Litosfericele

Litosfericele are a theoretical subdivision of the Earth's lithosphere defined as discrete blocks with coherent geology and rheology that contrast with adjacent regions. They are used in geophysical interpretations to explain localized anomalies in seismic velocity, anisotropy, and electrical conductivity. The concept is not universally adopted; it is a modeling construct advanced by researchers seeking to account for lateral heterogeneity within the lithosphere.

Evidence for litosfericele comes from seismic tomography, receiver function analysis, and magnetotelluric surveys that reveal sharp, map-like boundaries and variable properties within the crust and upper mantle. They are thought to correspond to ancient cratonic cores, metasomatic zones, or preserved subduction-related features, and their boundaries often align with major tectonic sutures or former subduction zones.

In terms of composition and dynamics, litosfericele are envisaged as rock domains with distinct mineralogy and grain-scale fabrics, which may influence rheology and heat transport. Formation mechanisms include long-term differentiation, fluid-assisted metasomatism, and deformation under varying pressure-temperature conditions. They may persist for millions to billions of years, though their exact sizes and lifetimes remain debated.

The concept remains a topic of ongoing research and debate. If real, litosfericele could affect models of lithospheric evolution, mantle convection, and tectonic cycle assessment, highlighting the importance of small-scale heterogeneity in global geodynamics.