新弥彦-1号井において観察されたアパタイトのフィッション•トラックの消失とその意味
新弥彦-1号井において観察されたアパタイトのフィッション•トラックの消失とその意味
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Niiyahiko-1井观察到的磷灰石裂变径迹的消失及其意义
DOI：
10.3720/japt.62.544
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
尚久 吉村
中科院分区：
文献类型：
--
作者：
寛人 大平;陽子 磯野;正幸 榊原;尚久 吉村
在位于日本一个非常年轻的沉积盆地中的Shin-Yahiko-1井的样品中测量了磷灰石的裂变径迹衰减。裂变径迹密度太低，无法探测到封闭的裂变径迹，因此直接测量了半径迹长度，半径迹的平均长度和频率分布在4400 m以下随温度和深度的增加而明显递减，半径迹的衰落区跨度小于1500 m，Shin Yahiko-1井裂变径迹衰减的平滑趋势表明了相对简单的沉降埋藏历史，这与根据浮游有孔虫年龄粗略估计的埋藏历史相一致。裂变径迹在很短的有效加热时间内衰减GC/MS分析表明，新弥彦1井产出的原油来自高度成熟的寺渡渡组，寺渡组产于4，半径迹长度测量对于非常年轻的盆地，特别是在不含镜质体的火成岩基底中，也可以作为一种辅助的热指示手段。
Fission track fading in apatite has been measured in samples from the Shin-Yahiko-1 well, which is situated in a very young sedimentary basin in Japan. Fission track densities were too low to detect confined fission tracks, and consequently semi-track lengths were measured directly instead.Mean lengths and frequency distribution of semi-tracks decrease clearly and progressively with increasing temperature and depth below 4, 400m, and the fading zone of semi-tracks spans an interval of less than 1, 500m, and 40°C in temperature.The smooth trend of fission track fading in the Shin Yahiko-1 well suggests a relatively simple subsidence burial history, which is concordant with the burial history roughly estimated from ages of planktonic foraminifers.From the Shin Yahiko-1 well data, fission track fading over a a very short effective heating time (0.05Ma) delineates a zone on the vitrinite reflectance nomograph.GC/MS analysis suggests that the oil produced from the Shin Yahiko-1 originated from the highly matured Teradomari Formation, which occurs at a depth greater than 4, 500m and roughly corresponds to the top of apatite fission track fading zone.Semi-track length measurement is useful as a supplementary thermal indicator even for very young basins, especially in igneous basement rocks where vitrinites are absent.