Igneous rocks exposed in the southern Heritage Range include two diabasic sills (100 m and 300 m thick), three gabbroic stocks (outcrop areas each <0.5 km 2 ), a spessartite lamprophyre plug (200 m diameter), a 10-km 2 sanidine quartz phytic dacite stock, and numerous aphanitic to porphyritic dikes and lava flows. Lava flows that are largely basaltic, but range in composition from basalt to alkali rhyolite, compose about 10 to 15 percent of the 1,000-m thickness of the Liberty Hills Formation of the Heritage Group. Eighty-four samples have been analyzed for major, minor, and trace elements by x-ray fluorescence. Field relations and comparison of chemical composition of intrusive and extrusive rocks suggest that all igneous rocks in the southern Heritage Range except the dacite stock were emplaced in Cambrian time; all have undergone pumpellyiteactinolite or greenschist facies metamorphism. A four-point Rb-Sr isochron yields a mid-Devonian (369 + 18 Ma) emplacement age for the dacite stock. The extrusive igneous rock suite is dominated by basalts but also includes rhyolites, dacites, and sparse andesites and is thus bimodal. The relict primary mineralogy, distribution of alterationresistant trace elements (Nb, Ti, Y, Zr), and incorporation within a thick sequence of carbonate and clastic sedimentary rocks all suggest that the mafic igneous rocks are continental basalts whose original chemical compositions were largely mildly tholeiitic or transitional between tholeiitic and alkali basalt; some calc-alkaline traits are also evident. Discrimination diagrams based on alteration-resistant trace elements and distribution of large ion lithophile elements (Ba, Rb, Sr) suggest that the felsic and intermediate rocks also possess tholeiitic, calc-alkaline, and alkaline traits. Age relations and comparison of chemical compositions indicate that the southern Heritage Range igneous rocks are not correlative with either the Jurassic Ferrar Supergroup or the Jurassic Kirwan Volcanics of the Transantarctic Mountains. The most likely possible correlatives might be diabasic sills and dikes and subordinate plugs and sills of felsic porphyry intrusive into the upper Precambrian Patuxent Formation, which crops out in the Neptune Range of the Pensacola Mountains 500 km to the southeast.

The paper discusses modern views of the structure of the main producing plays in the southern Siberian Platform: Riphean, Vendian, and Lower Cambrian. The major zones of oil and gas accumulation have been distinguished. Forecast resources have undergone differentiated expert evaluation, and methods for their development have been recommended.

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On the basis of experimental studies of the temperature fields over a permeable plate during ice-water sublimation from it into a vacuum, we propose an explanation for the mechanism of heat and mass transfer.

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