Reference

Hafnium sulfate-water (vapor) system

Hafnium sulfate-water (vapor) system. Spasibenko, T. P. (Gor'k. Inzh.-Stroit. Inst., Gorkiy, USSR). Zh. Neorg. Khim. 19527-28-7 and 89013-60-5 which are cas registry numbers are also used here., 29(1), 230-2 (Russian) 1984. CODEN: ZNOKAQ. ISSN: 0044-457X. DOCUMENT TYPE: Journal CA Section: 78 (Inorganic Chemicals and Reactions) Tensimetric titrns. in the Hf(SO4)2-H2O(g) system indicate the formation of Hf(SO4)2.nH2O (I) (n = 3.5, 4). Both hydrates were identified by IR spectra. I (n = 4) is relatively stable to internal solid-phase hydrolysis. .

Genesis of the southern Abitibi greenstone belt, Superior Province, Canada: evidence from zircon hafnium isotope analyses using a single filament technique

Genesis of the southern Abitibi greenstone belt, Superior Province, Canada: evidence from zircon hafnium isotope analyses using a single filament technique. Corfu, Fernando; Noble, Stephen R. (Dep. Geol., R. Ontario Mus., Toronto, ON M5S 2C6, Can.). Geochim. Cosmochim. Acta, 56(5), 2081-97 (English) 1992. CODEN: GCACAK. ISSN: 0016-7037. DOCUMENT TYPE: Journal CA Section: 53 (Mineralogical and Geological Chemistry) Hafnium isotopic analyses, together with U-Pb geochronol., have been performed on zircons from the main units of the Late Archean southern Abitibi greenstone belt in the Superior Province. A new anal. method in which Hf is loaded and run with a mixt. of Ir-Mo and C on single filaments was used. The results indicate a relatively homogeneous isotopic compn. of the greenstone belt, with eHf values of 6.3-4.2 for the 2730-2700 Ma pre-orogenic assemblages and 4.7-3.6 for the 2690-2675 Myr synorogenic intrusions. Hafnium isotopes and U-Pb ages indicate that the greenstone belt formed in a relatively short time interval within an ensimatic setting, with minimal interaction with older sialic crust. Primary magmas were derived from mantle sources with a depleted isotopic signature of eHf u 5.5 ± 0.5, corresponding to published eNd u 2.5, 87Sr/86Sr u .7011, 207Pb/204Pb u 14.4, and 206Pb/204Pb u 13.2. Slightly lower eHf values in some rocks may record moderate degrees of source heterogeneity; in the case of the alkalic plutons, the lower eHf can be interpreted in terms of mantle wedge contamination by subducted components isotopically similar to sedimentary rocks in the adjacent Pontiac Subprovince. The consistent, pos. eHf signature confirms that the Archean mantle was already depleted prior to formation of 3.0-2.7 Gyr Superior Province crust.