Effects of Feldspar Contamination on Equivalent dose and the Shape of Growth Curve for OSL of Silt-Sized Quartz Extracted from Chinese Loess
Effects of Feldspar Contamination on Equivalent dose and the Shape of Growth Curve for OSL of Silt-Sized Quartz Extracted from Chinese Loess
复制标题
DOI：
10.2478/v10003-008-0010-0
复制
发表时间：
2008
期刊：
影响因子：
3
通讯作者：
Zhongping Lai;H. Brückner
中科院分区：
文献类型：
--
作者：
Zhongping Lai;H. Brückner
长石污染对中国黄土粉晶石光致发光当量剂量和生长曲线形状的影响研究了不同程度的长石污染(氟硅酸刻蚀不同时间段和纯石英与不同比例的未刻蚀颗粒混合)对中国黄土中石英(38-63μm)蓝光受激发光的影响。特别是，将检查de值和生长曲线的形状。结果表明：(1)长石测得的De明显被低估，红外受激发光法比红外受激发光法有更大的低估。对于没有氟硅酸刻蚀的等分样品，对于预期年龄为∼22ka的样品，∼的De被低估了30%，对于BLSL，∼被低估了19%，对于IR后的BLSL，∼被低估了10%。对于石英BLSL，由于长石未被氟硅酸刻蚀溶解，其污染将不可避免地导致年龄低估。我们建议对每一等分进行红外线检查。如果观察到明显的IRSL信号，则应从最终反计算中排除等分。(2)对于被测样品，蓝光LED刺激可以使长石的IRSL和BLSL信号同时复位，而IR刺激不能使长石的BLSL信号复位。(3)对于多矿物溶液，红外后BLSL的生长曲线形状与IRSL不同，在25Gy时与纯石英BLSL的生长曲线形状相同。长石在石英中的污染会改变石英BLSL生长曲线的形状。
Effects of Feldspar Contamination on Equivalent dose and the Shape of Growth Curve for OSL of Silt-Sized Quartz Extracted from Chinese Loess This study examines the effects of feldspar contamination of different extent (by fluorosilicic acid etching for different time periods and mixing pure quartz with different percentage of unetched grains) on blue-light stimulated luminescence (BLSL) of quartz (38-63 μm) for Chinese loess. In particular, the De values and the shape of growth curves will be examined. The results show that: (1) The De determined using feldspar in Chinese loess is obviously underestimated, and infra-red stimulated luminescence (IRSL) has a greater underestimation than BLSL. For aliquots with no fluorosilicic acid etching, an IRSL De underestimation of ∼30% is observed for a sample with an expected age of ∼22 ka, ∼19% underestimation for BLSL, and ∼10% for post-IR BLSL. For quartz BLSL, the contamination of feldspar, which has not dissolved by fluorosilicic acid etching, will inevitably lead to age underestimation. We suggest that the IR-checking should be performed for every single aliquot. An aliquot should be excluded from the final De calculation if obvious IRSL signal was observed. (2) For the sample under examination blue LED stimulation can reset both IRSL and BLSL signals of feldspars, while IR stimulation cannot reset the BLSL of feldspars. (3) For multiple-mineral aliquot the growth curve shape of the post-IR BLSL is different from that of the IRSL, and within 25 Gy it is identical to that of the pure quartz BLSL. The contamination of feldspars in quartz will change the shape of a growth curve for quartz BLSL.