Bookmark and Share

Geothermal study suggests far more extensive resources in area

Like an artesian well percolating up from the Earth, momentum for harnessing the area’s geothermal resources has gained momentum during the past month.

Along with newly-acquired data from recent scientific research on the area’s geothermal resources, area residents discussed geothermal issues at a state conference in Denver last Thursday, while Saturday saw the Geothermal Greenhouse Partnership (GGP) hosting a fund-raiser and information presentation, taking a step towards moving forward on building geothermal greenhouses in the downtown area.

Earlier this month, the Colorado School of Mines Geophysics Department (CSM) released results of research recently conducted throughout the area.

After spending two weeks in Pagosa Country this past May, studying characteristics of the area’s geothermal aquifer, a team of CSM students and faculty members provided a lengthy report on findings during that visit.

The full report can be downloaded at http://geophysics.mines.edu/GEO-Field-Camp.

While not quite as exciting as the almost certain discovery of the Higgs boson that was announced on Tuesday, the report provided some interesting suggestions regarding geothermal resources in the area.

Primary among the findings was a suggestion of geothermal resources far more extensive than had been previously postulated.

That report indicated the discovery of three previously unknown faults north, south and west of the “Mother” spring (the Great Pagosa Hot Springs that provides water for local bathers and heating systems).

“First, the seismic results from both the Stevens Airport and the Barn 3 (south of town) line show that the Eightmile Mesa Fault, and possibly other faults nearby, penetrates the basement material,” the report reads.

This discovery shows that faults in the area can penetrate the basement (several layers of strified rock that sit atop the water) and provide a conduit for deep and hot water transport.

These surveys also showed a complex system of faults within the basement material, which could provide an area for cold water to circulate and gain heat deep in the basement. Geochemical studies have confirmed that the water the hot springs produces is meteoric water (water gathered from precipitation such as rain or snow), which requires the water to be transported along layers and conduits in the subsurface. “

Furthermore, the report indicated that access to water hot enough to generate energy (reaching temperatures higher than 144° Fahrenheit, the current high end found in local springs, just below the threshold necessary for power generation in so-called binary cycle power plants) can be found at depths much more shallow than had been previously suspected.

“Fractures within the basement material allow the water to remain in the basement for long periods of time, allowing for a heat source in the basement, likely the natural geothermal gradient, to heat the water to high temperatures. This water becomes less dense as the water increases in temperature, allowing it to flow back up Victoire’s fault (the name of one of the newly-discovered faults) and back into the western member of the Dakota sandstone where it reenters the fractures,” the report continued.

The report’s introductory remarks went on to say, “Contrary to initial suspicions, the Eightmile Mesa Fault is not crucial to the geothermal system even though seismic surveys confirm that it penetrates the basement. This is because the Victoire fault cuts off the Dakota Sandstone which carries the system’s main source of cold water, removing the majority of water from the member that encounters the Eightmile Mesa Fault. Finally, the faults interpreted along the north line may be similar to, or even an extension of, the Victoire fault and may allow this system to extend northward. However, more data will be necessary to positively confirm this theory as part of the system.”

It was that last sentence that suggested more research was required to accumulate more data on the aquifer. In fact, CSM faculty has already scheduled a return visit to Pagosa Country in September (with a smaller contingent of researchers returning for that work) and, quite possibly, another large-scale field camp mobilizing in the area next May — similar to the one organized earlier this year.

Essentially, while the CSM report of field camp finding provided some provocative suggestions regarding the extent and characteristics of the various geothermal systems lying beneath the feet of local residents, the ultimate conclusion was that more will be known only after follow-up research has been conducted.

Following on the heels of the CSM report, several area residents were invited to present at the Colorado Energy Office’s Geothermal Working Group last Thursday. While none of those presentations referred to findings in the CSM report, general conclusions from that report seemed to coincidentally arise during the discussions.

Likewise, at Saturday’s GGP fund-raiser, most of those in attendance at the celebration were there not only to raise money for the project to construct geothermally-heated domes in Centennial Park in downtown Pagosa Springs, but also as a result of their recognition of the need to use a valued resource that the Mines study has only begun to reveal. If preliminary results from CSM research are correct, there is, quite possibly, a lot of that resource to go around.

See next week’s SUN for more on the conference and the GGP fund-raiser.

jim@pagosasun.com

blog comments powered by Disqus
TERMS OF USE