A HISTORY OF NORTHAMPTONSHIRE central England, owing to a broad belt of elevated land stretching across what is now Britain, from Wales to the east coast, during the Upper Carboniferous period. Without contesting in any way the general con- clusion referred to above, it may be remarked that the evidence available from deep borings tends to show that the proved absence of coal from cer- tain parts of Northamptonshire admits of and requires another explanation, and this may here be briefly discussed. Coal, or a near approach to it, lignite, may be found in any of the stratified rocks of Northamptonshire, in small pieces or larger patches, no doubt originally consisting of drift wood. Morton records[1] various diggings or borings for coal in the county previous to 171 2 ; and an energetic attempt appears to have been made at Kettering in 1766.[2] A more ambitious scheme was formed in 1836, and a company commenced sinking a shaft at Kings- thorpe near Northampton. This venture was made on the advice of ' practical men,' and in opposition to the opinions of Wm. Smith ('the father of English geology ') and Mr. Richardson (of the British Museum).[3] £30,000 was expended, and a depth of 967 feet reached without either finding the Coal Measures or proving their absence. An attempt was made to revive the scheme about 1854, and again in 1869, but nothing came of either.
No accurate record of the strata passed through in making the Kingsthorpe shaft was kept, and the only available figures as to the thick- nesses of the various formations are certainly wrong somewhere. It will suffice here to record that after passing through the Lower Lias they apparently met with Red Sandstone 60 feet (or 80 feet ?), Red Marl 12 feet, Conglomerate 15 feet, and stopped at 967 feet, without reaching the Old Land Surface ; but considering that the Conglom- erate consisted chiefly of Carboniferous Limestone pebbles in a greenish sandy matrix, as at Gayton, there can be no reasonable doubt of its occurrence only a little below. The problem of finding coal in Northamptonshire involves a con- sideration of several of the preceding sections and some of those which follow, thus : — In the early part of the Carboniferous period the dis- trict was mostly well under water and receiving marine deposits (cf Gayton and Northampton), and since the whole of the Carboniferous rocks were deposited in a gradually subsiding area, it seems more likely than not that the Coal Measures, the uppermost division of the system, did actually cover the whole or parts of the county, and that they, as in the West of England and in Wales, rested directly upon Carboniferous Limestone without the intervention of the Millstone Grit, or even in other parts of the county upon Archsan rocks, as in certain districts of Leices- tershire. If consideration be given to the great gap between the Car- boniferous Limestone formation and the Keuper (see Table of Formations,
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