在這門學(xué)科的早期,英國人是最活躍的,因此在地質(zhì)詞語中英國的名稱占了絕大部分。泥盆系(即德文系)當(dāng)然源自英格蘭的德文郡。寒武紀(jì)來自羅馬人對威爾士的叫法,而奧陶紀(jì)和志留紀(jì)使人想起了古代的威爾士人部落:奧陶人和志留人。但是,隨著地質(zhì)學(xué)后來在其他地方的崛起,世界各地的名稱漸漸出現(xiàn)。侏羅紀(jì)跟法國和瑞士交界處的侏羅山有關(guān)。二疊紀(jì)使人想起俄羅斯烏拉爾山脈里的彼爾姆,而白堊紀(jì)(源自拉丁文白堊)是由一位比利時地質(zhì)學(xué)家命名的,他自己也有個漂亮的名字,叫做J.J.德奧馬利馬斯·德霍洛伊。
Originally, geological history was divided into four spans of time: primary, secondary, tertiary,and quaternary. The system was too neat to last, and soon geologists were contributingadditional divisions while eliminating others. Primary and secondary fell out of use altogether,while quaternary was discarded by some but kept by others. Today only tertiary remains as acommon designation everywhere, even though it no longer represents a third period ofanything.
原先,地質(zhì)史分為4個時期:第一紀(jì)、第二紀(jì)、第三紀(jì)和第四紀(jì)。這個體系過于簡單,因此壽命不太長。地質(zhì)學(xué)家很快就用新的劃分方法來替代這種劃分方法。第一紀(jì)和第二紀(jì)已經(jīng)完全不用,第四紀(jì)有的人已經(jīng)不用,但有的人仍然在用。今天,只有第三紀(jì)還在廣泛使用,雖然已經(jīng)不代表第三紀(jì)任何東西。