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海底多金属结核和富钴结壳的He同位素对比研究 总被引:9,自引:0,他引:9
对东太平洋海盆C- C 区海底多金属结核及西太平洋马绍尔地区富钴结壳的He 同位素组成进行了对比研究。发现结核的3He/4He 比值普遍较高,为(1.73 ~13 .26) ×10- 5 。所有结核样品的3 He/4 He 比值均高于MORB 的平均3 He/4 He 比值,有些样品的3 He/4 He 比值甚至高于地幔热柱的值。磁性部分相对非磁性部分3 He/4He 比值和4 He 含量均明显偏高。结壳的3 He/4 He 比值相对较低,变化范围为6 .05 ×10 - 8 ~8 .08 ×10 - 5 相似文献
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河北汉诺坝新生代玄武岩中幔源包体和高压巨晶的氦同位素地球化学研究 总被引:3,自引:0,他引:3
对该地区新生代玄武岩中幔源包体和高压巨晶的氦同位素进行了初步研究。幔源包体中橄榄石的3 He 4 He值为 (0 .15~ 7.4)× 10 - 6,较MORB值明显偏低 ,甚至低于大气的值 ,说明该地区曾发生过强烈的地幔交代作用。高压巨晶辉石和石榴子石的氦同位素组成与此明显不同 ,其3 He 4 He值为 (5 .7~ 2 4.3)× 10 - 6。提出幔源包体和高压巨晶不是同源的 ,二者可能与寄主玄武岩均无必然成因联系。在汉诺坝地区一件石榴子石巨晶中还发现了异常高的3 He 4 He值。 相似文献
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硅同位素标准物质的研制 总被引:2,自引:0,他引:2
本文所研制的硅同位素标准物质为:GTB1,选用震旦亚界长城系常州沟组石英砂岩中的石英;GTB2,选用上海试剂一厂生产的高纯二氧化硅试剂。2个标准物质均按国家计量技术规范统一标准物质〈JJG100686〉的规定,用SiF4法进行了均匀性检验及定值分析工作。结果表明其硅同位素组成均匀,定值准确,并获得了GTB1标准物质的δ30SiNBS28(‰)为-0.02±0.10,GTB2标准物质的δ30SiNBS28(‰)为-2.68±0.10。经两年多的稳定性检查,硅同位素值无变化。 相似文献
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Helium isotope studies of the mantle xenoliths and megacrysts from the Cenozoic basalts in the eastern China 总被引:9,自引:2,他引:7
Helium isotope compositions of the mantle xenoliths and megacrysts in the Cenozoic basalts in the eastern China were measured.
The samples were collected from Ludao of Heilongjiang, Huinan and Jiaohe of Jilin, Kuandian of Liaoning, Hannuoba of Hebei,
Nüshan of Anhui, Dingan of Hainan. The3He/4He ratios of the mantle xenoliths and megacrysts from the most areas were about 1 × 10-5, and were similar to those of the MORB, thus reflecting the characteristics of the MORB-typed depleted mantle. The3He/4He ratios of the mantle xenoliths from Jiaohe were 4.8×10-6 and the3He/4He ratios of xenoliths from Hannuoba vary from 0.15× 10-6 to 7.4 ×10-6, obviously lower than those of the MORB, and even lower than the atmospheric helium isotope ratios, indicating that the continental
mantle was strongly replaced in Jiaohe and Hannuoba areas. The helium isotope compositions of the mantle xenoliths and megacrysts
in the same region vary in a very wide range. It is inferred that the mantle xenoliths and megacrysts were from different
parts of the continental mantle. There were not necessary origin relations between the mantle xenoliths, megacrysts and their
host basalts. An extremely high3He/4He ratio of garnet megacryst from Hannuoba, Hebei was found. 相似文献
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中国南海海水蒸发实验过程中地球化学行径 总被引:9,自引:0,他引:9
本文所介绍的是中国南海海水室内等温蒸发过程中析序列、常量及微量元素含量分布规律,着重研究了海水蒸发过程中液相和固相矿物中结晶水氢氧同位素组成变化规律,并与四川盆地深层海源同生卤水进行了对比,从而,对卤水形成机理、资源远景评价综合利用途径等提供了科学依据。 相似文献
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确定平原地下水4He年龄方法的尝试 总被引:1,自引:0,他引:1
放射性衰变产生的氦组分(3H衰变质产生3He,U/Th衰变产生4He)广泛地用水地下水测年。本文分析了地下水中惰性气体的组成,采用过剩空气非分馏(UA)模型进行了单独氦组分的分离。结果表明,河北平原第三含水组(Q2)中的过剩4He是含水组内原地内原地产量和深部地壳通量的共同作用的结果。由于缺乏确定氦平衡参数的约束很好的客观分析,选择应用地下水流模型主观调节来估算迭代过程中的外部通量和流速场,然后根据这个模型所取得的4He年龄与应用其他方法包括14C测年和水文模型取得的年龄进行了对比。 相似文献