• Definition of Isotopes
• Binding Energy, how to calculate it.
• Which element has the highest BE?
• Chart of Nuclide
• Valley of Stability
• Modes of radioactive decays (α, β, and EC or e+)
• Brief history of our field. Brief history of the Universe (Chemical Evolution)

• Nuclear Stability
• Fusion, Fission, and alpha-decay
• Law of radioactivity
• Half-life, mean-life, and “5 half-life rule of thumb”
• Isochron concept

• How elements are made?
• • From H-Fe (fusion)
  • From Fe and above (neutron addition)
  • Cannot add too much neutron: fission occurs
• s-process, r-process, and p-process for heavy elements
• Neutron drip line
• s- and r-processes peaks, “magic neutron numbers”

January 17, 2008
Lecture 4

• Cosmic chemical abundance “9th symphony of Goldschmidt”
• Oddo-Harkins rule
• Atomic Weight Calculations (with radiogenic isotope)

• Column Chemistry
• Mass Spectrometry Principles
• Energy Filtering
• How a high resolution is achieved

• How a high resolution is achieved
• How charged particle signals are recorded and converted as voltage, how the calculation is done
• Small signal (for small sample) amplification through Secondary Electron Multiplier (SEM)
• How the isotopic/atomic P/D ratio is calculated.
• Isotope Dilution and Isotope Mixing
• Error Magnification in isotope dilution

January 29, 2008
Lecture 7

• Instrumental Mass Fractionation Correction
• Cases when isotope dilution do not apply.
• Advantages and disadvantages of isotope dilution.
• Linear Regression (Conceptual, more to follow)
• Conservation Laws for Nuclear Reactions
• Terminology
• Completion of Part I
• Start of Part II Radiogenic Isotope Geochronology
• Chapter 3: Rb-Sr method

January 31, 2008
Lecture 8

• What is BABI, how it is defined and what does it mean? What is ADOR, ALL?
• Plotting ⁸⁷Sr/⁸⁶Sr vs. ⁸⁷Rb/⁸⁶Sr (isochron diagram): slope is time (function of t)
• Plotting ⁸⁷Sr/⁸⁶Sr vs. time (evolution diagram): slope is ⁸⁷Rb/⁸⁶Sr times decay constant
• Model Ages: how to calculate and how to represent it geometrically in evolution diagram
• Metamorphic resetting: mineral vs. whole rock
• Sr in seawater (sources and sinks) and its evolution over geologic time
• Glacial erosion and Sr isotopic evolution in seawater
• Divergence at 2.5 Ga vs. the building up of continents
• Himalayan uplift and high resolution Sr isotope chronology
• Improving Sr isotope seawater curve in deep time.
• Residence time and how to calculate it.

Feb. 5, 2008
Lecture 9

• Least square fit (unweighted vs. weighted regression)
• MSWD and its meaning
• Simple/Practical Error Propagation
• What is CHUR? What does it represent?
• What is ¹⁴⁷Sm/¹⁴⁴Nd and ¹⁴³Nd/¹⁴⁴Nd value for CHUR?
• Evolution diagram: Difference with Rb-Sr system
• Epsilon Nd? e(0) vs. e(T)
• f _Sm/Nd?

Feb. 7, 2008
Lecture 10

• Mixing Theory
• Two component mixture: Chemical Expression
• Two component mixture: Isotopic Expression (for one element)
• Examples at micro- and mega-scale
• Fictitious isochron (mixing line)
• Dissect the mixing equation
• Binary mixing of two elements with different concentration and isotopic compositions.
• Examples

• Nd model ages relative to CHUR or DM (Depleted Mantle). Which one is older?
• Intra-crustal melting and mixed provenance.
• Nd model age vs. Stratigraphic age. Deviation and its significance
• Very early differentiation at ~4Ga ago: +4 epsilon

Feb. 12, 2008
Lecture 11

• Seawater Nd: residence time
• Why there is difference in Nd isotopes between Pacific, Indian, and Atlantic. What does it tell us?
• Crustal Growth Problem
• ²³⁸U, ²³⁵U and ²³²Th decay chain and their positions in the chart of nuclide
• Three decay equations for the U-Th-Pb systems and three independent age constraints
• How the primordial Pb isotopic compositions are defined and determined (troilite from Canyon Diablo)

Feb. 14, 2008
Lecture 12

• The m and k values
• Pb-Pb isochron and Pb-Pb age
• Why Pb-Pb age is so precise in the beginning?
• Clair Patterson’s “Age of Earth” (1956) and its limitation
• Concordia Diagram, a.k.a. Wetherill Diagram
• Discordia: upper and lower intercept ages
• Suitable minerals for U-Pb geochronology
• Common lead corrections
• In-situ analyses: ion-probe vs. laser ablation

Mid-term (in class)
Close book. You may bring hand calculator. No computer/laptop, please.

Feb. 21, 2008
Lecture 13

• Evaporation method (Kober method)
• Tera-Wasserburg diagram
• U-Pb, Th-Pb, vs. Pb-Pb isochrons: open systems
• It is all about m and k values
• Holmes-Houtermans Model (Single-stage Pb isotope evolution)
• Conformable Pb
• Two stage Pb isotope evolution model
• Pb-Pb dating and crustal evolution
• Closed system Pb isotope evolution of the Mantle
• Open System Pb Isotope Evolution of the Mantle
• Stacey and Kramers (1975) model
• Terrestrial Pb Paradox I
• Pb Isotopes and Core formation
• U-Pb modeling of core formation and its limitations: two equations, three unknowns

Feb. 26, 2008
Lecture 14

• Pb isotope growth curve vs. Concordia curve
• Short-lived radioactivities in the early Solar System and the birth place of solar neighborhood
• How the “fossil isochron” for extinct radionuclides works
• Discovery of ¹²⁹I and ²⁶Al
• Supernova trigger vs. X-wind theory
• High resolution relative chronology
• Scientific motivation
• Standard model of planet formation
• Canonical ²⁶Al/²⁷Al in the early Solar System
• Dating the first stage of planet formation with ⁵³Mn-⁵³Cr system (half-life 3.5 Ma)

Feb. 28, 2008
Lecture 15

• Dating planetary accretion and differentiation through ¹⁸²Hf-¹⁸²W, ¹²⁹I-²⁴⁴Pu-Xe and ¹⁴⁶Sm-¹⁴²Nd clocks
  • Dating the last stage of planet formation with ¹⁸²Hf-¹⁸²W system (t_1/2=9 Ma)
  • Magma oceanography with ¹⁴⁶Sm-¹⁴²Nd system.
  • Missing reservoirs and geochemical paradoxes

• ¹⁸⁷Re-¹⁸⁷Os and ¹⁹⁰Pt-¹⁸⁶Os systems
• Geochemical behavior of Re, Os, and Pt and their distribution in nature, and the corresponding Os isotopic compositions

March. 4, 2008
Lecture 16

• gOs (percent deviation of ¹⁸⁷Os) and e¹⁸⁶Os
• f_Re/Os and f_Pt/Os
• Mantle evolution defined by OsIr alloy
• Model Ages: relative to CHUR(T_CHUR), Depleted Mantle(T_DM) and T_RD (Re Depletion Age: minimum age)
• Core contribution from ¹⁸⁶Os signature vs. alternative interpretation.
• Combining geothermetry (T) and geobarometry (P) with Os model ages to construct continental root structure
• Dating sediments (black shales), ore deposits (MoS), and crude oils with Re-Os system
• Seawater Os evolution compared with Sr

March 6, 2008
Lecture 17

• ¹⁷⁶Lu-¹⁷⁶Hf decay system
• Half-life issue
• Elemental compatibility pattern for Rare Earth Elements (consider Hf next to Sm)
• CHUR for Lu-Hf compared with Sm-Nd
• Depleted cumulate eucrites in Lu-Hf and Sm-Nd spaces
• Jack Hills zircons on Lu-Hf evolution diagram
• CHUR parameter issue
• e_Hf and e_Nd correlation for MORBs and OIBs
• Is there a hidden reservoir we are not sampling?
• Model ages relative to CHUR or DM
• Lu/Hf fractionation in sediments: zircon is to blame
• ⁴⁰K-⁴⁰Ar-⁴⁰Ca branched decay system
• Atmospheric ⁴⁰Ar contamination and corrections using (⁴⁰Ar/³⁶Ar)_atms=295.5
• ⁴⁰Ar* budget of the Earth and un-degassed mantle
• High ⁴⁰Ar/³⁶Ar of MORB vs. low ⁴⁰Ar/³⁶Ar for OIBs
• ⁴⁰Ar-³⁹Ar method of dating
• J value for the standard monitor with known age
• Step wise Ar release pattern and plateau age
• Grain size distribution and diffusional loss of Ar: theory and observations
• Cooling rate, closure temperature and thermochronology
• ⁴⁰K-⁴⁰Ca system: Evolution diagram, isochron, and e_Ca vs. e_Nd mixing line
• ¹³⁸La-¹³⁸Ce-¹³⁸Ba branched decay systems
• Branched decay equations
• Opposite partition behaviors for La/Ce and Sm/Nd or Lu/Hf
• Negative correlation between e_Ce and e_Nd vs. positive correlation between e_Nd and e_Hf.

March 11, 2008
Lecture 18

Guest Lecture by Prof. Kari Cooper on U-series (I)

Finals preparation week (March 17-21, 2008)