Fractal Properties of Various Clay Minerals Obtained from SEM Images

Table 1

Interpretation of PSD, lacunarity, and fractal dimension analyses for the internal pore space of different clay groups and dissolution holes obtained from the box counting method.

	Kaolinite A	Kaolinite B	Chlorite A	Chlorite B	Smectite A	Smectite B	Dissolution holes A	Dissolution holes B
SEM image resolution (μm)	0.250	0.187	0.294	0.130	0.055	0.100	0.197	0.250
Fractal dimension ()	1.63	1.56	1.66	1.51	1.53	1.85	1.63	1.65
Correlation coefficient	0.9981	0.9974	0.9978	0.9985	0.9857	0.9970	0.9979	0.9980
Lacunarity ()	0.55	0.63	0.55	0.99	0.82	0.18	0.56	0.62
Circularity (average of all pores)	0.44	0.41	0.56	0.48	0.59	0.63	0.71	0.76
Box size range (),	[5-211]	[5-144]	[5-233]	[5-185]	[5-259]	[5-260]	[5-259]	[5-239]
Perimeter-area correlation	0.9308	0.9365	0.8695	0.8475	0.9327	0.9642	0.9456	0.9553
Processed image size (pixels)
Processed image size (μm^2)	27600	15422	38170	7463	1336	4416	17138	27600
Pore count density (per 100 μm^2)	2.25	1.31	2.72	5.44	50.46	61.30	8.17	4.88
Average pore size density (μm^2)	3.92	1.96	3.03	0.75	0.01	1.02	0.75	1.27
Average perimeter (μm)	11.86	8.89	8.23	4.36	1.42	4.26	3.56	4.16
Pore count	620	202	1040	406	674	2707	1400	1346
Pore size distribution range (μm^2)	[0.06-87.69]	[0.03-23.0]	[0.08-64.0]	[0.05-14.57]	[0.003-2.62]	[0.01-44.54]	[0.04-32.83]	[0.06-119.75]
Perimeter range (μm)	[0.7-233.4]	[0.5-55.75]	[0.8-63.2]	[0.7-21.6]	[0.015-12.02]	[0.28-52.43]	[0.55-38.45]	[0.7-99.97]