ON THE PLANT-BEARING CHERTS AT RHYNIE, ABERDEENSHIRE. 211 



Trench No. 4.— In first field north of Easaiche Bridge, on south-east 

 side of ditch, and 250 feet north-east of road. 



A greenish and yellowish clayey and micaceous shale, with brown 

 bands, was met with at a depth of 8 feet. This was weathered into a 

 soft material that could be dug with a spade. The bedding planes indi- 

 cated a dip to the north at 35°. 



Trench No. 5.— In first field north of Easaiche Bridge, on south-east 

 side of ditch, and 300 feet north-east of the road. Tliis trench was 6 feet 

 deep. At its north end, near the bottom, reddish clayey shale was 

 found; at its south end, greenish shale. The rock was very much 

 decomposed, but the fragments, often flat or lenticular in shape, dipped 

 to the north. The section was not a good one, but there is little doubt 

 that this material is in situ here. 



Trench No. 6. — In first field north of Easaiche Bridge, on south-east 

 side of ditch, and 400 feet north-east of road. This trench went to a 

 depth of 8 feet, but no solid rock was reached. A gravelly sand was 

 found at the bottom. 



Trench No. 7. — In first field north of Easaiche Bridge, on south-east 

 side of ditch, and 475 feet north-east of road. This trench went to a 

 depth of about 5 feet. Brownish and greenish thin-bedded shale with 

 a dip to the north was found in it. 



Trenches Nos. 8, 9, 10, 11 (sites as on map). — These trenches varied 

 in depth from Gh feet to 9 feet. No rock was met with in any of them. 



Trench No. 12. — In north-east corner of field close to Windyfield 

 farmhouse. A yellowish- gireen flaky sandstone was met with at about 

 7 feet from the surface. The dip was probably to the south-south-east.' 

 A snowstorm interrupted operations, and the section was never clearly 

 exposed. 



B. Evidence from other Sections in the Area. 

 i. Glamlach Burn Section. 



In the Glamlach Burn (fig. 1), on the north-east side of the field 

 in which trenches 1, 4, 5, 6, and 7 were dug, there is a continuous 

 section of shales and fine sandy flags, extending from the north end 

 of the Cross Ditch down to within a few yards of the junction of the 

 Glamlach Burn with the Easaiche Burn. The beds dip to the north 

 at angles of about 30°, and belong to the Dryden Flag group. They 

 overlie the plant-bearing cherts and associated strata exposed in trenches 

 1 and 2. 



ii. Easaiche Burn Section. 



A few rock exposures occur in the Easaiche Burn (fig. 1), to the 

 south-west of the field in which the trenches have been dug, at two 

 localities — one about 400 feet, the other about 200 feet from the base 

 line of the Cross Ditch. Flaggy sandstones cross the strf^am and dip 

 with a high angle in a northerly direction. They belong to the Dryden 



' As the sandstone found in this trench evidently belongs to the Drydeu 

 Flags the western boundary fault must run along the north-west side of this 

 trench. Its exact position here has not been determined. 



P 3 



