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