ISSN:0016-786X    

DOI:10.1080/11035897809454464

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The Rb-Sr isochron age of the Varberg charnockite, south-western Sweden is 1450+53 Ma (λ = 1.39 × 10−11a−1). The initial87Sr/86Sr ratio is 0.7049±0.0006.

ISSN:0016-786X    

DOI:10.1080/11035897809454465

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Eight samples from the Rönnäng tonalite–granodiorite intrusion on Tjörn Island, south-western Sweden, were investigated in a Rb-Sr geochronological study. The whole-rock Rb-Sr system is disturbed and the eight samples describe a 1615-Ma age-reference line, which does not qualify as an isochron. However, an isochron age of 1710 ± 115 Ma (λ = 1.39 × 10−11a−1) at a low, initial,87Sr/86Sr ratio is obtained when only four of the samples poorest in Rb are employed. This age is interpreted as dating the intrusion. The event which disturbed the whole-rock Rb-Sr system was identified from combined mineral and whole-rock data. An isochron of 1010 ±105 Ma and a reference line of 1015 Ma were obtained. This age coincides with the age of Sveconorwegian intrusions and metamorphism. A compilation of Rb-Sr data from southwestern Sweden identifies a zone of late Sveconorwegian regeneration of the whole-rock isotopic systems.

ISSN:0016-786X    

DOI:10.1080/11035897809454466

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

During the final phase of the snow-melting in the spring of 1977, mass movements of water-soaked, silty-sandy deposits were recorded in central Värmland. The precipitation was approximately twice the seasonal mean value. In a narrow valley beside Säterberget Hill, as a result of these mass movements, a gully was formed in a sequence of more than 15 m of silt and fine sand. At the bottom of the gully, the silt was clayey. The gully has a depth of 3–20 m, a width of 20–40 m and a length of more than 100 m. In less than three days, about 20 000 m3of silt and fine sand were transported almost 300 m through an old gully to an adjacent river. Human modification of the landscape was a contributory factor in the gully formation. A defective drain-pipe under a three-road junction caused a rivulet to flood and take a new course. The drainage area of the rivulet had been enlarged by ditches constructed along the hillside road. Furthermore, the run-off down the slope had been increased due to the clear-cutting of timber.

ISSN:0016-786X    

DOI:10.1080/11035897809454467

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0016-786X    

DOI:10.1080/11035897809454468

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue

ISSN:0016-786X    

DOI:10.1080/11035897809454453

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor