Mussett, Alan E; Barker, Peter F (1983): (Table 1) Apparent ages from 40Ar/39Ar heating steps for DSDP Hole 72-516F basalts. PANGAEA, https://doi.org/10.1594/PANGAEA.811444, Supplement to: Mussett, AE; Barker, PF (1983): 40Ar/39Ar age spectra of basalts, Deep Sea Drilling Project Site 516. In: Barker, PF; Carlson, RL; Johnson, DA; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 72, 467-470, https://doi.org/10.2973/dsdp.proc.72.116.1983
Always quote above citation when using data! You can download the citation in several formats below.
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.
Latitude: -30.276500 * Longitude: -35.285000
Date/Time Start: 1980-03-11T00:00:00 * Date/Time End: 1980-03-11T00:00:00
Minimum Elevation: -1313.0 m * Maximum Elevation: -1313.0 m
72-516F * Latitude: -30.276500 * Longitude: -35.285000 * Date/Time: 1980-03-11T00:00:00 * Elevation: -1313.0 m * Penetration: 1270.6 m * Recovery: 690.1 m * Location: South Atlantic/CONT RISE * Campaign: Leg72 * Basis: Glomar Challenger * Device: Drilling/drill rig (DRILL) * Comment: 127 cores; 1092.5 m cored; 9 m drilled; 63.2 % recovery
Blanks indicate not measured. 40Ar/30Ar, 39Ar/36Ar, and 37Ar/36Ar ratios corrected for mass discrimination and interfering isotopes.
|#||Name||Short Name||Unit||Principal Investigator||Method||Comment|
|1||Sample code/label||Sample label||Mussett, Alan E||ODP sample designation|
|2||Piece||Piece||Mussett, Alan E|
|3||Comment||Comment||Mussett, Alan E||Irradiation number|
|4||Heating step||Heating step||Mussett, Alan E|
|5||Temperature, technical||T tech||°C||Mussett, Alan E||#0 = fusion|
|6||Argon||Ar||%||Mussett, Alan E||Radiogenic; # = a zero measured 36Ar caused these results|
|7||Argon-39||39Ar||%||Mussett, Alan E||Released; = percentage of total released over steps measured|
|8||Correction||corr||Mussett, Alan E||Interfering isotopes|
|9||Argon-40/Argon-36||40Ar/36Ar||Mussett, Alan E||# = a zero measured 36Ar caused these results|
|10||Argon-39/Argon-36||39Ar/36Ar||Mussett, Alan E||# = a zero measured 36Ar caused these results|
|11||Argon-37/Argon-36||37Ar/36Ar||Mussett, Alan E||# = a zero measured 36Ar caused these results|
|12||Age, dated||Age dated||ka||Mussett, Alan E||Apparent|
|13||Age, standard deviation||Age std dev||±||Mussett, Alan E||Apparent|
499 data points