hich formed in the Late Carboniferous–Early Permian. The deformations have been dated by the 40Ar–39Ar method on the basis of syntectonic micas and amphiboles, whose structural and spatial positions have been determined in oriented thin sections. The geometrical analysis of macro- and microstructures has revealed three development stages of the structures, which followed one another in progressive deformation. The first (thrust-fault) stage (316–310 Ma) comprised a group of N-verging thrust sheets. In the second (fold deformation) stage (305–303 Ma), they were folded. The third (strike-slip fault) stage (286 Ma) comprised high-angle shears, along which V-shaped blocks were squeezed westward from the most compressed areas. All the structures developed under near-N–S-trending compression. The thrusting in the Tunka bald mountains was coeval with the major shear structures in the eastern Central Asian Fold Belt (Main Sayan Fault; Kurai, Northeastern, and Irtysh crumpled zones, etc.). Also, it was simultaneous with the formation of continental-margin calc-alkalic and shoshonite series (305–278 Ma) as well as that of the alkali and alkali-feldspar syenites and granites (281–278 Ma) of the Tarim mantle plume in the Angara–Vitim pluton, located near and east of the studied region. Thus, the simultaneous development of the Late Paleozoic structures, active-margin structures, and plume magmatism in southern Siberia might have resulted from the global geodynamic events caused by the interaction between the tectonic plates which formed the Central Asian Fold Belt.

Detailed geologic surveys (including mapping, drillings, trenches, and mineralogical and chemical analyses) have delimited a new giant lateritic bauxite deposit with 642 million metric tons (Mt) of 42.7% Al2O3 (available) in the world-renowned Amazon Province, northern Brazil. The mineral resource is part of a mature laterite profile and consists of reddish to mottled clay at the base that narrows upward to massive bauxite, followed by ferruginous bauxite, and is capped by an iron horizon (nodular and columnar ferruginous crust) and nodular bauxite with a clayey matrix; a thick clay cover sealed the profile after abrupt contact.

As a member of the Danish Government Expedition to East Green­ .fi. land in 1 926-27 under the leadership of Dr. LAUGE Kocu I had ample opportunity of studying the sedimentary deposits within the Scoresby Sound area, especially the Jurassie beds in Jameson Land and Liverpool Land. The present paper deals with the Lias, which l subjected to a particular investigation. It is rny p leasant duty to thank the leader of the expedition, Dr. LAUGE Kocu, for p leasant company and much unselfish assistance during the expedition and for handing over to me for description a number of Liassic fossils from Liverpool Land. I am also indebted Lo Dr. ToM HARRIS, Cambridge, my fellow-member on the expedition, who has p laced valuable Liassic material collected in J ameson Land at my disposal . Finally, my acknowledgements are due to my Greenlandish assistants, who with great zeal assisted me in my work, notably MIKAEL Ku:sAK, Eu l'iAPARTOK, and JoiL\:S ABELSE:s. <...>

The East Indies have long been renowned as a source of profuse and beautifully preserved Middle Jurassic ammonites. The fossil localities are widely scattered. from the Sula Islands in the west to New Guinea in the east and Timor-Roti in the south . Their faunas have been extensively described. and the older accounts were critically reviewed by ARKEL(L1 956). By far the most important collection came from two principal areas: the island of Taliabu in the Sula Islands of the northern Moluccas in Indonesia. described by BOEHM(1 912) and KRUIZING(1A9 26). and various localities around Geelvink Bay in north-western Irian Jaya. in the western part of the island of New Guinea. described by BOEHM(1 913) and VISSER& HERME(S19 62) .