Radioisotope daughter/parent ratios may be interpreted on the basis of a model for daughter accumulation, an isochron diagram, or a mixing line. Each of these interpretive treatments is evaluated for its constraint on resolution of apparent disagreement between radiometric age and the chronological specifications in the Pentateuch. A mixing-line interpretation gives no direct specification regarding time, and consequently avoids conflict between Biblical specifications and radioisotope data for minerals associated with fossils and geologic features that were formed after the beginning of Creation Week.
However, a mixing line places limits on the model age for the source material components that are required for mixing to form these minerals. Consequently, when a mixing line interpretation is used for radioisotope data associated with geologic features and fossils formed during and following the Flood, i.e., within the last 5500 years, there remains a need for a corresponding treatment of the model age limits indicated by the mixing line. Treatment of radioisotope model ages for inorganic material from a short-chronology (young earth) creationist viewpoint will be determined by the interpreter's exegesis of Genesis 1: 1,2,8-10. One viewpoint constrains the terms heaven and earth, as used in connection with the Creation Account, within the definitions given in Genesis 1 :8-1 0; and allows model ages to have a relationship with time between an uspecified primordial creation and the creation episode described in Genesis. Another viewpoint infers the entire physical universe, or at leastthe Solar System, to be designated by these terms; and requires radioisotope model age relationships to be design features expressed at or subsequent to the beginning of the Genesis One Creation Week.