<sup>36</sup>Ar/<sup>40</sup>Ar v. <sup>39</sup>Ar/<sup>40</sup>Ar inverse isochron diagrams. Analytical data for <sup>40</sup>Ar-<sup>39</sup>Ar dating. Origin of lamprophyres from the northern margin of the North China Craton: implications for mantle metasomatism

<sup>36</sup>Ar/<sup>40</sup>Ar v. <sup>39</sup>Ar/<sup>40</sup>Ar inverse isochron diagrams