鐵礦主要分布于華北地臺北緣的吉林東南部、鞍山—本溪、冀東—北京、內蒙古南部和地臺南緣的許昌—霍丘、魯中地區(qū)。以受變質沉積型鐵硅質建造礦床為主,常稱“鞍山式”鐵礦。多為大型礦床,鐵礦床主要賦存于鞍山群、遷西群、密云群、烏拉山群、泰山群、登封群、霍丘群等。其巖石變質程度多屬角閃巖相,部分屬麻粒巖相或綠片巖相,并受混合巖化。礦石以條紋狀、條帶狀、片麻狀構造為特征,被稱為條帶狀磁鐵石英巖型鐵礦。該時代儲量占41.4%。
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] [75] [76] [77] [78] [79] [80] [81] [82] [83] [84] [85] [86] [87] [88] [89] [90] [91] [92] [93] [94] [95] [96] [97] [98] [99] [100] 下一頁 |