Impact Induced Atmosphere-Mantle Exchange Sets the Volatile Elemental Ratios on Primitive Earths

التفاصيل البيبلوغرافية
العنوان: Impact Induced Atmosphere-Mantle Exchange Sets the Volatile Elemental Ratios on Primitive Earths
المؤلفون: Chen, Howard, Jacobson, Seth A.
سنة النشر: 2022
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Earth and Planetary Astrophysics
الوصف: Conventional planet formation theory suggests that chondritic materials have delivered crucial atmospheric and hydrospheric elements such as carbon (C), nitrogen (N), and hydrogen (H) onto primitive Earth. However, recent measurements highlight the significant elemental ratio discrepancies between terrestrial parent bodies and the supposed planet building blocks. Here we present a volatile evolution model during the assembly of Earth and Earth-like planets. Our model includes impact losses, atmosphere-mantle exchange, and time dependent effects of accretion and outgassing calculated from dynamical modeling outcomes. Exploring a wide range of planetesimal properties (i.e., size and composition) as well as impact history informed by N-body accretion simulations, we find that while the degree of CNH fractionation has inherent stochasticity, the evolution of C/N and C/H ratios can be traced back to certain properties of the protoplanet and projectiles. Interestingly, the majority of our Earth-like planets acquire superchondritic final C/N ratios, implying that the volatile elemental ratios on terrestrial planets are driven by the complex interplay between delivery, atmospheric ablation, and mantle degassing.
Comment: 24 pages, 10 figures, 3 tables; accepted to Earth and Planetary Science Letters
نوع الوثيقة: Working Paper
DOI: 10.1016/j.epsl.2022.117741
URL الوصول: http://arxiv.org/abs/2207.13087
رقم الأكسشن: edsarx.2207.13087
قاعدة البيانات: arXiv
الوصف
DOI:10.1016/j.epsl.2022.117741