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SIMS and MC-ICP-MS Applications in Isotope Cosmochemistry — with Yin Lab Examples
Qing-Zhu YinDepartment of Geology
University of California-Davis
IGG-CAS, BeijingApril 5, 2012
Why I love cosmochemistry,Meteorites in particular?
Chondrite (CHUR)=Bulk Solar System
With chondrite in hand, you hold the entire Solar System
Today4567.2±0.6Ma Ago
Meteorites:Cosmochemical Windows
Cartoon Credit: L. Nittler
lots of stars
500nm
Graphite grains
Spinel grains
Silicate grain
Silicon carbide
Corundum
Diamond
Burning down the haystack to find the needle!!!
中文贴切翻译: 海底捞针
Cosmic Abundance of Elements
Goldschmidt (1938): his “9th Symphony”
After Woosley (2007) Nature Physics
Solar AbundancesCosmic Abundances
=Mix from many Stellar Sources
s- and r-process: (slow and rapid neutron addition) B2FH (1957) and AGWC (1957)…
AGWCAlastair Graham Walter Cameron
(1925-2005)
one man, same number of initials,
single handedlyand independently
in 1957Chalk River ReportNo.41 (unclassified)
…At the end, the audience sat in awed silence until someone in the rear of the room asked,
"What didyou do on the seventh day?"
Al responded, "I rested."
Now you know we are all made of star
dust!!!
Recycling in the Universe
Processing, Production
Consumption
Discarding
Storage & Collectionin Interstellar Medium
pe
53Mn/55Mn
MC-ICP-MS
SIMSLaser ablation
Analytical Tools
Short-Lived Radionuclides
Wadalite:Ca-Al-Cl-Rich Secondary Phase in CAIs
Ca6Al5Si2O16Cl3
First discovery in meteorite (Ishii…Yin, 2010 Am. Min.)
FIB and TEM Confirmation(Ishii…Jacobsen…Yin 2010)
Distribution of Cl in CAIs
Wadalite predominately found in the interiors of igneous (remelted) CAIs
Sodalite and nephelineprimarily found at theedges and rims of CAIs,and in fine-grained CAIs
Cl-bearing minerals formedlate on the Allende parentbody Red = Wadalite
Green = NephelineYellow = Sodalite
Cl is found in the interior of CAIs
Cl-S Measured by NanoSIMS Cl-S isotope data obtained withLawrence Livermore NationalLaboratory NanoSIMS
Cs+ primary beam ~ 200-300nanometers
Mass resolving power of ~3600was used, sufficient to eliminateany potential isobaric interference.
Due to the low intensity of 36S-,the background at mass 36 wascarefully evaluated.
Single grain NanoSIMS Isotope Mapping
• Jacobsen…Yin et al. (2011 ApJL)
36Cl−36S Systematics of Wadalite • Jacobsen…Yin et al. (2011 ApJL)
Al-Mg Systmatics of AJEF Grossular: No Evidence for 26Al
Al-Mg isotopes in grossular associated with wadalite provide upper limit agefor wadalite at ~4 Ma after CAI crystallization
26Al and 36Cl are not correlated• The initial abundance of 36Cl is 4x higher than found
in previous studies in sodalite
• No resolvable excess of 26Al observed in grossular
• 26Al (t1/2 = 0.7Ma) and 36Cl(t1/2= 0.3Ma) are neverfound together in secondary minerals
This suggests different sources for these two SLRs:
• 26Al stellar source• 36Cl irradiation
What to do
• Al-Mg were not measured in wadalite, but in grossular
• What about 41Ca (0.1 Ma)?
Yin et al. (2002)Nature
Top: Our data show r- and p-process excesses
Bottom: pure s-process pattern
Nicolussi et al. (1998) Arlandini et al. (1999)
Earth
Earth
r- & p-process
s-process
Yin et al. (2001) LPSC
7000K Plasma torch does the trick!
– We decided to send fine presolar grains in suspension directly through a micro-nebulizer and into the inductively coupled plasma torch on an ICP-MS. The ~7000 K torch temperatures in the plasma combust the grains and ionize most of its constituents, which are simultaneously analyzed online as ICP-MS measurements.
Elemental Pattern vs. Theoretical Prediction
Condensation under Reducing Condition
“50% CT” (K)• Nd 1602• Sm 1590• Eu 1356• Gd 1659• Tb 1659• Dy 1659• Ho 1659• Er 1659• Tm 1659• Yb 1487• Lu 1659• Hf 1684 • Pack et al. (2004 Science)
• Lodders and Fegley (1993 EPSL)
Isotopic Structure in “diamond residue”
— Clear s-Process signature
pe
53Mn/55Mn
Wasserburg (1987)
Jerry’s FUN Egg-3• A) Previous ion probe studies on
Egg 3 yielded an excellent isochron with 26Al/27Al ~5×10-5
(Armstrong et al 1984; Hutcheon,unpublished data).
– Also shows both large Mg isotope mass-fractionated (7‰ per amu) and Ti isotope anomalies (Niederer et al. 1981).
Esat, DAP, & GJ Wasserburg (1980)
• B) A study by Esat et al. (1980) on pyroxenes and spinels using TIMS showed that pyroxenes exhibited a range in δ26Mg of -0.9 to +0.8‰. A line fit through spinel and pyroxene, extrapolated to 27Al/24Mg = 0, hinted at an initial δ26Mg significantly below 0.
mel-rich mantle
WLR
sp band
Brecciated area
px
mel
400 µm
Egg-3 Fragment
Egg3 and Initial 26Mg/24Mg
δ26MgI = -0.096 0.075 (‰)
Esat et al. (1980)B. Jacobsen… Yin et al. (2008b)
B. Jacobsen et al (2008 EPSL)
CAI
Secondary Ion Mass Spectrometry (SIMS)• Using UCLA ims 1270 MC-SIMS
– ~30 µm ion spot size– Mass resolution at ~ 4800– Test of precision and accuracy:
• Gravimetrical 26Mg isotope enriched standards showed better than 0.5‰ agreement between MC-SIMS and MC-ICP-MS
Spinel (Diamonds)Pyroxene (Squares)
A44A (Black)AJEF (Open)A43 (Gray)A39 (Dark Gray)
Wasserburg, Wimpenny and Yin (2011)
Characterising pit depth: AFM
Characterising pit depth: AFM
Sapphire: 50 pulses ~ 800nm depth
Depth Profile (sapphire)
Case study: Mg fluence in silicon flight sample
Mg Implant Results
Sum of 25Mg above background ~560cps
Flight Sample Results
Sum of 25Mg above background N/A
Solar Wind Mg Fluence
= (203/195) × 1.7×1012
= 1.77×1012 atoms/cm2
Accounting for 25Mg and 26Mg this becomes a total Mg fluence of 2.24×1012
atoms/cm2