Fi:HKr.\KV, 101 _'. 



Kxo\\i.i:nr,K. 



November, 19111, gets over this difiiciilty by concluding 

 that their deposition took place, alonj; with other fine- 

 grained deposits, in still and semi-isolated lagoon waters. 

 Four lagoon or .Uorfio/</-phascs are recognised in the 

 Avonian of (jower. By a lagoon-phase is meant a series 

 o( rocks whose characters show that they have been deposited 

 in coastal areas of wide extent, but so extremely shallow as to 

 have become effectively isolated frou) the neighbouring deeper 

 parts of the sea. and thus the sites of peculiar types of 

 sediment and fauna. Three of these lagoon-phases arc 

 calcareous, and besides typical shallow-water deposits sucli 

 as oolites, ostracod-beds, and beds containing fragments 

 of conteniporanoous sediments, they contain peculiar rocks 

 consisting mainly of very fine-grained homogeneous limestones 

 ("chinastone-limestones "I, landscape marbles, and calcite- 

 bearing mudstones. These rocks are all distinguished by a 

 uniform fineness of grain, which suggests that their deposition 

 w:is an exceedingly slow and gentle process. The fourth and 

 uppermost lagoon-phase in Gower, consists of radiolarian cherts 

 interbedded with laminated shales containing a few shallow- 

 water lamellibranchs and plant fragments. From this associa- 

 tion is inferred a shallow-water origin for the cherts, which 

 view is supported by several lithological features. The cherts 

 are banded or laminated, the laminae diftcring in the propor- 

 tion and nature of their detrital material. Many of the 

 laminae are decidedly lenticular or wedge-bedded. This 

 points to the play of gentle currents laden with various fine 

 sediments. It is also shown that radiolaria are not exclusively 

 deep-sea organisms, but are found at all depths. Moreover, 

 lagoon-conditions would be favourable to their development, 

 provided that the salinity of the water was not greater than 

 that of ordinaiy sea-water, a condition that would be 

 supplied by the proximity of a river. 



PILLOW L.WAS IN THE DALRADIAN SCHISTS.— 

 Pillow lavas associated with the Loch .-Xwe group of the 

 Oalradian Schists are described in a recently-issued Memoir 

 of the Geological Survey (Sheet 2iS. Knapdalel. These occur 

 in the Tayvallich peninsula of the Kn.ipdale district of 

 .Argyllshire. Their successful study has depended on the low 

 grade of metamorphism in the Tayvallich peninsula. The 

 degree of metamorphism of the schists gradually decreases in 

 a direction across the strike from south-east to northwest, 

 and also along the strike from north-east to south-west. The 

 minimum of metamorphism is attained in the Knapdale 

 district, where the rocks are little more than cleaved. The 

 quartzites of the Loch .-Xwe group are now considered 

 to pass under the limestone and slate division, whereas, 

 beforehand, on the evidence of certain conglomerate bands, 

 the re\erse was supposed to be the case. The evidence for 

 this change of opinion has been obtained mainly from the 

 study of the associated pillow-lavas. In several places the 

 latter form pillow-shaped masses exactly similar to those 

 developed at Ballantrae (Ayrshire), Cornwall, and other 

 British localities. They are slaggy. vesicular, and intercalated 

 with thin beds of ash. black slate and limestone. The striking 

 contrast between the tops and bottoms of the lowermost flows 

 .has provided the clue to the true stratigraphical succession in 

 the district. The second lava of the type-section in the bay 

 to the south of Port-an-Sgadain gives most conclusive 

 evidence that the whole series is " right side up." The base 

 of this flow conforms exactly to the bedding of an underlying 

 thin seam of dolomite, and is characterised by large steam- 

 tubes (■■ pipe-amygdaloids"') an inch in diameter, and reaching 

 one foot in length. These are set at right angles to the base 

 of the lava, and were probably caused by the uprise of steam 

 from the moist sediment below. The interior of the flow 

 contains parallel bands of spherical vesicles, and it is overlaid 

 by a thin dolomite which fills up all irregularities, and does 

 not appear " baked." .As the lavas are interbedded with Hme- 

 stone, and underlaid by black slate and i|uartzite, the inference 

 is that the order named is fhe true descending order of 

 succession. Similarly, the Loch Awe group is underlaid, in 

 the same descending succession, by the .Ardrishaig Phyllites, 

 stiH"right-way-up." The Tayvallich pillow-lavas thus provide 

 a most striking clue to the true succession in the complicated 

 district of the south-western highlands. 



MP:T HOROLOGY. 



By JoH.N A. Curtis, F.R.Met.Soc. 



The weather of the week ended December 23rd, as set out 

 in the W'eckh- Weather Report issued by the Meteorological 

 Oflice, was mild and wet. with thunderstorms in Scotland on 

 the 17th, and in Ireland on the 17th and 18th. 



Temperature was much above the average in all Districts, 

 the excess reaching 6° -9 in England, R. The highest maximum 

 was 58° at Hawarden Bridge, but 57^ was reported at places 

 as far apart as Glencarron, Dublin and Jersey. The lowest 

 of the minima was 25' at Balmoral. At many stations, how- 

 ever, no frost was observed, and in the English Channel the 

 temperature did not fall below 43° daring the week. The 

 lowest reading on the grass was 20° at Crathes and Newton 

 Rigg- 



Rainfall was also in excess in all Districts, and was very 

 greatly so in many cases. Thus, in England, S.E., the total 

 was more than four times, and in the Midlands more than 

 three times the usual amount. .At most of the stations rain 

 was measured on each day of the week. There were, howevei, 

 no exceptionally heavy falls, the greatest amount repoited on 

 one day being 1-07 inches, at Plymouth on the 20th. and at 

 Crieft' on the 23rd. 



In spite of the rainfall the sunshini' was in excess in 

 Scotland, N. and E., and in Ireland, N. In the other districts, 

 however, it was normal, or in defect. The highest aggregates 

 were 14-1 hours (31%) at Nairn, and 14-7 hours (29%) at 

 Birr Castle. .At Westminster, the total was only 0-9 hours 

 (2"„i. The mean temperature of the sea water varied from 

 4r -7 at Kirkwall to 4g°-.S at Salcombe. 



The week ended December 30th was also mild and wet, 

 with thunderstorms at Bournemouth on the 24th, and at 

 Tunbridge Wells. Cardiff and Markree Castle on the 25tb. 



Temperature was above the average in all districts, the 

 greatest excess being e^'-O in England, S.E. Maxima 

 exceeding 50° were reported from all the districts except 

 Scotland N., where the highest reading was 49°. The highest 

 of the maxima, 56°, was reported at Bawtry, Blacksod Point 

 and Killarney. The lowest readings recorded were 26° at 

 West Linton, and 28° at several stations. In England, E., 

 the minimum was 32°. and in the English Channel it was 40°. 

 On the grass, minima down to 20 (at Newton Rigg) were 

 reported. 



The rainfall was again in excess, except in Ireland, S., 

 where it was just normal. The differences from average were, 

 however, in no case very large. At some stations in England, 

 N.E., the amounts were quite small, under 0-2 inch, although 

 made up of amounts on five or six days. .At Glencarron. on 

 the other hand, the total for the week rose to 3-62 inches, or 

 half as much again as usual. 



Sunshine was deficient except in England. N.E., where it 

 was normal. The greatest deficiency was in the Western 

 districts, and at Dublin the total for the week was only 

 0-6 hours or 22% below the average. In Westminster, the 

 total was 2-4 hours (5%). 



The mean temperature of the sea-water ranged from 4r-2 

 at Burnmouth to 49° -8 at Salcombe. 



The New Year opened with a continuance of dull, wet 

 weather. .Aurora was observed at Gordon Castle on the 

 5th, and a thunderstorm at Jersey on the 6th, on which day, 

 in the Northern districts, snow and sleet were generally 

 experienced. 



Temperature was still above the a\erage in all districts, 

 the excess reaching 6° -3 in the Midlands and England, S.E. 

 The maxima exceeded 50° in all parts and rose to 56° at Leith 

 and Hawarden Bridge on the 1st. At no station was the 

 maximum for the week reported as less than 49°. The 

 lowest reading for the week was 27° at Poltalloch, on the 5th, 

 but at quite a number of stations the temperature did not fall 

 to freezing point, and at some it did not fall even to 40°. 



Rainfall was in excess of the average except in Scotland, 

 E. and W.. where it was slightly below it. The excesses 

 however were not great, in spite of the fact that at a few 

 stations large aggregates were reported, np to 4-13 ins. at 

 Glencarron. 



