概括
甲纪中期的鱼牙揭示了三个时期的低同位素比率,与海洋无氧事件和大火性省份有关. 这些流量比白纪地生产率预测的要小.
科学领域:
- 地质化学 地质化学
- 古海洋学是古海洋学.
- 在平流图学上,平流图学是平流图学.
背景情况:
- 甲纪中期 (大约1.25亿至8.9亿年前) 经历了重要的地质事件,包括大洋高原的形成和海洋无氧事件.
- 海洋档案中的同位素 ((87) Sr/ (86) Sr) 作为跟踪全球气候变化和热水流变化的关键代理.
研究的目的:
- 用鱼牙作为高分辨率档案,重建了同位素在白纪中期变化的历史.
- 为了研究同位素游览,海洋无氧事件和大型火山性省份的位置之间的关系.
主要方法:
- 在意大利东北部阿佩尼尼斯山脉和威尼斯阿尔卑斯山脉中从中白纪和黑页岩形成中恢复的鱼牙中 (87) Sr / 86) Sr 的比率的分析.
- 石同位素数据与已建立的海洋无氧事件标记床的相关性 (例如,Livello Selli,Livello 113).
主要成果:
- 三个不同的低 (87) Sr/ (86) Sr比率的时期被确定为121124万年,110115万年和8991万年.
- 这些低 (87) 斯里尔/ (86) 斯里尔游览与主要的海洋无氧事件和通-爪,Kerguelen和加勒比高原的安置相吻合.
- 与高原位置相关的模拟的流量与喷发量一致,但根据拟议的白纪地生产率,比预期的要低.
结论:
- 在白纪中期,大型火山性省份的位置显著影响了全球流和海洋化学.
- 观察到的同位素模式提供了地幔羽毛活动,海洋无氧事件和海洋预算变化之间的联系的证据.
- 模拟和预期的流量之间的差异凸显了估计白纪地生产率的不确定性.
相关概念视频
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According to its composition, the matter can be classified into two broad categories — pure substances and mixtures.
A pure substance is a form of matter that has a constant composition throughout with uniform properties. For example, any sample of sucrose has the same composition and same physical properties, such as melting point, color, and sweetness, regardless of the source from which it is isolated.
A mixture is composed of two or more types of...
According to its composition, the matter can be classified into two broad categories — pure substances and mixtures.
A pure substance is a form of matter that has a constant composition throughout with uniform properties. For example, any sample of sucrose has the same composition and same physical properties, such as melting point, color, and sweetness, regardless of the source from which it is isolated.
A mixture is composed of two or more types of...
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Molecules and Compounds
Atoms and Molecules
Qualitative Analysis
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...


