Eizo Nakamura et al. (1986) K-Ar ages of basalts from the Higashi-Matsuura district, northwestern Kyushu, Japan and regional geochronology of the Cenozoic alkaline volcanic rocks in eastern Asia, Geochemical Journal, 20, 91-99, doi: 10.2343/geochemj.20.91. < 20150918180709-838886 > pub

Map on Earth or stone. Places and analyses are shown.

  • abstract:

    Seven new K-Ar age determinations are presented on whole rock samples from alkaline and tholeiitic basalts of the Higashi-Matsuura district, northwestern Kyushu, Japan. Ages obtained range from 2.92 ± 0.03Ma to 3.01 ± 0.04Ma; these ages are essentially identical within analytical errors and yield an average age of 2.98 ± 0.03Ma (Late Pliocene). When combined on an isochron type diagram the six Higashi-Matsuura samples give an age of 3.00 ± 0.03 Ma with the composition of nonradiogenic 40Ar/36Ar = 294.2 ± 2.0. The excellent age agreement of samples with different K contents and petrographic characteristics provides strong evidence that the tholeiitic and alkaline basalts were erupted for an extremely short period in the Higashi-Matsuura district. A basalt from Ogawashima Island yields a K-Ar age of 3.58 ± 0.04Ma. This study and previously reported data support the hypothesis that alkaline volcanic activity in southwestern Japan commenced some 10Ma ago and continued intermittently until Recent times. Systematic variations of age and distribution of Cenozoic alkaline basalts are recognized in northeastern China, Korea and southwestern Japan. It is suggested that these variations are related to the initiation of “mantle plumes” resulting from convection in the mantle wedge caused or controlled by subduction of the Kula and Pacific plates.

  • doi: 10.2343/geochemj.20.91
  • modified at 2 h ago


(a) Flame emission spectrometry on Shimadzu AA6200
(b) isotope dilution mass spectrometry with 38Ar spike on Micromass VG5400
Img 7231@b052c23a57069faf2f31b23 thumb 80811-3 < 20121101085414-158-819 >pub
  • IGSN: IEDRM00A4
  • classification: volcanic:basaltic
  • physical-form: hand specimen
  • quantity (kg): 0.32
  • age (Ma): 3 (0)
  • description: Hawaiite; Kogakura, Higashi-Matsuura District, northwestern Kyushu
  • modified at 2019-07-02
Img 7313@9dbad84b0f6c912af38842e thumb 80908-5 < 20121114085119-111-481 >pub
  • IGSN: IEDRM00A6
  • classification: volcanic:basaltic
  • physical-form: hand specimen
  • quantity (kg): 0.17
  • age (Ma): 3 (0)
  • description: Alkali basalt lava flow; on a road from Funakaratsu to San-ri, Takashima-cho, Nagasaki pref.
  • modified at 2019-07-02
Img 7314@f767c34a3936155efa2d7a7 thumb 80821-3 < 20121114085125-558-275 >pub
  • IGSN: IEDRM00A7
  • classification: volcanic:basaltic
  • physical-form: hand specimen
  • quantity (kg): 0.14
  • age (Ma): 3 (0)
  • description: Olivine-tholeiite basalt lava flow; on a road from Kirigo to mt.Nodakayama; Higashi-Matsuura District, northwestern Kyushu
  • modified at 2019-07-02
Img 7230@d0026eb5b6163148f424343 thumb 80901-2 < 20121101085405-319-559 >pub
  • IGSN: IEDRM00A3
  • classification: volcanic:basaltic
  • physical-form: hand specimen
  • quantity (kg): 0.34
  • age (Ma): 3 (0)
  • description: Alkali basalt; Dachiku, Hizen-cho, Higashi-Matsuura District, northwestern Kyushu
  • modified at 2019-07-02
Img 7235@a38ff7b32831928e1650497 thumb 80807-9 < 20121101085448-606-122 >pub
  • IGSN: IEDRM00A5
  • classification: volcanic:basaltic
  • physical-form: hand specimen
  • quantity (kg): 0.325
  • age (Ma): 4 (0)
  • description: Hawaiite lava flow; Ogawashima island, Yobuko-cho
  • modified at 2019-07-02
name box-type global-id
binder of K-Ar ages of basalts from the Higashi-Matsuura district, northwestern Kyushu, Japan and regional geochronology of the Cenozoic alkaline volcanic rocks in eastern Asia pub container 20160212151625-931102
Eizo 2 pub container 20091110090458125.hkitagawa
Eizo 4 pub container 20091110090454791.hkitagawa
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80811-3 pub Micromass VG5400 1 20190513115549-167320
80811-3 pub Shimadzu AA6200 1 20190513115540-702588
80908-5 pub Shimadzu AA6200 1 20190513115540-754005
80908-5 pub Micromass VG5400 1 20190513115549-885804
80821-3 pub EPMA 8 20190514155031-266563
80821-3 pub Micromass VG5400 1 20190513115549-112166
80821-3 pub Shimadzu AA6200 1 20190513115540-734246
80821-3 pub MSZ mass-spectrometer 3 20190514144618-151022
80821-3 pub INAA (Instrumental Neutron Activation Analysis) 14 20190514151019-940605
80821-3 pub XRF PANalytical PW2400 14 20190514150547-697135
80901-2 pub Shimadzu AA6200 1 20190513115540-901982
80901-2 pub Micromass VG5400 1 20190513115549-022375
80807-9 pub Shimadzu AA6200 1 20190513115540-346342
80807-9 pub Micromass VG5400 1 20190513115549-440390
name spots global-id
caption ID assembly stone
Table 1. K-Ar ages for whole rock samples of basalt from the Higashi-Matsuura district and the Ogawashima island, NW Kyushu, Japan pub 20190513115711-582875 K-Ar dating (Nakamura et al., 1986) 5
manual
  • name
  • Eizo Nakamura
  • McDougall, I.
  • Campbell, Ian H.