Table of Contents

1. Experimental Results on Fractionation of the Highly Siderophile Elements (HSE) at Variable Pressures and Temperatures during Planetary and Magmatic Differentiation

INTRODUCTION AND SCOPE

SOLID METAL –LIQUID METAL PARTITIONING

EXPERIMENTAL APPROACH TO SOLID METAL–LIQUID METAL PARTITIONING (DSM/LM)

HSE SOLUBILITY EXPERIMENTS: IMPLICATIONS FOR METAL–SILICATE PARTITIONING

CALCULATING THE METAL–SILICATE MELT PARTITION COEFFICIENT FROM SOLUBILITY DATA

Controls on the metal–silicate partition coefficient

Metal inclusions in experiments and the analysis of contaminated phases

Possible mechanisms of metal inclusion formation

Experimental methods to measure HSE solubility and metal–silicate partitioning

Summary of experimental data

Application of results to core formation

SILICATE AND OXIDE CONTROL ON HSE FRACTIONATION

Experimental approach

Spinel–melt partitioning of HSEs

Silicate mineral–melt partitioning of HSEs

Origin of the variation in partitioning

Local PGM saturation during chromite growth

MAGMATIC SULFIDE AND ASSOCIATED PHASES

Experimental approach

MSS–sulfide melt partitioning

MSS–ISS–sulfide melt partitioning

Sulfide melt–silicate melt and MSS–silicate melt partitioning

Role of the chalcogens (Se, Te, As, Bi, Sb)

SILICATE MELT–AQUEOUS LIQUID–VAPOR PARTITIONING

Theoretical considerations

Experimental methods

The volatile/melt partitioning of Au

The volatile/melt partitioning of PPGE

The volatile/melt partitioning of IPGE and Re

CONCLUDING REMARKS

ACKNOWLEDGMENTS

REFERENCES

2. Analytical Methods for the Highly Siderophile Elements

INTRODUCTION

DATA QUALITY CONSIDERATIONS FOR THE HSE

Sample heterogeneity and reproducibility

MEASUREMENT PROCEDURES

Chemical separation of HSE

REFERENCE MATERIALS FOR HSE ANALYSIS

APPENDIX

REFERENCES

3. Nucleosynthetic Isotope Variations of Siderophile and Chalcophile Elements in the Solar System

INTRODUCTION

ORIGIN OF ELEMENTS: STELLAR NUCLEOSYNTHESIS

Production of elements from He to Fe via hydrogen to silicon burning

PRESOLAR GRAINS

Types of presolar grains and their origin

ISOTOPE ANOMALIES OF SIDEROPHILE AND CHALCOPHILE ELEMENTS IN BULK METEORITES

Isotope anomalies of siderophile elements in bulk meteorites

Isotope anomalies of chalcophile elements in bulk meteorites

INTERNAL ISOTOPE ANOMALIES PRESENT IN CHONDRITES

CAIs

Acid leachates and residues

Isotopic constraints on the s-process nucleosynthetic component

ORIGIN OF PLANETARY SCALE ISOTOPE ANOMALIES IN METEORITES

CONCLUDING REMARKS

ACKNOWLEDGMENTS

REFERENCES

4. Highly Siderophile Elements in Earth, Mars, the Moon, and Asteroids

INTRODUCTION

MOTIVATION FOR STUDY AND BEHAVIOR OF THE HSE IN PLANETARY MATERIALS

METHODS APPLIED TO INVESTIGATING SIDEROPHILE ELEMENTS IN PLANETARY MATERIALS

HSE ABUNDANCES

The rhenium–osmium, platinum–osmium and palladium–silver isotope systems

Standardization in planetary studies

Metal-sulfide–silicate modeling in chondritic systems

Partial melt modeling of planetary mantles

“Pristinity” of crustal and mantle samples

Estimation of planetary mantle composition

What do chondritic or nearly/broadly chondritic actually mean?

PLANETARY MATERIALS

Early Solar System materials

Fragments of planetary cores and/or metal-rich melt pools

Primitive achondrite meteorites

Meteorites from differentiated asteroids

Mars

The Moon

Terrestrial mantle composition

Secondary alteration effects

PLANETARY FORMATION PROCESSES

Initial conditions and homogeneity of starting materials

Partial melting and partitioning of the HSE

Core crystallization

‘Late-accretion’

Alternative hypotheses for the abundances of the HSE in planetary mantles

Magmatic processes

Later impacts into planetary crusts

COMPARATIVE PLANETOLOGY AND IMPLICATIONS FOR TERRESTRIAL FORMATION

FUTURE DIRECTIONS

ACKNOWLEDGEMENTS

REFERENCES

5. Distribution and Processing of Highly Siderophile Elements in Cratonic Mantle Lithosphere

INTRODUCTION

THE CRATONIC MANTLE SAMPLE: PECULIARITIES, OPPORTUNITIES AND PITFALLS

DATABASE

MINERALOGY AND HSE HOSTS IN CRATONIC MANTLE PERIDOTITES

ANALYTICAL TECHNIQUES FOR CRATONIC MANTLE PERIDOTITES

Whole rocks and mineral separates

Single-grain techniques

UTILIZATION OF THE RE–OS ISOTOPE SYSTEM IN CRATONIC MANTLE STUDIES

EFFECT OF MELT DEPLETION DURING CRATONIC LITHOSPHERE STABILIZATION ON SULFUR AND HSE SYSTEMATICS

Sulfur and the persistence of sulfides

Alloy saturation

Chalcogens

HSE PROCESSING DURING MANTLE METASOMATISM

Modification during intraplate mantle metasomatism

Modification during craton margin processes—subduction

MODELLING OF PRIMARY VS. SECONDARY HSE SIGNATURES IN CRATONIC MANTLE

HSE Concentrations of the Archean convecting mantle (ACM)

Modelling Rationale

Effects of partial melt extraction on HSE based on modelling

Post-core formation, sluggish downward mixing of a late veneer

SUMMARY

ACKNOWLEDGMENTS

REFERENCES

6. Highly Siderophile Element and 187Os Signatures in Non-cratonic Basalt-hosted Peridotite Xenoliths: Unravelling the Origin and Evolution of the Post-Archean Lithospheric Mantle

INTRODUCTION

CONSTRAINING THE HSE AND 187Os/188Os ISOTOPIC COMPOSITION OF THE PRIMITIVE BULK SILICATE EARTH

PETROLOGY AND LOCATION OF NON-CRATONIC PERIDOTITE XENOLITHS

A BRIEF REVIEW OF HSE AND Os ISOTOPE ANALYTICAL METHODS AND HSE NORMALIZATION VALUES

HOST MINERALS OF HIGHLY SIDEROPHILE ELEMENTS IN NON-CRATONIC PERIDOTITE XENOLITHS

Nature of the host minerals

Petrography of the base metal sulfides

Origin of the base metal sulfides and platinum group minerals

HIGHLY SIDEROPHILE ELEMENTS AND 187Os/188Os RESULTS FROM NON-CRATONIC PERIDOTITE XENOLITHS

Summary of results from whole-rock studies

Summary of results from base metal sulfides and other mineral phases

Reconciling 187Os/188Os results from whole-rock and base metal sulfide analyses

THE LIFE OF A XENOLITH, AS RECORDED IN HSE- AND Os-ISOTOPE SYSTEMATICS

The HSE and 187Os composition of the Primitive Upper Mantle

Whole-rock observations on samples representing melting residues

Mineralogical control of HSE fractionation during partial melting

Ancient melt-extraction events recorded by 187Os/188Os systematics

Post-melting petrological history

Syn- to post-eruptive processes

CHRONOLOGICAL INTERPRETATION OF OS-ISOTOPIC DATA AND TECTONIC IMPLICATIONS

Obtaining age information from Os isotopes of whole rocks

Obtaining age information from Os isotopes of base metal sulfides

Tectonic interpretation of Os model ages

CONCLUSIONS

ACKNOWLEDGEMENTS

REFERENCES

7. Re–Pt–Os Isotopic and Highly Siderophile Element Behavior in Oceanic and Continental Mantle Tectonites

INTRODUCTION

BREVIA OF CONCEPTS, TERMINOLOGY, AND ANALYTICAL CAVEATS

Re–Pt–Os parameters

Normalization of concentration data

Precision and accuracy of concentration data and analytical issues

HIGHLY SIDEROPHILE ELEMENTS IN MANTLE TECTONITES FROM DIFFERENT GEODYNAMIC SETTINGS

Summary of mantle tectonites and their geodynamic settings

HSE IN ABYSSAL PERIDOTITES FROM SPREADING OCEANIC LITHOSPHERE

HSE in mantle tectonites from continental extensional domains and continent–ocean transitions

HSE in ophiolites that formed at fast spreading ridges with little or no influence from subduction processes

High-temperature orogenic peridotites from convergent plate margin settings

Highly siderophile elements in peridotites and melt-reacted lithologies of ophiolites influenced by convergent plate margin magmatism

Highly siderophile elements in the mantle sections of ophiolites of uncertain origin

DISCUSSION

Influence of low-temperature alteration processes on the HSE in bulk rocks and minerals

The influence of melt infiltration and partial melting on HSE abundances in mantle tectonites

Summary—Mantle melting and mantle–magma interaction—different sides of the same coin

Os isotopic heterogeneity in the mantle

The role of recycled oceanic lithosphere in producing HSE and Os isotope signatures in magmas

The relationship between abyssal peridotites and MORB: an osmium isotope perspective

Interpretation of Re–Os model ages

ACKNOWLEDGMENTS

REFERENCES

8. Chalcophile and Siderophile Elements in Mantle Rocks: Trace Elements Controlled By Trace Minerals

INTRODUCTION

BACKGROUND

Sulfides in the upper mantle and mantle rocks

Abundance and phase control on chalcophile and siderophile elements in the fertile upper mantle

Partial melting of the mantle: a BMS-removing and PGM producing petrogenetic process

Chalcophile/siderophile element systematics in pyroxenites

Low-pressure BMS dissolution in regional-scale open system melting of the sub-continental lithospheric mantle

BMS precipitation associated with magma percolation/metasomatism

Platinum-group minerals and magmatic percolation of the lithospheric mantle

CONCLUDING REMARKS

ACKNOWLEDGMENTS

REFERENCES

9. Petrogenesis of the Platinum-Group Minerals

INTRODUCTION

PHASE RELATIONS AND ORIGIN OF THE PGM

Chemical properties of the PGM

Extraterrestrial occurrences of the PGM

Origin of the terrestrial PGM: Mantle melting, metasomatism, and metal transfer

PGM IN LAYERED MAFIC–ULTRAMAFIC INTRUSIONS

Chromitite-hosted layered intrusion PGM

Non-chromitite-hosted PGM in layered intrusions

PGM IN OPHIOLITES

PGM in ophiolite peridotites

PGM in ophiolite chromitites

PGM in sulfide-rich ophiolite lithologies

PGM IN PERIDOTITES OF THE SUBCONTINENTAL LITHOSPHERIC MANTLE

Subcontinental lithospheric mantle peridotite massifs

SCLM peridotite xenoliths

PGM IN CONCENTRICALLY ZONED URALIAN–ALASKAN–ALDAN-TYPE COMPLEXES

PGM in dunite, pyroxenite and gabbro

Chromitite-hosted PGM in CUAAC

PGM and sulfide mineralization in CUAAC

PGM IN NI-SULFIDE DEPOSITS

Komatiite-associations

Magmatic Ni–(± Cu–± PGE)–sulfide deposits in non-komatiitic rocks

EXAMPLES OF UNCONVENTIONAL PGM OCCURRENCES

Kimberlite- and Cu-porphyry-hosted PGM

OUTLOOK AND FUTURE WORK

Assessing the mineralogical and textural complexity of PGM assemblages

Constraints on quantifying the distribution and grain size of PGM

Advancing our understanding of the link between PGM assemblage and PGE geochemistry

ACKNOWLEDGEMENTS

REFERENCES

APPENDIX

PGM in placers associated with ophiolite complexes

PGM mineralization in CUAAC placer deposits

REFERENCES

10. Mantle Sulfides and their Role in Re–Os and Pb Isotope Geochronology

INTRODUCTION

BACKGROUND

ANALYTICAL METHODS AND PRACTICAL ASPECTS OF SAMPLE PREPARATION

BASE-METAL SULFIDE OCCURRENCE, MAJOR ELEMENT GEOCHEMISTRY AND PETROLOGY

Peridotite-hosted sulfides

Pyroxenite-hosted sulfides

Diamond-hosted sulfides

Re–Os–Pb MASS BALANCE IN ULTRAMAFIC SAMPLES

Osmium mass balance

Rhenium mass balance

Lead mass balance

GEOCHRONOLOGICAL METHODS, MODEL AGES, AND POTENTIAL PITFALLS

Sulfide Re–Os isochrons, TMA, TRD, and gOs

Potential pitfalls with sulfide geochronology

THE UTILITY OF Re–Os AND Pb ISOTOPE GEOCHRONOLOGY

Dating the formation of diamonds

Diamond formation through time

The age of the continental lithospheric mantle and the assembly of its domains

The relationship between the age of the SCLM and the overlying crust

The inherent heterogeneity within the oceanic mantle

CONCLUDING REMARKS AND FUTURE DIRECTIONS

ACKNOWLEDGMENTS

REFERENCES

11. Highly Siderophile Element and Os Isotope Systematics of Volcanic Rocks at Divergent and Convergent Plate Boundaries and in Intraplate Settings

INTRODUCTION

HIGHLY SIDEROPHILE ELEMENT DISTRIBUTION AND BEHAVIOR IN THE UPPER MANTLE

Core formation and the late accretion of impactor material

Highly siderophile elements in mantle minerals

Highly siderophile element behavior accompanying fractional crystallization

THE 187Re–187Os ISOTOPE SYSTEM AND THE FORMATION OF MID-OCEAN RIDGE BASALT (MORB)

Introduction

Analytical techniques

Rhenium–Osmium elemental variations in MORB glass

The 187Os/188Os isotope variations in MORB glass

Analytical issues associated with MORB

SULFIDES IN MID-OCEAN RIDGE BASALTS

Petrology and chemistry

187Re–187Os behavior in MORB sulfide

The 187Os/188Os composition of the MORB mantle source

LOWER OCEANIC CRUST

Assimilation of gabbroic lower crust

HSE ABUNDANCES AND Re–Os ISOTOPE SYSTEMATICS OF INTRAPLATE VOLCANISM

Mantle melting processes

Osmium isotopes as tracers of hotspot sources

Crustal and lithospheric mantle assimilation/contamination

The origin of Continental Flood Basalts (CFB) and Large Igneous Provinces (LIP)

Continental intraplate alkaline volcanism

Processes affecting the HSE compositions of sub-aerial volcanism

HIGHLY SIDEROPHILE ELEMENT SYSTEMATICS OF ARCS

HSE and 187Os/188Os in arc lavas

HSE and 187Os/188Os in arc xenoliths

Radiogenic Os from slab components or from crustal contamination

Mechanical mixing processes

CONCLUSIONS AND PERSPECTIVES

ACKNOWLEDGMENTS

REFERENCES

12. Highly Siderophile and Strongly Chalcophile Elements in Magmatic Ore Deposits

INTRODUCTION

CLASSIFICATION OF THE DEPOSITS

Reef or stratiform deposits

Contact deposits

Ni-sulfide deposits

MINERALS HOSTING THE PLATINUM-GROUP ELEMENTS

Base metal sulfides

Platinum-group minerals

Chromite

Mass Balance

GEOCHEMISTRY

Introduction

Normalization to mantle or chondrite?

Recalculation to 100% Sulfides or whole rock

Other chalcophile elements

INTERPRETATION

Composition of the silicate melt

Saturation of the magma in a sulfide liquid

Upgrading of the Sulfides

Crystallization of a sulfide liquid

Late magmatic fluids

Subsolidus events

UTILIZATION OF THE Re–Os ISOTOPE SYSTEM IN STUDIES OF MAGMATIC Ni–Cu–PGE ORE GENESIS

Background

The “R-factor” and its application to Re–Os isotopes

Examples of the application of the Re–Os isotope system to magmatic ore deposits

CONCLUSIONS

ACKNOWLEDGMENTS

REFERENCES