Non-axial planar S1 cleavage in the Hawick Rocks of the Galloway area, Southern Uplands, Scotland

Stringer, Peter; Treagus, J. E.

doi:10.1016/0191-8141(80)90020-6

Cited by 66 publications

(25 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, the Hawick Group tracts are more folded and are affected by a stronger cleavage than is apparent in the older tracts to the north, with a tendency for the cleavage to be clockwise transecting, up to 20° locally (Stringer & Treagus 1980;Anderson 1987). The plunge of the fold hinges may be highly variable and folds are downward-facing locally.…”

Section: The Deformational Sequencementioning

confidence: 97%

The Southern Uplands Terrane in Scotland – a notional controversy revisited

Stone

2014

SJG

View full text Add to dashboard Cite

show abstract

Section: The Deformational Sequencementioning

confidence: 97%

The Southern Uplands Terrane in Scotland – a notional controversy revisited

Stone

2014

SJG

View full text Add to dashboard Cite

show abstract

“…Both sets of authors have mapped the shore-line on a similar scale although in 1959 we did not publish our 1:2,500 maps nor the detailed cross-sections. For the sake of comparison we enclose a section drawn up by ourselves on the same scale as that published by Stringer and Treagus (1981 fig. 4, p. 136 from [NX 5815 4941]), of the section from Knockbrex through Corseyard to Kirkandrews (Fig.…”

Section: Sirsmentioning

confidence: 99%

“…It should be pointed out that in our reinterpretation of the fold structure of the Hawick Rocks (Stringer and Treagus 1981), we did not contest the locally unequal development of folding and the presence of essentially flat-lying areas per se, but rather we questioned the established concept arising from these features, of a major monoclinal fold of about 7 k m wavelength stepping down to the north-west, with a markedly unequal distribution of smaller scale folds between the flat-lying limb and the steep limbs (Craig and Walton 1959, pp. 213-9;Walton 1961, pp.…”

Section: Sirsmentioning

confidence: 99%

“…These observations are not substantiated by the sheet-dips of the folded strata calculated along the t w o sections ( Table 1). The sheet-dips have been derived from our original 1:2000 scale surface observations (Stringer and Treagus 1981, fig. 4a, reduced in scale), by constructing vertically extended fold profiles separately for concentric, chevron and similar Fi fold geometry.…”

Section: Sirsmentioning

confidence: 99%

“…

…”

mentioning

confidence: 99%

See 2 more Smart Citations

Asymmetrical folding In the Hawick Rocks of the Galloway Area, Southern Uplands: comment

Craig

Walton

1983

SJG

View full text Add to dashboard Cite

SIRSStringer and Treagus (1981) have commented on our paper on the over-all folding in the southern part of the Southern Uplands . We are particularly interested in their contesting two of our conclusions, a) that folding, as measured in terms of fold hinges per unit distance, is unequally developed, and b) that there are essentially flat-lying areas interspersed by zones of steeply dipping beds. Both sets of authors have mapped the shore-line on a similar scale although in 1959 we did not publish our 1:2,500 maps nor the detailed cross-sections. For the sake of comparison we enclose a section drawn up by ourselves on the same scale as that published by Stringer and Treagus (1981 fig. 4, p. 136 from [NX 5815 4941]), of the section from Knockbrex through Corseyard to Kirkandrews (Fig. 1).We regarded the rocks along this section of coast as belonging to one of our flat belts. By a flat belt we meant that although the area was strongly folded, a notional stratigraphic horizon changed very little traced from one end of the section to the other, as can be seen from Figure 1. At the time we supposed that the enveloping surface of the flat belt (we used the German term Faltenspiegel) was essentially horizontal. The recognition of such stratigraphically flat zones associated with zones where the stratigraphic horizon changed markedly led us to the concept of a monoclinal structure stepping down to the NW. We were searching for an over-all model to replace the Lapworthian anticlinorium-synclinorium. The monoclinal model seemed to fit the data better although 20 years ago we could not visualize the stages leading to the deformation of a pile of horizontal rocks into the present over-all structure; steep belts always seemed to be too wide. The currently popular, accretionary-prism model resolves our problem by emphasizing faulting and relegating folding to a secondary role. Nevertheless it remains important there should be a clear appreciation of the detailed structural pattern.Is folding equally distributed? A simple test of this is to plot the cumulative number of fold hinges against distance across strike (Fig. 2). Two points emerge. The number of fold hinges per km as judged from the slope of the curve is similar over most of the Hawick rocks but as can be seen from Stringer and Treagus's sections (e.g. 1981, fig. 4, p. 137) the number is much more variable on a scale of hundreds of metres. The number does tend to decrease towards the south-east and is significantly lower in the Wenlock rocks of Meikle Ross. One steep belt occurs in the Wenlock.Are there flat-belts? Here we have to concede that the construction of a simple Scott.

show abstract

Non‐axial planar cleavage and Caledonian sinistral transpression in eastern Ireland

Murphy

1985

Geological Journal

View full text Add to dashboard Cite

Transected Fl fold structures in eastern Ireland are associated with subhorizontal stretching in the S1 cleavage whereas axial planar cleavage contains a vertical elongation direction. This suggests that the non-axial planar cleavage was influenced by a distributed strike-slip ductile shear.A major NE-SW trending F, syncline is described in which the minor F, folds show systematic variations in cleavage transection parameters. O n the steep limb of the major syncline the cleavage trmsects the minor F1 folds in a consistently clockwise sense, whereas on the normal limb anticlockwise transected folds are seen. kdal planar cleavage occurs at the core of the major syncline.Fold profile analysis indicates that the buckling of the layers began before the initiation of the cleavage. Open, parallel folds at the major synclinal hinge zone are progressively 'flattened' on the steep limb towards a major D1 sinistral transcurrent fault. The angular transection, A, attains a maximum of 15" dockwise which diminishes to 6" at higher strains adjacent to the major fault.Incremental fibre growth in pressure shadows show a two-stage tectonic strain superposition of vertical pure shear followed by sinistral transcurrent simple shear during the development of the clockwise transecting cleavage. Anticlockwise transected folds were influenced by local dextral strike-slip on the southern margins of a rigid terrane. As a regional feature, the clockwise transection is explained by a sinistral transpressive deformation of end-Silurian age.

show abstract

Non-axial planar S1 cleavage in the Hawick Rocks of the Galloway area, Southern Uplands, Scotland

Cited by 66 publications

References 34 publications

The Southern Uplands Terrane in Scotland – a notional controversy revisited

The Southern Uplands Terrane in Scotland – a notional controversy revisited

Asymmetrical folding In the Hawick Rocks of the Galloway Area, Southern Uplands: comment

Non‐axial planar cleavage and Caledonian sinistral transpression in eastern Ireland

Contact Info

Product

Resources

About