that melt segregated and left its source. Dyke thicknesses range from a few centimetres up to several metres. In general, early dykes are parallel to the foliation in the host rock, while the later dykes cut the foliation. Plagioclase (An20–50) is the dominant mineral (85–100%) in the dykes and the leucosome, but 0–15% amphibole is generally present. Field relations, geochemistry and preliminary melting-experiments strongly suggest that the anorthosites originated by H2O-fluxed anatexis of the gabbroic host rock.

scholarly journals Sr-bearing phosphates of the apatite supergroup from the alkaline rocks of the Konder pluton, Khabarovsk Krai

2021 ◽  
pp. 46-59
Author(s):  
A.S. Osipov ◽  
A.A. Antonov ◽  
N.S. Vlasenko
Keyword(s):  
Chemical Composition ◽  
Host Rock ◽  
Khabarovsk Krai ◽  
Crystallization Sequence ◽  
Alkaline Rocks ◽  
Variable Chemical

The paper presents a mineralogical description of Sr-bearing phosphates of the apatite supergroup found in eudialyte-aegirine-albite rocks of the Konder pluton, Khabarovsk krai. The Sr-dominant phases are associated with minerals of the lamprophyllite group and titanite, whereas the Ca-dominant phases are associated with calciocatapleite and kainosite-(Y), which are the products of the decomposition of eudialyte. The phosphates probably formed during post-magmatic alteration of host rock in a following sequence: stronadelphite > fuorostrophite > Sr-rich fuorapatite (fuorocaphite) > Na-REE-fuorapatite. Their variable chemical composition indicates decreasing Sr, Ba and F contents and increasing Ca, Na, REE and (OH) contents during crystallization. The crystallization sequence could refect a decrease in alkalinity of the mineral-forming conditions. Keywords: stronadelphite, fuorostrophite, fuorocaphite, Sr-rich fuorapatite, fuorapatite, alkaline rocks, hydrothermal alterations, Konder pluton, alkaline-ultramafc complexes.

Host rock geochemistry, texture and chemical composition of magnetite in iron ore in the Neoarchaean Nyong unit in southern Cameroon

2017 ◽  
Vol 126 (3) ◽  
pp. 129-145 ◽  
Author(s):  
N. N. Chombong ◽  
C. E. Suh ◽  
B. Lehmann ◽  
A. Vishiti ◽  
D. C. Ilouga ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Host Rock ◽  
Iron Ore ◽  
Southern Cameroon

The chemical composition and physical properties of the residual glass of the Kap Daussy tholeiite dike, east Greenland

1950 ◽  
Vol 29 (208) ◽  
pp. 46-62 ◽  
Author(s):  
E. A. Vincent
Keyword(s):  
Chemical Composition ◽  
Physical Properties ◽  
Residual Glass ◽  
Upper Carboniferous ◽  
East Greenland ◽  
Dike Swarm

In the course of a petrological examination of some hundreds of specimens from the Tertiary coastal dike swarm of east Greenland, collected at various times by L. R. Wager and W. A. Deer, it was decided to investigate the nature of the residual glassy mesostasis of one of the olivine-tholeiites, in the hope that it might shed some light on the trend of differentiation of the magma responsible for the bulk of the rocks in the swarm. An account of the petrology of the swarm as a whole will be published in due course, but it was thought that a note on the chemical and physical properties of this glassy residuum might be worthy of independent publication, particularly as it provides an interesting comparison with the results of work carried out by Walker (1930, 1935) on the residual glass from one of the Upper Carboniferous tholeiites from central Scotland. The general features of the east Greenland coastal dike swarm have already been described by Wager and Deer (1938) and Wager (1947).

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