Ancient Rock Layers Reveal How Continents Formed Billions of Years Ago
Scientists used seismic imaging to map hidden geological boundaries beneath Scandinavia, revealing how continents assembled 2 billion years ago. The discovery shows Earth's deep crustal structures persist across geological timescales, providing critical data for understanding mineral deposits, earthquake risk, and subsurface resource management in Nordic regions.
Originaltitel: Seismic probing of buried ancient terrane boundaries - insight into Fennoscandia’s Palaeoproterozoic continental formation
<p>Terrane boundaries are usually mapped from structures, lithologies and ages of the bedrock geology. Geophysical studies occasionally used to image terrane boundaries at depth typically yield localised information. In this contribution we demonstrate that it is possible to map Palaeoproterozoic terrane boundaries over large areas in northwest Fennoscandia through modelling of the crustal structure using receiver function inversion. Our new model suggests the existence of three “arms” of thick crust interpreted as deep expressions of Palaeoproterozoic terrane boundaries. We also observe previously unknown high velocity lower crust that we relate to Palaeoproterozoic rifting. The deep structural information shows that crustal structures can be preserved over billions of years and yields a three-dimensional crustal terrane model. This model improves our understanding of Palaeoproterozoic tectonics and continent formation processes.</p>