福建牛头山火山口岩石中的放射性核素

Radionuclides in Volcanic Rocks from the Niutou Hill, Fujian Province

用HPGe-γ谱方法测定了在福建省牛头山火山口采集的岩石中的放射性核素^238U、226Ra、^210Pb、^228Th、^228Ra和^40K，样品有玄武岩和花岗岩，结果给出6种核素的比活度为1．6～94．7、LD为30．5Bq/kg、LD为26．6Bq／kg、3．3～106Bq／kg、4．9～113Bq／kg和28-1267Bq／kg，平均为13．5Bq／kg、5．5Bq／kg、8．9Bq／kg、13．0Bq／kg．16．1Bq／kg和293Bq／kg。按放射性核素含量水平可以将玄武岩样品分为两个组。第1组样品中6种核素的含量平均为21．0Bq／kg、14．8Bq／kg、14．7Bq／kg、26．0Bq／kg、29．8Bq／kg和749Bq／kg；第2组样品中6个核素含量平均为7．0Bq／kg、2．0Bq／kg、6．0Bq／kg、4．9Bq／kg、7．7Bq/kg和142Bq/kg；花岗岩中6种核素的含量平均为57．7Bq／kg、19．0Bq／kg、21．7Bq／kg、62．2Bq／kg、67．4Bq／kg和894Bq／kg。含量水平为：花岗岩大于第1组玄武岩第一组玄武岩大于第2组玄武岩。

The natural radionuclides in volcanic rocks from the Niutou Hill, Fujian Province, were measured by HPGe-γ spectroscopy. The samples include granite and basalt, The contents of ^238U, ^226Ra, ^210Pb, ^228Th, ^228Ra and ^40K in all samples are 1.6-94, 7, LD -30.5 Bq/kg, LD-26.6 Bq/kg, 3.3-106 Bq/kg, 4.9-113 Bq/kg and 28-1267 Bq/kg respectively, and the mean values are 13.5 Bq/kg, 5.5 Bq/kg, 8.9 Bq/kg, 13.0 Bq/kg, 16.1 Bq/kg and 293 Bq/kg. There are two groups of basalt samples that have different radionuclide values. The average contents of the six nuclides in the first group of basalt samples are 21.0 Bq/kg, 14.8 Bq/ kg, 14.7 Bq/kg, 26.0 Bq/kg, 29.8 Bq/kg and 749 Bq/kg, those in the second group of basalt samples are 7.0 Bq/kg, 2.0 Bq/kg, 6.0 Bq/kg, 4.9 Bq/kg, 7.7 Bq/kg and 142 Bq/kg, and those in granite are 57.7 Bq/kg, 19. 0 Bq/kg, 21.7 Bq/kg, 62. 2 Bq/kg, 67.4 Bq/kg and 894 Bq/kg. The content level of 6 radinuclides in samples is in order of granite rocks 〉 the first group of basalt rocks 〉 the second group of basalt rocks.