Chronology of the Central Atlantic Magmatic Province: Implications for the Central Atlantic rifting processes and the Triassic–Jurassic biotic crisis
Chronology of the Central Atlantic Magmatic Province: Implications for the Central Atlantic rifting processes and the Triassic–Jurassic biotic crisis
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DOI：
10.1016/j.palaeo.2006.06.034
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发表时间：
2007-02
期刊：
影响因子：
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通讯作者：
S. Nomade;K. Knight;E. Beutel;P. Renne;C. Vérati;G. Féraud;A. Marzoli;N. Youbi;H. Bertrand
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文献类型：
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作者：
S. Nomade;K. Knight;E. Beutel;P. Renne;C. Vérati;G. Féraud;A. Marzoli;N. Youbi;H. Bertrand
中大西洋岩浆省（CAMP）是地球上最大的火成岩省之一，与三叠纪-侏罗纪（TJ）边界同步或恰在其之前就位。200毫安在很大程度上，由于有争议的CAMP的发生和T-J边界的事件之间的联系，更好地限制这个省的持续时间和喷发年表的需求有所增加。在过去的15年中，已经发表了100多个新的40 Ar/39 Ar年龄，其中一半以上是在过去的3年中。仔细审查和选择可用的年龄，以及16个新时代的出版物从哥伦比亚，纽瓦克盆地（美国），法属圭亚那和摩洛哥。明智的选择产生了58个公认的年龄测定CAMP岩浆活动，从202年至190马覆盖的CAMP的每一个部分。一个更完整的图片开发与侵入CAMP岩浆活动开始早在202马。挤压活动在200 Ma突然开始，在199 Ma左右在非洲边缘达到峰值。CAMP岩浆活动的主要时期被确认为短暂的，但建议至少包括两个阶段超过1.5Ma，与岩浆活动开始沿着非洲-北美边缘和稍晚沿着南美边缘。两个体积较小，但独特的岩浆峰集中在195和192马反映在所有三个大陆的数据，并突出了我们的统计方法。模型描述裂谷和热输入和岩浆生产在这些时间尺度上进行了探索。尽管我们对CAMP年表的理解取得了重大进展，但需要更多质量更好和地理覆盖范围更广的数据来完全描述CAMP的演变并推断其地球动力学起源。此外，缺乏一个明确的T-J边界年龄，以及缺乏一个相关的基础之间的U/Pb和40 Ar/39 Ar数据的比较，这一时期仍然是限制因素，明确地连接CAMP在时间上与事件的T-J边界。
The Central Atlantic Magmatic Province (CAMP) is among the largest igneous provinces on Earth, emplaced synchronously with or just prior to the Triassic–Jurassic (T–J) boundary ca. 200 Ma. In great part due to the controversial connection between the occurrence of CAMP and the events of the T–J boundary, the demand for better constraints on the duration and eruptive chronology of this province has increased. More than 100 new40Ar/39Ar ages have been published in the last 15 years, with more than half of these in the last 3 years. A careful review and selection of available ages, as well as the publication of 16 new ages from the Carolinas, Newark Basin (USA), French Guyana and Morocco are presented. Judicious selection yields a total of 58 accepted age determinations for CAMP magmatism, ranging from 202 to 190 Ma covering every part of the CAMP. A more complete picture develops with intrusive CAMP magmatism commencing as early as 202 Ma. Extrusive activity initiated abruptly ∼200 Ma, reaching peak volume and intensity around 199 Ma on the African margin. The main period of CAMP magmatism is confirmed as brief, but is suggested to consist of at least two phases over ∼1.5 Ma, with magmatism commencing along the Africa–North American margins and slightly later along the South American margin. Two volumetrically minor, but distinctive magmatic peaks centered at 195 and 192 Ma are mirrored in data from all three continents and highlighted by our statistical approach. Models describing rifting and thermal input and magma production on these timescales are explored. Despite significant advances in our understanding of the chronology of CAMP, more data of better quality and broader geographical coverage are needed to completely characterize the evolution of the CAMP and infer its geodynamic origin. In addition, lack of a well-defined T–J boundary age, as well as the absence of a relevant basis for comparison between U/Pb and40Ar/39Ar data for this time period remain limiting factors to unambiguously linking CAMP in time with the events of the T–J boundary.