gilgais package:MASS R Documentation _L_i_n_e _T_r_a_n_s_e_c_t _o_f _S_o_i_l _i_n _G_i_l_g_a_i _T_e_r_r_i_t_o_r_y _D_e_s_c_r_i_p_t_i_o_n: This dataset was collected on a line transect survey in gilgai territory in New South Wales, Australia. Gilgais are natural gentle depressions in otherwise flat land, and sometimes seem to be regularly distributed. The data collection was stimulated by the question: are these patterns reflected in soil properties? At each of 365 sampling locations on a linear grid of 4 meters spacing, samples were taken at depths 0-10 cm, 30-40 cm and 80-90 cm below the surface. pH, electrical conductivity and chloride content were measured on a 1:5 soil:water extract from each sample. _U_s_a_g_e: gilgais _F_o_r_m_a_t: This data frame contains the following columns: '_p_H_0_0' pH at depth 0-10 cm. '_p_H_3_0' pH at depth 30-40 cm. '_p_H_8_0' pH at depth 80-90 cm. '_e_0_0' electrical conductivity in mS/cm (0-10 cm). '_e_3_0' electrical conductivity in mS/cm (30-40 cm). '_e_8_0' electrical conductivity in mS/cm (80-90 cm). '_c_0_0' chloride content in ppm (0-10 cm). '_c_3_0' chloride content in ppm (30-40 cm). '_c_8_0' chloride content in ppm (80-90 cm). _S_o_u_r_c_e: Webster, R. (1977) Spectral analysis of gilgai soil. _Australian Journal of Soil Research_ *15*, 191-204. Laslett, G. M. (1989) Kriging and splines: An empirical comparison of their predictive performance in some applications (with discussion). _Journal of the American Statistical Association_ *89*, 319-409 _R_e_f_e_r_e_n_c_e_s: Venables, W. N. and Ripley, B. D. (2002) _Modern Applied Statistics with S._ Fourth edition. Springer.