Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand
Molybdenite mineralization occurs within the Bald Hill Prospect (West Nelson) in brecciated and hornfelsed Greenland Group slates and metagreywackes and associated quartz trondhjemite porphyry minor intrusions (Lyell Porphyry). Potassium argon (K-Ar) ages of the Lyell Porphyry, several granites form...
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ftvictoriauwfig:oai:figshare.com:article/16999192 2023-05-15T16:28:02+02:00 Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand Eggers, Allan John 1978-01-01T00:00:00Z https://doi.org/10.26686/wgtn.16999192.v1 https://figshare.com/articles/thesis/Geology_and_Mineralization_of_the_Bald_Hill_Molybdenum_Occurrence_Buller_District_West_Nelson_New_Zealand/16999192 unknown doi:10.26686/wgtn.16999192.v1 https://figshare.com/articles/thesis/Geology_and_Mineralization_of_the_Bald_Hill_Molybdenum_Occurrence_Buller_District_West_Nelson_New_Zealand/16999192 Author Retains Copyright Earth Sciences not elsewhere classified Molybdenum Bald Hill West Nelson School: School of Geography Environment and Earth Sciences 049999 Earth Sciences not elsewhere classified Marsden: 260199 Geology not Elsewhere Classified Degree Discipline: Geology Degree Level: Masters Degree Name: Master of Science Text Thesis 1978 ftvictoriauwfig https://doi.org/10.26686/wgtn.16999192.v1 2021-11-18T00:08:12Z Molybdenite mineralization occurs within the Bald Hill Prospect (West Nelson) in brecciated and hornfelsed Greenland Group slates and metagreywackes and associated quartz trondhjemite porphyry minor intrusions (Lyell Porphyry). Potassium argon (K-Ar) ages of the Lyell Porphyry, several granites forming part of the adjacent Karamea Granite batholith (Bald Hill Granites) and mineralized hornfelsic country rocks fall in the range 102-120 Ma (mid-Cretaceous). Adjacent lower Ordovician Greenland Group slates yielded four K-Ar ages in the range 112-226 Ma indicating partial argon outgassing of these older metasediments. The Bald Hill Granites and the Lyell Porphyry granitic rocks belong to separate petrogenic provinces. Bald Hill Granites forming the western margin of the Karamea Granite batholith occur as a suite of foliated, medium-grained, muscovite-bearing leucogranites, pink microgranites and biotite-granites. Chemically these rocks are peraluminous-potash granites with 72-75% SiO2, MgONa2O with Rb > Sr and always contain more than 30% normative quartz and 3% normative corundum. In contrast, the Lyell Porphyry rocks intruding both Greenland Group and Bald Hill Granite country rocks, form a series of small, high-level plutons and cross-cutting dykes of quartz trondhjemite, granodiorite, quartz diorite, lamprophyre and quartz-bearing gabbroporphyry. Chemically the Lyell Porphyry intrusive rocks are soda-rich calc-alkaline granitoids containing 46-70% SiO2, >1% MgO, >2.2% CaO, with Na2O>K2O and Sr>Rb with less than 28% normative quartz and less than 2% normative corundum. From their studies of granite batholiths in southeastern Australia, Chappell and White (1974) recognise two contrasting granitoid types called I-type and S-type granites. The Lyell Porphyry and several other intrusive stocks associated with molybdenum mineralization in West Nelson and North Westland are shown to correspond to I-type granites, in contrast to the Karamea batholith granites (including Bald Hill Granites) which conform ... Thesis Greenland Open Access Victoria University of Wellington / Te Herenga Waka Greenland New Zealand Marsden ENVELOPE(66.067,66.067,-67.867,-67.867) Bald Hill ENVELOPE(-132.788,-132.788,65.758,65.758) |
institution |
Open Polar |
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Open Access Victoria University of Wellington / Te Herenga Waka |
op_collection_id |
ftvictoriauwfig |
language |
unknown |
topic |
Earth Sciences not elsewhere classified Molybdenum Bald Hill West Nelson School: School of Geography Environment and Earth Sciences 049999 Earth Sciences not elsewhere classified Marsden: 260199 Geology not Elsewhere Classified Degree Discipline: Geology Degree Level: Masters Degree Name: Master of Science |
spellingShingle |
Earth Sciences not elsewhere classified Molybdenum Bald Hill West Nelson School: School of Geography Environment and Earth Sciences 049999 Earth Sciences not elsewhere classified Marsden: 260199 Geology not Elsewhere Classified Degree Discipline: Geology Degree Level: Masters Degree Name: Master of Science Eggers, Allan John Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand |
topic_facet |
Earth Sciences not elsewhere classified Molybdenum Bald Hill West Nelson School: School of Geography Environment and Earth Sciences 049999 Earth Sciences not elsewhere classified Marsden: 260199 Geology not Elsewhere Classified Degree Discipline: Geology Degree Level: Masters Degree Name: Master of Science |
description |
Molybdenite mineralization occurs within the Bald Hill Prospect (West Nelson) in brecciated and hornfelsed Greenland Group slates and metagreywackes and associated quartz trondhjemite porphyry minor intrusions (Lyell Porphyry). Potassium argon (K-Ar) ages of the Lyell Porphyry, several granites forming part of the adjacent Karamea Granite batholith (Bald Hill Granites) and mineralized hornfelsic country rocks fall in the range 102-120 Ma (mid-Cretaceous). Adjacent lower Ordovician Greenland Group slates yielded four K-Ar ages in the range 112-226 Ma indicating partial argon outgassing of these older metasediments. The Bald Hill Granites and the Lyell Porphyry granitic rocks belong to separate petrogenic provinces. Bald Hill Granites forming the western margin of the Karamea Granite batholith occur as a suite of foliated, medium-grained, muscovite-bearing leucogranites, pink microgranites and biotite-granites. Chemically these rocks are peraluminous-potash granites with 72-75% SiO2, MgONa2O with Rb > Sr and always contain more than 30% normative quartz and 3% normative corundum. In contrast, the Lyell Porphyry rocks intruding both Greenland Group and Bald Hill Granite country rocks, form a series of small, high-level plutons and cross-cutting dykes of quartz trondhjemite, granodiorite, quartz diorite, lamprophyre and quartz-bearing gabbroporphyry. Chemically the Lyell Porphyry intrusive rocks are soda-rich calc-alkaline granitoids containing 46-70% SiO2, >1% MgO, >2.2% CaO, with Na2O>K2O and Sr>Rb with less than 28% normative quartz and less than 2% normative corundum. From their studies of granite batholiths in southeastern Australia, Chappell and White (1974) recognise two contrasting granitoid types called I-type and S-type granites. The Lyell Porphyry and several other intrusive stocks associated with molybdenum mineralization in West Nelson and North Westland are shown to correspond to I-type granites, in contrast to the Karamea batholith granites (including Bald Hill Granites) which conform ... |
format |
Thesis |
author |
Eggers, Allan John |
author_facet |
Eggers, Allan John |
author_sort |
Eggers, Allan John |
title |
Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand |
title_short |
Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand |
title_full |
Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand |
title_fullStr |
Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand |
title_full_unstemmed |
Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand |
title_sort |
geology and mineralization of the bald hill molybdenum occurrence, buller district, west nelson, new zealand |
publishDate |
1978 |
url |
https://doi.org/10.26686/wgtn.16999192.v1 https://figshare.com/articles/thesis/Geology_and_Mineralization_of_the_Bald_Hill_Molybdenum_Occurrence_Buller_District_West_Nelson_New_Zealand/16999192 |
long_lat |
ENVELOPE(66.067,66.067,-67.867,-67.867) ENVELOPE(-132.788,-132.788,65.758,65.758) |
geographic |
Greenland New Zealand Marsden Bald Hill |
geographic_facet |
Greenland New Zealand Marsden Bald Hill |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
doi:10.26686/wgtn.16999192.v1 https://figshare.com/articles/thesis/Geology_and_Mineralization_of_the_Bald_Hill_Molybdenum_Occurrence_Buller_District_West_Nelson_New_Zealand/16999192 |
op_rights |
Author Retains Copyright |
op_doi |
https://doi.org/10.26686/wgtn.16999192.v1 |
_version_ |
1766017637770330112 |