Field Techniques Flashcards
An essential piece of equipment for the detailed observation of all rock types and fossils materials.
Hand Lens
Most have a lens with ___ magnification
10x
Some lens contains both a (1)___ and a (2)___ or (3)___.
(1) 10x
(2) 15x
(3) 20x
- Essential for most geological fieldwork
- Used in breaking and collecting rock example
- Used to expose a fresh portion of the outcrop
Geologic hammer
In using a hammer, ____ must come first.
safety
Step on the sample and move your head (1)____ in the direction of hammer motion to avoid the (2)___ due to impact.
(1) away
(2) projectiles
Essential in taking down notes and sketching outcrops for better understanding
Field Notebook and Writing Materials
What to note?
- Date
- Weather
- GPS Reading/ Location
- Facing direction
- Scale
- Sketch
-Observations
-Pin point on your sketch where you get the strike where you get the strike and dip or observable features
Observations on Field Notebook
- Weathering
- Attitudes
- Structures
- Materials Present
- Sizes of grains or materials
- Remarks
Upper crust, outer zones of mountain belts
Pressure solution cleavage
Upper crust, outer zones of mountain belts; fine-grained rocks
Slaty cleavage
Upper crust, outer zones of mountain belts; competent rocks
Fracture cleavage
High strain faults and shear zones at all but shallowest depths
Mylonitic foliation
Middle crust, inner zones of mountain belts; metamorphosed rocks (1)
Schistosity
Middle crust, inner zones of mountain belts; metamorphosed rocks (2)
Crenulation cleavage
Dissolution of soluble grains to directed stress
Pressure solution cleavage
Alignment of platy grains by rotation, dissolution, and crystallization during applied stress
Slaty cleavage
Tensional failure under high fluid pressure* in competent rock types
Fracture cleavage
Extreme flattening and stretching in narrow, high-strain zones of shearing
Mylonitic foliation
Mineral alignment under applied stress, during metamorphic crystallization
Schistosity
Microfolding of a pre-existing planar fabric (tectonic and sedimentary)
Crenulation cleavage
Dark/pale colour striping; partially dissolved fossils, clasts; stylolitic surfaces
Pressure solution cleavage
Fine fabric that rock cleaves along; typically associated with folds
Slaty cleavage
Spaced cracks in competent rock type
Fracture cleavage
Strongly planar fabric; other high-strain features
Mylonitic foliation
Visible mineral grains; millimeter to centimeter-scale folia, rougher than slaty cleavage
Scistosity
Microfold hinges, crenulation lineation
Crenulation cleavage
Compass-clinometer is used to measure:
- The orientation of geological planes and lineation with respect to north
- Angle of dip of geological feature with respect to the horizontal
Can also use in conjuction with a topographic map to accurately determine location
Compass-clinometer
More sensitive device because of the in-built spirit levels and the graduation of scales in 1 degree and 2 degree increments
Brunton-type
Other type of Compass-clinometer
Silva-types
Sampling- Things to do:
- Know your sampling method
- Get the sample that has the bulk composition of the outcrop
- Get a fist size sample for petrology, and crushed sample for geochemistry
- Get a duplicate
- Name the sample properly
