Pedro Waterton

• PhD
• Professor (Assistant) at University of Copenhagen

Mantle residues beneath Archean cratonic nuclei have been extensively studied, whereas less attention has been given to the mantle lithosphere beneath Proterozoic mobile belts that link these nuclei. Rare mantle tectonites within tectonic mélanges of Paleoproterozoic mobile belts provide information important to understanding the broader processes...

Archean and Proterozoic layered intrusions represent an important portion of the igneous rock archive and their parental magma composition may provide crucial insights into the Earth’s magmatic and geodynamic evolution. Both komatiitic and boninitic parental magmas have been suggested for several major Archean layered intrusions, which could imply...

Tracing Early Earth evolution: Insights from Chromite and Osmium isotopes

The Ujaragssuit Intrusion, North Atlantic Craton (NAC), Greenland, is thought to host the oldest chromitites (>3.8 Ga) on Earth, showing evidence of both Hadean mantle depletion events and nucleosynthetic isotopic heterogeneities. We set out to verify the age of the intrusion and identify the Os isotope composition of the Ujaragssuit mantle source....

Continental arcs are associated with volcanism concentrated into two main belts—the main arc and back arc, often separated by fold and thrust belts. The Loicas Trough, Argentina, is a post-orogenic extensional feature that obliquely cuts the fold and thrust belts. The trough hosts large Pliocene–Holocene volcanic centres, including Domuyo and Trome...

We present high precision negative ion thermal ionisation mass spectrometry (N-TIMS) Os isotope measurement results for the DROsS reference material, to investigate the limits on the precision of TIMS-based 186Os/188Os measurements. We use analytical conditions previously highlighted to optimise precision, present a new flexible data processing pro...

Komatiites are ultra-hot ultramafic lavas, largely restricted to the Archaean. They represent an extreme endmember of terrestrial magmatism and challenge our understanding of how mantle melting operates. We briefly introduce this compositionally diverse group of lavas and critically evaluate constraints on their formation. Despite evidence for mode...

We analyze a large database of abyssal peridotite clinopyroxene compositions using log-ratio transformation, principal component analysis (PCA) and k-means clustering, to better understand clinopyroxene compositional systematics in abyssal peridotites. We combine this analysis with open-system melting models to investigate the potential sources of...

A critical component of our understanding of the evolution of Earth's mantle comes from rocks identified as direct mantle samples. Eoarchaean dunite lenses from the Isua Supracrustal Belt (ISB), North Atlantic Craton, Greenland, have been previously interpreted as depleted mantle wedge residues, complementary to arc-like volcanic rocks in the supra...

The platinum-group element (PGE) contents of komatiites have been used to estimate the PGE contents of their mantle sources and investigate temporal variations in the PGE systematics of the mantle throughout Earth history. However, the use of mantle melts to investigate source characteristics is critically dependent on understanding the fractionati...

Zircon U-Pb geochronology places high-temperature geological events into temporal context. Here, we present a comprehensive zircon U-Pb geochronology dataset for the Meso- to Neoarchean Maniitsoq region in southwest Greenland, which includes the Akia Terrane, Tuno Terrane, and the intervening Alanngua Complex. The magmatic and metamorphic processes...

Komatiitic magmatism is a characteristic feature of Archean cratons, diagnostic of the addition of juvenile crust, and a clue to the thermal evolution of early Earth lithosphere. The Slave craton in northwest Canada contains >20 greenstone belts but no identified komatiite. The reason for this dearth of komatiite, when compared to other Archean cra...

The Nagssugtoqidian orogen (NO), which forms the northern margin of the North Atlantic craton in West Greenland, is largely comprised of ~2870 to 2720 Ma juvenile continental crust reworked during Paleoproterozoic orogenic events. Sparse evidence of components older than 3100 Ma in the area (Usingle bondPb zircon ages and bulk-rock Smsingle bondNd...

The study of chromite from chromitite-bearing layered intrusions can provide significant insights into their petrogenetic origin and tectonic setting. The Fangmayu Alaskan-type ultramafic intrusion in the North China Craton contains layered and massive chromitite associated with a serpentinized ultramafic suite. This study presents zircon and apati...

Large meteorite impacts have a profound effect on the Earth's geosphere, atmosphere, hydrosphere and biosphere. It is widely accepted that the early Earth was subject to intense bombardment from 4.5 to 3.8 Ga, yet evidence for subsequent bolide impacts during the Archean Eon (4.0 to 2.5 Ga) is sparse. However, understanding the timing and magnitude...

The northern part of the North Atlantic Craton (NAC) in southern West Greenland comprises a large tract of exposed Meso-Neoarchaean continental crust, divided into the ca 3300–2900 Ma Akia and ca 2900–2500 Ma Tuno terranes. We combine aeromagnetic, stream sediment geochemical, new litho-chemical and zircon geochronological data with previously publ...

Chromite deposits hosted in a layered ultramafic–mafic intrusion in the Archean Chithradurga greenstone belt are part of a suture that divides the Western and Central Dharwar craton blocks in southern India. Serpentinised ultramafic rocks including dunite, peridotite, and phlogopite-rich clinopyroxenite occur with massive chromitite. The olivine co...

Major and trace element data

High precision olivine and chromite analyses for Al-in-olivine thermometry

U-Pb data

EPMA data

Major, trace and platinum group element data. Bulk rock O isotopes and Hf-Nd isotopes

EPMA mineral analyses

Compositions in mol% used for phase equilibria modelling

LA-ICP-MS and SIMS U-Pb zircon analyses

Major and trace element data

XRF standards for major and minor element data

EPMA data for pyroxene and chromite

We present new data for the ∼3.0 Ga Maniitsoq Norite Belt of the Akia Terrane, West Greenland, with the aim of understanding its petrogenesis. The Maniitsoq Norite Belt is hosted in regional tonalite-trondhjemite-granodiorite (TTG) and dioritic orthogneisses, intruded by later sheets of TTG and granite pegmatites, and comprises two main rock types:...

The rock type most commonly associated with komatiite throughout Earth's history is tholeiitic basalt. Despite this well-known association, the link between komatiite and basalt formation is still debated. Two models have been suggested: that tholeiitic basalts represent the products of extensive fractional crystallisation of komatiite, or that bas...

The rock type most commonly associated with komatiite throughout Earth’s history is tholeiitic basalt. Despite this well-known association, the link between komatiite and basalt formation is still debated. Two models have been suggested: that tholeiitic basalts represent the products of extensive fractional crystallization of komatiite, or that bas...

The lithospheric mantle should be depleted in base- and precious-metals as these elements are transferred to the crust during partial melting. However, some melt-depleted mantle peridotites are enriched in these ore-forming elements. This may reflect re-fertilization of the mantle lithosphere and/or sequestering of these elements by residual mantle...

The oxygen fugacities of nine mantle-derived komatiitic and picritic systems ranging in age from 3.55 Ga to modern day were determined using the redox-sensitive partitioning of V between liquidus olivine and komatiitic/picritic melt. The combined set of the oxygen fugacity data for seven systems from this study and the six komatiite systems studied...

Komatiites are high temperature, high MgO lavas that have the potential to provide geochemical and thermal insights into the evolution of the Earth's mantle. However, komatiite studies are frequently hampered by the altered nature of all komatiites and the presence of large gaps in the komatiite record, most notably during the Proterozoic. This the...

The Proterozoic spans the longest portion of Earth's history, yet in contrast to the Archaean, the record of komatiites and related high MgO igneous rocks from this Eon is sparse. This paper describes the pristine Palaeoproterozoic Winnipegosis Komatiites, from Manitoba, Canada, which form part of the Circum-Superior Belt large igneous province. We...