Mixed varves

Mixed varves: The three different varve types (clastic, biogenic, endogenic) rarely exist as pure end members. Only clastic varves can exist without significant biogenic and endogenic components. Organic varves often contain runoff-related minerogenic contributions deposited during winter or spring or endogenic minerogenic components precipitated during spring or summer. These mixed varves largely depend on a combination of factors like catchment geology, existence of surficial inflow, occurrence of fine-grained clastic sediments in the catchment area and seasonally contrasting precipitation.