¹Karina López García,¹Tetsuya Yokoyama,¹Ikshu Gautam,¹Makiko K. Haba,²Tsuyoshi Iizuka,¹Nao Nakanishi,³Ryota Fukai
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.70109]
¹Department of Earth and Planetary Science, Institute of Science Tokyo, Tokyo, Japan
²Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan
³Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Kanagawa, Japan
Published by arrangement with John Wiley & Sons

Ryugu materials closely resemble CI chondrites’ mineralogical, chemical, andisotopic compositions; yet minor but resolvable differences in certain elemental abundances areevident. In this study, the bulk chemical compositions of eight individual Ryugu particles(1.5–4.3 mg) from the first touchdown site (TD1) were determined using triple–quadrupoleinductively coupled plasma mass spectrometry (TQ-ICP-MS). These samples show broadabundance ranges (0.4–4 9 CI) for elements commonly hosted in minor secondary phasesincluding P, Ca, Mn, Sr, Y, Ba, and rare earth elements (REE), and display distinctcovariation patterns among these elements. Combining our data with previous analyses of TD1 Ryugu particles, we identified three compositional types: Type 1 particles are enriched by>20% in P, Ca, Mn, Sr, and REE relative to the Ryugu average; Type 3 particles are depletedby >20% in these elements but show slight enrichments (up to 30%) in siderophile andchalcophile elements; Type 2 particles have most elemental abundances within 20% of theRyugu average. These wide abundance ranges reflect heterogeneous distribution (nugget effect)of minor secondary minerals within Ryugu’s parent body. Such heterogeneity provides insightsinto the evolving conditions of alteration fluids and the consequent elemental fractionationpatterns.