Devon and Cornwall

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The numbers in square brackets, e.g. [SS413880; 51.569238,-4.292622], are the British grid reference followed by latitude and longitude. The - means longitude west.

Hele Bay, Ilfracombe, and Combe Martin, Devon

MapIlframcombe.jpg.MapIlframcombeGoogle.jpg

Ilfracombe Bay. SS 529 474


Structure/Foliation/85_408. Pressure solution cleavage. Note the narrow dark bands crossing the sandy mudstone beds. Quartz has been removed from these bands and deposited in quartz veins nearby. The more massive layers have fewer dark solution bands running across them. [SS529474; 51.210233,-4.112678]


Structure/Foliation/ 85_409. Note the relatively quartz rich microlithons (lighter layers) crossing several of the dark layers. [SS529474; 51.210233,-4.112678]

../Structure/Foliation/85_410.JPG
Structure/Foliation/ 85_410.  This outcrop is crowded with microlithons of relatively quartz rich material alternating with darker bands from which the quartz is removed. [SS529474; 51.210233,-4.112678]


Structure/Foliation/ 85_413. Pressure solution cleavage, with shears and folds. [SS529474; 51.210233,-4.112678]


Structure/Foliation/ 85_411. Pressure solution concentrates in high stress zones, such as the cusps of folds. [SS529474; 51.210233,-4.112678]


Structure/Foliation/ 85_412. Pressure solution cleavage, with folded quartz veins showing the shortening involved is greater than 50%. [SS529474; 51.210233,-4.112678]

Hele Bay

../Structure/Fold/Folds1/85_404.JPG
Structure/Fold/Folds1/85_404.JPG. Asymmetrical folds and cleavage.  Hele Bay, Ilfracombe, Devon, England. [SS532475; 51.212707,-4.093795]

../Structure/Veins/85_405.JPG
../Structure/Veins/85_405.JPG. Fold hinge with tension gashes.  Hele Bay, Ilfracombe, Devon, England. [SS532475; 51.212707,-4.093795]
The tension gashes indicate extension parallel to the fold hinge.

Combe Martin, Devon, England. [SS575475.

../Structure/Fold/Transposed/85_415.JPG
Structure/Fold/Transposed/85_415.JPG. Transposed sandstone lenses along cleavage. In this case, apparent transposition results from pressure solution. [SS575475; 51.209959,-4.032383]

../Structure/Fold/Transposed/85_416.JPG
Structure/Fold/Transposed/85_416.JPG. Pressure solution has isolated the sandstone lenses that originally were part of a single bed. Further differentiation at higher grades would give the appearance of a gneiss.
[SS575475; 51.209959,-4.032383]

Hartland Quay, Devon, to Millook Haven, Cornwall

This section of coast makes a wonderful field trip illustrating the Devonian turbidites and their structures.
MapHartland2Millook.jpg

Hartland Quay, Devon. SS 223 247.

MapHartlandQuay.jpg.MapHartlandQuayGoogle.jpg

../Structure/Fold/Folds1/85_428.JPG
Structure/Fold/Folds1/85_428.JPG. Kink Folds in Carboniferous Culm facies.  England , Hartland Quay, Devon, Eng. [SS225250; 50.995643,-4.531395]
These chevrons are a puzzle. One idea is that they develop from conjugate kinks with the migration of kink boundaries  until the final boundary is vertical.

../Structure/Fold/Folds1/85_423.JPG.../Structure/Fold/Folds1/85_421.JPG
                                                                                          Structure/Fold/Folds1/85_423.JPG. Chevron folds with a tight core.  Hartland Quay, Devon.      Structure/Fold/Folds1/85_421.JPG. Kink Fold with saddle reef and thrust. Hartland Quay, Devon.
[SS225250; 50.995643,-4.531395]

../Structure/Foliation/85_518.JPG
Structure/Foliation/85_518.JPG. Pressure solution and related tension gashes running horizontally across the slide near the large vein. Hartland Quay, Devon, England. [SS225250; 50.995643,-4.531395]


../Structure/Veins/85_425. Encephalon tension gashes in a shear zone.  Hartland Quay, Devon, England.  [SS225250; 50.995643,-4.531395]
The cracks indicate a shear of the top to the right. The orientation of the veins is perpendicular to the long axis of the strain ellipse.

Welcombe Mouth, N. of Bude, Devon. [SS 212 181.

MapWelcombeMouth.jpg.MapWelcombeMouthGoogle.jpg

../Structure/Fold/Folds2/85_440.JPG
Structure/Fold/Folds2/85_440.JPG. Refolded recumbent fold. Upright F2.  Welcombe Mouth, N. of Bude, Devon. [SS212181; 50.934558, -4.546003]


../Structure/Veins/85_439. Folded tension gashes.  Welcome, north of Bude, Devon, England. [SS212181; 50.934558, -4.546003]


../Structure/Veins/85_441. Tension gashes offset on one limb of fold. Welcome, north of Bude, Devon, England. [SS212181; 50.934558, -4.546003]

Northcott Mouth, Cornwall. SS 202 085.

MapNorthcottMouth.jpg.MapNorthcottMouthGoogle.jpg

../Structure/Fold/Folds1/85_431.JPG
Structure/Fold/Folds1/85_431.JPG. Chevron syncline and rounded anticline. Northcott Mouth, N. of Bude, Cornwall. [SS202085; 50.848006, -4.555493]

../Structure/Fold/Folds1/85_429.JPG
Structure/Fold/Folds1/85_429.JPG. Box fold. Northcott Mouth, N. of Bude, Cornwall, Eng. [SS202085; 50.848006, -4.555493]

../Structure/SSdikes/85_432.JPG
Structure/SSdikes/85_432.JPG. Ptygmatic sandstone dikes with 30% vertical shortening. The book lies on a bedding plane. The rocks are Carboniferous sandstone and shale. England. Cornwall, N. of Bude, Northcott Mouth.
[SS202085; 50.848006, -4.5554933]

../Structure/SSdikes/85_433.JPG
Structure/SSdikes/85_433.JPG. Folded dike with 30% shortening (close-up of 85_432). England. Cornwall, N. of Bude, Northcott Mouth. [SS202085; 50.848006, -4.555493]

../Structure/SSdikes/85_434.JPG
Structure/SSdikes/85_434.JPG.  Folded dikes. England. Cornwall, N. of Bude, Northcott Mouth. [SS202085; 50.848006, -4.555493] John Cosgrove of Imperial College.

Widemouth Bay, Cornwall. SS 200 030.

MapWidemouthBay.jpg.MapWidemouthBayGoogle.jpg

../Structure/Faults/85_443.JPG
Structure/Faults/85_443.JPG. Dog leg on normal fault. Widemouth Bay, south of Bude, Cornwall, England. [SS200030; 50.794939,-4.558225]

../Structure/Faults/85_442.JPG
Structure/Faults/85_442.JPG. Small normal faults showing tips to the right. Widemouth Bay, south of Bude, Cornwall, England. [SS200030; 50.794939,-4.558225]

Wanson Mouth, Cornwall, England.  SS 195 012.

MapWansonMouth.jpg.MapWansonMouthGoogle.jpg

../Structure/Fold/Folds1/85_507.JPG
Structure/Fold/Folds1/85_507.JPG. Periclinal fold (i.e. plunge change).  Wanson Mouth, south of Bude, Cornwall, England. [SS195012; 50.780958,-4.56418]

../Structure/Fold/Folds1/85_506.JPG
Structure/Fold/Folds1/85_506.JPG. Recumbent fold with cleavage.  Wanson Mouth, south of Bude, Cornwall, England. [SS195012; 50.780958,-4.56418]

../Structure/Foliation/85_508.JPG
Structure/Foliation/85_508.JPG. Pressure solution pathways in sandstone.  Wanson Mouth, N. of Bude, Devon. [SS193011; 50.780958,-4.56418]

Millook Haven, south of Bude, Cornwall, England. [SS 183 003.

.MapMillookGoogle.jpg

../Structure/Fold/Folds1/85_509.JPG
Structure/Fold/Folds1/85_509.JPG. Recumbent chevron folds.   Millook Haven, south of Bude, Cornwall, England. [SS183003; 50.772364,-4.577193]

../Structure/Fold/Folds1/92-008.JPG
Structure/Fold/Folds1/92-008.JPG. Close up view of recumbent folds in Carboniferous turbidite. Millook Haven, Cornwall. [SS183003; 50.772364,-4.577193]


../Structure/Veins/85_511. Tension gashes on overturned limb. Millook Haven, Cornwall. [SS183003; 50.772364,-4.577193]


../Structure/Veins/85_512. Core zone of recumbent fold with tension gashes in the lower limb. Millook Haven, Cornwall. [SS183003; 50.772364,-4.577193]


../Structure/Veins/85_513. En echelon tension gashes defining a series of parallel shear zones. Millook Haven, Cornwall. [SS183003; 50.772364,-4.577193]


../Structure/Veins/85_514. Tension gashes in a progressive shear. Millook Haven, Cornwall. [SS183003; 50.772364,-4.577193]


../Structure/Veins/85_515. Tension gashes rotated during a progressive shear. Millook Haven, Cornwall. [SS183003; 50.772364,-4.577193]


../Structure/Veins/85_516. Tension gashes in conjugate shears. Millook Haven, Cornwall. [SS183003; 50.772364,-4.577193]


../Structure/Veins/85_517. Tension gashes rotated during a progressive shear.  Millook Haven, Cornwall. [SS183003; 50.772364,-4.577193]


Tintagel and Boscastle, Cornwall

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Tintagel, Cornwall. SX 052 890

../Structure/Foliation/85_524.JPG
Structure/Foliation/85_524.JPG. Tintagel slates. Tintagel, Cornwall, England. Note the castle ruins; legend has it that this was King Arthur's site of the Round Table. Taken from [SX052890; 50.66742,-4.757384]

Boscastle,  Cornwall. SX 095 915

../Structure/Fold/Folds1/85_523.JPG.../Structure/Fold/Folds1/92-009.JPG
Structure/Fold/Folds1/85_523.JPG. Fold tips. Boscastle, Cornwall, England.                          Structure/Fold/Folds1/92-009.JPG. Kinked foliation. Boscastle, Cornwall.
[SX095915; 50.691844,-4.698765]

../Structure/Fold/Folds2/85_520.JPG
Structure/Fold/Folds2/85_520.JPG. F2 folds, horizontal axial plane, with crenulation cleavage. Boscastle, Cornwall. [SX095915; 50.691844,-4.698765]

../Structure/Fold/Folds1/92-010.JPG
Structure/Fold/Folds1/92-010.JPG. Recumbent folds in Devonian slate. Boscastle, Cornwall. [SX095915; 50.691844,-4.698765]

Bodmin Moor

MapBodminGoogle.jpg

../Structure/Joint/92_013.JPG
Structure/Joint/92_013.JPG. Horizontal offloading joints in granite. Rough Tor, Bodmin Moor, Cornwall, England. [SX147808; 50.597435, -4.619614]

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