0 引言
1 区域地质背景
2 样品和方法
3 实验结果
3.1 总有机碳含量
表1 贵州温水村剖面页岩岩石组成综合测试数据Table 1 Comprehensive test data of shale rock composition of Wenshuicun section, Guizhou |
样品编号 | TOC/% | X射线全岩矿物/% | ICP-AES元素/(μg/g) | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
黏土矿物 | 石英 | 长石 | 方解石+白云石 | 黄铁矿 | V | Ni | Ba | Sr | Al | U | Th | ||
WSC-3 | 5.41 | 29 | 63 | 6 | 1 | 0 | 60.17 | 4.76 | 1 966 | 20.28 | 45 700 | / | / |
WSC-4 | 4.78 | 30 | 65 | 3 | 1 | 0 | 89.35 | 5.3 | 1 862 | 26.36 | 66 100 | / | / |
WSC-4-2 | 2.6 | 27 | 66 | 6 | 1 | 0 | 16.33 | 2.92 | 1 430 | 15.22 | 15 500 | / | / |
WSC-5 | 2.17 | 26 | 65 | 7 | 1 | 0 | 92.06 | 6.72 | 2 315 | 37.43 | 69 600 | / | / |
WSC-6 | 1.44 | 36 | 54 | 9 | 1 | 0 | 61.03 | 14.57 | 1 828 | 32.80 | 58 400 | / | / |
WSC-7 | 1.11 | 23 | 68 | 8 | 1 | 0 | 56.46 | 14.72 | 1 359 | 30.33 | 61 300 | 21.88 | 5.56 |
WSC-8 | 3.22 | 37 | 52 | 8 | 2 | 0 | 78.61 | 9.42 | 1 096 | 32.89 | 69 100 | / | / |
WSC-9 | 1.26 | 39 | 51 | 7 | 2 | 0 | 63.69 | 12.00 | 2 637 | 44.57 | 81 700 | 16.06 | 6.35 |
WSC-10 | 2.92 | 34 | 58 | 6 | 1 | 0 | 84.89 | 20.85 | 1 007 | 32.28 | 66 500 | / | / |
WSC-11 | 2.81 | 17 | 46 | 35 | 0 | 0 | 47.90 | 11.80 | 976 | 97.06 | 72 700 | / | / |
WSC-11-1 | 1.41 | 21 | 49 | 28 | 0 | 0 | 63.07 | 13.35 | 2 149 | 74.81 | 66 000 | / | / |
WSC-11-2 | 1.11 | 19 | 47 | 32 | 0 | 0 | 62.83 | 6.45 | 1 102 | 69.82 | 77 200 | / | / |
WSC-12 | 1.71 | 19 | 44 | 35 | 0 | 0 | 53.45 | 6.48 | 1 063 | 74.95 | 77 400 | 24.35 | 15.38 |
WSC-13 | 2.92 | 20 | 44 | 34 | 0 | 0 | 57.17 | 17.12 | 1 084 | 71.17 | 73 300 | / | / |
WSC-14 | 2.84 | 23 | 41 | 32 | 0 | 3 | 53.93 | 17.34 | 741 | 69.42 | 78 300 | / | / |
WSC-16 | 3.05 | 21 | 41 | 35 | 1 | 0 | 65.02 | 6.88 | 1 017 | 87.61 | 69 800 | / | / |
WSC-17 | 3.31 | 19 | 41 | 38 | 0 | 0 | 60.70 | 7.26 | 1 042 | 91.95 | 73 100 | / | / |
WSC-18 | 3.5 | 20 | 43 | 35 | 0 | 0 | 69.97 | 7.98 | 1 214 | 82.92 | 58 400 | / | / |
WSC-19 | 3.1 | 18 | 45 | 34 | 1 | 0 | 65.6 | 5.17 | 1 018 | 99.12 | 65 500 | / | / |
WSC-21 | 3.46 | 19 | 43 | 36 | 0 | 0 | 72.22 | 12.67 | 318 | 82.3 | 70 800 | / | / |
WSC-22 | 3.43 | 19 | 45 | 34 | 0 | 0 | 73.43 | 9.66 | 975 | 90.53 | 70 000 | / | / |
WSC-23 | 3.33 | 18 | 43 | 37 | 0 | 0 | 76.65 | 20.24 | 403 | 81.23 | 66 300 | 18.62 | 9.93 |
WSC-24 | 3.03 | 17 | 39 | 34 | 4 | 5 | 55.22 | 35.36 | 331 | 116.1 | 63 900 | 21.28 | 9.48 |
WSC-26 | 3.13 | 17 | 41 | 30 | 5 | 5 | 67.02 | 36.25 | 343 | 103.2 | 63 700 | 34.47 | 16.72 |
WSC-28 | 3.26 | 42 | 31 | 22 | 4 | 0 | 40.37 | 4.05 | 463 | 41.2 | 24 400 | 30.67 | 9.98 |
平均值 | 2.81 | 24 | 49 | 23.64 | 1 | 0.52 | 63.49 | 12.37 | 1 190 | 64.22 | 64 188 | / | / |
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3.2 沉积构造特征
图2 贵州温水村剖面牛蹄塘组页岩沉积构造(a)距底5.5 m,块状构造,粒度、颜色、矿物组成无明显变化,整体呈均质特征;(b)距底10 m,水平纹层状构造,粒度、颜色、矿物组成出现突变现象,单层厚度在1 mm左右,间隔反复变化,发育层理; (c)样品WSC-17,块状构造,粒度、颜色、矿物组成无明显变化,整体均质发育;(d)样品WSC-19,水平纹层状构造,粒度、颜色、矿物组成出现突变现象,单层厚度小于1 mm,间隔反复变化; (e)样品WSC-18,块状构造,粒度、颜色、矿物组成无明显变化,整体均质发育; (f)样品WSC-9,水平纹层状构造,粒度、颜色、矿物组成出现突变现象,单层厚度大于1 mm,间隔反复变化 Fig.2 Shale sedimentary structure of Niutitang Formation in Wenshuicun section, Guizhou |
3.3 矿物组成
3.4 主、微量元素含量
4 讨论
4.1 页岩岩相类型
表2 贵州温水村剖面页岩岩石中硅成因表征含量参数值Table 2 The characteristic parameter values of Silico genesis in shale rocks of Wenshuicun section, Guizhou |
元素表征含量 | 样品编号 | ||||||
---|---|---|---|---|---|---|---|
WSC-7 | WSC-9 | WSC-12 | WSC-2 | WSC-24 | WSC-26 | WSC-28 | |
Si/% | 70.77 | 73.02 | 62.68 | 66.74 | 68.57 | 63.54 | 68.01 |
Fe/% | 0.25 | 1.77 | 1.07 | 0.61 | 0.25 | 0.10 | 0.22 |
Al/% | 6.13 | 8.17 | 7.74 | 6.63 | 6.39 | 6.37 | 2.44 |
Ca/% | 1.63 | 1.30 | 0.76 | 2.29 | 3.67 | 3.99 | 0.48 |
Si/(Si+Fe+Al+Ca) | 0.90 | 0.87 | 0.87 | 0.87 | 0.87 | 0.86 | 0.96 |
图3 贵州温水村剖面牛蹄塘组页岩三端元投点图(划分方案修改自文献[19])Ⅰ类为差脆性黏土质页岩;Ⅱ类为强脆性硅质页岩;Ⅲ类为高脆性碳酸盐岩质页岩;Ⅳ类为高脆性混合质页岩;Ⅴ类为中等脆性中黏土质页岩;Ⅵ类为中等脆性硅/黏土混合质页岩;Ⅶ类为中等脆性碳酸盐岩/黏土混合质页岩;Ⅷ类为高脆性硅/碳酸盐岩混合质页岩;Ⅸ类为高脆性中硅质页岩;Ⅹ类为高脆性中碳酸盐岩质页岩 Fig. 3 Three terminal element projection map of Niutitang Formation shale in Wenshuicun section, Guizhou(the division scheme was modified from the Ref.[19]) |
图4 贵州温水村剖面牛蹄塘组各类页岩岩相发育比例 Fig.4 Development proportion of various shale lithofacies of Niutitang Formation in Wenshuicun section, Guizhou |
4.2 页岩沉积环境
4.2.1 热液活动
表3 贵州温水村剖面页岩稀土元素含量Table 3 REE content in shale of Wenshuicun section, Guizhou |
元素含量 | 样品编号 | 北美页岩标准化值 /(μg/g) | ||||||
---|---|---|---|---|---|---|---|---|
WSC-7 | WSC-9 | WSC-12 | WSC-23 | WSC-24 | WSC-26 | WSC-28 | ||
Eu/(μg/g) | 0.94 | 1.14 | 1.45 | 1.00 | 1.14 | 1.38 | 1.15 | 2.0 |
EuN/(μg/g) | 0.47 | 0.57 | 0.73 | 0.50 | 0.57 | 0.69 | 0.58 | / |
Sm/(μg/g) | 2.00 | 3.40 | 6.73 | 4.59 | 5.15 | 7.09 | 5.31 | 7.0 |
SmN/(μg/g) | 0.29 | 0.49 | 0.96 | 0.66 | 0.74 | 1.01 | 0.76 | / |
Gd/(μg/g) | 1.80 | 3.26 | 6.53 | 3.51 | 3.88 | 5.74 | 4.30 | 6.1 |
GdN/(μg/g) | 0.30 | 0.53 | 1.07 | 0.57 | 0.64 | 0.94 | 0.70 | / |
δEu | 1.62 | 1.12 | 0.72 | 0.81 | 0.83 | 0.71 | 0.79 | / |
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4.2.2 古氧化还原条件
表4 贵州温水村剖面页岩中古氧化还原条件判别指标Table 4 Discriminant index of medieval redox conditions of shale in Wenshuicun section, Guizhou |
判别指标 | Vi/(Vi+Ni) | U/Th |
---|---|---|
范围值 | 0.61~0.94 | 1.58~3.84 |
平均值 | 0.84 | 2.47 |
指示结果 | 厌氧 | 厌氧 |
4.2.3 古生产力
4.2.4 古盐度
4.2.5 古水深
表5 贵州温水村剖面页岩古水深表征特征参数值Table 5 The characteristic parameter values of paleowater depth in shale rocks of Wenshuicun section, Guizhou |
参数 | 样品编号 | ||||||
---|---|---|---|---|---|---|---|
WSC-7 | WSC-9 | WSC-12 | WSC-23 | WSC-24 | WSC-26/ | WSC-28 | |
Zr/(μg/g) | 188.37 | 105.57 | 198.05 | 259.18 | 223.89 | 256.65 | 252.58 |
Al/(μg/g) | 61 300 | 81 700 | 77 400 | 66 300 | 63 900 | 63 700 | 24 400 |
(Zr/Al) | 0.003 | 0.001 | 0.003 | 0.004 | 0.004 | 0.004 | 0.010 |
Co/(μg/g) | 8.79 | 7.96 | / | / | 20.02 | 22.34 | / |
La/(μg/g) | 29.15 | 21.99 | / | / | 39.82 | 44.69 | / |
h/m | 22.59 | 22.79 | / | / | 110.44 | 129.83 | / |
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4.2.6 古气候
表6 贵州温水村剖面页岩常量元素含量及CIA值Table 6 Major elements and CIA values of shale in wenshuicun section, Guizhou |
样品编号 | 元素含量/% | CIA | |||
---|---|---|---|---|---|
CaO | Al2O3 | Na2O | K2O | ||
WSC-7 | 0.246 | 9.778 | 0.086 | 2.85 | 75.45 |
WSC-9 | 1.767 | 7.925 | 0.097 | 1.73 | 68.80 |
WSC-12 | 1.072 | 12.66 | 1.043 | 3.22 | 70.35 |
WSC-23 | 0.247 | 13.14 | 2.608 | 3.24 | 68.31 |
WSC-24 | 0.614 | 14.04 | 1.679 | 3.87 | 69.49 |
WSC-26 | 0.101 | 13.8 | 0.932 | 3.76 | 74.22 |
WSC-28 | 0.216 | 13.49 | 2.413 | 3.16 | 69.97 |