Which sediment transport mechanism causes varves to form in glacial lakes during seasonal changes?

💡 Explanation

When meltwater discharge varies seasonally, density currents form because sediment-laden inflows sink to varying depths based on density differences, depositing coarser sediments in the summer and finer clays in the winter, due to reduced flow. Therefore, graded bedding results, forming varves rather than flocculation, eolian sorting or saltation which involve different transport conditions.

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