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Easter field meeting (extension) to Minsterley
EASTER FIELD MEETING.
6. 7. 8. 9.
339
LAPWORTH, C. Summary of Progress for 1915, pp. 36-37. 1916. WATTS, W. W. Proe. Geot. Assoc., vol. 36, pp. 340-343. 192.'). STUBBLEFIELD, C. J. and BULMAN, O. M. B. Quart. 10uYI!. Geol. Soe., vol. 83, pp. 96-145. 1927. WHITTARD, W. F. Ibid., vol. 83, pp. 737-758. 1927.
EXPLANATION OF PLATES. PLATE 10. A. Stiperstones Quartzite, Nill's Hill (north quarry), Pontesbury, showing ripple-marks on bedding surfaces. B. Stiperstones Quartzite, Nill's Hill (north quarry), Pontesbury, showing bedding. PLATE II. A. View looking east-north-east from the head of Crew's Nest Dingle (Mytton Flags). In the middle distance are the Mytton Flags overlooking Snailbeach (S) and the ridge of the Stiperstones Quartzites (Q) : in the far distance is the Uriconian hill of Pontes ford (P) and the Trias plain. B. Volcanic agglomerate in the Stapeley 'Ashes' (Llanvirn) at Leigh Farm. Note the numerous pebbles which are contained in a tuffaceous matrix.
EASTER FIELD MEETING (EXTENSION) TO MINSTERLEY. April 8th to 11th, 1931. Report by the Director: W. F. WHITTARD, Ph.D., D.LC., A.R.C.S., F.G.S. [Received June znd, 1931.]
THE excursion was planned, firstly, to make a traverse across the Ordovician rocks of Shelve, and, secondly, to visit the Valentian rocks of the Longmynd-Shelve outcrop. Altogether 34 members attended on various days. The Bath Arms Hotel was selected as headquarters. After the completion of the Bridgnorth excursion (see p. 370), several members motored from Shrewsbury to Minsterley on Tuesday evening, April 7th, where they were joined by others who had arrived that day. In the evening the Director gave a short account of the Ordovician and Silurian geology of the Shelve country, aided by the 6-in. map prepared by Professors Lapworth and Watts in 1895. Professor Watts then mentioned the outstanding facts of the igneous rocks of the region. WEDNESDAY, APRIL 8th.
Hope Valley and Stiperstones. Driving from headquarters along the Hope Valley, the first exposure was in Purple Shales at Wagbeach; but the rain of the previous week-end had flooded the brook, and a proper inspection was not made. At Hope Quarry, a landslide provided a quantity of specimens of Pentamerus oblongus, and it was re marked that they showed distinct similarity to Pentamerus esthonus described by Eichwald. The unconformity between the
34°
W. F. WHITTARD,
Pentamerus Beds and the underlying Hope Shales (Ordovician) was studied. Continuing up the Hope Valley, the party next halted just above the Fox Inn and collected a large fauna from the Upper Hope Shales. Dr. C. J. Stubblefield discovered a previously unrecorded Starfish; this he has sent to Dr. W. K. Spencer, who reports that it is a species of Palceura," " Palceura is a genus of Starfish which shows immediate pre-Ophiuroid structure, that is, it has a disc with long thin arms, but the ambulacralia have not as yet become vertebrre. Previous to this discovery, forms of this type had only been known from the Dry (Arenig) beds of Bohemia. Although a fair number of the genera are known from the Bohemian beds, only one of the Bohemian genera (Uranaster) was known from corresponding horizons in Britain. The rather delicate structure of the specimen suggests that it was a direct ancestor of the true Ophiuroid, Protaster salteri, found in the Welsh Caradocian." The Valentian outliers resting on the flank and on the top of the Hope Valley were next visited, and the Director explained that from these outlying patches of rock an approximate profile could be obtained for the valley which existed in this region during Valentian times-a valley which has been re-excavated by the modern drainage. The Lower Hope Shales were not seen in the Hope Valley section; but by reference to two localities in the Main 'China-stone Ash,' the Shelve Church anticline was clearly evident. The motors were rejoined at Hope Village, and the drive continued to Shelve Church, where a plentiful supply of graptolites and dendroids was found in the Arenig beds. After lunch, the members were conducted to the nearest point to the Bog Mine outliers and then walked across the swampy ground, so aptly named The Bog. The Valentian outliers yielded a harvest of fine specimens, including many cranidia of Deiphon d. forbesi. At Ritton Castle, representatives of the Staneley Volcanic Group are developed in the faulted syn cline; and from a small mound the salient folds of the Shelve country were explained by reference to the triple outcrop of the Stapeley rocks. Professor Watts alluded to the structure of Corn don Hill, and showed that it is a laccolite intruded along an anti cline which has sagged in the middle. Proceeding by car to Tankerville, a collection of fossils was made from the topmost Mytton Flags at John Rhodes' locality. A slab of rock was found, slightly hardened by dolerite, and covered with Didymo graptus hirundo .
Well-laden tables awaited the party at the Stiperstones Inn, and, after tea, the majority of the members returned to Tankerville, and then crossed the rough, heather-covered country leading to the Devil's Chair. From here the view * The specimen is housed in the Museum of Practical Geology, No. 51237-8.
EASTER FIELD MEETING.
34 1
was not particularly extensive, but a panorama including the Breidden Hills in the north-west and the Clee Hills in the south east was much appreciated. Thence our route led along the top of the Stiperstones escarpment, past crags, many of which exhibit brecciated quartzite, and over the bluff of the hill to the divide between Perkin's Beach and Mytton Beach. Again the Mytton Flags yielded well, and a few Cystid plates were recovered. From the point of view of scenery, Mytton Beach probably offers the best in the Shelve country, but owing to the poor light it was not so impressive as usual. The party descended from the Stiperstones by way of Crew's Nest Dingle, carved out of Mytton Flags (Plate IIA). The motors were boarded at the road, and, after spending a few minutes collecting galena, blende, barytes, and mauve-pink calcite from the Snailbeach dumps, the return was made to Minsterley. THURSDAY, APRIL oth.
Bromlow Callow and Wotherton. Low clouds and drizzling rain greeted our departure from headquarters, but the wealth of fossils that were to be discovered later, disarmed the weather of its unpleasantness. The Hope Valley road was taken in preference to the smaller lane leading from Plox Green to Bentlawnt, and was followed to about one mile above the Tankerville Inn; a lane on the right led to Bromlow Callow, and hence the motors were sent round to Rorrington Village. Selecting a footpath trending westwards across four fields, an exposure in massive tuffs belonging to the Stapeley Volcanic Group was visited, and then the party de scended into the branch of the Betton Dingle east of Ganderbeach. Here the succession is complicated by strike faulting, but the Stapeley Shales provided their characteristic fossils. Farther down the Dingle the flaggy beds of the Weston Stage yielded an unusual crop of fossils, including a trilobite apparently inter mediate in structure between Calymene and Homalonotus, and a crinoid calyx. At Lyde, the Betton Beds were examined in the stream section and on the tip-heaps of the adit north of the road leading to Meadowtown. Among other specimens, the zonal fossil Didymograptus murchisoni was obtained in abundance. At Meadowtown quarry the bedding surfaces showed several individuals of Ogyginus corndensis, while the overlying flaggy bands were seen to carry a large fauna rich in Trinucleus lloydi and Rafinesquina d. llandeiloensis. Since our departure from Minsterley the rain had not abated, but, owing to the kindness of Mr. Jones, the party was permitted to seek shelter in his farmhouse while tea was served. After lunch the Rorrington Beds were visited south of Desert, and although the rocks were not prolific in organic remains, the finding of Nemagraptus gracilis,
34 2
W. F. WHITTARD,
var. remotus was a sufficient index of the age of the beds. Thence the route led up the escarpment of the Spy Wood Grit, where many brachiopods, trilobites, and graptolites, associated with swarms of Tetradella com-plicaia, were collected. Descending the dip slope of the Grit, an exposure in tuff was crossed and the Aldress Shales examined in the banks of the Rorrington Brook. After tea at Rorrington Village, the motors were taken along the Wotherton road as far as Ox Wood Coppice. A small exposure of tuff, interleaved in the Aldress Shales, was found to be characterized by Sotnerbyella sericea var. soudleyensis and Di-plograptus sp., d. prisiis. The road-section exhibited fine exposures in the Hagley Volcanic Group, Hagley Shales, and Whittery Volcanic Group, and the traverse was completed by Whittery Shales containing Amplexograptus perexcaoatus. The higher Ordovician is covered by Valentian rocks which are seen in the old mineshaft at Wotherton. The party then motored to Leigh Farm, where the last exposures of the day were situated; here, fossiliferous shales are interbedded with fragmentary vol canic beds of Stapeley age, and a crag in a field on the north side of the road shows a development of volcanic agglomerate, with many pebbles set in a tuffaceous matrix. (Plate lIB). The thanks of the party were conveyed to Miss G. M. Bauer, who acted as Excursion Secretary; the small accommodation available at Minsterley had made her task of housing the party extremely difficult. The Director expressed his appreciation of her kindly co-operation. FRIDAY, APRIL loth.
The Longmynd Flank and Snead. The commencement of the excursion for this day was the Onny Section, and, during the pleasant drive from Minsterley, the salient features of interest in the Stretton Valley were indicated. 'the River Onny was found to be flooded, but a few members ventured round the steep bank of the section to see the unconformity between the Purple Shales (Valentian) and the Trinucleus Mudstones (Ordovician). The small angle of discordance between the rocks was demonstrated, and attention directed to the peculiar disturbed band of Purple Shales contained between two dirt-planes. The normal suites of fossils were obtained. Rejoining the motors, the party travelled along the Onny Valley and thence up the beautiful Horderley Valley, where the road passes almost along the outcrop of the most westerly of the Church Stretton faults. At New House Farm, near Marshbrook, a visit was made to the Valentian outlier which is limited on the west by the main Church Stretton fault. The throw of the fault in this region is 600 feet. Thence the way led back along the Horderley Valley and up to Hamperley,
EASTER FIELD MEETING.
343
whence the motors were sent to Plowden. From the Valentian sea-stack south-west of Oldchurch More, the Director indicated the more important features of the view which extended as far as Bringewood Chase, overlooking Ludlow; the sweeping escarp ments of the Wenlock and Aymestry Limestones were clearly visible. The walk from Hamperley to Plowden lay along the south-east flank of the Longmynd, and many alongshore struc tures developed in the Arenaceous Phase of the Pentamerus Beds were studied; they include small pebble-beaches, pebble bars, and sea-stacks of Longmyndian rock protruding through accumulations of pebbles and sand of Valentian age. Fossils were collected at Hillend from conglomerates and grits. At Plowden, Mr. Pye, the gamekeeper, had cleared the excavation which shows to perfection the unconformity between the Valentian and Pre-Cambrian rocks of the Longmynd. A short visit was paid to the rocks exposed in the railway cutting at Plowden Station. Here the lowest Wenlock Shales comprise alternating beds of purple shale and normal greenish-brown shale. Attention was directed to the fact that both lithologically and faunistically these Purple Wenlock Beds are allied to the true Wenlock Shales which immediately succeed them. Owing to the summer weather that the party was fortunate in enjoying, tea was taken out-of-doors at the Onny Lodge. After tea the members were driven to Snead, where Pentamerus Beds exhibiting rapid alternations of sandstone and mudstone were found to be unusually poor in organisms; it was only an occasional limestone which provided a reasonable fauna. The large quarries in coarse-grained dolerite at Dysgwylfa (Squilfer) were next examined: this rock has altered the overlying Valentian rocks, and is thus post-Lower Silurian in age. The programme for the day was concluded by a visit to the Tasgar quarry, where shales intercalated in volcanic rocks of Stapeley age have yielded a rich fauna. In the evening, the president (Professor W. W. Watts) passed a vote of thanks to the Director; an appreciation was also given of Lapworth's work in Shropshire, more particularly in the Shelve country. SATURDAY, APRIL
i
rth.
The Habberley lane section. Walking from Minsterley along the lane leading to Habberley, the first exposure in Purple Shales was seen. A varied fauna was obtained, and the party was fortunate in finding several trilobites. Beyond the bridge over the Snailbeach Mineral Railway, the Lower Hope Shales exhibit a reversed dip due to strike faulting. Here the members were joined by Mr. T. H. Whitehead. The Lower Hope Shales cropping out in the stream on the south
344
EASTER FIELD MEETING.
side of the lane yielded Cyclopvge binodosa, At the top of the bank, Mr. Whitehead pointed out the features of the land scape to the east, and traced the course of several transverse faults which side-step bands of conglomerate developed in the western beds of the Longmynd. At Granham's Moor quarries the artificial section figured here on page 324 was discussed. Dr. C. ]. Stubblefield found a cephalon of Shumardia pusilla and a Lingulella nicholsoni, thus proving that the sandy and flaggy shales at the eastern end of the section are truly Tremadocian in age (bed a in text-figure 43). There was a general agreement that a thin conglomerate marks the base of the Ordovician, and that it is unconformable upon the Cambrian. After lunch, the walk led over the Mytton Flags of Eastridge Coppice and so to the tip-heaps from Perkin's Level at Snailbeach, where numerous fossils were discovered, including Monobolina plumbea and Synhomalonotus murchisoni. The field-path was then followed towards Minsterley, and the majority of the members returned home by the afternoon train to Shrewsbury.
6. 7. 8. 9.
339
LAPWORTH, C. Summary of Progress for 1915, pp. 36-37. 1916. WATTS, W. W. Proe. Geot. Assoc., vol. 36, pp. 340-343. 192.'). STUBBLEFIELD, C. J. and BULMAN, O. M. B. Quart. 10uYI!. Geol. Soe., vol. 83, pp. 96-145. 1927. WHITTARD, W. F. Ibid., vol. 83, pp. 737-758. 1927.
EXPLANATION OF PLATES. PLATE 10. A. Stiperstones Quartzite, Nill's Hill (north quarry), Pontesbury, showing ripple-marks on bedding surfaces. B. Stiperstones Quartzite, Nill's Hill (north quarry), Pontesbury, showing bedding. PLATE II. A. View looking east-north-east from the head of Crew's Nest Dingle (Mytton Flags). In the middle distance are the Mytton Flags overlooking Snailbeach (S) and the ridge of the Stiperstones Quartzites (Q) : in the far distance is the Uriconian hill of Pontes ford (P) and the Trias plain. B. Volcanic agglomerate in the Stapeley 'Ashes' (Llanvirn) at Leigh Farm. Note the numerous pebbles which are contained in a tuffaceous matrix.
EASTER FIELD MEETING (EXTENSION) TO MINSTERLEY. April 8th to 11th, 1931. Report by the Director: W. F. WHITTARD, Ph.D., D.LC., A.R.C.S., F.G.S. [Received June znd, 1931.]
THE excursion was planned, firstly, to make a traverse across the Ordovician rocks of Shelve, and, secondly, to visit the Valentian rocks of the Longmynd-Shelve outcrop. Altogether 34 members attended on various days. The Bath Arms Hotel was selected as headquarters. After the completion of the Bridgnorth excursion (see p. 370), several members motored from Shrewsbury to Minsterley on Tuesday evening, April 7th, where they were joined by others who had arrived that day. In the evening the Director gave a short account of the Ordovician and Silurian geology of the Shelve country, aided by the 6-in. map prepared by Professors Lapworth and Watts in 1895. Professor Watts then mentioned the outstanding facts of the igneous rocks of the region. WEDNESDAY, APRIL 8th.
Hope Valley and Stiperstones. Driving from headquarters along the Hope Valley, the first exposure was in Purple Shales at Wagbeach; but the rain of the previous week-end had flooded the brook, and a proper inspection was not made. At Hope Quarry, a landslide provided a quantity of specimens of Pentamerus oblongus, and it was re marked that they showed distinct similarity to Pentamerus esthonus described by Eichwald. The unconformity between the
34°
W. F. WHITTARD,
Pentamerus Beds and the underlying Hope Shales (Ordovician) was studied. Continuing up the Hope Valley, the party next halted just above the Fox Inn and collected a large fauna from the Upper Hope Shales. Dr. C. J. Stubblefield discovered a previously unrecorded Starfish; this he has sent to Dr. W. K. Spencer, who reports that it is a species of Palceura," " Palceura is a genus of Starfish which shows immediate pre-Ophiuroid structure, that is, it has a disc with long thin arms, but the ambulacralia have not as yet become vertebrre. Previous to this discovery, forms of this type had only been known from the Dry (Arenig) beds of Bohemia. Although a fair number of the genera are known from the Bohemian beds, only one of the Bohemian genera (Uranaster) was known from corresponding horizons in Britain. The rather delicate structure of the specimen suggests that it was a direct ancestor of the true Ophiuroid, Protaster salteri, found in the Welsh Caradocian." The Valentian outliers resting on the flank and on the top of the Hope Valley were next visited, and the Director explained that from these outlying patches of rock an approximate profile could be obtained for the valley which existed in this region during Valentian times-a valley which has been re-excavated by the modern drainage. The Lower Hope Shales were not seen in the Hope Valley section; but by reference to two localities in the Main 'China-stone Ash,' the Shelve Church anticline was clearly evident. The motors were rejoined at Hope Village, and the drive continued to Shelve Church, where a plentiful supply of graptolites and dendroids was found in the Arenig beds. After lunch, the members were conducted to the nearest point to the Bog Mine outliers and then walked across the swampy ground, so aptly named The Bog. The Valentian outliers yielded a harvest of fine specimens, including many cranidia of Deiphon d. forbesi. At Ritton Castle, representatives of the Staneley Volcanic Group are developed in the faulted syn cline; and from a small mound the salient folds of the Shelve country were explained by reference to the triple outcrop of the Stapeley rocks. Professor Watts alluded to the structure of Corn don Hill, and showed that it is a laccolite intruded along an anti cline which has sagged in the middle. Proceeding by car to Tankerville, a collection of fossils was made from the topmost Mytton Flags at John Rhodes' locality. A slab of rock was found, slightly hardened by dolerite, and covered with Didymo graptus hirundo .
Well-laden tables awaited the party at the Stiperstones Inn, and, after tea, the majority of the members returned to Tankerville, and then crossed the rough, heather-covered country leading to the Devil's Chair. From here the view * The specimen is housed in the Museum of Practical Geology, No. 51237-8.
EASTER FIELD MEETING.
34 1
was not particularly extensive, but a panorama including the Breidden Hills in the north-west and the Clee Hills in the south east was much appreciated. Thence our route led along the top of the Stiperstones escarpment, past crags, many of which exhibit brecciated quartzite, and over the bluff of the hill to the divide between Perkin's Beach and Mytton Beach. Again the Mytton Flags yielded well, and a few Cystid plates were recovered. From the point of view of scenery, Mytton Beach probably offers the best in the Shelve country, but owing to the poor light it was not so impressive as usual. The party descended from the Stiperstones by way of Crew's Nest Dingle, carved out of Mytton Flags (Plate IIA). The motors were boarded at the road, and, after spending a few minutes collecting galena, blende, barytes, and mauve-pink calcite from the Snailbeach dumps, the return was made to Minsterley. THURSDAY, APRIL oth.
Bromlow Callow and Wotherton. Low clouds and drizzling rain greeted our departure from headquarters, but the wealth of fossils that were to be discovered later, disarmed the weather of its unpleasantness. The Hope Valley road was taken in preference to the smaller lane leading from Plox Green to Bentlawnt, and was followed to about one mile above the Tankerville Inn; a lane on the right led to Bromlow Callow, and hence the motors were sent round to Rorrington Village. Selecting a footpath trending westwards across four fields, an exposure in massive tuffs belonging to the Stapeley Volcanic Group was visited, and then the party de scended into the branch of the Betton Dingle east of Ganderbeach. Here the succession is complicated by strike faulting, but the Stapeley Shales provided their characteristic fossils. Farther down the Dingle the flaggy beds of the Weston Stage yielded an unusual crop of fossils, including a trilobite apparently inter mediate in structure between Calymene and Homalonotus, and a crinoid calyx. At Lyde, the Betton Beds were examined in the stream section and on the tip-heaps of the adit north of the road leading to Meadowtown. Among other specimens, the zonal fossil Didymograptus murchisoni was obtained in abundance. At Meadowtown quarry the bedding surfaces showed several individuals of Ogyginus corndensis, while the overlying flaggy bands were seen to carry a large fauna rich in Trinucleus lloydi and Rafinesquina d. llandeiloensis. Since our departure from Minsterley the rain had not abated, but, owing to the kindness of Mr. Jones, the party was permitted to seek shelter in his farmhouse while tea was served. After lunch the Rorrington Beds were visited south of Desert, and although the rocks were not prolific in organic remains, the finding of Nemagraptus gracilis,
34 2
W. F. WHITTARD,
var. remotus was a sufficient index of the age of the beds. Thence the route led up the escarpment of the Spy Wood Grit, where many brachiopods, trilobites, and graptolites, associated with swarms of Tetradella com-plicaia, were collected. Descending the dip slope of the Grit, an exposure in tuff was crossed and the Aldress Shales examined in the banks of the Rorrington Brook. After tea at Rorrington Village, the motors were taken along the Wotherton road as far as Ox Wood Coppice. A small exposure of tuff, interleaved in the Aldress Shales, was found to be characterized by Sotnerbyella sericea var. soudleyensis and Di-plograptus sp., d. prisiis. The road-section exhibited fine exposures in the Hagley Volcanic Group, Hagley Shales, and Whittery Volcanic Group, and the traverse was completed by Whittery Shales containing Amplexograptus perexcaoatus. The higher Ordovician is covered by Valentian rocks which are seen in the old mineshaft at Wotherton. The party then motored to Leigh Farm, where the last exposures of the day were situated; here, fossiliferous shales are interbedded with fragmentary vol canic beds of Stapeley age, and a crag in a field on the north side of the road shows a development of volcanic agglomerate, with many pebbles set in a tuffaceous matrix. (Plate lIB). The thanks of the party were conveyed to Miss G. M. Bauer, who acted as Excursion Secretary; the small accommodation available at Minsterley had made her task of housing the party extremely difficult. The Director expressed his appreciation of her kindly co-operation. FRIDAY, APRIL loth.
The Longmynd Flank and Snead. The commencement of the excursion for this day was the Onny Section, and, during the pleasant drive from Minsterley, the salient features of interest in the Stretton Valley were indicated. 'the River Onny was found to be flooded, but a few members ventured round the steep bank of the section to see the unconformity between the Purple Shales (Valentian) and the Trinucleus Mudstones (Ordovician). The small angle of discordance between the rocks was demonstrated, and attention directed to the peculiar disturbed band of Purple Shales contained between two dirt-planes. The normal suites of fossils were obtained. Rejoining the motors, the party travelled along the Onny Valley and thence up the beautiful Horderley Valley, where the road passes almost along the outcrop of the most westerly of the Church Stretton faults. At New House Farm, near Marshbrook, a visit was made to the Valentian outlier which is limited on the west by the main Church Stretton fault. The throw of the fault in this region is 600 feet. Thence the way led back along the Horderley Valley and up to Hamperley,
EASTER FIELD MEETING.
343
whence the motors were sent to Plowden. From the Valentian sea-stack south-west of Oldchurch More, the Director indicated the more important features of the view which extended as far as Bringewood Chase, overlooking Ludlow; the sweeping escarp ments of the Wenlock and Aymestry Limestones were clearly visible. The walk from Hamperley to Plowden lay along the south-east flank of the Longmynd, and many alongshore struc tures developed in the Arenaceous Phase of the Pentamerus Beds were studied; they include small pebble-beaches, pebble bars, and sea-stacks of Longmyndian rock protruding through accumulations of pebbles and sand of Valentian age. Fossils were collected at Hillend from conglomerates and grits. At Plowden, Mr. Pye, the gamekeeper, had cleared the excavation which shows to perfection the unconformity between the Valentian and Pre-Cambrian rocks of the Longmynd. A short visit was paid to the rocks exposed in the railway cutting at Plowden Station. Here the lowest Wenlock Shales comprise alternating beds of purple shale and normal greenish-brown shale. Attention was directed to the fact that both lithologically and faunistically these Purple Wenlock Beds are allied to the true Wenlock Shales which immediately succeed them. Owing to the summer weather that the party was fortunate in enjoying, tea was taken out-of-doors at the Onny Lodge. After tea the members were driven to Snead, where Pentamerus Beds exhibiting rapid alternations of sandstone and mudstone were found to be unusually poor in organisms; it was only an occasional limestone which provided a reasonable fauna. The large quarries in coarse-grained dolerite at Dysgwylfa (Squilfer) were next examined: this rock has altered the overlying Valentian rocks, and is thus post-Lower Silurian in age. The programme for the day was concluded by a visit to the Tasgar quarry, where shales intercalated in volcanic rocks of Stapeley age have yielded a rich fauna. In the evening, the president (Professor W. W. Watts) passed a vote of thanks to the Director; an appreciation was also given of Lapworth's work in Shropshire, more particularly in the Shelve country. SATURDAY, APRIL
i
rth.
The Habberley lane section. Walking from Minsterley along the lane leading to Habberley, the first exposure in Purple Shales was seen. A varied fauna was obtained, and the party was fortunate in finding several trilobites. Beyond the bridge over the Snailbeach Mineral Railway, the Lower Hope Shales exhibit a reversed dip due to strike faulting. Here the members were joined by Mr. T. H. Whitehead. The Lower Hope Shales cropping out in the stream on the south
344
EASTER FIELD MEETING.
side of the lane yielded Cyclopvge binodosa, At the top of the bank, Mr. Whitehead pointed out the features of the land scape to the east, and traced the course of several transverse faults which side-step bands of conglomerate developed in the western beds of the Longmynd. At Granham's Moor quarries the artificial section figured here on page 324 was discussed. Dr. C. ]. Stubblefield found a cephalon of Shumardia pusilla and a Lingulella nicholsoni, thus proving that the sandy and flaggy shales at the eastern end of the section are truly Tremadocian in age (bed a in text-figure 43). There was a general agreement that a thin conglomerate marks the base of the Ordovician, and that it is unconformable upon the Cambrian. After lunch, the walk led over the Mytton Flags of Eastridge Coppice and so to the tip-heaps from Perkin's Level at Snailbeach, where numerous fossils were discovered, including Monobolina plumbea and Synhomalonotus murchisoni. The field-path was then followed towards Minsterley, and the majority of the members returned home by the afternoon train to Shrewsbury.