Diagrams of δr − δz showing the motion of the gas accreted into the outer region of LG1-4337 from different sources (similar to Fig. 9) between lookback time 11.60 Gyr and 10.1 Gyr (upper panels) and between lookback time 6.5 Gyr and 4.9 Gyr (lower panels). The diagrams in the upper panels illustrate the accretion of a high-z galaxy that exhibits an outer drop, with a dominant contribution from metal-poor unbound gas (62% of the accreted gas). The diagrams in the lower panels illustrate a low-z galaxy with an outer rise, with the clear indication recycled metal-rich gas from the CGM being the main source of accretion (56% of the accreted gas).