Geological sources

An explosion rupturing an ammonia separator (still) in an ammonia production unit, probably because mercury vapour from geological sources entered with hydrogen syngas originating from natural gas and reacted to give explosive nitride deposits. The separator remains crackled when scraped [1]. For a more academic study of the effects of mercury on ammonia plants, including embrittlement and corrosion, as well as explosive deposits [2],... 

As the field of chemistry developed, so did the interest in the chemistry of soil. This was natural because the early chemists extracted elements from geological sources and, in the broadest sense, from soil itself. In fact, the development of the periodic table required the extraction, isolation, and identification of all of the elements, many of which are found abundantly in soil. 

SpycketeUe G, Gteinet AG, Albrecht P, Ourisson G, Aromatic hydtocarbons from geological sources. Patt 111. A tettahydrochrysene derived from tritetpenes, in recent and old sediments 3,3,7-ttimethyl-l,2,3,4-tettahydrochtysene,/ Chemical Research 12 330—331, 1977. 

SpycketeUe G, Gteinet AG, Albtecht P, Outisson G, Aromatic hydrocatbons from geological sources. Part IV. An octahydtochrysene derived from tritetpenes, in oil shale 3,3,7,12a-tetramethyl-l,2,3,4,4a,l l,12,12a-octahydrochrysene, / Chemical Research 12 332—333, 1977. 

Industrial emissions collectively accounted for only 5% of the particulate mass, a result that was not surprising given that these sources were well controlled before field sampling began. Some industrial source Impacts, however, may not have been identifiable because of emissions that chemically resembled geologic sources. 

Traditionally, archaeological chemistry has been restricted almost en-tirely to the study of problems for which the only remaining evidence was the material to be analyzed. For example, earlier studies in our laboratory which provided results that allowed identification of the geological sources of Hopewell obsidian artifacts (I) are what could be called classical archaeological chemistry. Must we, however, restrict archaeological chemistry to periods and areas where artifacts are the chief sources of information and avoid problems of importance in more recent times simply because written records exist Clearly, the significance of the problem to be studied should be the criterion, and two of the three studies reported here indicate a close and productive interaction between... 

Figure l. Comparison ofINAA elemental ratios for the four major western Mediterranean Island obsidian sources. Only geologic source samples are... 

Locations for the geological sources mentioned in this study are shown in Figure 1. Table I lists the geographic coordinates. Descriptions of the sources are presented here. 

During the past 15 years, archaeologists have identified a dozen geological sources of obsidian in southern Peru which were previously unknown. Fourteen compositional profiles have been recognized for these twelve sources. It appears that only ten of the sources were exploited prehistorically and that three of the sources, Chivay, Quispisisa, and Alca account for more than 94% of the Prehispanic obsidian used in Peru. 

Donato, M.M., Lamothe, PJ. and Sanzolone, R.F. (2004) Geologic sources and geochemical mechanisms of arsenic contamination in southwestern Idaho ground water preliminary results. Abstracts with Programs-Geological Society of America, 36(4), 32. 

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