U-Pb Isotopic ratio measurements of zircon grains from two ash samples outcropping in the Pisco Basin (MG11-10; 14°11.13'S, 76°08.65'W; MG11-60; 14°11.17'S, 76°6.99'W). Analyses were carried out University of Florida, using a Nu-Plasma® Laser Ablation Multi-Collector Inductively Coupled Plasma Mass Spectrometer (LA-MC-ICP-MS). Data reduction was referenced to standard zircon (FC-1) from the Duluth Gabbro dated at 1099.0 ± 0.7 Ma and 1099.1 ± 0.5 Ma (Black et al., 2004). Single-ages are reported in Million of years (Ma) with standard error uncertainties at 2σ and 95% confidence intervals. Ash beds were collected as a tool for determining U-Pb maximum depositional ages by DO and TdV in 2022.