Allanite-(Ce) as an indicator of the origin of granitic rocks in Japan: Importance of Sr-Nd isotopic and chemical composition

作者：Hoshino Mihoko^*; Kimata Mitsuyoshi; Arakawa Yon; Shimizu Masahiro; Nishida Norimasa; Nakai Shunichi

来源：The Canadian Mineralogist, 2007, 45: 1329-1336.

DOI：10.3749/canmin.45.6.1329

• allanite-(Ce)
• Mn content
• rare-earth elements
• strontium isotopes
• neodymiurn isotopes
• granitic rocks
• origin
• Japan

The isotopic compositions of Sr and Nd were analyzed for sixteen samples of allanite-(Ce) from Mesozoic-Cenozoic granitic rocks in Japan (11 samples of an Mn-rich type, and five samples of an Mn-poor type). The Mn-rich allanite-(Ce) crystals have an initial Sr-87/Sr-86 value in the range 0.70811-0.71398 and an initial Nd-143/Nd-144 value in the range 0.512148-0.512471, whereas for crystals of Mn-poor allanite-(Ce), the analogous intervals are 0.70499-0.70704 and 0.512547-0.512606. There is a negative correlation between Sr-87/Sr-86 and Nd-143/Nd-144 values. The trend of these isotopic data for Mn-rich and Mn-poor allanite-(Ce) is parallel to that for ilmenite- and magnetite-series granitic rocks from Japan, respectively. This parallelism suggests that the genesis of these two groups of allanite-(Ce) is related to that of ilmenite-series and magnetite-series granitic rocks. The characteristics of allanite-(Ce) can shed light on the petrogenesis of granitic rocks.

• 出版日期2007-12