The Paleoproterozoic Kolvitsa Anorthosite Massif: New Data on the U–Pb Age (ID TIMS) and Geochemical Features of Zircon

2018 ◽  
Vol 479 (1) ◽  
pp. 366-370 ◽  
Author(s):  
E. N. Steshenko ◽  
A. I. Nikolaev ◽  
T. B. Bayanova ◽  
S. V. Drogobuzhskaya ◽  
V. V. Chashchin ◽  
...  
Keyword(s):  
Anorthosite Massif

Age and tectonic position of the Khorogochi gabbro-anorthosite massif (Dzhugdzhur-Stanovoi superterrane)

2008 ◽  
Vol 423 (1) ◽  
pp. 1312-1315 ◽  
Author(s):  
I. V. Buchko ◽  
E. B. Sal’nikova ◽  
A. B. Kotov ◽  
A. P. Sorokin ◽  
A. M. Larin ◽  
...  
Keyword(s):  
Anorthosite Massif ◽  
Tectonic Position

scholarly journals Geochronology of granites of the western Korosten AMCG complex (Ukrainian Shield): implications for the emplacement history and origin of miarolitic pegmatites

2021 ◽  
Vol 33 (6) ◽  
pp. 703-716
Author(s):  
Leonid Shumlyanskyy ◽  
Gerhard Franz ◽  
Sarah Glynn ◽  
Oleksandr Mytrokhyn ◽  
Dmytro Voznyak ◽  
...  
Keyword(s):  
Economic Value ◽  
Ukrainian Shield ◽  
Western Region ◽  
The South ◽  
Anorthosite Massif ◽  
Granitic Intrusion ◽  
Plutonic Complex ◽  
Flow Through ◽  
Basic Rocks ◽  
North Western

Abstract. The origin of large miarolitic (also known as “chamber”) pegmatites is not fully understood although they may have great economic value. The formation of cavities in magmatic bodies is related to melt degassing and gas or fluid flow through partially solidified magma. In this paper, the origin of the Volyn pegmatite field, located in the Palaeoproterozoic Korosten anorthosite–mangerite–charnockite–granite (AMCG) complex, North-Western region of the Ukrainian Shield, is discussed. Pegmatites of the field host deposits of piezoelectric quartz that is accompanied by gem-quality beryl and topaz. The Volyn pegmatite field is confined to granites located in the south-western part of the Korosten complex and extends for 22 km along the contact with the anorthosite massif within the Korosten plutonic complex. Geological data indicate hybridization of basic melts and partly crystallized granites, as well as direct impact of fluids derived from basic melts on the chamber pegmatites. The new U–Pb zircon ages obtained for granites and pegmatites of the Korosten complex confirm that the rock assemblage in the northern part of the complex crystallized between 1800 and 1780 Ma, whereas rocks in the southern part intruded mainly between 1768 and 1755 Ma. U–Pb zircon ages for granites from the south-western part of the Korosten complex indicate that granites were emplaced at 1770–1765 Ma, a few million years prior to the intrusion of the gabbro–anorthosite massif (1762–1758 Ma), while chamber pegmatites in these granites crystallized at 1760 ± 3 Ma, coevally with the basic rocks. Ultimately, the formation of the chamber pegmatites was related to the reheating of the semi-crystallized granitic intrusion and to fluids migrating from the underlying gabbro–anorthosite massif.

NEW RESULTS OF POLYMETALLIC, PGE AND REE MINERALIZATION RESEARCH IN THE SUWAŁKI ANORTHOSITE MASSIF (NE POLAND)

2018 ◽  
Vol 472 (472) ◽  
pp. 271-284 ◽  
Author(s):  
Janina Wiszniewska ◽  
Ewa Krzemińska ◽  
Olga Polechońska ◽  
Zdzisław Petecki ◽  
Michał Ruszkowski ◽  
...  
Keyword(s):  
Deep Structure ◽  
Gravity Anomalies ◽  
Magnetic Anomalies ◽  
Ore Deposits ◽  
Borehole Data ◽  
Ne Poland ◽  
Anorthosite Massif ◽  
Deep Boreholes ◽  
Thick Overburden ◽  
Rock Suite

Suwałki Anortosite Massif (SAM) occurs in the crystalline basement of NE Poland within 200 km of the magmatic, Mesoproterozoic AMCG (anorthosite–mangerite–charnockite–granite) rock suite terrane called the Mazury Complex. SAM was discovered as a result of the drilling research of the prominent negative magnetic and gravimetric anomalies. There is an extensive negative anomaly of both potential fields related to the anorthosite massif. Gravimetric anomaly is surrounded by the bands of positive anomalies caused by rocks with elevated densities, such as granitoids, monzondiorites and granodiorites. A negative magnetic anomaly is surrounded by the bands of positive anomalies with significant amplitudes, particularly strongly marked from the south, west and north. Positive magnetic anomalies are associated with the presence of rocks with proven strong magnetic susceptibility due to the content of ferrolites (ilmenite-magnetite rocks) with accompanying Fe-Cu-Ni-Co sulphide mineralization. Fe-Ti-(V) ore deposits in the SAM were discovered in the early 1960s, in the region of Krzemianka and Udryn, but also Jeleniewo and Jezioro Okrągłe, under a thick overburden of Phanerozoic sedimentary rocks within small positive magnetic anomalies. These deposits were documented in about 100 deep boreholes to a depth of 2300 m, and the resources in C1 + C2 category were estimated for about 1.5 billion tons of titanium-magnetite ores with vanadium, mainly in the Krzemianka and Udryn ore fields. The model age obtained by the Re-Os NTIMS method for Fe-Ti-V ores and sulphides from the Krzemianka and Jezioro Okrągłe ore deposits was 1559 ±37 Ma with an initial ratio of 187Os/188Os = 1.16 ±0.06. This age was recognized as the age of the entire Suwałki Massif. Despite many years of research, the deep structure and the form of the massif has not been fully recognized. At present, geophysical and geological 3D modelling of borehole data is carried out using the OasisMontaj (Geosoft) software package. The 3D model is generated in the GeoModeller 3D application (Intrepid Geophysics) in order to recognize the geological correctness and interpretation of magnetic-gravity anomalies of the whole massif and its cover.

A model for the origin of the Lac St. Jean anorthosite massif

1976 ◽  
Vol 13 (2) ◽  
pp. 389-399 ◽  
Author(s):  
R. A. Frith ◽  
K. L. Currie
Keyword(s):  
Experimental Data ◽  
Partial Melting ◽  
Metamorphic Rocks ◽  
High Grade ◽  
Calc Alkaline ◽  
Grenville Province ◽  
Thermal Event ◽  
Anorthosite Massif ◽  
Mineral Assemblages ◽  
Potassic Rocks

An ancient tonalitic complex becomes migmatitic around the Lac St. Jean massif, ultimately losing its identity in the high grade metamorphic rocks surrounding the anorthosite. Field relations suggest extreme metamorphism and anatexis of tonalitic rocks. Experimental data show that extensive partial melting of the tonalite leaves an anorthositic residue. The same process operating on more potassic rocks would leave monzonitic or quartz syenitic residues. Synthesis of experimental data suggests that the process could operate at pressures of 5–8 kbar and temperatures of 800–1000 °C, which are compatible with mineral assemblages around the anorthosite massif. Slightly higher temperatures at the end of the process could generate magmatic anorthosite.Application of the model to the Grenville province as a whole predicts generation of anorthosite during a long-lived thermal event of unusual intensity. Residual anorthosite would occur as a substratum in the crust, overlain by high-grade metamorphic rocks intruded by anorthosite and syenitic rocks, while higher levels in the crust would display abundant calc-alkaline plutons and extrusives.

Crystallization and emplacement of the Lac St-Jean anorthosite massif (Quebec, Canada)

1981 ◽  
Vol 76 (3) ◽  
pp. 343-350 ◽  
Author(s):  
G. Woussen ◽  
E. Dimroth ◽  
L. Corriveau ◽  
P. Archer
Keyword(s):  
Anorthosite Massif

Re-Os study of Fe-Ti-V oxide and Fe-Cu-Ni sulfide deposits, Suwałki Anorthosite Massif, northeast Poland

2000 ◽  
Vol 35 (5) ◽  
pp. 391-401 ◽  
Author(s):  
J. W. Morgan ◽  
H. J. Stein ◽  
J. L. Hannah ◽  
R. J. Markey ◽  
J. Wiszniewska
Keyword(s):  
Sulfide Deposits ◽  
Anorthosite Massif

Very high temperature, moderate pressure metamorphism in the New Russia gneiss complex, northeastern Adirondack Highlands, metamorphic aureole to the Marcy anorthosite

1999 ◽  
Vol 36 (1) ◽  
pp. 1-13 ◽  
Author(s):  
J Alcock ◽  
Peter Muller
Keyword(s):  
New York ◽  
High Temperature ◽  
Moderate Pressure ◽  
Dehydration Melting ◽  
Eastern Margin ◽  
Gneiss Complex ◽  
Anorthosite Massif ◽  
Metamorphic Gradient ◽  
High Temperature Metamorphism ◽  
Very High

The New Russia gneiss complex in the northeastern Adirondack Highlands of New York includes meta-anorthosite gneiss and anatectic gneiss derived from metagabbro, mangerite, and charnockite. Metamorphic conditions during anatexis (850-950°C, highest near the anorthosite, with pressure ~750 MPa) are inferred from minerals and textures produced by dehydration melting of pargasitic hornblende and from ternary feldspar in anatectic segregations. The complex abuts and is crosscut by the eastern margin of the ~1130 Ma Marcy anorthosite massif. The crosscutting contact, the presence of meta-anorthosite gneiss within the complex and undeformed meta-anorthosite in the massif, and the occurrence of deformed and undeformed anatectic segregations within the New Russia gneisses indicate an approximate synchroneity of penetrative deformation, very high temperature metamorphism, and emplacement of anorthosite with both intrusion and anatexis outlasting deformation. The position of the New Russia gneisses, the metamorphic gradient within them, and the contemporaneity of anatexis with intrusion of anorthosite imply that the complex is the metamorphic aureole of the Marcy anorthosite.

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