Upper Cretaceous Shoreface/Tidal Couplets In The San Juan Basin, New Mexico, USA: Significant High Frequency Events Resolved From The Gallup Clastic Wedge

High-frequency stratigraphic events, denominated ‘‘Shoreface/Tidal Couplets’’ were<br>recognized in the Western San Juan basin, New Mexico. This was possible by conducting a highresolution<br>genetic stratigraphic study in a 1000 km2 area. We used 2000 m of measured section<br>calibrated with 1200 m of outcrop gamma ray from 25 sections and 85 plugs. This study helped to<br>establish the 3-D stratigraphic architecture and facies distribution of the Turonian-Coniacian Gallup<br>Sandstone, Crevasse Canyon Formation and Mancos Shale. Shoreface/tidal couplets in the<br>Gallup Clastic Wedge are restricted to the lower part of the wedge and are within a long-term base<br>level fall.