與此同時(shí),地質(zhì)學(xué)有大量的分類工作要做,這項(xiàng)工作不是什么都一帆風(fēng)順的。從一開始,地質(zhì)學(xué)家就想把巖石按其形成的時(shí)期來(lái)進(jìn)行分類,但在怎么劃分時(shí)期的問(wèn)題上經(jīng)常發(fā)生激烈的爭(zhēng)論——而且是一場(chǎng)曠日持久的爭(zhēng)論,后來(lái)被稱之為“泥盆紀(jì)大爭(zhēng)論”。劍橋大學(xué)的亞當(dāng)·塞奇威克斷言有一層巖石是寒武紀(jì)的,而羅德里克·默奇森認(rèn)為它完全屬于志留紀(jì),爭(zhēng)論于是就發(fā)生了。爭(zhēng)論持續(xù)了好多年,而且越來(lái)越激烈。“巴謝是個(gè)下流痞子。”默奇森在給一位朋友的信中氣呼呼地說(shuō)。
Some sense of the strength of feeling can be gained by glancing through the chapter titles ofMartin J. S. Rudwick's excellent and somber account of the issue, The Great DevonianControversy. These begin innocuously enough with headings such as "Arenas of GentlemanlyDebate" and "Unraveling the Greywacke," but then proceed on to "The Greywacke Defendedand Attacked," "Reproofs and Recriminations," "The Spread of Ugly Rumors," "Weaver RecantsHis Heresy," "Putting a Provincial in His Place," and (in case there was any doubt that this waswar) "Murchison Opens the Rhineland Campaign." The fight was finally settled in 1879 with thesimple expedient of coming up with a new period, the Ordovician, to be inserted between thetwo.
在《泥盆紀(jì)大爭(zhēng)論》一書里,馬丁·J.S.魯?shù)峡藰O好而又有些沮喪地描述了這場(chǎng)爭(zhēng)論。只要瞥一眼該書各章的標(biāo)題,就可以知道一點(diǎn)上述感情的強(qiáng)烈程度。開頭幾章的標(biāo)題的語(yǔ)氣倒還溫和,比如《紳士們的辯論舞臺(tái)》和《破譯雜砂巖之謎》,但接著就是《捍衛(wèi)雜砂巖與攻擊雜砂巖》、《指摘與反駁》、《散布惡毒的謠言》、《韋弗撤回邪說(shuō)》、《殺殺鄉(xiāng)下人的氣焰》(惟恐你還懷疑這不是一場(chǎng)戰(zhàn)爭(zhēng))、《默奇森發(fā)起萊茵蘭戰(zhàn)役》等等。爭(zhēng)論于1879年得以解決,辦法很簡(jiǎn)單,在寒武紀(jì)和志留紀(jì)中間加一個(gè)時(shí)期:奧陶紀(jì)。