Astrogeology

Passive Magmatism On Earth And Earth-like Planets

By Keith Cowing
Compuscript Ltd
March 31, 2022
Filed under
Passive Magmatism On Earth And Earth-like Planets
Decoupling between active migration of the South Atlantic mid-oceanic ridge and passive mantle convection beneath the divergent lithospheric mantle-level spreading center. The neutrally buoyant compositional anomalies are deduced to be detached lithospheric mantle. Based on this model, the toroidal and poloidal mantle convection under the South Atlantic Ocean is passively controlled by the combined effect of plume, slab window, LLSVP and asymmetric extension. In the Neo-Mesozoic, the African Plate was relatively fixed and the South American Plate drifted westward with a clockwise rotation. CREDIT GeoGeo

In this article researchers from the Ocean University of China, Qingdao, China, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China, University of Illinois at Urbana-Champaign, Urbana, IL, USA and Northwest University, Xi’an, China discuss how magmatism has occurred throughout Earth’s history.

From the early Earth to the modern plate-tectonic Earth, the amount of magmatism has varied, but it has always occurred on multiple scales, in various tectonic environments and at various depths in the crust and mantle. Magma compositions are also variable.

In this article, the authors put forward that the mechanism of magma emplacement has generally been passive at all stages of Earth evolution. They conclude that most magmatism related to subduction, rifting, mid-oceanic spreading, flood basalts and large igneous provinces and related to mantle upwellings, magma underplating, slab windows, orogenic collisions as well as Archean TTG formation are predominantly passive from the lithosphere-scale to the crystal-scale. The results of their research discussed in this article weigh against the view that magmatism drives plate motions. Most of the magmatism on other Earth-like planets is also passive regardless of the tectonic environments.

Article reference: Sanzhong Li, Xiyao Li, Jie Zhou, Huahua Cao, Lijun Liu, Yiming Liu, Guozheng Sun, Yanhui Suo, Yang Li, Shengyao Yu, Zhaoxia Jiang, Passive magmatism on Earth and Earth-like planets, Geosystems and Geoenvironment, Volume 1, Issue 1, 2022, 100008, ISSN 2772-8838, https://doi.org/10.1016/j.geogeo.2021.10.003.

Astrobiology

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) πŸ––πŸ»