THE IMPACT OF THE CONTACT SUBALKALINE GABBROIDS (MAFITES) OF POCROVO-KYRIYV MASSIF IN ALKALINE GRANITES

• Дата: 2016
• Автори: Kryvdik, S.G., Gatsenko, V.O., Lunev, E.S.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: Institute of Geological Sciences, NAS of Ukraine 2016
• Теми: the altered granites; the impact of the contact; the subalkaline gabbroids; the Pokrovo-Kyriyv massif; the Azov megablock; измененные граниты; контактовое воздействие; субщелочные габброиды; Покрово-Киреевский массив; Приазовский мегаблок; змінені граніти; контактовий вплив; сублужні габроїди; Покрово-Киріївський масив; Приазовський мегаблок; 552.331(477.7)
• Онлайн доступ: http://geojournal.igs-nas.org.ua/article/view/97247
• Назва журналу: Geological journal

Pokrovo-Kyriyv massif is situated on the north-eastern part of the Azov megablock (Ukrainian shield), in its junction Donbass folden structure. This massif is composed of subalkaline gabbro, pyroxenites, malignites, nephelines syenites and various basalts. In the one of the profiles a quite thickness (35-40 m) body of altered granites was drilled. Alterations of this granite bodi had been coased by influence of subalkaline pyroxenites, gabbro and numerous dikes of subalkaline gabroids. This alteration (transformation) of this granite is displayed in the appearance of small fields (“spots”), that is composed of fine-grained aggregate of new-formed amphibole (such as Naactinolite type) and magnetite, celadonite and magnetite, which obviously replace pseudomorphically primary amphiboles (ferric hornblende) and biotite in country granites. In addition, there is albitization of K-feldspar, also as well is single graines of garnet (purely andradite), new formed apatite and crystallization (nest, veins) of calcite. Such exocontact alterations of granite are differ from thermal metamorphism and hornfelsing and fenitization that are accompanying intrusive rocks of carbonatite complexes. Obviously subalkaline composition of the intrusions is caused not usual tape exocontact alterations of granites.