Conglomerate. This character in an exaggerated degree would be expressed by the figure. Whether this inequality is to be ascribed to an original unevenness in the area of deposition at the time of the subsidence of the sediment which formed the ironstone, or whether it is due to the effect of disturbance subsequent to the deposition, is a some what doubtful question. The ironstone does not seem to make its appearance at the natural basset of the strata at Ipstones, and some of the facts observed by Mr. Binns render it probable that its place is occupied by a kind of black band with black shale, and in other parts even by a bed of impure coal. Some of the attempts to reach the Froghall stone by borings and sinkings in the underlying strata, where they occupy the surface, have as might be expected been unattended by success, although the occurrence of reddish beds or even thin seams of coal is here, as elsewhere, not unfrequent in the Millstone Grit and its associated shales. LXXXVII-RED SHAG, SHELTON COLLIERY, HANLEY, AND APEDALE, NEWCASTLE (By A. DICK.) (Nos. 230 and 238 of the Illustrated Catalogue.) Description.-Clay iron ores. No. 230, colour, dark brown to black; structure, compact; with reddish brown flattened impressions of fossil shells. No. 238 consists of numerous thin layers, varying in colour from light brown to black; structure, compact. Analysis by Method No. III. Water, hygroscopic and combined : 48 67 grs. of ore lost of water at 100° C. This water contained a little tarry matter, which makes the number higher than it should be. By the action of hydrochloric acid:- Alumina 0.385 0.42 0.15 Phosphoric and sulphuric acids, and bisulphide of iron, 43.29 grs. of ore gave of― Pyrophosphate of magnesia Sulphate of baryta (from sulphates) Sulphate of baryta (from bisulphide of iron) 27 43 grs. of ore gave of carbonic acid Iron by standard solution of bichromate of potash : I. II. Standard: 1 gr. of iron = 8·44 cub. cent. of solution. 8.62 8.615 Cub. cent. of solution. Per cent. iron. Nearly all the iron exists as protoxide, only an extremely small quantity occurring as peroxide. No metal precipitable by sulphuretted hydrogen from the hydrochloric acid solution of 780 grains was detected. LXXXVIII.-GUTTER MINE, SHELTON COLLIERY, HANLEY. (By J. SPILLER.) (No. 231 of the Illustrated Catalogue.) Description. The ore is composed of alternate layers of clay ironstone, coaly matter, and fossil shells; the clay ironstone predominating towards the middle of the specimen. It readily cleaves in the direction of the plane of stratification, the shells thus displayed bearing the evidence of compression in a direction perpendicular to the plane of cleavage. A small quantity of zinc blende was found in the ore. In selecting the sample for analysis a cross section was taken, so as to include all the various layers occurring in the specimen. Phosphoric and sulphuric acids, and bisulphide of iron : 1.025 0.65 0.05 6.18 0.86 0.67 0.24 0.12 traces 3.89 trace Iron, by standard solution of bichromate of potash :- Iron, total amount (soluble in hydrochloric acid):— Distinct traces of lead and copper were detected in 760 grains of the ore. LXXXIX.-RED MINE, APEDALE. (No. 239 of the Illustrated Catalogue.) Description.-Clay iron ore, consists of thin layers; colour, various shades of dark brown; structure, compact. Minute crystals of galena and zinc-blende occur, very sparingly diffused through the ore. Water, hygroscopic: Analysis by Method No. III. 57 24 grs. of ore lost of water at 100° C. By the action of hydrochloric acid :— Alumina Sulphate of lime Pyrophosphate of magnesia. grs. 0.17 0.17 0.05 44 31 grs. of ore gave of Phosphoric and sulphuric acids, and bisulphide of iron : Pyrophosphate of magnesia. Sulphate of baryta (from sulphates) Sulphate of baryta (from hisulphide of iron) 34 28 grs. of ore gave of carbonic acid : Iron, by standard solution of bichromate of potash :- Iron, total amount (soluble in hydrochloric acid) : grs. 0.64 0.56 0.10 0.12 2.30 0.08 0.51 0.09 0.51 11.588 Per cent. iron. 39.75 39.58 39.33 50 73 0'45 1.86 0'26 2'52 1.26 33 89 0'73 0'08 0'30 Undetermined 6'41 0'72 99 21 0'38 0'32 0'03 0'14 0'87 39 84 No metals precipitable by sulphuretted hydrogen from the hydrochloric acid solution of 680 grains of ore was detected. |