Geology of Mt Alta - Triple Peak


Gamble, Michael.


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Haast Schist (Greenschist Facies, Textural Zone IV) rocks of the study area have undergone four recognizable deformation phases. All four deformation phases are post-metamorphic in origin. The earliest of these phases produced a macroscopic recumbent fold which dominates field area structure. The latest phase shears and offsets a suite of post-metamorphic intrusive lamprophyre dykes and related rock types.
A diatreme complex consisting dominantly of brecciated schist country rock with lesser amounts of lamprophyre and carbonatite, is described from Mt Alta. Diatreme emplacement probably occurred under highly fluidised conditions at shallow depth. Common carbonate alteration zones in the study area are here considered to be genetically related to lamprophyre/carbonatite magmatism.
A mineralized quartz reef was found near the Mt Alta diatreme, and a possible genetic relationship to magmatic rocks is suggested.

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83 p. : ill. (some col.), maps ; 30 cm.


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POLYGON ((168.980268037617918 -44.512085381587632,168.912605292374394 -44.508608151123951,168.912110778939564 -44.480008024062379,168.927615701185687 -44.472345381763304,168.965819375803733 -44.475489796589521,168.982131722925232 -44.48499775678787,168.980268037617918 -44.512085381587632))




Gamble, Michael., “Geology of Mt Alta - Triple Peak ,” Otago Geology Theses, accessed May 22, 2024,

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