TY - JOUR N2 - The article describes the influence of anomalous values and local variability on the structure of variability and the estimation of deposit parameters. The research was carried out using statistical and geostatistical methods based on the Pb accumulation index in the shale series in part of the Cu-Ag ore deposit, LGCD (Lubin-Głogów Copper District). The authors recommend the use of a geostatistical tool, the so-called semivariogram cloud to determine the anomalous values. Anomalous values determined by the geostatistical method and removed from the dataset have resulted in a significant reduction of the relative variability of data, which is still very large in the case of the analyzed parameter or parameters with similar statistical features such as extreme variability and strongly asymmetric distribution. Calculations of the resources of this element can be treated only as estimates and formally classified to category D. The hypothetical assumption of the absence of sampling errors, resulting in a decrease in the magnitude of local variation, leads to a certain reduction of the median error of resource estimates. However, they are still high (> 35%). This is due to the large natural variability of the accumulation index of Pb on the local observation scale. The current method for collecting samples from mine workings of the Cu-Ag deposits in the Lubin-Głogów Copper District (LGCD), aimed at the proper assessment of copper resources, the Cu content, and at estimating the quality of copper output, makes it impossible to achieve an accuracy of estimates of Pb resources similar to that obtained for the main metal. Theoretically, this effect can be achieved by a strong concentration of the sample collection points and thanks to a multiple increase in the samples weight; this, however, is unrealistic for both economic and organizational reasons. It is therefore to be expected that the assessment of Pb resources and other accompanying elements of similar statistical features (e.g. As), located in parts of the deposit where mining activities are to be carried out, will be subject to significant errors. L1 - http://journals.pan.pl/Content/109349/PDF/auguscik-mucha.pdf L2 - http://journals.pan.pl/Content/109349 PY - 2017 IS - Nr 100 EP - 20 KW - Cu-Ag ore deposit LGCD KW - semivariogram KW - anomalous values KW - local variability KW - lead A1 - Auguścik, Justyna A1 - Mucha, Jacek PB - Instytut Gospodarki Surowcami Mineralnymi Polskiej Akademii Nauk CY - More info at Journal site: https://min-pan.krakow.pl/wydawnictwo/czasopisma/zeszyty-naukowe-instytutu-surowcami-mineralnymi-i-energia-pan/ https://min-pan.krakow.pl/wydawnictwo/wp-content/uploads/sites/4/2018/02/Wskazowki-ZN-ang-2018.pdf DA - 2017 T1 - The influence of anomalous values and local variability on the structure of variability and the estimation of deposit parameters SP - 7 UR - http://journals.pan.pl/dlibra/publication/edition/109349 T2 - Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi Polskiej Akademii Nauk ER -