[Steptoe孤峰][1]是一个石英岩“岛”的黄土被称为帕卢斯山,华盛顿东部和西部的爱达荷州在美国。根据维基百科:>岩石形成的孤峰超过4亿岁没有这一说法的来源。环顾四周,我发现(这一页)[2]从美国地质调查局宣称Steptoe孤峰的一部分(带超群)[3],以年龄为1.4 - 1.5美元。也可以发现类似的信息和年龄[这爱达荷大学网页][4]。现在是[这个东华盛顿大学页面][5],号称(我强调):>石英岩的孤峰* *超过4亿岁,原岩的变质砂岩,灼热的温度和压力下到哈代变质岩被称为石英岩几乎完全是由联锁粒石英和其他矿物质石英岩(见照片)。北部低奇迹峰会的一部分,它与长石玻璃石英岩矩阵*超群,最初解释为前寒武纪带*(御夫座、1998和附加的地质地图)。但是,使用碎屑锆石的年龄分布导致主导高点1.7岁到19亿岁(埃利斯et al ., 2004),这与碎屑锆石的年龄高峰从寒武纪(例如罗斯和维伦纽夫,2003;林德等,2017)。*这些信息意味着石英岩老不如一度被认为是,但仍然相当老*。我不能理解这最后一段。 The cited [abstract (Ellis et al., 2004)][6] goes: > The youngest grains observed constitute a dominant age peak at approximately 1.7-1.9 Ga. Older minor peaks occur at 2.45, 2.6-2.7, 2.9 and 3.3 Ga. Despite the apparent difference in degree of deformation, quartzites on Steptoe and Kamiak Buttes are likely correlative. The detrital zircon signatures are consistent with those determined for easterly derived units of the Belt-Purcell Supergroup which contain a strong Laurentian signature (Ross and Villeneuve, 2003), but lack the younger 1.45-1.5 Ga syn-depositional detrital zircon signature that characterizes some sections of the Belt-Purcell sequence such as the nearby Wallace Formation. But I don't see how this tells us that Steptoe Butte is not part of the Belt Supergroup and is thus of Cambrian age, as the previous text implies. So, I'd like to ask: **how old is Steptoe Butte?** [1]: https://en.wikipedia.org/wiki/Steptoe_Butte [2]: https://wa100.dnr.wa.gov/columbia-basin/steptoe-butte [3]: https://en.wikipedia.org/wiki/Belt_Supergroup [4]: https://webpages.uidaho.edu/geolsci/geology101/STOP1.html [5]: https://floodexplorer.org/items/show/87 [6]: https://gsa.confex.com/gsa/2004RM/webprogram/Paper72909.html