Province Boundaries Research Articles

Marine Upper Paleozoic Deposits of Arctic: ABSTRACT

Marine upper Paleozoic deposits within the Arctic are widespread in Novaya Zemlya, the Pechora basin, Taimyr, the Verkhoyansk basin, northeastern USSR, Spitsbergen, Greenland, the Arctic Archipelago of Canada, and Alaska. The upper Paleozoic in all these regions includes not only Permian, but also widespread middle-Upper Carboniferous deposits. Fossils of middle-Upper Carboniferous deposits in the western Arctic sector (Pechora basin, Novaya Zemlya, Spitsbergen, Greenland, Arctic Archipelago of Canada) do not generally differ from those of the corresponding deposits of the Urals, Russian platform, and other regions of the tropic paleozoogeographical province. The middle-Upper Carboniferous fauna of the eastern Arctic sector (Taimyr, Verkhoyansk basin, northeastern USSR) is marked by complete lack of fusulinids, colonial corals, and some other groups. This fauna contains several endemic genera of brachiopods and ammonoids (Yakutoproductus, Orulgania, Taimyrella, Yakutoceras, and others). This fact allows one to consider the region as a boreal zoogeographical province. Within this region the Bashkirian and Moscovian stages and the Upper Carboniferous are tentatively recognized. The boundary between the Carboniferous and the Permian is drawn at the appearance of Yakutoproductus verchoyanicus, which does not correspond to the base of the Schwagerina zone. A westward shift of the boundaries of the boreal province occurred in the Permian. At the beginning of the Late Permian this province covered all the territory considered. In the Early Permian two stages may be distinguished and traced here: the Asselian within the Schwagerina zone and the Artinskian, within the limits established by A. P. Karpinskiy. The Lower-Upper Permian boundary is determined by the appearance of brachiopod genera such as Grumantia, Megousia, and Pterospirifer, and by flourishing pelecypods of the genera Prosrassatella, Prooxytoma, Pseudobakewellia, and a development of the genus Kolymia. This renovation of the fauna is connected with a general transgression of the seas and establishment of short-term connections between the Arctic and Tethys seas. The Pay-Khoy and Kazanian stages may be distinguished in the Upper Permian. In the Arctic, ammonoids became extinct at the end of the Pay-Khoy stage, and brachiopods in the middle of the Kazanian. End_of_Article - Last_Page 2510------------

New Type of Sediment-Distribution Map: Preliminary Result for Gulf of Mexico: ABSTRACT

Normal sediment-distribution maps present the lithologic characteristics of only the upper 4-6 in. of the sedimentary column. Cores collected from any area commonly reveal considerable changes in lithologic character through the thickness of the beds which are cored. Such variations can be expressed in vertical sections or in fence diagrams. Information concerning the upper sediment column to a depth of at least 30 ft is important for studies on sediment transport and deposition, basin filling, geotechnical properties, placing of laboratories on the sea bottom, salvaging sunken objects, acoustical measurements, and interpretation of high-frequency, shallow-penetration, and continuous seismic-reflection profiling. Standard have been determined from samples collected in long piston cores which penetrated different lithologic units and successions. The new sediment-distribution map constructed on the basis of the 30-ft cores shows the distribution of these standard patterns and thus reveals the sedimentary characteristics of the upper 30 ft. The patterns can be portrayed by colors, shades, and symbols, or combinations. Other properties, such as geotechnical characteristics, can be added to the standards of the map or can be superimposed on the standard presentation. The main divisions of the sediment-distribution map correspond to the boundaries of the physiographic provinces of the Gulf of Mexico. End_of_Article - Last_Page 707------------

A Mathematical Method of Analyzing Biogeographical Data. I. Herpetofauna of Illinois

A divergence factor (D) is defined which indicates the rate of species replacement in a given area. All geographical points having equal values of D may be connected by a contour line (isometabasis). The resulting contour map indicates regions of little change (equivalent to biotic provinces) and regions of rapid change (equivalent to province boundaries). This procedure reduces the possibility of subjective bias in analyzing zoogeographic data. The herptofaunal data from the state of Illinois are used to illustrate the potential advantages of the method.

神居古潭結晶片岩中の特殊鉱物について

The Kamuikotan metamorphic complex develops as irregular long zone between the Mesozoic and Cenozoic formations along the western side of the Hidaka mountain ridge in Central Hokkaido. It runs about 200 km in a direction of nearly north to south, from areas of boundary of Teshio and Kitami Provinces to Hidaka Province.In general the normal Kamuikotan complex is made up the products due to slight regional metamorphism, in which the chief petrological members are black siliceous schists and next comes an abundance of green schists, small amonnts of quartzite, phyllite, mylonite and crysrtalline limestone are intercalated in the complex. From the geological and petrographical points of view, it may reasonably be assumed that the Kamuikotan complex can be readily correlated with the Franciscan formation in California.Comparatively large lenses or belts of the ultra-basic rocks run parallel with the trend of the Kamuikotan complex, being restricted mainly to the tectonic lines is the zone of the complex. It is noticeable that various interesting crystalline schists locally develop between the normal schistose rocks of the Kamuikotan complex and the ultra-basic intrusives, which have attracted special attention because of the presence of some special minerals, especially soda-bearing silicates. These special rocks may be a product brought about by contact metamorphic action due to ultra-basic intrusion and occurrence of the special minerals in them originated from pyrometasomatism, primarily owing to the action of some especially soda-rich hydrothermal solution drived from the ultra-basic intrusions.The subject matter of this paper is an outline of these some special minerals in the pyro-metasomatized rocks, with special reference to the general properties of the following members ; (A) glaucophane and crossite, (B) riebeckite and crocidolite, (C) aegirine-augite, (D) stilpnomelane, (E) piedmontite, (F) garnet, (G) lawsonite, and (H) pumpellyite.

The Plains Border Physiographic Section

In the physiographic subdivision of the United States prepared by Fenneman (1931) approximately one third of the area of Kansas is placed in the Plains Border section of the Great Plains physiogrophic province. Furthermore, about two thirds of this section is in Kansas. The section is brought to a narrow point of extinction as it passes southward across the Oklahoma panhandle into north Texas, and is abruptly terminated in southern Nebraska along the north side of the Republican River Valley. North of the Plains Border the High Plains section extends eastward into eastern Nebraska. The eastern boundary of the Plains Border section in Kansas coincides with the province boundary between the Great Plains and the Central Lowlands.

Population and Settlement in the Gambia

T HE slender strip of the Gambia stretches over 200 miles into the West African interior and lies almost wholly in the savanna belt of seasonal rains. The three natural regions into which it can be divided also run west to east along the river axis. They are the mangrove swamps; the banto faros,I developed on Pleistocene-Recent river alluvium; and the Eocene-Pliocene sandstone extension of the region that I call the Senegambian Tertiary Plateau. The banto faros can be subdivided into two divisions, an estuarine and an upper river. The boundary between them corresponds roughly to the upstream boundaries of North Bank and South Bank Provinces. The soils of the estuarine division are heavier than those of the upper, having a higher clay content, and during the rains (July-October) these lower-river banto faros are flooded with salt water. The saline flooding renders much of the area useless for agriculture. In the upper-river division the soils are lighter, loamier, and more fertile; and although these river flats too are inundated during the rains, it is with fresh water. The upper banto faros are, therefore, much more useful agriculturally, especially for the growing of rice. The soils of the plateau are light, sandy, lateritic, and of limited fertility. According to the I93I census, the total population of the Gambia was 199,520, of whom 14,370 lived on St. Mary's Island, chiefly in Bathurst,2 the only town of any real importance. In November, 1944, a census was taken in Bathurst alone, when 2I,I52 people were counted, and figures for 1946 show an increase in the population of the protectorate to 228,114. Seasonally the population is increased by the influx of strange farmers, migrants from neighboring French and Portuguese territory, who come in to grow groundnuts on the Gambian farm lands.3 Figure I shows the distribution of the villages; isolated dwellings are, of course, unknown. It will be noticed how settlement in the lower river

A Monograph on the Evolution of the Boundaries of the Province of New Brunswick

A Monograph on the Evolution of the Boundaries of the Province of New Brunswick

<italic>A Monograph on the Evolution of the Boundaries of the Province of New Brunswick</italic>. By William F. Ganong, M.A., Ph.D. [Transactions of the Royal Society of Canada. Second Series. 1901–1902. Vol. VII., Section II. Pp. 139–449.

<italic>A Monograph on the Evolution of the Boundaries of the Province of New Brunswick</italic>. By William F. Ganong, M.A., Ph.D. [Transactions of the Royal Society of Canada. Second Series. 1901–1902. Vol. VII., Section II. Pp. 139–449.

Maps of Old Geological Coast-lines, &c., &c

I NOTICE in Woodward's “Manual of the Mollusca,” when speaking of the “Boundaries of Natural History Provinces,” p. 352, the following:—