GEOCHEM TECHNIQUES Flashcards
Electron Probe MicroAnalyzer (EPMA)
?Point Specific In Situ Chemical/Elemental Analysis of mineral grains at Microns Scale (In-Situ XRF)
Xray diffraction
?Examine physico-chemical make up of unknown solids
?ID of Minerals basd on their Crystal Structure (Mineralogical Studies)
?Can be used in Clay Minerals
Xray Fluoresence
?Major and trace element analyses of bulk rocks, minerals, sediments and fluid
?Based on Intenstity of Spectrum of the secondary X-ray or Flourescent which is proportional to the concentration of individual elements
Inductively Coupled Plasma Mass Spectrometry (ICPMS)
?Capable of detecting metals and several non metals at very low concentrations (Trace Elements up to ppt)
Incuctively Coupled Plasma Atomic Emisson Spctrometer
?Examine Phsico-chemical make-up of unknown solids
?Major and Trace Elements of up to ppb
?Optical emission method excited by inductively couple plasma
Instrumental Neutron Activation Analysis
?Non Dest Determination the Concentration of Major and Trace elements (REEs) with high level of accuracy (Bulk Rock)
?Bombardement by Neutrons to produce Gamma Radation
Atomic Absortion Spectrometry
?Rapid and Precise used for quantitative Determiation of a lagre number of samples for MULTIELEMENTAL ANALYSIS
?Absrorbence of a characteristic radiation of desired metal is measured for computation of elemental concentration
?Approx 30 elements can be determined from one solution
Secondary Ion Mass Spectrometry
?In Situ Elemental, Isotopic and molecular composition of SOLID SURFACES
Thermal Ionization Mass Spectrometry
?Measure the Isotope Ratios of elements used in geochronology and tracer studiesl (Nuclear Materal Analysis)
Sensitive High Resolution Ion Microprobe
Measure Isotopic and elemental abundances at a micrometer scale; U-Th-Pb Geochron
Scanning Electron Microscope
?Generates high resolution images of shapes/objects (SEI) and shows spatial variations in chemical compositions
Transmission Electron Microscope
?Used in Metallurgical studies inclding defect structres in alloy material
?Quantitative Measurements on Crystal Structure Data from electron diffraction and Compositional data from Xray emissions
Fire Assaying
?Quantitative Determination in which metals are separated from impurities by fusion processes and weighed to determine the amount present in original sample
?Most accurate but totally destructuive for determination of Precious Metals
AAS
XRF
Major Element Dertemination
ICP-AES
ICPMS
INAA
Trace and Rare Earth Elements
SEM
TEM
EPMA
surface and structure related compositional analysis
Carbon Dating
Used to Establish Exploration/Mining/Smelting Heritage
SHRIMP
SIMS
TIMS
Isotope studies
XRD
Mineralogy of Crystal Subtsances
Precious Metals
?Fire assaying finished w/ ICP-MS/ICP-ES/AAS
?INAA for solid forms
Base Metals in Stream Seds
?Strong Acid Attack (Nitric + HCl) finished w/ ICP-ES or AAS
Rock Analysis
?Fusion (Nitric + Perchloric + Hydroflouric Acid) finished w/ XRF/ICP-ES/ICP MS
For Anionic Elemntal Species
?Ion Chromatography
?Or some ICP-ES or XRF
