第四紀

fourth period / quaternary (geological period covering the recent ice ages over the last 180,000 years)

four / 4

(prefix indicating ordinal number, as in 第六[di4 liu4] "sixth") / (literary) grades in which successful candidates in the imperial examinations were placed / (old) residence of a high official / (literary) but; however / (literary) only; just

surname Ji / also pr. [Ji4]

order / discipline / age / era / period / to chronicle