扩散理论在陨石研究中的应用
华欣
摘要(Abstract)：
碳质球粒陨石中的镁橄榄石周围或中间存在着富铁橄柱石的边、脉和晕,这种现象在该类陨石的球粒、富钙富铝包裹体以及单个矿物颗粒中是很普遍的。富铁橄榄石凝聚后,铁开始向镁橄揽石中扩散。扩散的机理是橄榄石中存在着晶格缺陷或是形成了与莱河矿相似的,含Al~(3+)、Cr~(3+)的非化学当量配比的矿物相。通过计算机模拟扩散曲线计算出的冷凝速度,表明自铁橄榄石从太阳原始星云中凝聚出来以后,冷却过程是一个相当快的过程。我们估算的冷凝速度分别是:初始温度为900℃时,冷凝速度为10℃/天;初始温度为1200℃时,其为2000℃/天。
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作者(Author): 华欣
参考文献(References)：
- 〔1〕Albee, A. T. and Ray, L. Correction factors for electron probe microanalysis of silicates, oxides, carbonates, phosphates and sulfates. Anal. Chem., 1970, Vol. 42, pp. 1408-1414
- 〔2〕Bence, A. E. and Albee, A. L., Empirical correction factors for the electron microanalysis of silicates and oxides. J. Geol., 1968, Vol. 76, pp. 382-403
- 〔3〕Buening, D. K. and Buseck, P. R. (173), Fe-Mg lattice diffusion in olivine. JGR, 1973. Vol. 78, pp. 6852-6862
- 〔4〕Grossman, L., Condensation in the primitive solar nebula Geochim. Cosmochim. Acta, 1972, Vol. 36, pp. 597-619
- 〔5〕Hermeling, J. and Schmalzried, H.,Tracerdiffusion of the Fe-cations in Olivine (FexMg_1-x): SiO_4 (Ⅲ). Phys. Chem. Min., 1984, Vol. 11, pp. 161-166
- 〔6〕Kitamura, M., Shen, B. M., Banno, S. and Morimoto, N., Fine textures of laihunite, a nonstoichiometric distorted olivine-type mineral. Amer. Mineral., 1984, Vol. 69, pp. 154-160
- 〔7〕Kondoh, S., Kitamura, M. and Morimoto, N., Synthetic laihnnite, an oxidation product of olivine. Amer. Mineral., 1985, Vol. 70, pp. 737-746
- 〔8〕Nakamura, A. and Schmalzried, H. , on the nonstoichiometry and point defects of olivine. Phys. Chem. Min., 1983, Vol. 1O, pp. 27-37
- 〔9〕Nakamura, A. and Sehmalzried, H. , On the Fe~(2+)-Mg~(2+) int(?)rdiffusion in olivine (Ⅱ), Phys. Chem. , 1984, Vol. 88, pp. 140-145
- 〔10〕Palme, H. and Fegley, B., Jr., Formation of FeO-bearing olivines in carbonaceous chondrites by high temperature oxidation in the solar nebula. Lunar Planet. Sci., ⅩⅤⅢ, 1987, pp, 754-755
- 〔11〕Peck, J. A. and Wood, J. A., The origin of ferrous zoning in Allende Chondrule olivines. Geochim. Cosmochim. Acta (in press), 1986,
- 〔12〕Sanford, R. F. and Huebner, J. S. 1980, Model thermal history of 77115 and implications for the origin of fragment-laden basalts. Proc. Conf. Lunar Highlands Crust, 1980 pp. 253-269
- 〔13〕Shen, B. M. , Tamada, O. , Kitamura, M. and Morimoto, N., Superstructure of laihunite-3M. Amer. Mineral., 1986, Vol. 71, pp. 1455-1460