A. C. Demagnetization of Rocks: Analysis of Results

摘要: Summary The total magnetic composition of a rock sample can be revealed by stepwise demagnetization. Hence these progressive demagnetizations are the most valuable bases in palaeomagnetic research. best information is given combination few orthogonal projections curve, which endpoint resultant vector natural magnetization describes space during Such projection allows quick survey magnetizations present, their directions and size-ratios; moreover, directly from this, all data wanted exactly derived. Some such demagnetization diagrams given. By means it thus possible to identify, collection, various direction size. Next, determination different usually occurs tentatively according concerned, which, however, no definite. Therefore preferable avoid genetical denominations as long further available, instead of, for example, using term “primary” magnetization, speak “characteristic” group. In this connection an example characteristic, though syntectonic Devonian sediments Ardennes. It discussed how far hardness spectrum shows relation probable origin. From some examples showed that up now, single rule excepted (e.g., with entirely lower than 250 Oe almost certain secondary viscous magnetizations) generally does not allow decisive conclusions concerning origin magnetization. Further geological (field-tests), petrological mineralogical investigations comparative laboratory tests remain necessary establish true characteristic its value palaeomagnetism.