The Thermal Regime Of The San Juan Basin Since Late Cretaceous Times And Its Relationship To San Juan Mountains Thermal Sources
Journal Article: The Thermal Regime Of The San Juan Basin Since Late Cretaceous Times And Its Relationship To San Juan Mountains Thermal Sources
AbstractHeat-flow and coal-maturation data suggest that the thermal history of the San Juan Basin has been influenced by magmatic and volcanic activity in the San Juan Mountains-San Juan volcanic field located to the north of the Basin. Time-dependent isothermal step models indicate that the observed heat flow may be modelled by a (near) steadystate isothermal step extending from 30-98 km depth whose edge underlies the northern San Juan Basin. The observed maturation levels of the Fruitland formation coals in the northern and central Basin, however, require more heat than can be associated with conduction from a deep thermal source (steady-state step) and from the shallow crustal batholith which underlies the San Juan volcanic field. Magmatic activity within the Basin does not appear to be a reasonable source of additional heat. Increased burial depths of the coals may explain some of the elevated maturation levels observed in the central and northern Basin, but it seems likely that an additional source of heat is still required. Heat advection by groundwater movement may have influenced the coal maturation levels in the Basin as well. Both magmatic activity associated with the emplacement of the San Juan batholith and elevated geothermal gradients associated with the steady-state thermal source at depth may have contributed to heating of the groundwater. An appreciation of heat advection by groundwater flow may therefore be most important to understanding regional patterns of heat flow and hydrocarbon maturation.
- Gerry Clarkson and Marshall Reiter
- Published Journal
- Journal of Volcanology and Geothermal Research, 1987
- Not Provided
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Gerry Clarkson,Marshall Reiter. 1987. The Thermal Regime Of The San Juan Basin Since Late Cretaceous Times And Its Relationship To San Juan Mountains Thermal Sources. Journal of Volcanology and Geothermal Research. (!) .