124 DR. A. H. COX: REPORT ON MAGNETIC DISTURBANCES IN NORTHAMPTONSHIRE 
anticlines. In the case of the Rempstone—Melton Mowbray disturbances, however, 
geological evidence is available, as detailed above. 
Granted the presence of such an east—west anticlinal axis in the Palaeozoic rocks 
beneath the Melton Mowbray area, the significance of the Rempstone—Melton Fault, 
which is otherwise lacking, becomes manifest. It would be a strike-fault running 
nearly parallel with the anticlinal axis, and on the northern flank of the fold. With 
its northerly downthrow it served to relieve the folding and to accentuate the 
anticlinal structure. 
The line Rempstone—Melton Mowbray is thus one of considerable geological 
disturbance, as indicated by the post-Triassic folding and faulting,-ivhich appear to 
have been initiated on the lines of older structures among the Palaeozoic rocks below. 
It is also a line of high magnetic disturbance, in other words, a “ ridge-line” 
probably connected, as argued above, with occurrences of dolerite intrusions along the 
fault. It is within the limits of possibility that this line, along which the structure 
is anticlinal, marks a belt of folding and faulting that defines the at present 
unknown southern and south-eastern limits of the concealed coalfield. That the 
coalfield does not extend indefinitely to the south-east is shown by the presence of 
rocks older than the Coal Measures in various borings in East Anglia.* 
Thus the magnetic survey has served to emphasise the real significance of a belt 
of faulting which, if judged only from its effects on the surface rocks, would appear 
to be of only minor importance. 
The western continuation of the Rempstone Fault is lost under the great spread 
of alluvial deposits at the confluence of the Soar, Trent, and Derwent Valleys. But 
it is interesting to note that on the other side of the alluvium, a fault, again with 
a northerly downthrow, extends through the western outskirts of Derby, and thence 
in a north-north-westerly or north-westerly direction, bringing Lower Carboniferous 
Beds against the Trias, t This fault is in line with and may well represent the 
continuation of the Rempstone disturbance, in which case the curve of the Rempstone 
Fault from an east-west direction in the eastern part of its course to a north-west— 
south-east direction in the western part, would fall into parallelism with the curves of 
the anticlinal swells which cross the coalfield between Nottingham and Shefiield.J 
8. Other Possible Causes oe the Magnetic Disturbances. 
A number of other possibilities have been considered with regard to the origin of 
the magnetic disturbances. But in each case it can be shown that all the necessary 
conditions whereby the rock could give rise to the disturbances are not fulfilled. 
* A. Strahax, “Pres. Addre.ss,” ‘ Q. J. G. S.,’ vol. LXIX. (1913), p. Ixxxiv. and plate A. 
t “ The Geology of the Sonth Derbyshire Coalfield,” ‘ Mem. Geol. Survey,’ 1908, p. Ill ; and ‘ Geol. 
Map,’ New Series, 1-inch, Sheet 125. 
I W. G. Feahnsides, “Some effects of Earth-movement on the Coal Measures of the Sheffield 
l>‘sfcrict.Part IT,” ‘Trans. Inst. Min. Eng.,’ vol. LI., Part 3 (1916), p. 106. 
