Proceedings of the 7th New Zealand Geothermal Workshop 1985. Application of fluid inclusion geothermometry based on secondary inclusions in primary igneous quartz crystals. New Zealand Geothermal Workshop [7, 6-8 Nov. 1985, New Zealand].

Youngman, K.J.

1985

1067
CIENA

0-86869-065-1

Primary igneous quartz crystals in the cores and cuttings of volcanic rocks from the Wairakei-Tauhara geothermal field usually have been fractured. Secondary fluid inclusions have formed along many of the fracture planes as the fractures have healed. These inclusions exhibit little variation in the homogenization temperature within single fracture planes, suggesting that annealing was rapid. Due to the large size (up to 5mm diameter) and common occurrence of primary igneous quartz crystals at Wairakei-Tauhara, more detailed and complete fluid inclusion geothermometry of the field is now possible compared to the previous use of hydrothermal minerals only. This, in turns allows a better evaluation of past variations in the thermal regime of the field. Results for samples from well TH1, for example, show that temperatures of over 280°C have occurred at 975m depth in the past, but that it has since cooled to the present 250°C. ABSTRACT. INTRODUCTION. INCLUSIONS IN HYDROTHERMAL (SECONDARY) MATERIAL. INCLUSIONS IN PRIMARY MATERIAL. EXAMPLE OF THE APPLICATION OF FUILD INCLISION GEOTHERMOMETRY IN IGNEOUS QUARTZ AT WAIRAKEI-TAUHARA. ACKNOWLEDGEMENTS. REFERENCES.

Presenta diagrs.

NUEVA ZELANDIA; ENERGIA GEOTERMICA; GEOTERMIA; FLUIDOS GEOTERMICOS; GEOTERMOMETRIA;