| Q1 |
Worbarrow Tout. Purbeck
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| Q2 |
2.5 km
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| Q2A |
Strike East / West- dip
to North (90"), generally quite straight, perhaps a structure.
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| Q3 |
30 - 50 degrees
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| Q4 |
i) They are in the same
direction - younger going north
ii) They are at right angles to each other. iii) Seem to be steep dips, narrow outcrops. |
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| Q5 |
Not so narrow!
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| Q6 |
Follows quite closely,
The narrow outcrops here are scarp slopes of horizontally bedded strata.
Good indicators of horizontal beds.
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| Q7 |
Vertical scale is 3 times
horizontal
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| Q8 |
Measure outcrop width,
use dip given and formula t = w x sin @ Dip @ = 45 w = 700 so t = 700
x 0.5 = 350m in Worbarrow
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| Q9 |
Thin out from Swanage
towards Lulworth.
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| Q10 |
Wealden possibly less
resistant to erosion- forms bays and low ground.
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| Q11 |
Could be a anticline or
syncline.- actually the Purbeck Monocline, younger than Eocene- Alpine
orogeny (Miocene)
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| Q12 |
Southwest
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| Q13 |
Down thrown to southwest(normal)
tear (sinistral)
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| Q14 |
Older than Creechbarrow
beds - younger than London Clay
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| Q15 |
Creechbarrow Outlier -
younger beds surrounded by older; other examples at St Aldehms
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| Q16 |
V shape out crops point
in the direction of dip - the shallower the dip the more pointed the V.
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| Q17 |
Quartz, calcite, clay
minerals
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| Q18 |
calcite
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| Q19 |
aragonite
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| Q20 |
Precipitated, biological
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| Q21 |
CaCO3 + 2HCl
> CaCl + H20 +CO2 gas
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| Q22 |
When it is Dolomite -
CaMg substitution for CaC03.
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| Q23 |
Rain water containing
dissolved CO2 causes dissolution
CaCO3 + H2O +CO2 > (Ca3+) + (2HCO3-) |
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| Q24 |
Grains 1) bioclast 2)
ooid 3) peloid
Matrix 1) micrite 2) sparrite |
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| Q25 |
1)Shell debri
2) strong wave action and precipitation 3) biograzing/precipitation |
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| Q26 |
aluminosilicates
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| Q27 |
Final weathering products
of rock forming minerals. Amphibole ,mica and feldspar in particular.
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| Q28 |
Cohesion / "clumping"
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| Q29 |
Quartz / feldspars
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| Q30 |
Unaltered components of
other rocks
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| Q31 |
Triangle with mudstone/clay;
sandstone/quartz; limestone/calcite at the corners and intermediates along
the sides.
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| Q32 |
Calcite and silica (dolomite
and siderite are other carbonate cements)
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| Q33 |
Precipitated from pore
waters or pressure dissolution
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| Q34 |
Fine = salt; medium =
castor sugar; coarse = granulated sugar
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| Q35 |
1)Physical - higher latitude,
(freeze thaw)
2) Chemical - warm wet tropical, vegetated lowland humic acid in soils - faster reaction rates. |
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| Q36 |
Mineral
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Product
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Silicate structure
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Olivine
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Dissolved ions (Fe2+)
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isolated
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Pyroxine
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Dissolved ions
|
chains
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Amphibole minerals
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Dissolved ions and clay
minerals
|
chains / double chains
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Mica
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Clay minerals
|
sheets
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Feldspar
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Clay minerals
|
sheets
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Quartz
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Quartz
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frame work
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| Q37 |
Quartz / clay minerals
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| Q38 |
Sorting, grain size, sphericity,
roundness, cementation, texture, fabric correlation (matrix), maturity.
Grain or matrix supported.
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| Q39 |
Texturally and compositionally
immature > 15% mud cement by volume.
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| Q40 |
Sandstone with > 25%
feldspar
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| Q41 |
Laminar Cross Bedding
- Low
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Trough Cross Bedding -
High
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Herring Bone Cross Bedding
- Alternate (tidal)
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| Q42 |
i) current assymetric,
straight or sinuous curved, steep slope indicates current direction.
ii) wave action. Symetrical, bifurcating |
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| Q43 |
Calcite, gypsum , anhydrite
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| Q44 |
Anhydrite to gypsum -
removal of water
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| Q45 |
Chert biogenic,
silica-sponges (here, though, could be in solution from volcanic activity)
Chalk coccolith plates from plankton. Greensand quartz shoal sands, glauconite |
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| Q46 |
Stratigraphic correlation,
evolution studies, biological/environmental studies
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| Q47 |
Abundant, wide ranging,
rapid evolution
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| Q48 |
Rapid burial, anoxic -
water, particularly marine.
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| Q49 |
Depends on what you find
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| Q50 |
CHECK YOUR INTERPRETATION
WITH REFERENCE MATERIALS
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