Depositional Features of Dittonian Rocks: Pembrokeshire compared with the Welsh Borderland

1963 ◽  
Vol 100 (5) ◽  
pp. 385-400 ◽  
Author(s):  
J. R. L. Allen
Keyword(s):  
Colorado River ◽  
Lower Half ◽  
Close Similarity ◽  
The South ◽  
Red Sandstone ◽  
Cross Bedding ◽  
Animal Burrows ◽  
Floodplain Deposits ◽  
Primary Current

AbstractThe Dittonian Stage in Pembrokeshire comprises the Lower Marl Group (higher beds), the Sandstone-and-Marl Group, and the Upper Marl Group (at least lower half). These formations cannot be distinguished lithologically from Dittonian strata of the Welsh Borderland 100 miles away along the depositional strike.Cyclothems of intraformational conglomerate (scoured surface below) → sandstone → siltstone with concretions recur vertically in each area. The conglomerates in both districts consist of intraformational siltstone and concretionary debris. Flat-bedding, primary current lineation, planar cross-bedding, trough cross-bedding, and ripple-drift bedding are common to the sandstones. Suncracked siltstones abound in both Pembrokeshire and the Welsh Borderland. Slumped bedding, sandstone pipes, and animal burrows are the structures penecontemporaneous with deposition in each area.The Dittonian strata of the Welsh Borderland are shown to be probably floodplain deposits, by reason of their close similarity to the modern sediments of the Colorado Delta floodplain and Colorado River. The occurrence of an identical facies in Pembrokeshire suggests the even wider extent of this floodplain in early Lower Old Red Sandstone times, when the sea lay far to the south of both areas.

Mesolithic Flints from the Submerged Forest at West Hartlepool

1936 ◽  
Vol 2 (1-2) ◽  
pp. 161-168 ◽  
Author(s):  
C. T. Trechmann ◽  
A. S. Kennard
Keyword(s):  
Sand Dunes ◽  
The South ◽  
Red Sandstone ◽  
Main Portion ◽  
Boulder Clay

The submerged forest or peat bed on the Durham coast situated between Hartlepool and West Hartlepool and extending along the shore southwards towards Seaton Carew and northwards beneath the sand dunes has been known for many years. The main portion of it occupies a depression between two outcrops of Magnesian Limestone, the easterly one forming the isolated mass of rock on which the old town of Hartlepool is built and the westerly one being the edge of the main outcrop of the same rock on which West Hartlepool stands. To the south the Triassic red sandstone which is faulted down beneath a covering of boulder clay appears on the shore at Longscar Rock and Seaton Carew.

Devonian miospores from Papa Stour, Shetland

1988 ◽  
Vol 79 (1) ◽  
pp. 13-18 ◽  
Author(s):  
J. E. A. Marshall
Keyword(s):  
Close Similarity ◽  
Plate Tectonic ◽  
Red Sandstone ◽  
Good Preservation ◽  
Sedimentary Deposits ◽  
Volcanic Sequence ◽  
Fossil Fish ◽  
Fish Remains ◽  
Orcadian Basin ◽  
Age Range

ABSTRACTDevonian miospores have been discovered in the previously poorly dated Old Red Sandstone volcanic sequence of Papa Stour. They occur at two sites in minor sedimentary deposits between the lavas, and fossil fish remains are also present. The age range of the miospores is mid Eifelian to early Givetian, probably more specifically late Eifelian and from a position close to the Achanarras horizon. This allows a correlation of the Papa Stour volcanic sequence with that of the Upper Stromness Flags of Orkney and not the tuffaceous horizons in the Eday Sandstones. The good preservation and composition of the miospores indicate a close similarity to other Orcadian Basin sediments and support the view that the Old Red Sandstone sequences W of the Melby Fault have affinities with the Orkney and Caithness successions rather than with Shetland. The age of the volcanic sequence also provides a valuable datum point for plate tectonic models based on the geochemistry of Old Red Sandstone lavas.

Split-Twig Figurines in the Grand Canyon

1958 ◽  
Vol 23 (3) ◽  
pp. 264-274 ◽  
Author(s):  
Douglas W. Schwartz ◽  
Arthur L. Lange ◽  
Raymond de Saussure
Keyword(s):  
Colorado River ◽  
Grand Canyon ◽  
Senior Author ◽  
The South ◽  
The World ◽  
Archaeological Work ◽  
Area Of Study

The Grand Canyon in northwestern Arizona has long been a favorite area of study for geologists from all parts of the world, but until recently little intensive archaeological work has been done within the canyon itself. In 1953 the senior author began to investigate Cataract Creek Canyon, the only major drainage leading from the Coconino Plateau on the south to the Colorado River. Also in this year Walter W. Taylor (1954) made a quick survey of the lower reaches of the Grand Canyon by boat, but due to high and fast water he was unable to locate many sites. The present project was the first major excavation to be carried on in the main canyon area and it revealed material that should stimulate further work in the region.

Remarks on the distribution of Minerals in North Devon

1877 ◽  
Vol 1 (6) ◽  
pp. 212-214
Author(s):  
Townshend M. Hall
Keyword(s):  
Regular Sequence ◽  
The South ◽  
Northern Boundary ◽  
Ordnance Survey ◽  
Red Sandstone ◽  
Similar Series ◽  
The One ◽  
The Town

The district to which the following notes refer is contained in sheets 26 and 27 of the one inch Ordnance Survey Maps, and embraces an area of about 985 square miles, the northern boundary being formed by the Bristol channel, and that on the south by a line drawn through the town of Okehampton. The rocks composing this district belong to the Devonian and Carboniferous systems, with the exception of a small portion of new red sandstone and a patch of Greensand, occupying a few acres. The two older systems present a regular sequence of beds from north to south, which, interrupted by the granite of Dartmoor, are represented to a greater or less extent by a similar series in the southern portion of the county.

scholarly journals XIII. The Old Red Sandstone of the Orkneys

1900 ◽  
Vol 39 (2) ◽  
pp. 383-424 ◽  
Author(s):  
John S. Flett
Keyword(s):  
Point Of View ◽  
The South ◽  
South Side ◽  
Red Sandstone ◽  
Great Thickness ◽  
Subsequent Revision ◽  
The Subject ◽  
Lower Series ◽  
Local Base

As the result of two visits to Orkney, in which he was accompanied by Mr B. N. Peach, he pointed out that the yellow sandstones of Hoy did not pass down conformably into the flagstones which form the basis of that island, but were separated from them by a marked unconformity. At the base, of the upper sandstones lay a series of contemporaneous lavas and ash beds, which were in all probability erupted, from certain ‘necks’ in the low-lying district at the foot of the Hoy Hills. These rocks he regarded as belonging to the upper Old Red Sandstone. The lower Old Red Sandstone consisted principally of a great thickness of flagstones, with which were interstratified beds of yellow and red sandstone, and occasionally of conglomerate. The fossils belonged exclusively to this lower series; and a table is given, compiled by Mr C. W. Peach, showing the distribution 9f fossil fishes in the lower Old Red Sandstone of Lake Orcadie, including those of Orkney so far as known at that time. As Sir Archibald Geikie anticipated, subsequent revision has necessitated “considerable pruning of the fossil lists.” The conglomerates around the granite axis of Stromness formed merely a local base, “due to the uprise of an old ridge of rock from the surface of the sheet of water in which these strata were accumulated,” and were presumably not on the same horizon as the thick conglomerates on which, in Caithness, the lowest flagstones rest. The sandstones interbedded with the flagstones in South Ronaldshay were regarded as in all probability the northward continuation of the similar rocks at Gill's Bay, Huna, and John o'Groats, on the south side of the Pentland Firth. From a geological point of view, the brief notice of the Old Red Sandstone of the Orkneys contained in this paper forms by far the most important contribution to the knowledge of the subject published up to that time.

The Carboniferous System in Scotland Characterized by its Brachiopoda

The Geologist ◽  
1860 ◽  
Vol 3 (07) ◽  
pp. 258-265
Author(s):  
Thomas Davidson
Keyword(s):  
The South ◽  
Red Sandstone ◽  
The North ◽  
North Side ◽  
Sea Coast

“This group in Northumberland is seen, westward of Alnwick at Garmitage-bank and Crawley Dean, and on the flanks of the porphyry of the Cheviot in Biddleston Burn, and in the Coquet below Linn Brig; it occupies a considerable area in the south part of Berwickshire, and is largely developed on the Tweed at Carham, Coldstream, Norham, etc.; it is seen underlying the mountain-limestone on the sea-coast from near Lammerton Shiel to Burnmouth; on the north side of Lammermuirs it is intercalated between the Old Red Sandstone, and the mountain-limestone from the Pees mouth to the Cove harbour.” Mr. Tate observes also that the Campsie and Fifeshire beds resemble those of Northumberland.

scholarly journals XXIX. Conjectures on an antient Tomb in Salisbury Cathedral. By Mr. Gough

Archaeologia ◽  
1809 ◽  
Vol 2 (2) ◽  
pp. 188-193
Author(s):  
Gough
Keyword(s):  
Lower Half ◽  
The South ◽  
The West ◽  
South Side ◽  
Left Hand ◽  
Right Hand ◽  
Fourth Arch

On the south side of the nave of Salisbury cathedral, under the fourth arch from the west, lies a monument of blue speckled marble, with the figure of a bishop in pontificalibus, his right hand lifted up to give the blessing, his left hand holding the crosier. On the perpendicular sides or edge all round is cut an inscription in large capitals; and on the front of the robe, another in letters somewhat similar. The slab lay to deeply bedded in the stone foundation on which the pillars of the nave rest, that the first of these inscriptions had entirely escaped the notice of the curious, or if any had noticed it, the lower half of the letters being out of sight, rendered it unintelligible. Last summer I procured it to be raised, and the pavement disposed round it in such a manner, that it can henceforth receive no injury, but will remain the second oldest monument in that church, if the conjectures I have formed upon it are founded in truth.

VI.—The Geology of the Highland Border from Glen Almond to Glen Artney

1941 ◽  
Vol 60 (1) ◽  
pp. 171-193 ◽  
Author(s):  
Douglas A. Allan
Keyword(s):  
Field Survey ◽  
Central Valley ◽  
Present Communication ◽  
The South ◽  
Red Sandstone ◽  
Boundary Fault ◽  
Comprehensive Account ◽  
North East ◽  
The North ◽  
South West

The author (1928) of the present communication has already published the results of a field survey of the Lower Old Red Sandstone in Perthshire and Angus, which were linked with those derived by Campbell (1913) from his study of similar and older series of beds in Kincardineshire, to the north-east. For thirty-five miles to the south-west of the R. Tay, no detailed investigation of the sequence or tectonics of the rocks immediately adjacent to the Highland Boundary Fault, separating the Grampians proper from the Central Valley of Scotland, has been undertaken. A comprehensive account of the rocks of this belt in the region around Aberfoyle is available in the paper by Campbell and Jehu (1917).

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