Barron, J.A. and Bukry, D. 2007. Solar forcing of Gulf of California climate during the past 2000 yr suggested by diatoms and silicoflagellates. Marine Micropaleontology 62: 115-139.
Barron and Bukry (2007) developed high-resolution records of diatoms and silicoflagellate assemblages spanning the past 2000 years from analyses of a sediment core extracted from Guaymas Basin in the Gulf of California (27.92°N, 111.61°W). Results indicated that the relative abundance of Azpeitia nodulifera (a tropical diatom whose presence suggests the occurrence of higher sea surface temperatures), was found to be far greater during the Medieval Warm Period than at any other time over the 2000-year period studied, while during the Modern Warm Period its relative abundance was actually lower than the 2000-year mean.