From ancient times to the present day, gold has been valued by humans. Egypt was the principal gold-producing country in ancient times. Coptos, the present Quft on the eastern side of the River Nile, was the chief town of the Nomos of Harawi and was once politically important. In the eleventh dynasty (2133e1991 BC) it was overshadowed by Thebes, 50 km to the south, which became the capital of the Middle Kingdom (2133 BC) of ancient Egypt, the present-day Luxor (Figure 1.1).

Gold-copper-bismuth deposits of the Tennant Creek district, Northern Territory, Australia, are distinctive as some of the highest grade deposits within the Fe-oxide Cu-Au global family. They are unified by an association with epigenetic magnetite ± hematite - rich 'ironstones' that are hosted by a sequence -I860 Ma, low metamorphic grade, Fe-oxide rich greywacke, siltstone and shale. While many of the high grade gold orebodies are dominated by magnetite - chlorite ± minor hematite, muscovite and pyrite, there are significant variations representing a spectrum of styles from reduced (pyrrhotite-bearing) Cu-Au-Bi deposits to oxidised hematitic Au-Bi(Cu) deposits. Shear-hosted Au-Cu mineralisation outside ironstones further adds to the diversity of styles present in the district. Ironstones predated syn- to late-deformational ~1825-1830 Ma introduction of Au, Cu and Bi in ~-300-350°C, acidic, low-moderate salinity or hypersaline fluids, which were in places carbonic and nitrogenous. The very wide range of oxidation-reduction conditions during ore deposition across the district is interpreted as the product of both reduced (magnetite ± pyrrhotite stable, H2S > S04=) and oxidised (hematite stable, S04= > H2S) fluids reacting with ironstones and/or mixing. Oxygen and hydrogen isotope data point to an hybrid ore fluid source with input of evolved surficial or formation waters, whereas Sm-Nd reconnaissance data and sulfur isotope compositions are consistent with contributions from igneous sources.

Среди обширного материала из северо-двинских раскопок, оставшегося после смерти проф. Б. П. Амалицкого, имеется ряд скелетных остатков, которые могут быть отнесены к Формам из гр. Gorgonopsia Lyd. Из них два почти полных скелета в свое время были монтированы покойным профессором и выставлены в С.-Петербурге, один в 1900 г.5 (гр. Д»1 29), другой несколькими годами позже (IT>. Дя 97). Оба экземпляра были обозначены одним наименованием — Inostrancevia Alexandri Amal. Осталась также незаконченная рукопись покойного профессора с черновым наброском описания обоих скелетов, а равно еще одного черепа (гр. Д!> 70) и нескольких разрозненных костей, отнесенных Амалидким к тому же виду Inostrancevia. Им же были заготовлены несколько соответствующих Фотографий и три. прилагаемые нами, Фототипические таблицы (табл. I, I I и III). <...>

Grade control and ore/waste delineation in open pit mining operations was traditionally based on the comparison of estimated grades with an economic cutoff. In the 1990s, an alternative approach to ore selection was applied and established, taking into account financial indicators through the so-called economic classification functions in combination with grade uncertainty assessment.