Abstract: The Impact of Synorogenic Strata on Hydrocarbon Generation in the Denver Basin
RAYNOLDS, ROBERT G.
Over 750 m of synorogenic strata accumulated in two pulses in the Denver Basin. This load was imposed during the two phase local Laramide orogeny ranging from the latest Cretaceous through Eocene and comprises a critical ingredient to understanding the history of hydrocarbon maturation in the basin.
Vitrinite reflectance studies by earlier workers have been interpreted to indicate that two phenomena combined to produce the observed maturation patterns: (1) Laramide synorogenic loading and (2) localized anomalous heat flow along an extension of the Colorado Mineral Belt.
This study separates these two causes and demonstrates the modeled impact of simple subsidence and the separate influence of postulated thermal cells localized over anomalous heat sources. The bulk of hydrocarbons known in the Denver Basin owe their existence to the asymmetric wedge of orogenic debris which was of sufficient thickness along the Front Range to depress Lower to Middle Cretaceous source rocks into the oil window. After the accumulation of these Laramide strata, relatively little Tertiary material was deposited in the Denver Basin area. The late Tertiary has been characterized mostly by uplift and erosion.
AAPG Search and Discovery Article #90946©1997 AAPG Rocky Mountain Section Meeting, Denver, Colorado