Mammillary calcite (subaqueously deposited) intervals (≤0.5 mm in width) were identified in cores H (+9.5 m), I (+8 m), N (+6.5 m), J (+5.3), and G (+4.4). Because of spatial limitations associated with hand-held drilling techniques, these intervals could not be confidently dated without risking the incorporation of folia material. Instead, identified intervals with thin mammillary calcite layers are bracketed in age by (i) the following/previous dated boundaries along the same core and (ii) the presence of U-Th–dated folia boundaries that were deposited lower in vertical height, suggesting that, at the time of “lower” folia deposition, mammillary calcite layers could not be deposited above this height. For example, thin mammillary calcite layers were identified in core N (+6.5 m) between 262 and 193 ka. These layers are further constrained in age by evidence for a progressively decreasing water table level from +4.4 m at 245 ka. The water table remained below +4.4 m until 220.5 ka, when a folia-to-mammillary calcite boundary suggests that the water table rose above +3.1 m. It is possible that the water table could have risen to +6.5 m and deposited one or more thin mammillary calcite layers at this time (corresponding to MIS 7d). The end of mammillary calcite deposition is constrained by evidence for a decreasing water table at +1.8 dated to 217.4 ka. As shown in Fig. 2, a striped gray bar at +6.5 m between 220.5 and 217.4 ka represents this possible period of mammillary calcite deposition. Although independently constrained in time, we emphasize that the timing of these thin mammillary calcite deposits are estimations.

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