scholarly journals Magmatic evolution and controls on rare metal-enrichment of the Strange Lake A-type peralkaline granitic pluton, Québec-Labrador

Lithos ◽  
2018 ◽  
Vol 308-309 ◽  
pp. 34-52 ◽  
Author(s):  
Karin Siegel ◽  
Olga V. Vasyukova ◽  
Anthony E. Williams-Jones
Keyword(s):  
Rare Metal ◽  
Magmatic Evolution ◽  
Metal Enrichment ◽  
Granitic Pluton

scholarly journals New data concerning the age and composition of intrusion complexes of the northern part of Balygychan-Sugoi rift depression (North-Eastern Russia)

2021 ◽  
Vol 66 (3) ◽  
Author(s):  
Marina N. Petrova ◽  
◽  
Semen Iu. Petrov ◽  
Mihail Iu. Kurapov ◽  
◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Rare Metal ◽  
Ore Deposits ◽  
Point Of View ◽  
Structure Evolution ◽  
Magmatic Evolution ◽  
Geochemical Composition ◽  
North Eastern ◽  
Chukotka Volcanic Belt ◽  
First Time

The Balagychan-Sugoi (Omsukchan) riftogeneous depression is described by different authors both as a part of Okhotsk-Chukotka volcanic belt (OCVB) and as a separate structure. The unique Dukat gold and silver deposit and a lot of others ore deposits including rare-metal, such as Arylah, Lunnoe, Askold, Mechta, Tidid, Krasin, are associated with this structure. All mentioned objects are located in the south part of the depression and from this point of view are connected with OCVB structure. Evolution of the Balygychan-Sugoi depression is closely related to the stages of magmatic evolution of the region. In the article, these stages are characterized based on the data form intrusion bodies located in the northern part (Naygain depression). This part is the most outlying from the OCVB and less investigated. For the first time, the U-Pb zircon and baddeleyite dating and the description of petrographic and geochemical composition have been carried out for Mandychan gabbro-diorite and Nayahan gabbro leucogranite intrusion complexes from the northern part of the depression and for Omsukchan leucogranite complex. The Late Jurassic – Early Cretaceous intrusions of the Mandychansk complex dated as 143-139 Ma mark the beginning of the rift depression formation. Intrusion of granitoids of the Nayahan and Omsukchan complexes dated as 84-85 Ma and 81-82 Ma correspondently is related with new stage of magmatic activity, synchronous to OCVB formation. The petrographic and geochemical compositions of these granitoids indicate their belonging to the I-type granites, which are typical for extension environments, whereas leucogranites of the Omsukchan complex have some features corresponding to the A-type granites.

scholarly journals Geology, petrology and U-Pb geochronology of Serra da Rajada Granitic Pluton: implications about ediacaran magmatic evolution in NE portion of the Rio Piranhas-Seridó Domain (NE of Borborema Province)

2015 ◽  
Vol 15 (3-4) ◽  
pp. 83
Author(s):  
Alan Pereira da Costa ◽  
Marcos Antonio Leite do Nascimento ◽  
Antônio Carlos Galindo ◽  
Alexandre Ranier Dantas
Keyword(s):  
Magmatic Evolution ◽  
Granitic Pluton ◽  
Borborema Province

A atividade plutônica ediacarana, relacionada à orogênese Brasiliana/Pan-Africana, constitui uma importante feição geológica na Província Borborema, representada por inúmeros batólitos, stocks e diques. O Plúton Granítico Serra da Rajada (PGSR), situado na porção central do Domínio Rio Piranhas-Seridó, representa um exemplo desses corpos, objeto de estudos cartográ- fico, petrográfico, litoquímico e geocronológico. Suas rochas são aqui descritas como monzogranitos constituídos por K-feldspato, plagioclásio (oligoclásico-An23-24%), quartzo e biotita, tendo minerais acessórios opacos, titanita, allanita, apatita e zircão. Clorita, mica branca e carbonato são minerais de alteração. Dados litoquímicos evidenciam rochas bastante evoluídas (SiO2 , 69% a 75%), ricas em álcalis (Na2 O + K2 O ≥ 8,0%), empobrecidas em MgO (≤ 0,45%), CaO (≤ 1,42%) e TiO2 (≤ 0,36%) e teores moderados de Fe2 O3 t (2,16 a 3,53%). Apresentam natureza transicional entre metaluminosas e peraluminosas (predomínio das últimas) e possuem afinidade por rochas cálcio-alcalinas de alto K. Diagramas de Harker mostram correlações negativas em Fe2 O3 t, MgO e CaO, indicando fracionamento de máficos e plagioclásio. O espectro de ETR mostra enriquecimento dos ETR leves com relação aos ETR pesados (LaN/YbN = 23,70 a 10,13) e anomalia negativa no Eu (Eu/Eu* = 0,70 a 0,23), sugerindo fracionamento ou acumulação na fonte de feldspatos (plagioclásio). A integração dos dados permite correlacionar as rochas do PGSR àquelas descritas na literatura como Suíte Cálcio-Alcalina de Alto K Equigranular. Estudos geocronológicos/ isotópicos U-Pb e Sm-Nd indicam, respectivamente, que a biotita monzogranito possui idade de cristalização de 557±13 Ma, com idade modelo TDM de 2,36 Ga, tendo valor de εNd para a idade de cristalização de -20,10, permitindo inferir fonte crustal para o magma, gerada no paleoproterozoico

Sign in / Sign up

Export Citation Format

Share Document