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Oxygen isotope studies of the Suzhou granite have been made based on drill-hole samples. In the inner part, the δ18O values are less variable either in the whoe-rock, quartz or in feldspar. Oxygen isotopic compositions are in equilibrium between coexisting quartz and feldspar. Data points from the inner part are plotted in a small area in the δ18OQ-δ18Of dia-gram, indicating that this part has not been affected by meteoric hydrothermal fluids. But the whole-rock δ18O values of the margnal part vary greatly. Oxygen isotopic compesitions are in extreme disequilibrium between quartz and feldspar. Data points from the maminal part are displayed with a nearly vertical slope in the δ18Q-δ18Of diagram, implying that rocks of this part are affected by the meteoric hydrothermal fluids. Extreme waterrock interactions lead to mineralizations of rare-elements (Nb, Ta, as well as Zr, Hf, Th) in the margnal part. Source materials of the Suzhou granite are also discussed in this paper.
Oxygen isotope studies of the Suzhou granite have been made based on drill-hole samples. In the inner part, the δ18O values are less variable either in the whoe-rock, quartz or in Feldspar. Oxygen isotopic compositions are in equilibrium between coexisting quartz and feldspar. Data points from the inner part are plotted in a small area in the δ18OQ-δ18Of dia-gram, indicating that this part has not been affected by meteoric hydrothermal fluids. But the whole-rock δ18O values of the margnal part vary greatly. Oxygen isotopic compesitions are in extreme disequilibrium between quartz and feldspar. Data points from the maminal part are displayed with a nearly vertical slope in the δ18Q-δ18Of diagram, implying that rocks of this part are affected by the meteoric hydrothermal fluids. Extreme water rock interactions lead to mineralizations of rare-elements (Nb, Ta, as well as Zr, Hf, Th) in the margnal part. Source materials of the Suzhou granite are also discussed in this paper.