liejunrocktyyppeihin

Liejunrocktyyppeihin is a term used in some Finnish-language sedimentology discussions to refer to the classification of rocks formed primarily from fine-grained mud particles. The word combines lieju (sludge or mud) with rocktyyppeihin (to rock types), functioning as an umbrella label for mud-dominated lithologies within the broader rock taxonomy. It is not an official category in IUGS-based schemes, but it serves as a convenient descriptive shorthand in certain texts and discussions.

Scope and definitions: In practice, liejunrocktyyppeihin covers conventional mud-rich lithologies such as shale, mudstone, claystone, and siltstone. Distinctions among these are typically based on grain size distribution, mineralogy (especially clay minerals), and textural properties like fissility. Shale is characteristically fissile and clay-rich; mudstone has a substantial mud fraction with less pronounced fissility; claystone is very clay-dominated and often non-fissile; siltstone contains more silt-sized grains and exhibits weaker fissility.

Formation and environments: These rocks form in low-energy environments where fine particles settle, including deep marine basins, lakes, floodplains, and coastal settings. Diagenesis involves compaction and cementation, which reduce porosity and increase strength. Post-depositional deformation can affect fabric and fissility.

Applications: The framework is used in academic and practical contexts to discuss mud-dominated lithologies alongside standard names, with relevance for hydrocarbon reservoirs, groundwater dynamics, and geotechnical assessments.

See also: lithology, sedimentology, shale, mudstone, claystone, siltstone.