Structures of the Skiddaw Slates in the Caldew Valley, Cumberland

Roberts, David E.

doi:10.1002/gj.3350070202

Cited by 22 publications

(1 citation statement)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mitchell (1929Mitchell ( , 1934 interpreted the volcanic structure of Kentmere and Longsleddale in terms of NNE trending pre-Bala folds upon which were superimposed the ENE Caledonian folding and cleavage. O n this basis subsequent workers have tended to relate NNE and N-S strikes in the Borrowdale Group (Moseley 1964(Moseley , 1972Clark 1964) and even in the Skiddaw Slates (Roberts 1971 ;Jeans 1971) to a pre-Caradocian tectonic event.…”

Section: Introductionmentioning

confidence: 99%

Structure and stratigraphy of the Borrowdale Volcanic rocks of the Kentmere area, English Lake District

Soper¹,

Numan²

1974

Geological Journal

View full text Add to dashboard Cite

The Borrowdale Volcanic rocks of Kentmere have been reinvestigated. A previous structural interpretation (Mitchell 1929) involving Caledonian isoclines superimposed upon pre-Caradocian NNE trending folds is shown to be incorrect; neither set of structures exist. The geometry of the major structural elements in the area, the Nan Bield Anticline and the Caledonoid cleavage, is described. Evidence is adduced which suggests that the anticline was formed in pre-Caradxian time as a large open fold trending approximately E-W. Its present geometry and that of the Wren Gill Monocline result from the superimposition of the regional end-Silurian cleavage obliquely and inhomogeneously across this preexisting fold.The volcanic succession is divided into four compositionally and petrographically defined formations. In upward sequence these are the Nan Bield and Wren Gill formations (andesitic lavas and tuffs), Kentmere Formation (mainly dacitic pryoclastic rocks) and the Garbourn Formation (andesites and dacites), totalling over 2800 m. It is thought that much of this succession was deposited subaqueously.

show abstract

Section: Introductionmentioning

confidence: 99%

Structure and stratigraphy of the Borrowdale Volcanic rocks of the Kentmere area, English Lake District

Soper¹,

Numan²

1974

Geological Journal

View full text Add to dashboard Cite

show abstract

Palaeomagnetism of igneous rocks of the Lake District (Caledonian) terrane, Northern England: palaeozoic motions and deformation at a leading edge of Avalonia

Piper

1997

Geol. J.

View full text Add to dashboard Cite

The Lake District terrane of northern England comprises Upper Cambrian±Silurian sediments and volcanics accumulated at the northern margin of the Avalonian Plate during growth and demise of the Iapetus Ocean. Ocean closure and suturing resulted in Late Ordovician and Acadian tectonism and were accompanied by emplacement of a large regional batholith. Collectively the palaeomagnetic data from this terrane identify a hairpin in the apparent polar wander path during Late Ordovician (Caradoc±Ashgill) times corresponding to`soft' closure of the Iapetus suture and accompanying deformation. The same motion is recognized in contemporaneous data from the Welsh Caledonides where declinations are rotated by c. 558 relative to contemporaneous results from the Lake District. Adjustment for this (probable late Acadian) rotation beings fold trends of the Paratectonic Caledonides into alignment and identi®es a parallel mid-to late Ordovician destructive plate margin comprising forearc (Lake District) and backarc (North Wales). This arc was oriented latitudinally in mid-southerly latitudes during formation and the bulk of the magmatism occurred during a single normal-polarity chron. The relationships between magnetization and folding in both the Lake District and Welsh Borderlands identify the importance of Late Ordovician deformation along this arc during collision of Avalonia and Laurentia. Arc-related volcanism was succeeded in Silurian times by parallel foreland basins embracing the Welsh Basin and southern Lake District as the Laurentian Plate overrode the Avalonian Plate. #

show abstract

The structure of the Skiddaw Slates in the Blencathra‐Mungrisdale area, Cumbria

Roberts¹

1977

Geological Journal

Self Cite

View full text Add to dashboard Cite

Four phases of deformation (Dl-D4) and a ubiquitous non-tectonic bedding-cleavage are described. D1 structures are gravity collapse folds without an associated cleavage, formed before the extrusion of the Borrowdale Volcanics. Pre-Bala folds recognised in the Volcanics are not readily observable in the Slates on a small scale. but may be present on a wider aspect. D2-D4folds and cleavages are end-Silurian structures, the result of the main closure of the Lake District Geosyncline during the Caledonian Orogeny. D2 is the result of crustal shortening and is closely related in time to the emplacement of the Skiddaw Granite; D3 resulted from vertical shortening in conjunction with the intrusion of the Lake District Batholith; and D4 resulted from postgranite shortening of the existing fold axes. A correlation of the history of deformation with those of other areas is also suggested.

show abstract

Structures of the Skiddaw Slates in the Caldew Valley, Cumberland

Cited by 22 publications

References 17 publications

Structure and stratigraphy of the Borrowdale Volcanic rocks of the Kentmere area, English Lake District

Structure and stratigraphy of the Borrowdale Volcanic rocks of the Kentmere area, English Lake District

Palaeomagnetism of igneous rocks of the Lake District (Caledonian) terrane, Northern England: palaeozoic motions and deformation at a leading edge of Avalonia

The structure of the Skiddaw Slates in the Blencathra‐Mungrisdale area, Cumbria

Contact Info

Product

Resources

About