31 "* 



NOTES ON THE OCCURRENCE OF 

 BOULDERS OF SHAP GRANITE, ETC., IN 



LINCOLNSHIRE. 



THOMAS SHEPPARD, 



Hon. Secretary to Hull Naturalists' and Scientific Club ; Hull. 



Whilst examining the erratics in the vicinity of Barton for the 

 newly-formed Lincolnshire Boulder Committee, I found a boulder of 

 Shap Granite, measuring 2 feet 6 inches by 1 foot 3 inches, by 1 foot + . 

 This was at the foot of a gatepost at the entrance to Mr. Milson's 

 mill, near the top of the hill just outside Barton, on the South 

 Ferriby Road. The granite in question was well rounded and 

 thoroughly embedded in the ground, so that its precise dimensions 

 could not be ascertained. Owing to its long exposure to the 

 atmosphere the upper part is weathered, the large pink felspars 

 being very prominent. It was in its present position when 

 Mr. Milson took charge of the place several years ago, and I have 

 no doubt it came originally from the boulder clay which occurs in 

 the neighbourhood, though up to the present I have been unable to 

 get any definite information on the point. So for as I can learn,, 

 this is the first boulder of Shap Granite recorded for Lincolnshire. 



A few weeks later, when walking along the Humber bank 

 between South Ferriby Hall and the Chalk Pit, I was fortunate 

 enough to find a small pebble of the same rock in the Boulder Clay 

 at a depth of eighteen feet. I have this pebble before me as I write. 

 Though small, it is a very good sample, and there is no doubt 

 whatever that it is Shap Granite. The characteristic felspars are 

 exceptionally well shown, and, though the pebble is only an inch 

 and a half long, there are portions of no less than four porphyrinic 

 crystals of felspar thereon, one of them showing the twinning. This 

 specimen, it should be noted, was found in the clay only about two 

 miles from the previously mentioned boulder. 



1 There are two Boulder Clays in the cliff between Ferriby Chalk 

 Pit and the Hall. The lower one, which is only a thin deposit, is 

 of a dark colour, is very compact, and contains a fair quantity of 

 boulders of different sorts, including rhomb-porphyry and others 

 of Scandinavian origin.* The upper clay, however, is of a totally 

 different character. It attains a thickness of about 20 feet in its 

 highest part, which is near the centre of the cliffs, and gradual!) 

 thins out towards the east and west. It resembles the 'He sie* 



Tl -■-■-.-■ , , a—MUM H.tt — -----Lf — ' '■■-" ' l f ■■■■'■ >!■! ■ ■! I ■■ ■ ■ I I I *<' ■ ' 



For a list of the various rocks of Scandinavian origin found in Line >insiiire > 

 see the list which accompanies my paper 4 On the Occurrence of Scandinavian, 

 boulders in England' (Glac. Mag., vol Hi, 1895, p. 129). 



Nov, 1396. 



