0 引言
1 区域地质概况
2 样品选取及实验方法
3 结果与讨论
3.1 岩石学特征
表1 陇东地区L58井太原组铝土岩系样品全岩矿物成分定量分析测试结果Table 1 Quantitative analysis and testing results of the mineral composition of the entire rock of the Taiyuan Formation bauxite rock series samples from Well L58 in Longdong area |
序号 | 深度/m | 矿物含量/% | 定名 | ||||||
---|---|---|---|---|---|---|---|---|---|
石英 | 钾长石 | 绿泥石、高岭石 | 伊利石、伊/蒙混层 | 黄铁矿 | 锐钛矿 | 水铝石 | |||
1 | 4 040.00 | 0.6 | 0.4 | 59.3 | 35.0 | 1.6 | 3.1 | 铝土质泥岩 | |
2 | 4 040.62 | 0.4 | 0.79 | 47.2 | 27.6 | 7.3 | 2.3 | 14.3 | |
3 | 4 041.74 | 0.8 | 0.54 | 11.0 | 5.7 | 2.2 | 1.9 | 78.0 | 铝土岩 |
4 | 4 042.54 | 0.2 | 0.54 | 0.9 | 2.1 | 2.2 | 94.0 | ||
5 | 4 042.97 | 0.2 | 0.38 | 19.5 | 29.8 | 3.0 | 47.1 | 铝土质泥岩 | |
6 | 4 044.99 | 0.0 | 0.53 | 0.7 | 3.4 | 1.8 | 93.6 | 铝土岩 | |
7 | 4 044.99 | 0.1 | 0.37 | 0.2 | 0.8 | 1.6 | 96.9 | ||
8 | 4 045.24 | 0.1 | 0.60 | 0.1 | 1.1 | 2.1 | 96.1 | ||
9 | 4 045.90 | 0.1 | 0.51 | 0.1 | 1.0 | 1.9 | 96.4 | ||
10 | 4 047.40 | 0.1 | 0.69 | 0.1 | 0.8 | 1.8 | 96.5 | ||
11 | 4 048.25 | 0.1 | 0.96 | 0.1 | 1.3 | 2.2 | 95.4 | ||
12 | 4 049.58 | 0.1 | 0.94 | 0.1 | 0.7 | 2.5 | 95.6 | ||
13 | 4 050.76 | 0.6 | 1.39 | 4.3 | 14.6 | 5.7 | 73.5 | ||
14 | 4 051.10 | 0.3 | 0.67 | 1.9 | 8.9 | 2.7 | 85.7 | ||
15 | 4 051.71 | 1.3 | 1.19 | 8.3 | 31.9 | 6.3 | 51.0 | 铝土质泥岩 | |
16 | 4 052.39 | 7.9 | 1.10 | 6.0 | 48.8 | 5.5 | 30.8 | ||
17 | 4 053.29 | 11.6 | 1.85 | 2.2 | 62.5 | 5.2 | 16.6 | ||
18 | 4 053.99 | 11.6 | 1.8 | 2.2 | 62.6 | 5.2 | 16.5 | ||
19 | 4 055.26 | 5.5 | 1.1 | 1.7 | 39.0 | 4.5 | 48.0 |
图2 L58井太原组含铝岩系上部代表性岩心照片(a)L58井,4 040.00 m,铝土质泥岩,水铝石3.1%,伊利石35.0%,高岭石59.3%;(b)L58井,4 040.62 m,铝土质泥岩,水铝石14.3%,伊利石27.6%,高岭石47.2%;(c)L58井,4 040.00 m,铝土质泥岩,铁质侵染高岭石隐晶团块状,水铝石隐晶为主;(d)L58井,4 040.12 m,铝土质泥岩,高岭石隐晶质分布(正交光) Fig.2 Representative cores photos of the upper part of the bauxite series from Taiyuan Formation in Well L58 |
图4 L58井太原组含铝岩系下部代表性岩心照片(a)L58井,4 040.00 m,铝土质泥岩,水铝石3.1%,伊利石35.0%,高岭石59.3%;(b)L58井,4 040.62 m,铝土质泥岩,水铝石14.3%,伊利石27.6%,高岭石47.2%;(c)L58井,4 040.00 m,铝土质泥岩,铁质侵染高岭石隐晶团块状,水铝石隐晶为主;(d)L58井,4 040.12 m,铝土质泥岩,高岭石隐晶质分布(正交光) Fig.4 Representative cores photos of the lower part of the bauxite series from Taiyuan Formation in Well L58 |
3.2 矿物类型
3.2.1 铝质矿物
图5 扫描电子显微镜下铝质矿物形态特征(a)C3-25-11井,3 806.65 m,铝土岩,水铝石重结晶;(b)L47井,4 104.0 m,铝土质泥岩,水铝石团块状、裂隙充填状;(c)图(b)水铝石能谱;(d)L47井,4 107.0 m,铝土岩,孔隙中充填六方柱状水铝石;(e)图(d)六方柱状水铝石能谱;(f)L58井,4 038.16~4 038.30 m,铝土岩,短柱状水铝石;(g)L58井,4 049.50 m,铝土岩,柱状水铝石;(h)L58井,4 045.90 m,铝土岩,假六方板状水铝石;(i)假六方板状水铝石能谱 Fig.5 Morphological characteristics of bauxite minerals under scanning electron microscopy |
图6 扫描电子显微镜下多种矿物形态特征(1)(a)L58井,4 047.40 m,铝土岩,针状水铝石;(b)图(a)针状水铝石能谱;(c)L58井,4 049.84 m,铝土岩,自生锐钛矿及针状水铝石;(d)L58井,4 047.40 m,铝土岩,柱状、针状水铝石及锐钛矿;(e)图(d)柱状水铝石能谱;(f)L58井,4 047.10 m,铝土岩,自生金红石及针状、柱状水铝石;(g)环探1井,4 459.14 m,泥质铝土岩,菱铁矿及与铝石环带及黄铁矿团块;(h)L47井,4 107.0 m,铝土岩,绿泥石、菱铁矿、黄铁矿及少量磷灰石共生;(i)图(h)菱铁矿能谱 Fig.6 Morphological characteristics of multi minerals under scanning electron microscopy(1) |
表2 不同形态水铝石能谱分析结果Table 2 Energy spectrum analysis results of different forms of boehmite |
类型 | 样品编号 | 井深/m | 测点 | Na2O/% | MgO/% | Al2O3/% | SiO2/% | TiO2/% | FeO/% |
---|---|---|---|---|---|---|---|---|---|
水铝石 | L58-4 | 4 047.1 | 4-1 | / | / | 96.81 | 1.74 | 1.45 | / |
4-2 | / | / | 98.59 | 1.41 | / | / | |||
4-3 | / | / | 95.24 | 3.37 | 1.39 | / | |||
4-4 | / | / | 96.66 | 1.07 | 2.27 | / | |||
4-5 | / | / | 100 | / | / | / | |||
4-6 | / | 0.72 | 94.59 | 3.26 | 1.43 | / | |||
4-7 | / | / | 95.18 | 1.37 | 3.45 | / | |||
4-8 | / | / | 97.73 | 2.27 | / | / | |||
4-9 | / | / | 96.45 | 2.02 | 1.53 | / | |||
4-10 | / | / | 95.49 | 2.95 | 1.56 | / | |||
4-11 | / | / | 94.28 | 2.85 | 2.87 | / | |||
L58-1 | 4 044.99 | 1-1 | / | / | 96.49 | 2.2 | 1.31 | / | |
1-2 | / | / | 95.13 | 3.63 | 1.24 | / | |||
1-3 | / | / | 95.49 | 1.6 | 2.91 | / | |||
1-4 | / | / | 94.53 | 3.53 | 1.94 | / | |||
1-5 | / | / | 96.76 | 1.89 | 1.35 | / | |||
L58-6 | 4 048.16~4 048.30 | 6-1 | / | / | 95.03 | 2.42 | 2.55 | / | |
6-2 | / | / | 98.25 | 1.75 | / | / | |||
6-3 | / | / | 95.18 | 1.89 | 2.93 | / | |||
6-4 | / | 1.34 | 97.09 | 2.91 | / | / | |||
针状水铝石 | L58-4 | 4 047.10 | 4-12 | / | 1.8 | 71.12 | 15.99 | 5.18 | 5.91 |
4-13 | / | 2 | 69.02 | 19.6 | 2.82 | 6.56 | |||
L58-1 | 4 044.99 | 1-6 | / | 2.35 | 69.77 | 19.43 | 4.34 | 4.11 | |
L58-4 | 4 047.10 | 4-14 | / | 3.43 | 66.15 | 20.43 | 6.71 | 3.28 | |
4-15 | / | 2.47 | 64.21 | 21.83 | 5.84 | 5.65 | |||
4-16 | / | 2.42 | 73.85 | 17.54 | 1.87 | 4.32 | |||
4-17 | 1.08 | 2.67 | 67.26 | 20.26 | 3.43 | 4.92 | |||
4-18 | 0.56 | 2.27 | 68.91 | 18.85 | 4.22 | 5.19 | |||
4-19 | / | 2.56 | 62.89 | 20.88 | 7.00 | 6.67 | |||
4-20 | 1 | / | 65.84 | 21.5 | 6.12 | 5.54 | |||
4-21 | / | / | 66.35 | 22.27 | 4.99 | 6.39 | |||
4-22 | / | / | 72.57 | 16.1 | 6.21 | 5.12 | |||
L58-6 | 4 048.16~4 048.30 | 6-5 | / | 2.87 | 67.41 | 22.02 | 2.9 | 4.8 | |
6-6 | / | / | 69.83 | 21.57 | 3.88 | 4.72 | |||
L58-1 | 4 044.99 | 1-7 | / | 2.2 | 72.05 | 18.4 | 3.48 | 3.87 | |
1-8 | / | 1.62 | 74.62 | 16.82 | 2.52 | 4.42 | |||
1-9 | / | 2.89 | 74.1 | 18.03 | 0.99 | 2.79 | |||
1-10 | / | 4.84 | 65.98 | 23.79 | 1.92 | 3.47 | |||
1-11 | / | 2.38 | 68.95 | 19.95 | 4.61 | 4.11 | |||
1-12 | / | 2.14 | 73.87 | 18.08 | 2.13 | 3.78 | |||
柱状水铝石 | L58-4 | 4 047.10 | 4-23 | 1.92 | 5.07 | 46.74 | 36.52 | 0.53 | 9.22 |
4-24 | 1.61 | 8.45 | 51.59 | 32.04 | 3.44 | 2.87 | |||
4-25 | 1.76 | 8.52 | 46.61 | 31.91 | 5.75 | 5.45 | |||
4-26 | 1.94 | 8.16 | 51.28 | 32.45 | 1.79 | 4.38 | |||
4-27 | 1.76 | 8.52 | 46.61 | 31.91 | 5.75 | 5.45 | |||
4-28 | 1.82 | 5.14 | 46.33 | 36.98 | 0.92 | 8.81 | |||
4-29 | 1.94 | 8.16 | 51.28 | 32.45 | 1.79 | 4.38 | |||
L58-3 | 4 045.9 | 3-1 | 1.03 | 4.08 | 49.49 | 34.86 | / | 10.54 | |
L58-6 | 4 048.16~4 048.30 | 6-7 | 0.89 | 4.24 | 47.48 | 34.11 | 1.82 | 11.47 | |
6-8 | 1.85 | 5.06 | 46.93 | 37.13 | 1.32 | 7.7 | |||
L58-4 | 4 047.10 | 4-30 | 1.64 | 4.95 | 47.47 | 35.32 | 0.91 | 9.71 | |
L58-2 | 4 045.24 | 2-1 | 1.47 | 3.53 | 50.87 | 33.81 | 1.05 | 9.27 | |
L58-5 | 4 047.40 | 4-31 | 1.31 | 3.63 | 43.63 | 37.54 | 2.53 | 11.36 | |
L58-6 | 4 038.16~4 038.30 | 6-9 | 0.65 | 3.69 | 42.41 | 34.13 | 4.01 | 15.11 | |
6-10 | 1.43 | 3.37 | 45.34 | 38.63 | 0.29 | 10.95 | |||
6-11 | 0.69 | 2.72 | 45.31 | 31.75 | 5.04 | 14.5 | |||
6-12 | 0.34 | 3.61 | 46.89 | 31.17 | 4.61 | 12.97 | |||
6-13 | 1.44 | 3.39 | 47.93 | 35.29 | 0.79 | 11.16 | |||
6-14 | 1.09 | 3.22 | 50.57 | 34.1 | 0.57 | 10.45 | |||
L58-2 | 4 045.24 | 2-2 | 2.06 | 5.11 | 49.33 | 34.84 | 0.79 | 7.87 |
3.2.2 钛铁质矿物
图8 扫描电子显微镜下多种矿物形态特征(2)(a)L58井,4 045.24 m,铝土岩,草莓状黄铁矿及天青石;(b)图(a)天青石能谱;(c)L47井,4 107.0 m,铝土岩,绿泥石晶间孔中黄铁矿;(d)L58井,4 041.74 m,泥岩,黄铁矿团块中包裹水铝石团块;(e)图(d)中水铝石能谱;(f)L47井,4 107.0 m,不同形态黄铁矿及柱状水铝石;(g)城3-25-11井,3 808.11 m,泥质铝土岩,斑状高岭石黏土矿物;(h)环探7,4 446.18 m,铝土岩,高岭石黏土矿物;(i)图(h)高岭石能谱 Fig.8 Morphological characteristics of multi minerals under scanning electron microscopy(2) |
图9 扫描电子显微镜下多种矿物形态特征(3)(a)L58井,4 059.63 m,泥质铝土岩,斑状伊利石黏土;(b)L47井,4 107.0 m,铝土岩,孔隙充填充填板状绿泥石及菱铁矿;(c)图b绿泥石能谱;(d)L47-1C井,4 145.80 m,铝土质泥岩,菱铁矿溶孔充填板状绿泥石;(e)L58井,4 048.16~4 048.30 m,铝土岩,石膏充填孔隙;(f)图(e)石膏能谱;(g)L58井,4 048.16~4 048.30 m,自生纤维状天青石;(h)图(g)天青石能谱;(i)L58井,4 049.84 m,铝土岩,斑状石膏 Fig.9 Morphological characteristics of multi minerals under scanning electron microscopy(3) |
图10 扫描电子显微镜下多种矿物形态特征(4)(a)L58井,4 048.16~4 048.30 m,黄铁矿及天青石充填孔隙;(b)L58井,4 049.50 m,岩盐矿物及锐钛矿;(c)图(b)岩盐能谱;(d)L58井,4 050.76 m,铝土质泥岩,片状高铝叶腊石;(e)图(d)高铝叶腊石能谱;(f)L47井,4 116.0 m,铝土岩,黄铁矿与磷灰石形态;(g)L58井,4 044.99 m,铝土岩,短柱状水铝石及针状水铝石、锐钛矿、黄铁矿共生;(h)L58井,4 047.10 m,铝土岩,锐钛矿包裹水铝石;(i)图(h)锐钛矿能谱 Fig.10 Morphological characteristics of multi minerals under scanning electron microscopy(4) |