Premium
Primordial helium and neon in the Earth—A speculation on early degassing
Author(s) -
Honda Masahiko,
McDougall Ian
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/98gl01329
Subject(s) - neon , isotopes of neon , helium , astrobiology , geology , basalt , earth (classical element) , mineralogy , physics , argon , geochemistry , astronomy , atomic physics
Primordial helium‐neon abundance ratios in the Earth have been accurately determined, based on helium and neon isotopic systematics observed in mid‐ocean ridge basalts (MORBs) and Hawaiian ocean island basalt (OIB) samples. The mean primordial ³He/ 22 Ne ratios for the MORB and Hawaiian OIB samples are 10.2±1.6 and 6.0±1.4, respectively. The gross average of all values is 7.7±2.6, about twice the solar ³He/ 22 Ne ratio of 3.8. Thus, primordial helium and neon in the Earth are elementally fractionated from the solar composition, noting, however, that the Earth's primordial helium and neon are isotopically solar in composition. This elemental fractionation between helium and neon was probably caused by solubility‐controlled degassing processes at an early stage of the Earth's evolution.