This study establishes the authorship of the geological term “eluvium” and traces its evolution in geological and soil sciences. It confirms the priority of H. Trautschold (1817–1902) as the original author of this term, supported by analysis of his works from the 1870s. The term was first introduced by him in 1872. The article demonstrates that the modern interpretation of the term “eluvium” shows a high degree of correlation with H. Trautschold’s classical definition. The development of the concept of eluvium and ideas about eluvial processes is traced through the works of prominent Russian soil scientists – N.M. Sibirtsev, V.V. Dokuchaev, V.I. Vernadsky, B.B. Polynov, V.R. Williams, and N.P. Remezov. V.V. Dokuchaev systematized the concept of eluvium into a coherent framework: definition of eluvium → eluvial processes → stages and phases of eluvial rock transformations. He emphasized that “although these products are sometimes altered beyond recognition of the parent rock which they originated from, a genetic connection between them always persists.” Particular significance lies in the incorporation of the biogeochemical aspect into the concept of eluvium through the works of N.P. Remezov, who established biological accumulation of elements exceeding their removal during eluvial processes. This allowed eluvium formation to be viewed not as a purely abiotic process but as a phenomenon involving living organisms. The article reveals the historical continuity of scientific ideas in the hypothesis of the origin of the Russian Plain: H. Trautschold → V.V. Dokuchaev → B.B. Polynov → V.A. Kovda. H. Trautschold was the first to propose that the Russian Plain formed from deposits lying on top, which were influenced for millennia by atmospheric precipitation, initiating the concept of eluvial origin of plains. This idea was later reflected in the works of V.V. Dokuchaev and B.B. Polynov, and subsequently in V.A. Kovda’s hypothesis regarding the fluvioglacial origin of the Russian Plain. Our analysis confirms that the term “eluvium” is a fundamental concept uniting geology, geomorphology, geochemistry, and soil science, and its evolution reflects the advancement of understanding regarding the genesis of surface deposits and soils.

Built over five centuries ago using white stone, this unique Russian architectural monument stands as the sole surviving building from the estate of the Romanov boyars, located in the ancient part of Moscow known as “Zaryadye.” Today, it serves as the museum “Chambers of the Boyars of the Romanovs.” However, the masonry has begun to collapse under the influence of water, frost, and various technogenic loads.

The monument’s location is characterized by the presence of unfavorable engineering and geological processes, with flooding being the main issue. This has led to a rise in groundwater levels and their constant interaction with the foundation’s soil. The excess moisture content in the limestone pores, saturated with aggressive components (SO42-, NO3-,Cl-), has led to limestone dissolution and leaching, as well as salt crystallization both on the surface and inside the masonry.

To understand the weathering processes affecting the limestone, researchers conducted a study on samples taken from several parts of the monument, dividing them into several groups based on their structural stability. The results revealed that the structurally unstable, completely destroyed to a dispersed state (reminiscent of flour) samples, displayed significant changes in their physical, mechanical and chemical properties. This was due to the leaching of calcite, leading to a decrease in its content from 99 % down to 40-45 %, and an increase in porosity from 15 % up to 49 %, resulting in a density reduction from 2.29 down to 1.32 g/cm³.

The study also found that microbial components in the stone could also lead to an increase in the content of finely dispersed fractions. The walls of the monument, both inside and outside, were found to be colonized by mold fungi (9 species) and bacteria (2 species). The genera Penicillium (5 species) and Aspergillus (2 species), renowned as biodestructors of stone materials, were the most prevalent among the identified species. The content of these micromycetes varied significantly (ranging from 300 to 105 CFU/g) depending on the sampling location.