470 -Reports and Proceedings — 



occur. At Ellsworth and Northampton, reposing immediately, and perhaps un- 

 conformably, on the last-mentioned bed, occurs a bed of blue clay, containing 

 wood, plants, and bands of shells, some of which are said to be fresh-water forms 

 (Cyreim, etc.). A ferruginous band occurs at the base. This clay has received 

 the name of the Upper Estuarine Series. It is succeeded by about 25 feet of a 

 white marly limestone, full of marine shells, above which, where the sequence is 

 complete, is another clay, with abundance of Ostrea subrugulosa. These three beds, 

 viz. the two clays and the intermediate limestone, are referred to the Great Oolite. 

 Above all, there is frequently a capping of Boulder-clay. As we proceed north- 

 eastv/ards, however, it is found that the beds called Upper and Lower Estuarine 

 are no longer in contact, but that there is intercalated an Oolitic Limestone, which 

 presently assumes considerable importance, and at Stamford, on the N,E. extremity 

 of the district under consideration, attains to a thickness of 75 feet. 



This formation last referred to is ca,lled the Lincolnshire Limestone. The 

 party then proceeded to inspect the Ellsworth Ironstone Diggings, about one mile 

 and a quarter east of the station. This quarry has a face, including the "baring," of 

 about 30 feet. The base, or junction with the Upper Lias, was-not actually observed, 

 but the Lower Estuarine is seen at the top. The ironstone exists principally as a 

 sesquioxide, and that portion selected by sifting is said to contain as much as 40 

 per cent, of metallic iron. ' Few, if any, fossils were found by the party in this 

 quarry, although Mr. Sharp has obtained many — all, or nearly all, as casts. 



About a mile further on, a quarry in the Great Oolite Limestone, extracted 

 chiefly for -building, was visited. Here the party had an opportunity of observing 

 about 18 feet of Eoulder-clay, between which and the limestone there occurs about 

 18 inches of clay referred to the period of the Great Oolite. Several characteristic 

 fossils were found in this quarry. 



The town of Northampton, at present containing a population of about 45,000 

 inhabitants, is very favourably situated upon an angle of high ground, sloping 

 rapidly towards the river Nene on the south and towards the northern branch of 

 the Nene on the west. The valleys of these streams are excavated in the Upper 

 Lias. The bulk of the town, therefore, rests upon the sands of the Inferior Oolite, 

 including under that grouping the ironstones, or their calcareous equivalents, and 

 the Lower Estuarine Sands. This mass of rock, thus forming an escarpment 

 of moderate slope towards the south and west, is further eaten away by denuding 

 agents — on the north towards Kingsthorpe, and on the east just beyond Abington 

 — to such an extent as to form a peninsula with a connecting isthmus not much 

 over a quarter of a mile in width. It is a peninsula of Inferior Oohte, rising out 

 of a sea of Lias. 



After luncheon, the party proceeded in carriages to carry out the programme 

 already published. 



The first group of excavations visited all lay on the north side of the town. The 

 lowest of these is the Kingsthorpe Brick-pit, where the ferruginous beds of the North- 

 ampton Sand are seen in contact with the Upper Lias, on which they repose. 

 This is the only one of the numerous sections hereabouts where the actual contact 

 was observed. There seems to be a rubbly broken bed about the junction, which 

 may be a distinct passage-bed, or merely the disturbed upper surface of the Lias 

 Clay mixing with the Northampton Sand above. Unless there is a fresh, vertical 

 face at some distance below the actual surface of the soil, the indications are more 

 or less obscure. The Nursery Pit is a continuation upwards of the Northampton 

 Sand of the last pit. The beds here are ferruginous, but chiefly calcitic sandstones, 

 largely false-bedded, and sometimes Oolitic in texture. There are several vertical 

 pipes to be observed — a phenomenon common enough in chalk-pits, but the 

 peculiarity here is that the upper ferruginous beds are not attacked by the solvent, 

 and consequently form a sort of bridge at the top of the pipes. No fossils were 

 found in this quarry, though many hammers were brought to bear upon its layers 

 of rock. 



In the Kingsthorpe sand-pit, the white sandy Lower Estuarine was observed, 

 Mith its characteristic carbonaceous bed, from which a few species of Oolitic plants 

 have occasionally been obtained. A considerable mass of compact red sandrock 

 was here noticed ; this runs into loose white sand both above and below. Con- 

 tinuing to ascend, the party, on the high grounds of Kingsthorpe (Moulton Park), 

 again found the Great Oolite Limestone, and those who were intent upon fossils found 



