Quaternary geology of the north Klondike and upper Blackstone River systems, southern Ogilvie Ranges, Yukon Territory

1977 ◽  
Author(s):  
K E Ricker
Keyword(s):  
Yukon Territory ◽  
Quaternary Geology ◽  
River Systems ◽  
The North ◽  
Blackstone River

scholarly journals Types of river sources of the thin-grained aluminosilicaclastics for the Jurassic and lower cretaceous deposits of the West Siberian megabasin

2021 ◽  
Vol 63 (4) ◽  
pp. 52-61
Author(s):  
A. V. Maslov
Keyword(s):  
Lower Cretaceous ◽  
The Urals ◽  
River Systems ◽  
The West ◽  
Rock Composition ◽  
Fine Grained ◽  
The North ◽  
Catchment Areas ◽  
Cretaceous Deposits ◽  
West Siberian Basin

Background. The lithogeochemical features of fine-grained detrital rocks (mudstones, shales, and fine-grained siltstones) allow, with a certain degree of success, the main parameters of the formation of sedimentary sequences to be reconstructed. These parameters include (primarily in terms of their REE and Th systematics) the types of river systems supplying thin terrigenous suspension in the sedimentation area: the rivers of the 1st category – large rivers with a catchment area of more than 100,000 km2; 2nd category – rivers feeding on the products of erosion of sedimentary deposits; 3rd category – rivers draining mainly igneous and metamorphic rocks; and 4th category – rivers carrying erosion products of volcanic associations.Aim. To reveal, based on the analysis of interrelationships between such parameters as (La/Yb)N, Eu/Eu* and the Th content, the types of river systems that fed the Jurassic and Lower Cretaceous deposits of the Shaim oil and gas region (OGR) (Sherkalinsky, Tyumen, Abalak and Mulymya formations) and the region of the North Pokachevsky field of the Shirotnoe Priobye region (Sherkalinsky, Tyumen and Bazhenov formations, Lower Cretaceous deposits).Materials and methods. The ICP MS data for almost 100 samples of mudstones and fine-grained clayey siltstones were used to analyse the features of distribution of lanthanides and Th in the Jurassic and Lower Cretaceous clayey rocks of the Shaim OGR and the area of the North Pokachevsky deposits. Individual and average composition points for formations, members and layers were plotted on the (La/Yb)N-Eu/Eu*, (La/Yb)N–Th diagrams developed by us with classification areas of the composition of fine suspended material of modern rivers of different categories.Results and conclusion. The results presented in the article showed that during the formation of the deposits of the Shaim OGR in the Early and Middle Jurassic, erosion affected either mainly sedimentary formations or paleo-catchment areas that were very variegated in their rock composition. In the Late Jurassic, the source area was, most likely, a volcanic province, composed mainly of igneous rocks of the basic composition, and located within the Urals. This conclusion suggested that the transfer of clastic material from the Urals to the Urals part of the West Siberian basin “revived” much earlier than the Hauterivian. The Jurassic-Lower Cretaceous section of the vicinity of the North Pokachevsky field was almost entirely composed of thin aluminosilicaclastics formed due to the erosion of volcanic formations. These volcanic formations were located, as followed from the materials of earlier performed paleogeographic reconstructions, probably within the Altai-Sayan region or Northern Kazakhstan. Thus, the supply of detrital material in the considered territories of the West Siberian basin had a number of significant differences in the Jurassic and early Cretaceous.

The Tasmanian Trout Fishery. III. The Rivers of the North and East

1958 ◽  
Vol 9 (2) ◽  
pp. 167 ◽  
Author(s):  
AG Nicholls
Keyword(s):  
Growth Rate ◽  
Age Distribution ◽  
Total Catch ◽  
River Systems ◽  
The North ◽  
Full Capacity ◽  
The Mean ◽  
Trout Fishery ◽  
Distribution Of Fish

The study of the daily catch from the Korth and South Esk River systems, as derived from anglers' returns, shows a general fall which appears to be statistically significant in all rivers except the Meander. It appears to become increasingly important from west to east. It is accompanied by a fall in the annual catch per angler which is closely correlated with an increase in the number of licences issued, from which it might appear that these streams are being fished to their full capacity. A study of the mean lengths of fish at capture does not show any decrease compatible with over- fishing, and there has been no increase in growth rate, which might be expected under conditions of overfishing. The age distribution of fish caught bv anglers does not indicate any decrease in the proportions of older fish. A personal canvass of 53 anglers in one district showed a mean total catch per angler of 259 fish, whereas the figure derived from anglers' returns for the same season was 20 fish per angler. It is concluded that the apparent decline in catching rate was due to the returns from anglers being unrepresentative. So correlation was found between the catches by anglers and the fish available to them as a result of stocking these streams.

scholarly journals The Morphological Effects of Surges of the Donjek Glacier, St Elias Mountains, Yukon Territory, Canada

1972 ◽  
Vol 11 (62) ◽  
pp. 227-234 ◽  
Author(s):  
P. G. Johnson
Keyword(s):  
Yukon Territory ◽  
East Side ◽  
North East ◽  
The North ◽  
Glacier Terminus

Abstract The present surge of the Donjek Glacier on the north-east side of the St Elias Mountains, first noticed in 1969, is producing a number of morphological effects adjacent to the glacier in the terminus area. Although the effects of the surge are minimized by the lobate form of the glacier terminus, several types of push structure, erosional forms and certain drainage changes are being produced. These forms are similar to older forms close to, or on, the Neoglacial maximum moraine. It is considered that the similarities suggest that surges may have occurred throughout most of the Neoglacial period.

scholarly journals Acid Content of Snow from a Mid-Troposphere Sampling Site on Mount Logan, Yukon Territory, Canada

1985 ◽  
Vol 7 ◽  
pp. 153-160 ◽  
Author(s):  
G. Holdsworth ◽  
E. Peake
Keyword(s):  
Ice Core ◽  
Sampling Site ◽  
Gulf Of Alaska ◽  
Yukon Territory ◽  
Ion Concentration ◽  
Past Century ◽  
Short Term ◽  
The North ◽  
Volcanic Events ◽  
North American Arctic

An ice core 103 m long was extracted in 1980 from an altitude of 5340 m on the icefield plateau of Mount Logan, Yukon Territory (lat 60°35ˈN, long 140°30ˈW). The firn-ice transition occurs at a depth of 65 m, corresponding to about the year 1880. The chemistry of this upper 65 m is apparently dominated by acid-ion species, the peaks in which are provisionally identified with several documented volcanic events. Although the analyses cover only selected discontinuous intervals, it appears that there is no significant long-term trend in the background acidity level of the precipitation at this location over the past century, in contrast to the results from the North American Arctic and Greenland. Nitrate ion concentration shows pseudo-seasonal variations, which may be associated with stratospheric-tropospheric interactions, although other seasonally linked mechanisms are possible. This result has also been reported for ice-core sequences from Greenland. Other nitrate pulses are tentatively associated with local volcanic events and a possible meteorite event (the entry of Tunguska in 1908). One of the largest short-term sources of sulfate ions is probably from volcanic activity on the north Pacific rim. Background volcanically-quiet nitrate and sulfate ion concentrations are compared with similar Greenland data in an attempt to throw further tight on the origin of the acids. Since the moisture for this precipitation originates primarily in the Gulf of Alaska, the data has particular relevance to that region. Short-term climatic changes, as reflected by the oxygen isotope (δl8O) record, show some response to the major volcanic-acid events. The influences affecting the δl8O record are listed but not discussed.

Middle and Late Ordovician conodont faunas and biostratigraphy of graptolitic strata of the Road River Group, northern Yukon Territory

1987 ◽  
Vol 24 (4) ◽  
pp. 643-653 ◽  
Author(s):  
Alexander D. McCracken ◽  
Alfred C. Lenz
Keyword(s):  
Northwest Territories ◽  
Cold Water ◽  
Late Ordovician ◽  
Yukon Territory ◽  
Warm Water ◽  
Rare Occurrence ◽  
Carbonate Facies ◽  
The Road ◽  
Fine Grained ◽  
Blackstone River

Ordovician conodont faunas from the fine-grained clastic Road River Group in northern Yukon Territory contain a mixture of species from both warm- and cold-water regions. This group in southwestern Northwest Territories also has mixed faunas, whereas conodonts from the carbonate facies are more characteristic of the warm-water regions.Six conodont associations and biozones are identified from the Yukon. Some, such as the early Llanvirn "Cordylodus" horridus – Spinodus spinatus association, contain reworked elements. The Pygodus serra Zone (middle–late Llanvirn) is within the upper P. tentaculatus Zone and well below the G. euglyphus Zone. Genera include Ansella, Periodon, Protopanderodus, Pygodus, and Walliserodus.At Peel River, conodonts are within the P. pacificus Zone. The Blackstone River conodonts occur above the P. pacificus Zone and below the G. persculptus Zone (?) and include Oulodus rohneri, Plectodina florida, and Noixodontus. Amorphognathus ordovicicus, Gamachignathus ensifer, O. ulrichi, and Plectodina tenuis occur in both faunas. These represent Fauna 12, found in late Richmondian strata, rather than the Gamachian Fauna 13 and are assigned to the G. ensifer Zone; both occurrences of G. ensifer are biohorizons. The C.? extraordinarius and G. persculptus zones are not recognized at Peel and Rock rivers and Tetlit Creek.The Ozarkodina n. sp. A – Icriodella sp. B association occurs at Pat Lake between the G. persculptus Zone (?) and the underlying P. pacificus Zone. The Ozarkodina have a Silurian aspect but must be regarded as Ordovician.The Ordovician–Silurian boundary in the Road River Group of the Yukon is best defined using graptolites because of the rare occurrence of conodonts.

Mineralogical evidence for sediment derivation and ice movement within the Wash drainage basin, eastern England

Clay Minerals ◽  
1985 ◽  
Vol 20 (2) ◽  
pp. 209-220 ◽  
Author(s):  
R. D. Wilmot
Keyword(s):  
Recent Work ◽  
Drainage Basin ◽  
Clay Mineralogy ◽  
The South ◽  
River Systems ◽  
The North ◽  
Glacial Periods ◽  
Mineralogical Evidence

AbstractThe Wash drainage basin contains four principal river systems. Samples were collected from the freshwater and estuarine reaches of each of these, and silt- and clay-grade fractions were separated and examined by XRD. The clay mineralogy of each of the rivers is different; in the north the Witham sediments contain chlorite, the Welland and Nene samples contain vermiculite, with a higher proportion of kaolinite in the former, while in the south the Ouse sediments contain smectite. The clay fractions of the samples from the estuarine reaches all contain chlorite, confirming that non-fluvial sources must contribute to the sediments of the Wash. Comparison of this pattern of clay mineralogy with that for the underlying Jurassic and Cretaceous rocks shows that there was relatively little modification during the Pleistocene glacial periods. Such a pattern supports recent work which suggests that ice moved through the Wash gap and then fanned out from the Fenland area, rather than entering the region from the north.

Joint Canada-U.S. Survey in the Mount Kennedy Region

ARCTIC ◽  
1965 ◽  
Vol 18 (2) ◽  
pp. 70
Author(s):  
Canada. Surveys and Mapping Branch
Keyword(s):  
Large Scale ◽  
Field Measurements ◽  
The United States ◽  
Geodetic Survey ◽  
Yukon Territory ◽  
Mountain Range ◽  
National Geographic Society ◽  
National Geographic ◽  
The North ◽  
Alaskan Coast

In 1935 a National Geographic Society glaciological expedition working in the St. Elias mountain range near the Alaska-Yukon Territory boundary described an unnamed mountain in the area as "magnificent, a granite peak sheathed in snow and ice on the south and west sides, and on the north and east sides has fantastic rock cliffs." Thirty years later this same peak was officially named Mount Kennedy in honour of the late President John F. Kennedy. A surge of activity in the area followed immediately. Senator Robert Kennedy climbed the mountain, an expedition sponsored by the National Geographic Society is engaged in producing a large scale map of the mountain and its environs, and a joint U.S.-Canadian party has just completed a survey through the area which will determine the precise geographic position of the mountain's summit and its elevation. The survey party was composed of six men from the United States Coast and Geodetic Survey and two men from the Surveys and Mapping Branch of the Canadian Department of Mines and Technical Surveys. The main purpose of the work was to connect existing surveys along the Alaska Highway with similar surveys along the Alaskan coast. The work will strengthen the control surveys throughout the area and provide new control points for mapping. The decision to include Mount Kennedy in the survey, while adding a touch of glamour to the operation, greatly increased the difficulties. The survey itself consists of five main stations, connected by traverse, with auxiliary points established at alternate stations to provide additional checks on field measurements. The lengths of the four traverse courses varied from eight to thirty-nine miles; the distances were measured by electronic distance measuring equipment, and the angles were measured with precise theodolites using signal lights and heliotropes for targets. ...

Sign in / Sign up

Export Citation Format

Share Document