By matching the pattern of sediment deposition obtained from the floors of lakes adjacent to glaciers with known climatic patterns, archaeologists can calculate very precise dates. such research is called

varve analysis

The word varve originated from the Swedish word varv which means revolution in layers and circle. In this particular question, by “varve” we mean an annual layer of sedimentary rocks and varve analysis is the process by which archaeologists can calculate precise dates based on these sediments with known climatic patterns. 

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.