Sapphires in Upper Bari to occur in active Busang stream deposits. The sapphires gravel deposits associates with heavy minerals such as zircon, garnet, epidote, ilmenite, chrom diopside, chromite and magnetite. The colour varies from red-rose to light-blue, greenish blue, greenish grey, pink, and white. Some of the sapphires are opaque but suitable for cabochon polished gemstone…
Industrial minerals in Indonesia are widely distributed, although in some cases the deposits are not sufficiently abundant to be exploited in large scales. The Directorate of Mineral Resources is assigned to conduct mineral explorations and inventories, and has a long experience on these jobs. The mineral deposits will be discussed include bentonite, kaolin, natural zeolite, di…
The eminent volcanologist T.A. Jaggar in no way exaggerated the significance of volcanic phenomena when je stated that his conception of volcanicity was of a process which is everywhere at work within and beneath the earth’s crust. Today there are more than 500 volcanoes which are still active or at which activity has been recorded during historic times, while the number of extinct volcanoes,…
Salah satu kegunaan obsidian-perlit adalah sebagai bahan baku pembuatan agregat ringan )light weight aggregates) yang kini sedang dibutuhkan pemerintah dalam rangka meningkatkan pembangunan rumah murah untuk rakyat. Selain itu, dengan adanya kemajuan teknologi, baik dalam metoda pemrosesannya maupun dalam penggunaanya, bahan galian industri akan semakin penting artinya.
Volcanism is one of nature’s primal spectacles. It commands our attention, whether for its awesome power, its danger, or its beauty. The years 1975-85 brought dramatic examples of volcanism – from the 1980 blasts of Mt. St. Helens, through the continuing lava river of Hawaii, to the tragic eruption of Colombia’s Nevado del Ruiz in 1985 and these have been abundantly documented by the news…
The monograph Geothermal Resources: An Energy Alternative by Harsh K. Gupta presents for the first time a readable, coherent account of all facets of geothermal energy development. The development of alternative, renewable energy resources during the past decade has been spurred by a crunch in the supplies of traditional hydrocarbon energy resources, which have previously been inexpensive and r…
This book is based at the level of a bachelor’s degree in physical science. Experience at Standford indicate that a one-semester class in engineering systems theory provides helpful additional background. It will be readable to a general science and engineering audience and should be useful to anyone interested in computer modelling and data analysis in physical sciences.
The Copper - Gold Porphyry of Kaputusan shows a zoning of hydrothermal alteration. A potassic core is surrounded by a propylitic halo. A younger pyrite-rich quartz-sericitic alteration partly overprints the older alterations. Analyses from channel • samples from superficial trenches show that copper is mostly leached in the areas of quartz-sericitic alteration. Analysing…
The Copper - Gold Porphyry of Kaputusan shows a zoning of hydrothermal alteration. A potassic core is surrounded by a propylitic halo. A younger pyrite-rich quartz-sericitic alteration partly overprints the older alterations. Analyses from channel samples from superficial trenches show that copper is mostly leached in the areas of quartz- sericitic alteration. Analysing the wa…
This report which describes the geological setting and physical features of the most important coal deposits in Central Sumatra is based on detailed studies over 13 years by the Sub-Directorate of Coal and Peat Exploration, which is the most experienced and well equipped government coal exploration group in this country. The Sub-Directorate of Coal and Peat Exploration within the Directorate…