新-142的证据表明,哈迪纪的地地有证据
Jonathan O'Neil1, Richard W Carlson, Don Francis
1Earth and Planetary Sciences Department, McGill University, 3450 University Street, Montreal, Quebec, H3A 2A7, Canada. oneil_jo@eps.mcgill.ca
概括
研究人员在加拿大发现了古老的岩石,具有独特的同位素签名. 这些发现表明,这些岩石是在地球形成后不久形成的,可能代表着地球上最古老的地.
科学领域:
- 地质化学 地质化学
- 同位素地质学的同位素.
- 早期地球研究研究.
背景情况:
- 142 (142Nd) 同位素异常提供了对早期行星分化的见解.
- 加拿大北克省的Nuvvuagittuq绿石带是研究古代地岩石的关键地点.
研究的目的:
- 为了研究来自Nuvvuagittuq绿石带的岩石的同位素组成.
- 为了确定潜在的古老地材料的年龄和起源.
主要方法:
- 在岩石样本中分析 (Nd) 和 (Sm) 同位素比率 (142Nd/144Nd和Sm/Nd).
- 使用146Sm-142Nd等离子法进行放射测年.
主要成果:
- 一些Nuvvuagittuq岩石的142Nd/144Nd比率低于陆地标准 (epsilon142Nd = -0.07至 -0.15).
- 在一个马菲克两体单位内观察到142Nd/144Nd和Sm/Nd比率之间的正相关性.
- 这个单位的146Sm-142Nd等离子年龄为4,280±5300万年.
结论:
- 分析的岩石代表了不相容的元素丰富的物质,在地球历史的早期形成.
- 这些发现表明Nuvvuagittuq绿石带可能保留了地球上最古老的地部分.
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