Geologic map of the Vermejo Park quadrangle, Colfax County, New Mexico, and Las Animas County, Colorado

The Raton basin is a large asymmetric syncline (2500 mi2 area) that extends from Huerfano Park, Colorado to Cimarron, New Mexico. As used here, the basin is defined by the limits of the outcrop of the Trinidad Sandstone. The Cretaceous and Tertiary rocks are sharply flexed to form hogbacks along the western margin of the basin on the east flank of the Sangre de Cristo Mountains. These rocks assume more gentle dips along the other margins of the Raton basin and are highly dissected. The Late Cretaceous in the Raton basin was a period of emergence of land and retreat of the Cretaceous epeiric sea. The coastline advanced eastward across New Mexico, as broad prograding deltaic and barrier coastal plains were formed seaward of aggrading fluvial systems. This map depicts the stratigraphic context and areal extent of uppermost Cretaceous and Paleocene rocks in the Raton basin including the marine Pierre Shale, marginal-marine Trinidad Sandstone, non-marine coal-bearing Vermejo Formation, non-marine coal-bearing Raton Formation and non-marine, non-coal-bearing Poison Canyon Formation.

拉顿盆地（Raton Basin）是一处大型不对称向斜（syncline），面积达2500平方英里，其范围从科罗拉多州的韦尔法诺帕克延伸至新墨西哥州的锡马龙。本文所定义的该盆地，以特里尼达德砂岩（Trinidad Sandstone）的露头边界为界。白垩系与第三系岩层发生强烈褶皱，在圣克里斯托山脉东翼的盆地西缘形成猪背岭。在拉顿盆地的其余边缘地带，这些岩层的倾角更为平缓，且被强烈切割。拉顿盆地的晚白垩世时期，发生了陆地抬升与白垩纪陆表海的退缩。海岸线向东横跨新墨西哥州推进，在加积河流体系的向海一侧形成了广阔的进积三角洲与障壁滨海平原。本地图展示了拉顿盆地内最高层位白垩系与古新统岩层的地层背景与分布范围，包括海相皮埃尔页岩（Pierre Shale）、滨海相特里尼达德砂岩、非海相含煤韦尔梅约组（Vermejo Formation）、非海相含煤拉顿组（Raton Formation），以及非海相不含煤的波伊森峡谷组（Poison Canyon Formation）。