Publication Date:
2023-06-27
Description:
Submarine basalts are difficult to date accurately by the potassium-argon method. Dalrymple and Moore (1968) and Dymond (1970), for example, showed that, when the conventional K-Ar method is used, pillow lavas may contain excess 40Ar. Use of the 40Ar/39Ar step-heating method has not overcome the problem, as had been hoped, and has produced some conflicting results. Ozima and Saito (1973) concluded that the excess 40Ar is retained only in high temperature sites, but Seidemann (1978) found that it could be released at all temperatures. Furthermore, addition of potassium, from seawater, to the rock after it has solidified can result in low ages (Seidemann, 1977), the opposite effect to that of excess 40Ar. Thus, apparent ages may be either greater or less than the age of extrusion. Because of this discouraging record, the present study was approached pragmatically, to investigate whether self-consistent results can be obtained by the 40Ar/39Ar step-heating method.
Keywords:
72-516F; Age, dated; Age, standard deviation; Argon; Argon-37/Argon-36; Argon-39; Argon-39/Argon-36; Argon-40/Argon-36; Comment; Correction; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Glomar Challenger; Heating step; Leg72; Piece; Sample code/label; South Atlantic/CONT RISE; Temperature, technical
Type:
Dataset
Format:
text/tab-separated-values, 499 data points
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