Mineral deposits are usually classified and described by the metals or the substances which they contain; for instance, deposits of copper are described together, with little or no effort to separate them into genetic groups. Where a genetic treatment has been attempted it appears to me to have failed in not giving due weight to the physical conditions attending the genesis. Furthermore, it is the custom to divide the mineral deposits into two groups—the metallic and the non-metallic—a line of division which can hardly be defended except on the ground of long-established habit.

In Besprechungen des „Lehrbuchs der Erzlagerstättenkunde" 1941, Band I und in Zuschriften von Kollegen wurde ich wiederholt aufgefordert, einen kurzen Leitfaden über Erzlagerstätten zu schreiben. Auch beim eigenen Unterricht und besonders bei der Fernbetreuung der in der Wehrmacht eingezogenen Studenten machte sich immer mehr dieser Wunsch bemerkbar. Ich lege nun diesen kurzen Leitfaden vor, der etwa Umfang und Form hat, wie es sich zuletzt in einer zweisemestrigen Kurzvorlesung herausgebildet hatte. Leider gestattete die heute gebotene Knappheit im Umfang die Einschaltung von Abbildungen nicht. Sie hätten in so reichlicher Menge beigegeben werden müssen, daß das Buch dreimal umfangreicher geworden wäre. Es ist beabsichtigt, später einmal einen Atlas zu den Erzlagerstätten gesondert herauszugeben, der zur Illustrierung dieser „KurzVorlesung" dienen soll. Aus demselben Grunde wurde auch auf zusammenhängende Ausführungen über Lagerstättenprovinzen, Metallepochen und ihre Beziehungen zur Geotektonik und zum Geomagmatismus verzichtet, die nur mit vielen Karten verständlich werden. Auch die geochemische Verteilung der Elemente konnte deshalb nicht berücksichtigt werden.

We used samples from six Finnish ore deposits to evaluate the efficiency of sample pretreatment procedures — crushing, splitting and grinding — and to compare three analytical methods based on the atomic absorption determination of gold following: (1) classical lead fire assay (FA); (2) the aqua regia leach (AR) followed by Hg coprecipitation of Au; and (3) the sodium cyanide (NaCN) leach. Sample size used for the method comparison is 20 g. The Au deposits and ore types were: Suurikuusikko and Osikonma¨ki, refractory ores in which Au is associated with arsenopyrite and pyrite; Pampalo and Kutemaja¨rvi ores with metallic Au and Au tellurides; and Jokisivu and Pahtavaara ores containing coarse-grained metallic Au. After crushing, the samples were split into three parts, one of which was put aside into storage. Two splits were further divided into two subsamples which were ground to two grades of fineness (<0.03 and <0.06 mm). The four subsamples thus obtained were analysed for Au using the three analytical methods. Each determination was performed five times on each of the four subsamples. According to t-tests on the FA results of the two splits, crushing and splitting produced samples of equal Au content in all six cases. Grinding to a finer grain size gave a significant difference in Au results only for the Pahtavaara ore sample. If the FA results are assumed to represent 100% recovery of Au, we obtained greater than 95% recoveries for all but the Suurikuusikko sample (87% recovery) by the AR leach method. We also obtained recoveries of over 95% by the NaCN leach method for the Pampalo, Kutemaja¨rvi and Pahtavaara samples, whereas recoveries for the other three samples varied between 73 to 92%. The AR leach was also performed on 1-g samples and the NaCN leach on 250-g samples. For three of the ore samples, decreasing sample size from 20 g to 1 g did not cause a significant difference in the variance of the Au results. Increasing the sample size from 20 g to 250 g significantly improves the representativity of only the Pahtavaara sample. For the Kutemaja¨rvi, Pahtavaara and Jokisivu ores, a sample larger than 250 g is needed in order to obtain a precision equivalent to that for reference samples.

Рассмотрены редкие в природе шлировые пегматиты в массиве щелочных и субщелочных гранитов, зональность строения и особенности размещения. В составе рудных концентраций пегматитов на электронном сканирующем микроскопе с энергодисперсионным спектрометром установлен малоизвестный самирезит в виде псевдоморфоз по другому редкометалльному минералу состава Th-Y-Zr-Nb.

При моделировании геологических разрезов тела в виде штоков, тру­бок взрыва могут быть аппроксимированы однополюсным магнитом. Такой класс моделей характеризуется наименьшим числом искомых пареметров, а именно,глубиной залегания магнитоактивного источника и углом его нак­лона или направлением намагниченности. Решение обратной задачи сводит­ся, в первую очередь, к определению глубины залегания, для оценки кото­рой разработан ряд экспресс-способов

Conventionally, geochemical exploration for gold is based on the assumptions that (1) gold is chemically inert in surficial environments; (2) gold occurs mainly in discrete grains; and (3) gold is transferred by mechanical means to form clastic dispersion halos and dispersion trains. Consequently, the commonly adopted methodology has been (1) to determine gold in heavy mineral concentrates; (2) to use large samples in order to improve the reproducibility of gold analyses; (3) to use high detection limits and thresholds; and (4) to determine total gold contents and pathfinder elements in the samples. However, these methods are not always successful in locating gold deposits, and they have limited application in the search for buried or blind deposits.

In China, studies of the distribution and migration of particulate and ultrafine gold indicated that (1) gold is active and mobile in surficial environments; (2) gold occurs not only as discrete grains, but also as ultrafine particles and other complex forms; and (3) regional low-concentration gold anomalies as well as local anomalies over buried gold deposits originate from ultrafine gold and other complex forms of gold. The methodology developed in China for regional and local geochemical gold exploration is based on this experience. Results of investigations around two gold deposits in China are presented.

Включение в традиционную схему отработки золоторудных месторождений процесса подготовки техногенных месторождений формирует принципиально новый подход к решению проблемы рационального использования недр. Данное стратегическое направление позволит существенно укрепить сырьевую базу действующих предприятий и активизировать инвестиции на вовлечение в оборот коренных месторождений золота.

В книге описываются природные богатства Мирового океана и методы их освоения, анализируются различные трудности, стоящие на пути дальнейшего проникновения человека в недра моря. Особое внимание автор уделяет тех-нике и технологии разведки и добычи минерального сырья со дна и из недр морей и океанов, показу достижений со временной науки в этой области.