<b>Abstract</b>— <p>The very first Earth`s terrestrial ecosystems—biocrusts and microbial soils—appeared in the Archean. The Proterozoic weathering crust (WC) in the Pavlovsk granite quarry (Voronezh oblast) has inclusions of granite corestones. The weathering crusts are directly covered by Middle Devonian deposits. The corestones are surrounded by concentric, typically multilayered sheets: crusts (or rindlets). About 50 specimens of such crusts have been collected and analyzed in detail. Typically, they consist of three layers, some of two or four, ranging in thickness from 4 to 20 cm. XRD data showed that the unweathered granite, saprolite (WC material), and the studied corestone crusts consist of quartz, microcline, biotite, and kaolinite in different proportions. The obtained data show that crusts contain organic C (0.1–0.5%) and are characterized by the elevated concentrations of Fe, Mg, Mn, Ti, P, S, and K. Their layered structure is accompanied by the differentiation of properties: chemical, mineralogical, and magnetic. The surface layer is enriched in Fe, Mg, Mn, and S, and is depleted in Al, Si, P, and Na. The SEM study showed the presence of newly formed silicates (kaolinite and sanidine), gibbsite, Ti oxides, and gypsum. The Mössbauer spectroscopy demonstrates the presence of oxides including magnetite, Fe-sulfates, and pyrite. The SEM study showed a variety of fossilized microbiota: single cells of coccoidal shape and their colonies (cyanobacteria?), spores, green algae, etc. The obtained data allowed to conclude that the crusts are in situ developed soil-like biogenic bodies: microbial paleosols. Their macroscale development and horizontal stratification testify to a long duration (<i>n</i> × 10⁴ years) of the terrestrial stage which preceded the formation of the Mid-Devonian cover.</p>