Zirconium-hafnium rims were discovered and described for the first time within the Suwalki Anorthosite Massif (SAM). They are observed at boundaries of Fe-Ti oxides ilmenite, hematitoilmenite and titanomagnetite with plagioclases. The most frequent forms reach 80-250 μm in length and 4-30 μm in width. These are narrow rims covering even up to 70% ore mineral grains. The most spectacular forms were "blown candle flame” structures. Their average width ranges from 20 to 45 μm and the length exceeds 350 μm in . Chemical composition analysis was carried out on the largest clusters of zircon crystals/rims which show high local enrichment in Hf (0.5-0.8% by weight). The boundaries of these crystals are cracked and blurry. This may suggest their participation in later fluids inflow processes within the rocks. The enrichment in hafnium content in zircon grains, is related to significant reduction in the amount of Th, U and Pb and increased amount- sof Ti and Fe in zircon rims. A large variety of forms and variability of their chemical composition point to a complex physical chemical orgin process.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.