GEOPHYSICS (RADIOMETRIC SKEMANG) Flashcards
Survey that detects and maps natural radioactive emanations (Gamma Rays)
Radioactive survey
Products of Radioactive Decay
?Alpha Partices (2n, 2p)
?Beta Particles (High energy Electrons)
?Gamma Rays (very high frequency EM waves which can be treated as particles)
Where does Gamma Radiation originate?
From the natural decay of elements like U, Th, and K
Common radioactive minerals and their respective radioactive elements
Uranitite U238
Monazite Ce La Th Nd
Thorianite U232
Rubidium Rb87 Granite Pegmatite
K 40 in feldspars
Sylvite in Acid Ign Rocks
Radiocarbon C14
Associated non radioactive deposits
Zircon and Titanium
Terrestrual radiaton may come from these three dominant radioactive elements
K40
Th232
U238
Propert being measured
Emission count rates over a fixed period of time
Units
Roentgen [R]
An instrument equipped with a meter and earphone that responds to Beta Particles proximity of a radioactive source and is only limited to Ground Surveys
Geiger or Geiger-Muller Counter
This instruments detects emissions of flashing lights using a Photomultiplier at or near 100% detection of Gamma radiation and is the sole counter used for Airborne Radiometric surveys in collab with Airborne magnetics and EM surveys
Scintillation Counter
Gamma ray energies can be measured by this instrument
Spectrometer
Typrical Sprectrometer sensor
256 channel
Cost per line km increase?
10-20%
Mining and Econ Geol
?Nuclear Fuel and Associated Minerals
?Locating ALTERATION zones in Acid and Intermediate Intrusions (PCDs)
?Search for Phosphate and Placer Deposits
Structural
?Demarcation of Geol structures and Intrusives
?Geochronology of Rock Formations
Hydrogeol
?Can be of aid to Magnetic Mapping in identifying old river channels
