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Ar Ar法定年的特点是必须要有一套年龄从小到大的标准样。迄今用于新生代定年的国内标准样极少。为满足新生代矿物Ar Ar法定年的需要,初选了一个标准样候选者BT 1透长石。样品总重366g,粒级6080目,纯度100%,缩分为100瓶,每瓶3 66g。Ar Ar阶段加热法初测结果为:全部12个阶段给出的总气体年龄为30 8±0 9Ma,412阶段视年龄十分接近,年龄谱平坦,对应的39Ar析出量达96%,坪年龄为29 6±0 4Ma,等时年龄为29 6±0 6Ma,MSWD=1 01。40Ar/36Ar初始值为293 6±3 9,与尼尔值295 5相当。重复测定结果为:全部气体年龄为31 0±0 9Ma(全部9个阶段),坪年龄为29 5±0 4Ma,等时年龄为29 4±0 6Ma,MSWD=1 94,40Ar/36Ar初始值为282 2±6 3。这些结果表明,BT 1透长石不含过剩氩,作为新生代定年的Ar Ar法标准样品候选者是较为理想的。
The Ar Arbitration Year is characterized by the need to have a set of standards that are as young as age. To date, there are very few national standards for the Cenozoic years. In order to meet the needs of Ar Argon, a new generation of minerals, a candidate for the standard BT 1 is primaries. Total sample weight 366g, grain size 6080 mesh, 100% purity, reduced to 100 bottles, 3 66g per bottle. Ar Ar stage heating method preliminary test results show that: the total gas age of all 12 stages is 30 8 ± 0 9Ma, 412 stage as the age is very close, the age spectrum is flat, the corresponding 39Ar precipitation amount of 96%, Ping age 29 6 ± 0 4Ma, the isochronous age was 29 6 ± 0 6Ma, and the MSWD was 1 01. The initial value of 40Ar / 36Ar was 293 6 ± 39, which corresponded to the Neil value of 295 5. Repeated measurements showed that the total gas age was 31 0 ± 0 9 Ma (all 9 stages), the plateau age was 29 5 ± 0 4 Ma, the isochronous age was 29 4 ± 0 6 Ma, and the MSWD was 1 94 and 40 Ar / 36 Ar initial values 282 2 ± 6 3. These results show that the BT 1 periclase does not contain excess argon, which is ideal for the Ar Ar method standard sample candidates of the Cenozoic age.