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Terra Nova, 24, 326–332, 2012 Abstract Karst bauxites occur at a Late Cretaceous hiatus on a Bahamian‐type platform in Southern Apennines, Italy. In contrast to the well‐defined stratigraphic context, their origin remains controversial. Detrital zircon grains preserve textures and Th/U ratios consistent with crystallization from a melt, occasionally around older cores. U‐Pb isotopic data, collected using SHRIMP II, record several age populations. The youngest (∼90 Ma) falls into the age interval of bauxite formation as defined by stratigraphic criteria. The zircons must therefore be derived from a contemporary Cretaceous volcanic source. The older zircons may be interpreted as xenocrysts associated with the Cretaceous magmas or derived from different sources. Because the bauxite occurs on a isolated carbonate platform, the grains must come from far away sources, most probably transported by wind. The age, palaeogeography and inferred Cretaceous wind pattern are consistent with a prevailing origin from the Dinaric and Carpatho‐Balkan orogenic belts, with its Cretaceous bimodal volcanism.

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Mass spectrometer analyses of a number of mixtures such as ethylene oxide, ethylene, and carbon dioxide; alkyl iodides; aliphatic chlorides, ethers, and hydrocarbons; silicanes; and water, ether, and alcohol'are presented to show the utility of the instrument when used to analyze organic substances other than the usual hydrocarbons. The analysis of gas samples as small as 10 ml. and the qualitative identification of polymers and elastomers are discussed, and examples are given of organic elementary analysis for carbon, hydrogen, oxygen, sulfur, and nitrogen. solidated Engineering Corporation mass spectrometer, model 21-101) used throughout were: ionizing current 46 microamperes; ionizing voltage 50 volts; ion accelerating voltages at m/e 32,1342 or 2340 volts. ANALYSES OF GASEOUS MIXTURESAlthough a considerable amount of published information is available on the analysis of paraffin and olefin hydrocarbons in petroleum gases by mass spectrometry, the authors have found this instrument equally versatile in analyzing other compounds that are not ordinarily encountered in petroleum refining. For instance the infrared-inactive homopolar diatomic gases such as hydrogen, nitrogen, and oxygen, as well as other nonhydrocarbon gases, can usually be resolved by this means even in complex mixtures. Table IV, for example, shows an analysis of a mixture of ethylene oxide, ethylene, propane, nitrogen, oxygen, and carbon dioxide. In the case of this mixture, although the primary interest was centered about ethylene oxide, the mass spectrometer record provided complete data for a total analysis, which if attempted by conventional chemical methods would have been considerably more time-consuming.Another example of interest is the analysis of such sulfur compounds as hydrogen sulfide, carbon disulfide, sulfur dioxide, carbonyl sulfide, and methyl mercaptan (methanethiql). A complex mixture containing all five compounds can be easily and quickly resolved by means of the spectrometer in a fraction of the

A method which utilizes sintered disk valves is presented for both the storage and use of liquid and gaseous calibrating compounds and mixtures. A technique also Involving a sintered-disk valve is presented for preparing small quantities of liquid mixtures having accurately known compositions. These methods should find considerable application in the calibration and testing in infrared and mass spectrometers, particularly where calibrating compounds are available only in very small quantities. THE recent application of mass and infrared spectrometers to the analysis of complex hydrocarbon mixtures necessitates the repeated use of large numbers of highly purified compounds for calibrating and testing purposes. At present the methods in use for handling such compounds, which in many cases are available only in small quantities, are only partially adequate and often excessively time-consuming. There appears to be a need for methods of storing and using these calibrating compounds, and for preparing, storing, and using known mixtures of them which would be more rapid than existing methods, W'ould handle liquids as well as gases in a uniform manner, w'ould be free from the disadvantages common to the use of stopcocks, and would tend to conserve the limited supplies of pure hydrocarbons available.Principle of Method. The usefulness of the sintered-glass disk valve for introducing calibrating compounds into a mass spectrometer was originally proposed and successfully demonstrated by Hunter (S). The extension and development of this technique have proved highly successful, and it is felt that the principle may be applied equally well to infrared spectrometers. The control of gas flow by means of such sintered-glass disks has been proposed several times, particularly by Pyrtz (ß), Stock(5, 7), and Prausnitz {5). The disks used are porous to gases and liquids in general, but nonporous to mercury. Material may be transferred simply by touching together two sintered disks, thereby displacing the mercury seal covering them and allowing flow to take place through the disks.