endmember

Noun

endmember (plural endmembers)

1. A member at one end of a range or series made up of similar members.
   • Most significant is the observation that the vaporous for the more volatile end member occupies a decreasingly smaller portion of the diagram as the other end member becomes less volatile. Ultimately, when the less volatile end member is essentially involatile, the vaporous of the volatile end...1970, Arnold Reisman, “Condensed-vapor Phase Binary Diagrams Continued—Incongruently Vaporizing Systems”, in Phase Equilibria: Basic Principles, Applications, Experimental Techniques (Physical...
   • The physicochemical processes that control the estuarine filter must therefore be considered to operate in terms of a framework involving particulate-dissolved recycling associated with three estuarine end-members, i.e. river water, sea water (which may consist of more than one component...1990, Roy Chester, “The Transport of Material to the Oceans: The Atmospheric Pathway”, in Marine Geochemistry, London: Unwin Hyman, →DOI, →ISBN, page 43
2. (specifically) A mineral that occurs at one end in a range of solid solutions.
   • This group of tetragonal silicates seems to form a graduated series from akermanite to gehlenite, the constitution of the two end[-]members being (where R = Ca, with less Mg, Mn, Fe, Na₂): / Akermanite, R₄Si₂O₁₀, or R₃(RSi)Si₂O₁₀, / Gehlenite, R₃Al₂Si₃O₁₀, or R₃(Al₃)Si₃O₁₀, […]1892, The Mineralogical Magazine and Journal of the Mineralogical Society, volume 10, London: H[umphrey Sumner] Milford, Oxford University Press, →OCLC, page 33
   • These data may therefore represent mixtures of gases from two (or more) distinct sources. One endmember appears to be slightly enriched in ⁸⁴Kr and ¹³²Xe relative to the vug quartz fluids; the other endmember is relatively enriched in ³⁶Ar.1989, I. A. Franchi, S. R. Boyd, I. P. Wright, C. T. Pillinger, “Application of Lasers in Small-sample Stable Isotopic Analysis”, in W. C. Shanks III, R. E. Criss, editors, New Frontiers in Stable...