Tag Archive for 'Hafnium'

Schematic model of fluvial systems both before and after the development of land plants: before the Devonian period, minimal land plants, rapid channel migration and river systems dominated by braided rivers led to rapid sediment transfer, minimal development of mud-sized particles and minor deposition of mudrocks along continental margins; in contrast, after the Devonian, the expansion of vascular land plants led to the development of meandering rivers and the dramatic slowing of sediment transfer to marine environments; the red dashed line represents a generalized sediment transport path that is more sinuous post-Devonian and less sinuous pre-Devonian; these diametric depositional systems influenced the isotopic composition of sediment available for reworking and melting in magmatic systems along destructive plate boundaries. Image credit: Spencer et al., doi: 10.1038/s41561-022-00995-2.

Emergence of Land Plants Altered Composition of Earth’s Continental Crust, Researchers Say

Aug 31, 2022 by News Staff

The evolution of land plants took place about 430 million years ago (Silurian period), when North America and Europe were conjoined in a landmass called...

(A) the Milky Way Galaxy with superimposed spiral arms and geological events: the arm and the Solar System rotate clockwise at different rates; the ‘+’ number denotes the number of times Earth has passed through that arm; (B) model of the Oort cloud showing cometary nuclei; (C) schematic reconstruction of early Earth impact process; (D) early crustal nuclei development. Image credit: NASA / JPL-Caltech / ESO / R. Hurt / Kirkland et al., doi: 10.1130/G50513.1.

Transits through Milky Way’s Spiral Arms Helped Form Early Earth’s Continental Crust, Study Says

Aug 24, 2022 by News Staff

New research led by Curtin University geologists suggests that regions of space with dense interstellar clouds may send more high-energy comets crashing...

Earth’s internal structure: dense solid metallic core, viscous metallic outer core, mantle and silicate based crust. Image credit: NASA.

Material from Earth’s Core Has Been Leaking into Mantle for Billions of Years

Jul 12, 2019 by The Conversation

Earth’s magnetic field protects and makes our planet habitable by stopping harmful high-energy particles from space, including from the Sun. The source...