Hydrology of the Greater Tongonan geothermal system, Philippines, as deduced from geochemical and isotopic data

Journal Article · Fri Oct 01 04:00:00 EDT 1993 · Geothermics

DOI:https://doi.org/10.1016/0375-6505(93)90030-Q· OSTI ID:143819

Alvis-Isidro, R R; Solana, R R ^[1]; D`amore, F; Nuti, S ^[2]; Gonfiantini, R ^[3]

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1. Philippine National Oil Co.-Energy Development Corp., Fort Bonifacio (Philippines)
2. Inst. Internazionale per le Ricerche Geotermiche, Pisa (Italy)
3. International Atomic Energy Agency, Vienna (Austria)

Fluids in the Greater Tongonan geothermal system exhibit a large positive {sup 18}O shift from the Leyte meteoric water line. However, there is also a significant shift in {sup 2}H. The {delta}{sup 2}H-{delta}{sup 18}O plot shows that the geothermal fluids may be derived by the mixing of meteoric water with local magmatic water. The most enriched water in the Greater Tongonan system, in terms of {delta}{sup 18}O, {delta}{sup 2}H and Cl, is comprised of approximately 40% magmatic water. Baseline isotope results support a hydrogeochemical model in which there is increasing meteoric water dilution to the southeast, from Mahiao to Sambaloran and towards Malitbog. The Cl-{delta}{sup 18}O plot confirms that the geothermal fluid in Mahanagdong, further southeast, is distinct from that of the Mahiao-Sambaloran-Malitbog system.

• OSTI ID: 143819
• Journal Information: Geothermics, Journal Name: Geothermics Journal Issue: 5-6 Vol. 22; ISSN GTMCAT; ISSN 0375-6505
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
CHEMICAL COMPOSITION
COMPARATIVE EVALUATIONS
GEOCHEMISTRY
GEOTHERMAL FLUIDS
HYDROLOGY
ISOTOPE RATIO
TONGONAN GEOTHERMAL FIELD
WATER CHEMISTRY