【正文】 during their development. The tectonic setting of a coalfield exerts a strong influence on the type of coal that is formed within its boundaries. Hacquebard et al. (1967), Mackowsky (1968), Shibaoka and Smyth (1975), Hunt (1982) and others have demonstrated that coal position varies more in large paralic deposits than in limnic setting, because of the larger variety of factors influencing extensive continental shelf or foredeep environments. Moreover, coals formed in rapidly subsiding foreland basins are more likely to have high vitrite, clarite and ash contents than coals formed on cratonic shelves or in slowly subsiding cratonic basins. These coals are likely to be rich in dull coals consisting mainly of durite inertite. 2 Basin Formation as Part of Plate Tectonics The theory of plate tectonics, although primarily concerned with horizontal movements of the relatively rigid lithospheric plates (crust and uppermost mantle) over the softer asthenosphere (mantle), has also provided an explanation for the vertical movements that lead to subsidence and basin formation. The following crustal movements can be distinguished (after Dickinson 1974 and Fischer 1975): 1. Change in crustal thickness. According to the principle of isostasy thick lowdensity continental crust floats higher on heavy mantle material than thin highdensity oceanic crust. For example, an isostatically pensated continental crust of 50 km thickness extends 4 km above the sea, whereas a 6kmthin oceanic crust is covered by approximately 5 km of water (Holmes, 1965). Plate tectonics provides several mechanisms for both crustal thickening and thinning. The latter, which is of immediate interest here, is often exemplified in areas of continental rifting, where in the early stages of plate separation the crust along the rift zone is attenuated by extensional stepfaulting, thus forming rapidly subsiding grabens and halfgrabens. Erosional thining of anisostatically uplifted crustal portions also leads to subsequent subsidence. Uplift due to crustal thickening is of some interest in this context,because it creates potential source areas for coal measure sediments. This is particularly important in foredeeps, where basin formation is invariably coupled with uplift in nearby orogenic belts. Most examples of uplift due to crustal thickening are related either to the injection of magma into the crust or to continental collision. 2. Change in thermal regime. Convection currents in the plastic asthenosphere are responsible not only for horizontal plate movements but also for some vertical crustal motions which are independent of ceustal thickness. Upwelling magma from the mantle may cause uplift by forming heat bulges in the overlying crust, and new oceanic crust is formed where such mantle material is extruded along midoceanic rift zones. The latter are elevated above the sea floor because of thermal expansion of the affected crust which bees colder and denser with increasing age and distance fiom the rise crest. Areas of thermal tumescence within or along the margin of continental plates are subjected to erosional thinning, which accentuates their subsidence during the period of thermal decay. 3. Loading affects. When sediments accumulate on an isostatically pensated crust the additional load will create a disequilibrium which will be balanced by subsidence. This means that, whatever the initial cause for the creation of a depositional site, once sediments are beginning to accumulate, their weight and paction are in some measure responsible for the deposition of additional sediments. This, to some extent selfprepetuating process is particularly well shown by the flexural bending under load of the continental shelf margin (Walcott 1972). Other mon geotectonic sites for loadinduced subsidence and sedimentation are orogenic fordeep margins which are flexurally downwarped under the weight of the overriding thrust sheets generated in the adjacent fold belt (Price 1973。 ocanic crust。這是一個寬廣且復雜的領域，它吸收了聚集地球科學許多不同學科的知識。因此，在這個時期對于被選擇的題目做一個決定性的陳述是不可能的，但是，只是描述關(guān)于現(xiàn)代大地構(gòu)造因素方面的煤田分類是可以建立的。 這 固定的并嚴格層 序的解釋（ Kay 所強調(diào)的“ 后成優(yōu)地槽” 1951） 并沒有發(fā)生在現(xiàn)代大地構(gòu)造分析 中，其中的大部分造山帶被作為拼貼的本地成因 和異地 成因的 地形，即作為構(gòu)造地層組合與可能同時代不均勻的 地層記錄，反映其原產(chǎn)地在不同的地質(zhì) 上或 地理 上的領域（ Monger and Price 1979, Monger et al. 1982）。 事實上，情況甚至可能會更加復雜，將在 討論 。 此外，提到“ 冒地向斜 ” ， 冒地槽已在北美文獻中成為一個標準的原地術(shù)語，沉積階地邊緣超覆了大陸邊緣。 1 一個早期的煤田構(gòu)造分類的例子 大型煤田的形成可以發(fā)生的地方，只有在活躍的下陷地區(qū)，例如在沉積盆地。 他歸因于這樣的相似性，以對比程度的地殼的流動性，在歐洲的兩個主要成煤期受影響地區(qū)。他的結(jié)論的摘要列于表 ，這表明在 1937 年所有的煤炭儲量都已經(jīng)知道，約 71 ％的是發(fā)展構(gòu)造非?；钴S的環(huán)境，特別 是在穩(wěn)定地塊 盆地前淵發(fā)展來 的，其中毗鄰造山帶和從高地來的接收的許多風化碎片。 正如我們將在所后面討論的，這是涉及到大量的和長期沉陷的被認為在大陸邊緣受到附近俯沖的復雜的，作為一個造 山帶是與板塊邊緣共生的。 例如，所有的前泥盆紀造山帶發(fā)生的時候 ,植物界仍然不能滿足作為生產(chǎn)泥炭的作用。 不過，由于 von Bubnoff (1948a)指出，濱線的位置是相當偶然的，決定于地殼運動和海平面位置 .從地質(zhì)的角度來看，大陸架定義的擴大似乎是有用的，因此時間的因素可以忽略。 Krumbein and Sloss 1963)。 一個引人注目的現(xiàn)代的例子， 山脈之間內(nèi)泥炭的形成是發(fā)生在南美安第斯山脈高于海平面 3810 米蘆葦沼澤對海岸的的湖 。他們應該歸功于各種各樣的活動，包括造陸下陷大陸地殼和大陸裂谷。 在形成其邊界過程中 ,煤田的構(gòu)造環(huán)境有著重要的影響力。 2 盆地形成作為板塊構(gòu)造理論的一部分 板塊構(gòu)造理論，雖然主要關(guān)注相對剛性巖石圈 板塊（地殼與上地幔頂部在柔和的軟流圈（地幔）的橫向變動，但也提供了一個導致沉降和盆地的形成的垂直運動的解釋。 后者，這是對的切身利益 ，在這里，往往是體現(xiàn)在地區(qū)的大陸裂谷，如在早期階段板分離地殼沿裂谷帶衰減由伸展步斷層，從而形成迅速下沉地塹和半地塹。 大部分隆起的例子是由于地殼增厚是與要么巖漿進入地殼要么板塊碰撞有關(guān)。 熱隆起地區(qū)內(nèi)或沿緣大陸板塊受到剝蝕變薄，加劇他們在熱化階段的沉陷。 其他常見的大地構(gòu)造的負載引起的沉降和沉積的造山帶前淵邊緣是在相鄰的褶皺帶向下彎曲下的 ,在重量超過逆沖巖席下造成 的 (Price 1973。 額外的負荷的向下彎曲的地殼是所提供的大量的沉積物中產(chǎn)生的 穩(wěn)定地塊 盆地，在褶皺帶和運入發(fā)展中的前淵盆地 。 影響大地構(gòu)造環(huán)境的煤田就泥炭積累和煤的組成的調(diào)查，需要一個對地球主要地殼元素與他們的主要運動認識。 2. 聚合板塊邊 緣，那里的舊地殼俯沖到下地幔的主要邊緣 的推覆板塊。大陸邊緣中部是確定大陸架的沉積，而穩(wěn)定地塊和裂谷的設置是指內(nèi)部的綜合領域。 然而，并不是所有的前俯沖帶形成煤田，這是一個與聚合板塊性質(zhì)有關(guān)的問題，即他們是否構(gòu)成海洋或大陸地殼。 然而，只有大洋地殼參與，附近缺乏一個強有力的沉積物來源導致鄰近的海洋盆地缺失或泥炭堆積太深。 Aihara (1986) 所描述的 在 Hidaka盆地中央北海道 產(chǎn)生在 3000 米厚的早第三紀連續(xù)的褶皺和斷層中的煤層，是比較罕見的厚煤層的煤系序列形成和保存在 了 弧前環(huán)境 中 。沉淀的開始可能與在弧后區(qū)的伸展構(gòu)造相關(guān)，在俯沖仍在進行中的過程時。 因為它的厚度和密度低，大陸地殼只能部分被俯沖而導致的構(gòu)造疊加和重疊的兩個板塊的邊緣。 陸殼 。???代表海相沉積