ISSN:0035-919X    

DOI:10.1080/00359195709519011

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

Part of the material described was obtained from the hulls of ships and from immersed experimental plates in Table Bay Harbour; the rest was collected during ecological work on the South African coasts. In all 36 species have been recognized. Of these one,Parasmittina natalense, is considered a new species and three,Acanthodesia savarti, Conopeum reticulumandCryptosula pallasiana, do not appear to have been recorded previously from South Africa.

ISSN:0035-919X    

DOI:10.1080/00359195709519012

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The Geology and Geomorphology of the Fish River Canyon, as investigated during a reconnaissance expedition in January 1956, are briefy described, and certain evidence is put forward in support of the proposition that, despite previous assertions to the contrary by other authors, the double canyon consists of an erosional lower component carved by rejuvenation into the floor of the structural trough which forms the upper canyon. In so far as limited observations permit, certain tentative inferences are also drawn regarding the history of the canyon, as a basis for future, more detailed, investigation.

ISSN:0035-919X    

DOI:10.1080/00359195709519013

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The variation of mass defect with mass number (naturally occurring isotopes only) has been examined using the critically revised mass data of Wapstra (1955). Three principal features may be distinguished; two can be correlated with significant N = 50 and N = 82, and the third, with isotope abundance distribution and variation (Ahrens, 1957). The mass defect vs. A route followed by the odd A isotopes is very clearly defined whereas the spread of points about the even A trend is quite considerable, particularly over the range A = ~60 to A = ~140. This is due to overlapping of trough-like distributions of mass defect for each value of even Z. Each such isotopic distribution approximates roughly to a parabola with one shortened limb.

ISSN:0035-919X    

DOI:10.1080/00359195709519014

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

A thin porphyritic dyke, cream-brown in colour, is intruded into Upper Dwyka shales near the kimberlite pipe on Mukorob, South West Africa. Now highly calcitized, the rock was probably an olivine melilitite when fresh. Black ellipsoidal ilmenite-covered altered olivine inclusions give the rock its curious appearance. Other inclusions of rounded replaced olivine and rock types commonly found as cognate xenoliths in kimberlite are scattered throughout the dyke rock.

ISSN:0035-919X    

DOI:10.1080/00359195709519015

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

ISSN:0035-919X    

DOI:10.1080/00359195709519010

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor