TY - JOUR
T1 - Natural saturation of OSL and TT-OSL signals of quartz grains from Nilotic origin
AU - Faershtein, G.
AU - Porat, N.
AU - Matmon, A.
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/2
Y1 - 2019/2
N2 - The upper limit of optically stimulated luminescence (OSL) dating technique is usually defined by signal saturation. In nature the OSL signal saturates even faster than in the laboratory. Here we present a study on natural saturation of OSL and thermally transferred OSL (TT-OSL) signals of quartz grains from Nilotic origin. Quartz samples from two representative sections from the coastal plain of Israel, and which span approximately similar time frames, were used to construct semi-natural dose response curves (DRC) for OSL and TT-OSL by plotting the natural signal of samples against their depth and equivalent dose (De). Samples from these two sections, as well as from other sites, define typical OSL and TT-OSL DRC's for Nilotic quartz that was transported to the eastern shores of the Mediterranean Sea. The constructed semi-natural OSL DRC is unique to the quartz of Nilotic origin and indicates the upper limit for reliable OSL dating of this quartz at 140 Gy due to signal saturation. The natural TT-OSL luminescence grows linearly up to 400 Gy, and is constant for 400–600 Gy. Steady-state between TT-OSL trap-filling, due to ionizing radiation, and concurrent thermal emptying of these traps is achieved at 600 Gy. TT-OSL dating of the Nilotic quartz is expected to underestimate ages over ∼120 ka due to the low thermal stability of the signal.
AB - The upper limit of optically stimulated luminescence (OSL) dating technique is usually defined by signal saturation. In nature the OSL signal saturates even faster than in the laboratory. Here we present a study on natural saturation of OSL and thermally transferred OSL (TT-OSL) signals of quartz grains from Nilotic origin. Quartz samples from two representative sections from the coastal plain of Israel, and which span approximately similar time frames, were used to construct semi-natural dose response curves (DRC) for OSL and TT-OSL by plotting the natural signal of samples against their depth and equivalent dose (De). Samples from these two sections, as well as from other sites, define typical OSL and TT-OSL DRC's for Nilotic quartz that was transported to the eastern shores of the Mediterranean Sea. The constructed semi-natural OSL DRC is unique to the quartz of Nilotic origin and indicates the upper limit for reliable OSL dating of this quartz at 140 Gy due to signal saturation. The natural TT-OSL luminescence grows linearly up to 400 Gy, and is constant for 400–600 Gy. Steady-state between TT-OSL trap-filling, due to ionizing radiation, and concurrent thermal emptying of these traps is achieved at 600 Gy. TT-OSL dating of the Nilotic quartz is expected to underestimate ages over ∼120 ka due to the low thermal stability of the signal.
KW - Natural saturation
KW - Nilotic quartz
KW - OSL
KW - TT-OSL
KW - Thermal instability
UR - http://www.scopus.com/inward/record.url?scp=85046156990&partnerID=8YFLogxK
U2 - 10.1016/j.quageo.2018.04.002
DO - 10.1016/j.quageo.2018.04.002
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AN - SCOPUS:85046156990
SN - 1871-1014
VL - 49
SP - 146
EP - 152
JO - Quaternary Geochronology
JF - Quaternary Geochronology
ER -