Katkoyhtymät

Katkoyhtymät, also known as discontinuous or broken conglomerates, are a type of sedimentary rock deposit. They are characterized by the presence of angular to subangular clasts (rock fragments) that are poorly sorted within a matrix of finer-grained material. Unlike typical conglomerates which consist of rounded pebbles, the fragments in katkoyhtymät show little evidence of significant transport or abrasion. This suggests that the clasts were deposited relatively close to their source area. The matrix material, often sand or silt, fills the spaces between the larger fragments.

The formation of katkoyhtymät is generally attributed to specific depositional environments. These can include debris flows, glacial till, or talus slopes where large, angular rock fragments are rapidly transported and deposited with minimal reworking. The lack of rounding indicates that the clasts did not undergo extensive fluvial or marine transport, which would have smoothed their edges through abrasion. The angularity is a key distinguishing feature.

Geologically, the presence of katkoyhtymät can provide valuable information about past environments. They often indicate proximity to a mountainous or rugged source region. The lithology of the clasts can also offer clues about the bedrock composition of the source area. Studying the distribution and characteristics of katkoyhtymät can help geologists reconstruct paleotopography and understand the tectonic history of a region. They are distinct from breccias, which typically have even larger, more angular fragments and are often associated with faulting or impact events, although some overlap in interpretation can exist depending on the specific deposit.