Diattre - Kadou (English spelling)

Japanese: 火道 - かどう（英語表記）diatreme

A general term for volcanic pipes and vents that penetrate the surrounding rocks, and are the paths that lava and gas pass through from the underground magma chamber to the crater. They are opened in the surrounding rocks by the explosive energy of gas-containing magma [Daubree: 1891]. In many cases, it is a general term for vents or conduits that penetrate horizontally layered sedimentary rocks. It is mainly used for conduits formed by the explosive escape of volcanic gases, which are formed by explosive volcanic activity of gas-containing magma. They usually form cylindrical or irregular rock bodies with a circular or nearly circular cross section, and are often filled with essentially pyroclastic material and rock fragments that make up the conduit walls. Kimberlites containing diamonds are also considered to be one type of conduit [Katayama et al.: 1970].

Fire road

Near the top of a volcanic conduit, the passageway through which volcanic material is ejected to the Earth's surface.

Source: Asakura Publishing Dictionary of Petrology Information

Japanese:

周囲の岩石を貫通した火山筒（volcanic pipe）や火道（volcanic vent）を総合した名称で，熔岩やガスが地下のマグマ溜まりから噴火口に達するまでに通過する道．ガスを含んだマグマの爆発エネルギーによって周囲の岩石に開けられたものである［Daubree : 1891］．多くの場合は水平に成層した堆積岩を貫いて生じる火道または火道管の一般的な名称．主として火山ガスの爆発的な脱出作用によって形成された火道に用いられ，これはガスを含んだマグマの爆発的な火山活動でできたものである．普通は円形またはそれに近い断面をもつ円筒状または不規則な形の岩体となり，本質火砕物質や火道壁を作る岩石の破片などにより埋められていることが多い．ダイヤモンドを伴うキンバライトなどもその一種と考えられる［片山ほか : 1970］．