Kenji Shimizu et al. (2004) Discovery of Archean continental and mantle fragments inferred from xenocrysts in komatiites, the Belingwe greenstone belt, Zimbabwe, Geology, 32, 285-288, doi: 10.1130/G20162.1. < 20191011144441-950297 > pub

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

  • abstract:

    Controversy exists as to whether the 2.7 Ga Belingwe greenstone belt, Zimbabwe, is autochthonous or allochthonous. In this study we report direct evidence for an autochthonous continental setting for the Belingwe greenstone belt. Garnet and clinopyroxene xenocrysts were discovered in the fresh ultramafic komatiites. Major and trace element compositions of these xenocrysts suggest that they originated from mafic lower crust, presumably garnet granulite in composition, at a low temperature of ∼600 or ∼700 °C. Furthermore, in a komatiitic basalt sample, we have discovered orthopyroxene and clinopyroxene xenocrysts that may have originated from lithospheric mantle beneath the continental margin. Discoveries of these xenocrysts indicate that the komatiite magma was transported to the surface and quenched rapidly enough to prevent the complete melting of continental fragments.

  • doi: 10.1130/G20162.1
  • modified at 8 h ago
Tixhr 1651101979 thumb BW130 < 20160620142605-215044 >pub
  • IGSN: IEDRM00X2
  • classification: igneous
  • physical-form: powder
  • quantity (g): 3.02
  • description: Belingwe greenstone belt; SASKMAR drill site in the Reliance Formation; komatiite
  • modified at 2020-04-27
Tixhr298676629 thumb BW492 < 20160620142201-419125 >pub
  • IGSN: IEDRM00X8
  • classification: igneous
  • physical-form: powder
  • quantity (g): 2.39
  • description: Belingwe greenstone belt; Reliance Formation; komatiitic basalt
  • modified at 2020-04-27
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binder of Discovery of Archean continental and mantle fragments inferred from xenocrysts in komatiites, the Belingwe greenstone belt, Zimbabwe pub container 20191011144533-698725
name device size global-id
BW130 pub XRF PANalytical PW2400 12 20191016095655-024359
BW130 pub Muffle furnace ADVANTEC KM-420 1 20191016095801-413967
BW130 pub ICPMS Yokogawa PMS2000 1 20191016095851-346861
BW130 pub ICPMS Yokogawa PMS2000 27 20191016095823-581494
BW130 pub TIMS Thermo-Fisher MAT261/262 3 20191016140139-182489
BW130 pub TIMS Thermo-Fisher MAT261/262 4 20191016141432-919263
BW492 pub XRF PANalytical PW2400 12 20191016095657-129043
BW492 pub Muffle furnace ADVANTEC KM-420 1 20191016095802-144932
BW492 pub ICPMS Yokogawa PMS2000 1 20191016095852-504466
BW492 pub ICPMS Yokogawa PMS2000 27 20191016095826-780701
BW492 pub TIMS Thermo-Fisher MAT261/262 3 20191016140140-889449
BW492 pub TIMS Thermo-Fisher MAT261/262 4 20191016141433-364686
BW130_grt5 pub XRF PANalytical PW2400 10 20191011153402-213027
BW130_grt7 pub XRF PANalytical PW2400 10 20191011153403-836306
BW492_cpx2 pub XRF PANalytical PW2400 10 20191011153403-472320
BW492_opx1 pub XRF PANalytical PW2400 10 20191011153404-668683
BW130_grt12 pub XRF PANalytical PW2400 10 20191011153403-028765
BW130_grt2 pub XRF PANalytical PW2400 10 20191011153402-546352
BW492_cpx1 pub XRF PANalytical PW2400 10 20191011153403-689480
BW130_grt4 pub XRF PANalytical PW2400 10 20191011153402-030739
BW492_WR pub XRF PANalytical PW2400 10 20191011153427-238841
BW130_WR pub XRF PANalytical PW2400 10 20191011153427-565876
BW492_cpx1 pub ICPMS Yokogawa PMS2000 22 20191016095838-369460
BW492_cpx1 pub TIMS Thermo-Fisher MAT261/262 4 20191016141437-025315
name spots global-id
caption ID assembly stone
Table 1. Representative chemical compositions of xenocrysts and their host rocks pub 20191011153752-128321 major (Shimizu et al., 2004) 10
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  • name
  • Kenji Shimizu
  • Eizo Nakamura
  • Katsura Kobayashi
  • Maruyama, Shigenori