Thermal evolution of the Earth: the modes of mantle convection in the Precambrian

地球的热演化：前寒武纪地幔对流模式

• 批准号: 1753916
• 负责人: Jun Korenaga
• 金额: $ 34.61万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1753916&HistoricalAwards=false
• 关键词: Thermal; evolution; Earth; modes; mantle

Plate tectonics is a special class of mantle convection, being observed only on Earth among terrestrial planets in our solar system. It is responsible for a vast array of geological processes, from the generation of continental crust to the modulation of atmospheric composition. Yet, some fundamental questions about its history remain unresolved: when plate tectonics began on Earth and how it has evolved through time. This project aims to resolve the likely mode of mantle convection in the Precambrian (i.e., after the solidification of the putative magma ocean in the early Earth to the beginning of the Phanerozoic at 540 million years ago), by building a robust theoretical framework and exploring its implications for geological and geochemical observations. Reconstructing the evolutionary path of plate tectonics on Earth is one of the most fundamental geophysical problems, providing a global context for geological, geophysical, and geochemical processes, and the radius of the potential impact of this research would cover nearly all branches of solid Earth sciences. Expected research results should also find their applications in the physics and chemistry of terrestrial planets at large and are expected to become part of the theory of habitable planets. This project will provide support and training for a postdoctoral associate and a graduate student, as well as summer intern or thesis projects for undergraduates. The planned research has the following five major objectives: (1) Establishing a regime diagram of mantle convection as a function of internal Rayleigh number, the temperature dependency of viscosity, yielding criteria, and the internal heating ratio, so that we can estimate how the mode of convection has evolved in the past, (2) quantifying the relation between quasi-steady-state solutions and transient situations, in terms of the mode of convection and heat-flow scaling, so that we can analyze collectively different numerical approaches to the evolving mantle dynamics in a unifying fashion, (3) understanding 3-D effects on the mode of mantle convection on the basis of newly-developed scaling laws and published simulation results, (4) exploring the influence of the thermal evolution of the core on surface tectonics by a systematic investigation of coupled core-mantle evolution models, and (5) connecting internal mantle dynamics with surface observables, such as global sea level, plate velocity, and geomagnetic field strength, so that we can build falsifiable hypotheses for the evolution of mantle convection in the Precambrian.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

板块构造是一种特殊的地幔对流，在太阳系的类地行星中只在地球上观察到。从大陆地壳的生成到大气成分的调节，它负责一系列广泛的地质过程。然而，关于它的历史的一些基本问题仍然没有解决：板块构造何时在地球上开始以及它如何随着时间的推移而演变。该项目旨在解决前寒武纪地幔对流的可能模式（即，在地球早期假定的岩浆海洋凝固之后，到5.4亿年前的中生代开始，通过建立一个强大的理论框架并探索其对地质和地球化学观测的影响。重建地球板块构造的演化路径是最基本的地球物理问题之一，为地质、地球物理和地球化学过程提供全球背景，这项研究的潜在影响范围将涵盖固体地球科学的几乎所有分支。预期的研究结果还将应用于一般类地行星的物理和化学，并有望成为可居住行星理论的一部分。该项目将为一名博士后助理和一名研究生提供支持和培训，并为本科生提供暑期实习或论文项目。 计划中的研究有以下五个主要目标：（1）建立地幔对流的状态图，作为内部瑞利数、粘度的温度依赖性、屈服准则和内部加热比的函数，以便我们可以估计对流模式在过去是如何演变的，（2）量化准稳态解和瞬态情况之间的关系，在对流模式和热流标度方面，以便我们能够以统一的方式集体分析演化地幔动力学的不同数值方法，（3）在新发展的标度律和已发表的模拟结果的基础上理解三维对地幔对流模式的影响，（4）通过对核幔耦合演化模型的系统研究，探讨核热演化对地表构造的影响;（5）将地幔内部动力学与地表观测量（如全球海平面，板块速度，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Argon constraints on the early growth of felsic continental crust

• DOI: 10.1126/sciadv.aaz6234
• 发表时间: 2020-05-01
• 期刊: SCIENCE ADVANCES
• 影响因子: 13.6
• 作者: Guo, Meng;Korenaga, Jun
• 通讯作者: Korenaga, Jun

Archaean seafloors shallowed with age due to radiogenic heating in the mantle

由于地幔的放射性加热，太古宙海底随着年龄的增长而变浅

• DOI: 10.1038/s41561-020-00673-1
• 发表时间: 2021
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: Rosas, Juan Carlos;Korenaga, Jun
• 通讯作者: Korenaga, Jun

A wet heterogeneous mantle creates a habitable world in the Hadean

• DOI: 10.1038/s41586-021-04371-9
• 发表时间: 2022-03
• 期刊: Nature
• 影响因子: 64.8
• 作者: Y. Miyazaki;J. Korenaga

On the Timescale of Magma Ocean Solidification and Its Chemical Consequences: 2. Compositional Differentiation Under Crystal Accumulation and Matrix Compaction

• DOI: 10.1029/2018jb016928
• 发表时间: 2019-04-01
• 期刊: JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
• 影响因子: 3.9
• 作者: Miyazaki, Yoshinori;Korenaga, Jun
• 通讯作者: Korenaga, Jun

Rapid crustal growth and efficient crustal recycling in the early Earth: Implications for Hadean and Archean geodynamics

• DOI: 10.1016/j.epsl.2018.04.051
• 发表时间: 2018-07
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: J. Rosas;J. Korenaga