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華南中、晚二疊世含煤地層是中國南方最重要含煤層位，但它的變化很大，不能像華北一樣可以用1～2個剖面便可以代表�？偫ǖ乜�，它們在空間上是遞進的、漸變的，同時穿插復雜的巖相變化；在時間上是連續(xù)的，但又有所遷移。在巖石地層意義上，它們是夾在下部茅口期海相層位(灰?guī)r、硅質(zhì)巖)和上部長興期海相層位(灰?guī)r、硅質(zhì)巖)之間的一套碎屑巖含煤沉積，一部分是海陸交互相的，一部分是陸相的；在年代地層意義上，它們則貫穿了茅口階(卡贊階)、龍?zhí)峨A及長興階。我們可以大體地按東、中、西的地域并兼及不同時序，分別由3個剖面為代表來描述其地層特征。上一頁 [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55] [56] [57] [58] [59] [60] [61] [62] [63] [64] [65] [66] [67] [68] [69] [70] [71] [72] [73] [74] 下一頁 |
