Illite crystallinity and fluid inclusion techniques are used to understand the thermal histories of rocks on either side of the disconformity between the Lower and Upper Paleozoic strata in South Korea. Illite crystallinity studies show that the metamorphic grade of the upper strata of the Lower Paleozoic Joseon Supergroup, platform carbonates with subordinate siliciclastics, belongs to the epizone and that of the lowermost strata of the Upper Paleozoic Pyeongan Supergroup, paralic to nonmarine clastics, belongs to the anchizone. The maximum mode of homogenization temperature for fluid inclusion of the uppermost strata of the Joseon Supergroup is 260 to 270 °C and that of the lowermost strata of the Pyeongan Supergroup is 240 to 250 °C. These data reveal a difference in thermal histories of strata below and above the unconformity, suggesting that, in contrast to the previous supposition of a period of non-deposition, at least a 1-km thick section of sediment was removed by erosion during development of the unconformity. Burial and heat flux from a proposed hot spot are suggested as the dominant factors causing differences in a metamorphic grade for the Joseon Supergroup before the deposition of the Upper Paleozoic strata.

Geoarchaeological analysis of the Middle and Upper Palaeolithic record preserved in cave, rock-shelter and open-air sites in the northern sector of the Meso-Cenozoic of the Western Iberian Peninsula margin (Portugal) reveals several disconformities (erosive unconformities), hiatuses and surface stabilization phases. A recurrent disconformity, dated to ca. 29,500–32,000 cal yr BP, in the time range of Heinrich event 3, must correspond to a main erosive event related to the impacts of climate change on the landscape, including a reduction in vegetation cover and altered precipitation patterns, with the consequent accelerated down-cutting by stream systems, slope reactivation and endokarstic reorganisation, causing the erosion of sediments and soils accumulated in cave, rock-shelter and open-air sites. These processes create a preservation bias that may explain why Early Upper Palaeolithic finds in primary deposition context remains exceptional in the carbonate areas of central-western Portugal, and possibly elsewhere in the other places of Iberia. The impact of such site formation processes must therefore be duly considered in interpretations of the current patchy and scarce archaeological record of the Middle-Upper Palaeolithic transition in south-western Iberia.