Reports

Major Carbon-14 Deficiency in Modern Snail Shells from Southern Nevada Springs

Science  06 Apr 1984:
Vol. 224, Issue 4644, pp. 58-61
DOI: 10.1126/science.224.4644.58

Abstract

Carbon-14 contents as low as 3.3 Ā± 0.2 percent modern (apparent age, 27,000 years) measured from the shells of snails Melanoides tuberculatus living in artesian springs in southern Nevada are attributed to fixation of dissolved HCO3- with which the shells are in carbon isotope equilibrium. Recognition of the existence of such extreme deficiencies is necessary so that erroneous ages are not attributed to freshwater biogenic carbonates.