H umid P leistocene− H olocene transition and early H olocene in sub‐tropical northern M exico and possible G ulf of C alifornia forcing

A new geochemical record from the paaleolake S antiaguillo documents the hydrological variability of sub‐tropical northern M exico over the last ∼ 14 cal. ka. Summer‐season runoff, lake water salinity and deposition of sediments by aeolian activity were reconstructed from concentrations of K , Ca and Zr / K in bulk sediments. More‐than‐average runoff during c. 12.3 – 9.3 cal. ka BP represented an interval of enhanced summer precipitation. Arid intervals of c. 14 – 12.3 cal. ka BP and c. 6–4.3 cal. ka BP were characterized by average and more‐than‐average aeolian activity. Comparison with proxy records of summer as well as winter precipitation from tropical and sub‐tropical N orth A merica and sea surface temperatures from the A tlantic and P acific provides insight into the source of moisture and possible forcing. The wet P leistocene− H olocene transition and early H olocene was contemporary with warmer conditions in the G ulf of C alifornia. We suggest that the A tlantic had minimal influence on the summer precipitation of the western part of sub‐tropical northern M exico and that the source of moisture was dominantly P acific.