The cover art is a schematic illustration showing the evolution of the inner earth during the Hadean. The dry Earth was formed at 4.55 Ga. By 4.53 Ga, the mantle had solidified to form a layered structure and stagnant lid tectonics operated. Between 4.37 and 4.20 Ga, the ABEL Bombardment progressed to deliver atmospheric and oceanic components onto the dry Earth. Due to the destruction of the stagnant lid by huge impactors, stagnant lid tectonics transitioned to plate tectonics. By 4.30 Ga, the bi-modal lithosphere (continental crust and oceanic crust) appeared following bombardment to operate plate tectonics. Due to tectonic erosion, the primordial continents (anorthosite, komatiite, and KREEP I basalt) were transported into the deep mantle. The densest KREEP I basalt dripped down to the bottom of the mantle and accumulated (almost all KREEP I basalt should have accumulated at CMB by 4.0 Ga) (Maruyama et al., 2018).
(Shigenori MARUYAMA)
- Table of Contents (in Japanese)
- Relation between the Phase Transformations and the Magnetic, Physical and Mechanical Properties in 18Ni 350 Grade Maraging Steels
- 大店立地法に基づく大型店の出店調整—近鉄京都線高の原駅前を事例に—
- EC事業者における粗利益の傾向を利用した適切な価格設定法
- 石棒彙報