Testing the Plagioclase Discriminator on the GEOROC Database to Identify Porphyry-Fertile Magmatic Systems in Japan

Benedict J. Williamson, Matthew Hodgkinson, Akira Imai, Ryohei Takahashi, Robin N. Armstrong, Richard J. Herrington

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Despite showing favorable geology, there are no known porphyry-type deposits in Japan. This, therefore, provides an ideal porphyry-“barren” case area on which to test the recently developed plagioclase-based discriminator for porphyry-“fertile” calc-alkaline systems. The discriminator was applied to plagioclase data for Japan in the online GEOROC database for convergent margin settings. Of the 3933 data points available, and considered reliable, 91% fall in the “barren” field, which compares with 73% for equivalent data worldwide. “Fertile” signatures in certain parts of Kyushu and central Honshu should be further investigated, as well as areas where there are magnetite-series magmatic systems with elevated whole-rock Sr/Y but for which there are currently little or no plagioclase data (SW-, N-central-, and NE-Honshu). Why the Japanese arcs appear to show anomalously poor potential for porphyry deposits compared with other arcs worldwide, including Western Luzon, is as yet unclear but possibly relates to tectonic factors or the nature of the magmatic source or because melt PH2O in many of the magmatic systems was too low, as suggested from low average excess Al in plagioclase.

Original languageEnglish
Pages (from-to)138-143
Number of pages6
JournalResource Geology
Volume68
Issue number2
DOIs
Publication statusPublished - Apr 1 2018
Externally publishedYes

Fingerprint

Discriminators
porphyry
plagioclase
Testing
Deposits
Ferrosoferric Oxide
convergent margin
Tectonics
Geology
magnetite
Rocks
geology
melt
tectonics
rock

All Science Journal Classification (ASJC) codes

  • Geology
  • Geochemistry and Petrology

Cite this

Williamson, B. J., Hodgkinson, M., Imai, A., Takahashi, R., Armstrong, R. N., & Herrington, R. J. (2018). Testing the Plagioclase Discriminator on the GEOROC Database to Identify Porphyry-Fertile Magmatic Systems in Japan. Resource Geology, 68(2), 138-143. https://doi.org/10.1111/rge.12162

Testing the Plagioclase Discriminator on the GEOROC Database to Identify Porphyry-Fertile Magmatic Systems in Japan. / Williamson, Benedict J.; Hodgkinson, Matthew; Imai, Akira; Takahashi, Ryohei; Armstrong, Robin N.; Herrington, Richard J.

In: Resource Geology, Vol. 68, No. 2, 01.04.2018, p. 138-143.

Research output: Contribution to journalArticle

Williamson, BJ, Hodgkinson, M, Imai, A, Takahashi, R, Armstrong, RN & Herrington, RJ 2018, 'Testing the Plagioclase Discriminator on the GEOROC Database to Identify Porphyry-Fertile Magmatic Systems in Japan', Resource Geology, vol. 68, no. 2, pp. 138-143. https://doi.org/10.1111/rge.12162
Williamson, Benedict J. ; Hodgkinson, Matthew ; Imai, Akira ; Takahashi, Ryohei ; Armstrong, Robin N. ; Herrington, Richard J. / Testing the Plagioclase Discriminator on the GEOROC Database to Identify Porphyry-Fertile Magmatic Systems in Japan. In: Resource Geology. 2018 ; Vol. 68, No. 2. pp. 138-143.
@article{d2b62b5bcb3a45ac8b78bfce3b16735b,
title = "Testing the Plagioclase Discriminator on the GEOROC Database to Identify Porphyry-Fertile Magmatic Systems in Japan",
abstract = "Despite showing favorable geology, there are no known porphyry-type deposits in Japan. This, therefore, provides an ideal porphyry-“barren” case area on which to test the recently developed plagioclase-based discriminator for porphyry-“fertile” calc-alkaline systems. The discriminator was applied to plagioclase data for Japan in the online GEOROC database for convergent margin settings. Of the 3933 data points available, and considered reliable, 91{\%} fall in the “barren” field, which compares with 73{\%} for equivalent data worldwide. “Fertile” signatures in certain parts of Kyushu and central Honshu should be further investigated, as well as areas where there are magnetite-series magmatic systems with elevated whole-rock Sr/Y but for which there are currently little or no plagioclase data (SW-, N-central-, and NE-Honshu). Why the Japanese arcs appear to show anomalously poor potential for porphyry deposits compared with other arcs worldwide, including Western Luzon, is as yet unclear but possibly relates to tectonic factors or the nature of the magmatic source or because melt PH2O in many of the magmatic systems was too low, as suggested from low average excess Al in plagioclase.",
author = "Williamson, {Benedict J.} and Matthew Hodgkinson and Akira Imai and Ryohei Takahashi and Armstrong, {Robin N.} and Herrington, {Richard J.}",
year = "2018",
month = "4",
day = "1",
doi = "10.1111/rge.12162",
language = "English",
volume = "68",
pages = "138--143",
journal = "Resource Geology",
issn = "1344-1698",
publisher = "Wiley-Blackwell",
number = "2",

}

TY - JOUR

T1 - Testing the Plagioclase Discriminator on the GEOROC Database to Identify Porphyry-Fertile Magmatic Systems in Japan

AU - Williamson, Benedict J.

AU - Hodgkinson, Matthew

AU - Imai, Akira

AU - Takahashi, Ryohei

AU - Armstrong, Robin N.

AU - Herrington, Richard J.

PY - 2018/4/1

Y1 - 2018/4/1

N2 - Despite showing favorable geology, there are no known porphyry-type deposits in Japan. This, therefore, provides an ideal porphyry-“barren” case area on which to test the recently developed plagioclase-based discriminator for porphyry-“fertile” calc-alkaline systems. The discriminator was applied to plagioclase data for Japan in the online GEOROC database for convergent margin settings. Of the 3933 data points available, and considered reliable, 91% fall in the “barren” field, which compares with 73% for equivalent data worldwide. “Fertile” signatures in certain parts of Kyushu and central Honshu should be further investigated, as well as areas where there are magnetite-series magmatic systems with elevated whole-rock Sr/Y but for which there are currently little or no plagioclase data (SW-, N-central-, and NE-Honshu). Why the Japanese arcs appear to show anomalously poor potential for porphyry deposits compared with other arcs worldwide, including Western Luzon, is as yet unclear but possibly relates to tectonic factors or the nature of the magmatic source or because melt PH2O in many of the magmatic systems was too low, as suggested from low average excess Al in plagioclase.

AB - Despite showing favorable geology, there are no known porphyry-type deposits in Japan. This, therefore, provides an ideal porphyry-“barren” case area on which to test the recently developed plagioclase-based discriminator for porphyry-“fertile” calc-alkaline systems. The discriminator was applied to plagioclase data for Japan in the online GEOROC database for convergent margin settings. Of the 3933 data points available, and considered reliable, 91% fall in the “barren” field, which compares with 73% for equivalent data worldwide. “Fertile” signatures in certain parts of Kyushu and central Honshu should be further investigated, as well as areas where there are magnetite-series magmatic systems with elevated whole-rock Sr/Y but for which there are currently little or no plagioclase data (SW-, N-central-, and NE-Honshu). Why the Japanese arcs appear to show anomalously poor potential for porphyry deposits compared with other arcs worldwide, including Western Luzon, is as yet unclear but possibly relates to tectonic factors or the nature of the magmatic source or because melt PH2O in many of the magmatic systems was too low, as suggested from low average excess Al in plagioclase.

UR - http://www.scopus.com/inward/record.url?scp=85044638868&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85044638868&partnerID=8YFLogxK

U2 - 10.1111/rge.12162

DO - 10.1111/rge.12162

M3 - Article

AN - SCOPUS:85044638868

VL - 68

SP - 138

EP - 143

JO - Resource Geology

JF - Resource Geology

SN - 1344-1698

IS - 2

ER -