It turns purple from the presence of numerous microbes which have to have sunlight and have to have hydrogen sulfide, and we can detect their presence today -- we can see them -- but we can also detect their presence in the past.
紫色になるのは 日光と硫化水素を栄養源とする 多くの微生物が存在するからです 今日その存在が確認できます 実際に見えます しかも過去に それらの微生物が