WJEC A2 Geology
BGS Mapwork Exercises
I.G.Kenyon
The Geology of Hadrian’s Wall
Quartz
Dolerite
Describe the strike and dip of the
rocks shown on the map extract
Outline, using map evidence the likely
form of the quartz dolerite intrusion
N
The Geology of Wenlock Edge, Shropshire
X
9
N
10
Silurian
Rocks
Y
Describe the strike and dip of the beds shown on the extract above
Geology and Topography of
Wenlock Edge, Shropshire
X
Y
Periglacial Head
Boulder Clay
Aymestry
Limestone
Upper Ludlow Shales
LowerLudlow
Shales
Wenlock Limestone
Cross section along line X-Y from the map on the previous slide
Using the geology map on the previous slide
and the cross section above, outline the
relationship between lithology and topography
Clitheroe 1:50,000 Sheet 68 Solid & Drift
Describe the strike and dip
of the beds in this box
Suggest reasons to
explain the V-shaped
outcrop pattern here
Ayr 1:50,000 Sheet 14(W) Solid
Describe the likely
form of the igneous
intrusion here
This fault dips South West,
identify the type of fault
Describe and identify the
fold structure within this box
Exeter 1 inch : 1 mile Sheet 325 Solid & Drift
Carboniferous
grits and shales
N
Basic igneous rocks
Using this slide and the next, try to
identify the types of igneous features
Permo-Triassic
breccias and
conglomerates
Exeter 1 inch : 1 mile Sheet 325 Solid & Drift
Identify the types of igneous features
Dolerite (D)
Carboniferous
grits and shales
Perm-Triassic breccias
and conglomerates
Basalt(B)
Tuffs
Section along southern margin of the map of previous slide
Hexham 1 inch :1 mile Sheet 19 Solid
Identify the main fold structure in the yellow box, refer to dip
and strike values, symmetry and plunge where appropriate
Okehampton 1 inch : 1mile Sheet 324 Solid & Drift
Describe the outcrop pattern of igneous
rock D and identify the type of intrusion
Granite
Line of cross
section on
next slide
Estimate the width of the metamorphic aureole around the granite above
Okehampton 1 inch : 1mile Sheet 324 Solid & Drift
Describe the fold structure between
and B on the cross section below
A
A
B
What map evidence is there to confirm that this part of the
bed is overturned? How could you confirm this in the field?
LLandrindod Wells 1:25,000 Sheet 15/16 Solid
Describe the map evidence to suggest there is a plunging syncline and
anticline on the extract above. In which direction are the folds plunging?
LLandrindod Wells 1:25,000 Sheet 15/16 Solid
N
This fault plane dips
East at 76° Identify
the fault type
Harlech 1:50,000 Sheet 135 Solid
This fault dips SSE at 70°
Identify the type of fault
C
Describe and identify the major fold structure
along line C – D. Refer to strike and dip,
symmetry and plunge where appropriate
D
Wrexham 1:50,000 Sheet 121 Solid
Compare and contrast the strike
and dip values of the Silurian (b)
and Carboniferous (d) Beds
What happens to the
conglomerate here?
This bed is a basal conglomerate,
explain the significance of this with
respect to the junction between the
Silurian and Carboniferous beds
Carboniferous
Silurian
Brough-under-Stainmore 1:50,000 Sheet 31 Solid
Using map evidence, describe
and explain the outcrop of the
Carboniferous beds in the NE
corner of the extract
F
E
The Hilton Fault dips SW at
80° Identify the fault type
Brough-under-Stainmore 1:50,000 Sheet 31 Solid
F
d
E
b = Ordovician
d = Carboniferous
e = Permian
f = Triassic
Describe and identify the major geological
structures shown on the cross section above
Lake District 1:250,000 Sheet 54°N - 04° West Solid
Permian
Ordovician
Carboniferous
Describe the likely
nature of these
igneous intrusions
Silurian
Identify 2 unconformities
on the map extract
Lake District 1:250,000 Sheet 54°N - 04° West Solid
Carboniferous
Silurian
Permian
Ordovician
Shap Granite
Ordovician
Identify 2 unconformities on the cross section above,
use information from the previous slide to help you
Monmouth 1:50,000 Sheet 233 Solid & Drift
B
A
D
Note-basal
conglomerate
G
H
Describe and identify the major fold structure
along line G – H on the map extract
C
Identify the structures shown
in boxes A, B, C and D
The Roaches & Upper Dove Valley 1:25,000 Sheet SK06 Solid & Drift
Identify the major fold structure in the box above, refer
to strike, dip, symmetry and plunge where appropriate
The Roaches & Upper Dove Valley 1:25,000 Sheet SK06 Solid & Drift
Landslide
Oldest bed
Describe and identify the major fold structure on the extract above,
refer to strike, dip, symmetry and plunge where appropriate. Outline
the likely reason for the occurrence of the large landslide on the map
Church Stretton 1:50,000 Sheet 166 Solid
Describe the major
fold structure in the
highlighted box, refer to
strike, dip, symmetry and
plunge where appropriate
Suggest, with reasons the
likely form of the dolerite
intrusion on the extract
Dolerite
Miller’s Dale 1:25,000 Sheet 17 Solid & Drift
Describe and identify the major fold structure on the extract above,
refer to strike, dip, symmetry and plunge where appropriate
Bristol 1 inch:1mile Solid & Drift
Describe the relationship between beds f6 and d2 on the map extract
Identify the major fold structure in the box on the map extract above
Bristol 1 inch:1mile Solid & Drift
Describe and identify the
major fold structure in this
area of the map extract
Bristol 1 inch:1mile Solid & Drift
Describe and explain
the nature of the
faulting in this area
Describe the relationship between the
f6 Triassic beds and the Carboniferous
d1 to d3 beds on the extract
Identify the major fold
structure in this area
Pembroke & Linney Head 1:50,000 Sheets 244/245 Solid & Drift
P
Describe and identify the major
fold structures along line P – Q
Check your answer on the next slide
Q
Pembroke & Linney Head 1:50,000 Sheets 244/245 Solid & Drift
Describe the major fold structures on the cross section above.
Suggest areas where beds are likely to be overturned. What field
evidence could you look for to prove some limbs were inverted?
Pembroke & Linney Head 1:50,000
Sheets 244/245 Solid & Drift
Identify and describe 2 major fold structures on the map extract,
refer to strike, dip, symmetry and plunge where appropriate
Maidstone 1 inch:1 mile Sheet 288 Solid & Drift
J
Line of section
on next slide
N
This fault plane dips S at
77° State the type of fault
Check your answer
on the next slide
K
Maidstone 1 inch:1 mile Sheet 288 Solid & Drift
How could you calculate
the throw of the fault?
South
Reverse Fault
North
K
J
Hanging wall
upthrown
Footwall
downthrown
Lands End 1:250,000 Sheet 50N 06W Solid
Describe and account for the shape of the
metamorphic aureole around the St. Austell granite
St.Austell Granite
Edge of metamorphic aureole
Describe the drainage
pattern shown in the North
and Eastern part of the map
Maidstone 1 inch : 1 mile Sheet 288 Solid & Drift
Swansea 1:50,000 Solid Sheet 247
This fault plane dips WNW at
67°, state the type of fault
Identify the main fold structure,
refer to dip and strike, symmetry
and plunge where appropriate
N
Swansea 1:50,000 Solid Sheet 247
The Grovesend Fault
dips East at 40°
Y
This fault dips
west at 47°
Identify this
fault structure
Identify the structure
between these 2 faults
X
Swansea 1:50,000 Solid Sheet 247
Describe the major fault structures
on the cross section below
Cross section along line X-Y on previous slide
Coventry 1:50,000
Solid & Drift Sheet 169
A
Describe the strike and dip of the
coal seams in boxes A and B
B
Account for the variation in outcrop
pattern of the coal seams in boxes
A and B on the map extract
Coventry 1:50,000, Solid & Drift Sheet 169
A
Describe the map evidence to support the idea there is an angular
unconformity within highlighted box A on the extract above
Newton Abbot 1:50,000, Solid & Drift Sheet 339
Granite
Describe and account for the drainage pattern developed
on the granite on the western side of the map extract
Newton Abbot 1:50,000, Solid & Drift Sheet 339
Dolerite
What type of intrusion
is represented by
the dolerite?
Granite
m = metamorphic aureole
Give 2 pieces of map evidence to show that the granite
intrusion is younger than the dolerite on the extract above
Newton Abbot 1:50,000, Solid & Drift Sheet 339
Dolerite
75
A
Black Shales
A major quarry is located in box A above. Outline 2 problems
that the local geology may present to the quarrying activity.
Newton Abbot 1:50,000, Solid & Drift Sheet 339
State the map
evidence for these
beds being horizontal
Impermeable
Breccia
Landslip
Permeable
Sandstone
Periglacial Head
Gravel-Permeable
Outline the factors that may explain the formation
of the landslip shown on the extract above
The End