206 REPORTS ON THE STATE OF SCIENCE. — 1916. 



the attribution of which to Ginkgophylluni or some other genus is still 

 under investigation. 



The Committee asks for reappointment, with a grant of il. 



The Plant-hearing Cherts at Rhynie, Aberdeenshire. — Report of 

 the Committee, consisting of Dr. J. Horne (Chairman), 

 Dr. W. Mackie (Secretary), and Drs. J. S. Flett, W. T. 

 Gordon, G. Hickling, E. Kidston, B. N. Peach, and 

 D. M. S. Watson, appointed to excavate Critical Sections 

 therein. (Drawn up by the Chairman and Secretary.) 



CONTENTS. 



FASH 



I. Introduction 206 



II. Investigations of the Committee 209 



A. Record of Evidence in the Trenches 209 



B. Evidence from other Sections in tJie Area 211 



i. Glamlach Burn 211 



ii. Easaiche Burn . . . 211 



iii. Roadside Section 213 



III. Conclusions 215 



Report on the Plants. By Dr. Kidston, F.B.S 216 



I. Introduction. 



The Rhynie Old Red Sandstone outlier was first described in detail by 

 Sir Archibald Geikie in his comprehensive paper on ' The Old Red 

 Sandstone of Western Europe. '^ He divided the beds into the following 

 zones in descending order: — 



6. Greenish grey shales, with beds of flagstone. Dryden. 



5. Thick group of hard pale grey and reddish or purplish sandstones, with 

 occasional pebble beds, and numerous pipes, ' galls,' and irregular veinings of red clay. 

 Rhynie quarries, Burn of Craig, about 1,000 feet. 



4. Band of diabase-porphyrite, seen between Contlach and Auchindoir Manse. 



3. Very soft and crumbling, grey and red, pebbly sandstones, and conglomerates of 

 well-rounded pebbles, with bands of red shale, 300 or 400 feet, seen below Glenbogie, 

 where the valley is cut out of this soft series. 



2. Red shales, with calcareous red nodules, 40 or 50 feet ; seen in small ravine to 

 east of Glenbogie. 



1. Band of red and yellow conglomerate and breccia, sometimes with calcareous 

 cement. This lowest deposit immediately underlies the shales at the last-named 

 locality, and rests on the crystalline rocks 



The highest division (Dryden Flags) is practically the only one that 

 falls within the scope of this report. 



The beds of the Rhynie outlier are seen to lie unconformably on 

 the igneous rocks (diorites and granites), and the members of the 

 metamorphic series of West Aberdeenshire along the eastern margin 

 of the area, and to dip at fairly uniform angles of 15° to 20° to the 

 west, where they are cut off by a fault running north and south which 

 throws down the whole series against the clay-slates, grits, and diorites 

 on the west. 



' Trans. Roy. Soc. vol. xxviii. p. 423. 



