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Authors
Affiliations
1 Department of Applied Geology, Indian School of Mines, Dhanbad-826 004, IN
2 Mineral Exploration Corporation Limited, Nagpur-440 006, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 46, No 2 (1995), Pagination: 139-147
Abstract
The Phosphorite deposit (74°25' to 74°26'E : 22°58' to 23°00'N), Jhabua district, Madhya Pradesh, is one of the productive deposits in India, and has evoked great interest with regard to its phosphogenesis, stromatolite association and resource potential. It is a sedimentary-stromatolite type of deposit within the Precambrian metasediments of the Aravalli Supergroup and represents the southern extension of the well known Jhamarkotra phosphorite deposit of Rajasthan. The geological set-up shows that the phosphorite occurs in two separate host rocks of older carbonate and younger chert sediments. Geological Survey of India (Khan et al. 1979), using conventional cross-section method, estimated the weighted average grade of the Khatamba Blocks from the available 21 intersections in 12 trenches as 28.60% P2O5. In the present study, statistical modelling of exploration data of the Khatamba Blocks, using histogram plots, probability diagrams and skewness and kurtosis parameters for 20 intersections reveals a 3-parameter log-normal distribution for accumulation (grade-thickness) and thickness values. The graphical estimate of the average grade from the probability diagrams is 29.59% P2O5 and that estimated by computer is 29.40% P2O5.
A computer programme ONEPOP.FOR in interactive FORTRAN77 has been developed for statistical modelling of the exploration data. Using this approach the grade. estimated for phosphorite deposit of the Khatamba Blocks shows a marginal increase in the value of average grade of P2O5, content as compared to the estimate made by conventional method.
Keywords
Stromatolite, Phosphorite, Economic Geology, Statistical Geology.
