Loss of magmatic sulfides to the mantle is posited to explain the copper deficit of evolved arc magmas and the depleted Cu/Ag ratio of the continental crust. We address the question of whether saturating sulfides may instead be mechanically entrained with rising magmas, and how this would affect their geochemical fate in the upper crust. Entrainment is plausible considering sulfide wetting properties

Carbonate and silicate metasomatism occurring in subduction zones is an important mechanism underlying mantle heterogeneity and compositional diversity of mantle-derived rocks. However, distinguishing between the two kinds of metasomatism is often difficult. Lithium (Li) and its isotopes have great potential in this regard because of the different Li isotopic compositions of recycled marine carbonate

Duplexing plays important roles in the evolution of fold-and-thrust belts and accretionary wedges, and causes internal shortening of the system, which then impacts both rates of frontal advance and seismic-moment deficit. Nevertheless, the significance of this internal shortening has not yet been highlighted in previous studies in the Himalaya or elsewhere. We invoke geometric solutions to constrain

Infiltration triggered by selective dissolution of pyroxenes is a major mode of melt migration in the mantle. A common view, supported by experiments and numerical models, is that the geometry of the melt plumbing system is governed by the stress field induced by solid-state flow of the host peridotite. Yet, salient melt migration structures frozen at an early stage of development in the mantle section

We investigated the continent-ocean transition (COT) structure of three main marginal seas in the western Pacific Ocean (South China Sea, Coral Sea, and Woodlark Basin) to determine the tectono-magmatic processes acting during continental breakup. The COT formed from the activity of a low-angle normal fault system localizing deformation during final rifting. Extension was contemporaneous with magmatic

Exposed continents are one of Earth's major characteristics. Recent studies on ancient ocean volume and exposed landmasses suggest, however, that early Earth was possibly a water world, where any significant landmass was unlikely to have risen above sea level. On modern Earth, the thickness of continental crust seems to be controlled by sea level and the buoyancy of continental crust. Simply applying

Halogens (Cl, Br, I) are exceptional provenance tracers in crustal fluids because their ratios are not strongly altered during most fluid-rock interaction processes. The halogen systematics of metamorphic fluids are of particular interest because such fluids are key drivers of crustal-scale element fluxes and ore formation in orogenic belts, but they remain poorly studied due to analytical challenges

Accurately dating phenocrysts in Holocene volcanic rocks poses many challenges but is critical to placing magmatic processes that occur prior to eruption into a temporal frame-work. We dated alkali feldspar (i.e., orthoclase Or10 to Or46) crystals in four young phonolites from the Teide–Pico Viejo volcanic complex, Tenerife (Spain), using (226Ra)/(230Th) isotopes. Partition coefficients of Ra (DRa)

Oomurodashi is a newly discovered active, shallow, silicic submarine volcano only 60 km from Tokyo Bay. We reveal its past eruptive activity, and potential future hazards, by examining volatile contents of its subaerial and submarine pumice and lava deposits. These novel data for shallow silicic submarine eruption products were obtained using new Fourier transform infrared spectroscopy (FTIR) analytical

Chinese loess-paleosol sequences have long been regarded as the continental counterpart of deep-sea sediments in terms of their record of the Quaternary glacial–interglacial cycles. However, absolute chronologies for loess-paleosol sequences older than ca. 130 ka on the Chinese Loess Plateau are scarce. We conducted the first high-resolution luminescence dating, extending back to 350 ka, of the classical

Reservoirs with the geometry of structural lows trap negatively buoyant fluids, mirroring the way structural highs trap positively buoyant fluids. In both scenarios, lateral flow of reservoir water alters the trapping geometry by causing fluid contacts to tilt. Tilt increases in proportion to hydraulic head gradient increases and the density contrast between the flowing and trapped fluids decreases

The Midcontinent Rift of North America is a ca. 1.1 Ga, 3000-km-long failed rift that nearly split the Precambrian continent of Laurentia. Unlike most continental rifts, which are filled with a mixture of volcanic rocks and sediments, the Midcontinent Rift contains a large volume of flood basalts that were emplaced during both syn- and post-rift stages. Consequently, the Midcontinent Rift, which comprises

Submarine slides (including slides, slumps, and debris flows) pose major geohazards by triggering tsunami and damaging essential submarine infrastructure. Slide volume, a key parameter in hazard assessments, can increase markedly through substrate and/or water entrainment. However, the erosive potential of slides is uncertain. We quantified slide erosivity by determining the ratio of deposited (Vd)

Properties of the lithosphere control the transitions in elevation and plate deformation from hot, mobile orogenic belts to cooler, stronger cratons. The sharp, abrupt boundary of the North American Cordillera with the craton in western Canada has been suggested to be a result of recent (<50 Ma) heating and delamination of the lithosphere. To test this, we queried the fine structure in the thermal

The timing and ecological impacts of the Deccan Traps large igneous province eruption are vigorously debated. Pre–Cretaceous-Paleogene (KPg) boundary impacts of Deccan volcanism have been widely identified in marine sediments, but direct evidence of terrestrial impacts remains rare. We used mercury concentrations and isotopic compositions, a proxy for volcanic activity, to assess impacts on terrestrial

Subduction megathrusts exhibit a range of slip behaviors spanning from large earthquakes to aseismic creep, yet what controls spatial variations in the dominant slip mechanism remains unresolved. We present multichannel seismic images that reveal a correlation between the lithologic homogeneity of the megathrust and its slip behavior at a subduction zone that is world renowned for its lateral slip

The origin and provenance of eolian sediments such as loess can potentially reveal paleo-air circulation directions that drive temporal changes in climate. The provenance of these deposits has been mostly assessed by detrital zircon U-Pb geochronology and remains debated. Recent studies reveal that constraining sediment provenance using only detrital zircon yields a restricted view of the overall sediment

Understanding the complex patterns of latitudinal diversity gradients (LDGs) in deep time has been hampered by the absence of long-term records of LDGs through multiple climatic changes. We used records of marine invertebrate fossils to generate LDGs in each age bin from the Carboniferous icehouse to the Triassic greenhouse climates. We evaluated LDGs by subsampling, calculated evolutionary rates for

Pyroclastic density currents are hazardous, ground-hugging, hot mixtures of gas and solid particles produced by volcanoes. Currents generated by the largest explosive eruptions have traveled distances on the order of 100 km, and their devastating impact has repeatedly marked Earth's geologic history. We show that pyroclastic density currents from super-eruptions during the Oligocene in the Great Basin

Bubble and crystal textures evolve during magma ascent, altering properties that control ascent such as permeability and viscosity. Eruption style results from feedbacks between ascent, bubble nucleation and growth, microlite crystallization, and gas loss, all processes recorded in pyroclasts. We show that pyroclasts of the mafic Curacautín ignimbrite of Llaima volcano, Chile, record a history of repeated

Due to its size and observable record of ancient rock, Mars is key to understanding crustal formation on planetary bodies, including Venus and Earth, which may have derived their first stable crust from mantle-overturn melting. Recent evidence that ancient martian crust contains an evolved component supports inferences of a pervasive, buried feldspathic component to the crust. With data from the Compact

The deposits of Plinian and subplinian eruptions provide critical insights into past volcanic events and inform numerical models that aim to mitigate against future hazards. However, pyroclastic deposits are often considered from either a fallout or pyroclastic density current (PDC) perspective, with little attention given to facies exhibiting characteristics of both processes. Such hybrid units may

The punctuated distribution of major gold deposits along orogenic belts is poorly understood. In northern Perú, gold deposits cluster along trends that transect the subparallel Phanerozoic belts that accreted onto the western margin of the Archean–Proterozoic Amazonian craton. This suggests the influence of as yet unrecognized pre-Andean basement structures in controlling the localization of Phanerozoic

The Proterozoic assembly of Australia, the understanding of which is critical for reconstructing Proterozoic supercontinents, involved amalgamation of the West Australian (WAC), North Australian (NAC), and South Australian cratons (SAC). However, the basement between these Archean to early Proterozoic lithospheric blocks is mostly buried beneath younger basins; hence, its composition and age and the

The 50th anniversary of Geology provides not only a welcome occasion to celebrate past decades of extraordinary advances in geoscience knowledge but also the impetus to cast our gaze forward and envision what new directions and discoveries will guide geoscience research through the next 50 years and beyond. My research broadly concerns reconstructing the factors that have shaped the emergence and evolution

Loose sand, blown away from source regions by winds, is transported across Mars's surface into sand sheets and dunes and accumulates within topographic sinks. In the absence of plate tectonics, impact craters constitute a dominant sink for windblown sediments on Mars today. We analyzed the volume of all mapped eolian sands in martian craters >1 km in diameter to reveal spatiotemporal patterns of sediment

The continental rifting that precedes the breakup of a continent and the formation of a new ocean basin is one of the key processes of plate tectonics. Although often viewed as a two-dimensional process, rifted margins exhibit significant variations along strike. We document along-strike variations developed during the ca. 200–160 Ma continental rifting that formed the margins of the Gulf of Mexico

Triple oxygen isotope (δ17O and δ18O) values of high- and low-temperature altered oceanic crust and products of basalt alteration experiments were measured to better constrain ocean isotope compositions in deep time. The data define an array of δ18O and Δ′17O (Δ′17O=δ′17O − λRL × δ′18O + γ) values from mantle values toward 1‰ and −0.01‰, respectively, with a λ of ~0.523. The altered oceanic crust data

Natural diamonds and their inclusions provide unique glimpses of mantle processes from as deep as ~800 km and dating back to 3.5 G.y. Once formed, diamonds are commonly interpreted to travel upward, either slowly within mantle upwellings or rapidly within explosive, carbonate-rich magmas erupting at the surface. Although global tectonics induce subduction of material from shallow depths into the deep

Mercury (Hg) provides critical information on terrestrial planet formation and evolution due to its unique physicochemical properties and multiform isotopic compositions. Current knowledge of Hg is mainly limited to Earth's surface environments, and the understanding of Hg in the Earth's interior remains unclear. Accretionary orogens are major settings for continental crustal growth and crust-mantle

Convergent plate boundaries show sharp variations in orogenic width and extent of intraplate deformation. Analysis of late Cenozoic contractile deformation along the Andean mountain front and adjacent foreland highlights the contrasting degrees of deformation advance toward the plate interior. The retroarc positions of the Andean topographic front (marked by frontal thrust-belt structures) and foreland

One of the biggest challenges in volcanology is assessing the role of magma properties (volatile budgets, storage depths, and ascent rates) in controlling eruption explosivity. We use a new approach based on apatite to estimate volatile contents and magma ascent rates from a sequence of sub-Plinian, effusive, and Vulcanian eruption deposits at Rabaul caldera (Papua New Guinea) emplaced in 2006 CE to

Deep-focus earthquakes (DFEs) present an interesting scientific challenge in that they occur at depths where brittle failure should be impossible. The fact that their occurrence is confined to locations where subducting lithospheric slabs are crossing through the transition zone suggests that olivine phase transformations may be involved in the production of these earthquakes. Experimental studies

Understanding the causes of the formation of hardgrounds provides insights on the oceanographic evolution of a basin. Phosphate-rich hardground formation interrupted carbonate ramp deposition in the Mediterranean during the Miocene. We analyzed the εNd record of three central Mediterranean hardgrounds to identify the origin of the phosphate-rich waters that formed them within the frame of Mediterranean

Elucidating the compositions of melts from which Hadean zircons crystallized can provide insight into early crust construction. We calculated model melts using Ti-calibrated zircon/melt partition coefficients and trace element data for zircons from the Hadean, Archean, and possible analogue environments (e.g., rifts, hotspots, arcs) to constrain petrogenetic relationships. Model melts from oceanic

Stress on seismogenic faults provides critical information about how much elastic energy is stored in the crust and released by earthquakes, which is crucial in understanding earthquake energetics and recurrence. However, determining post-earthquake stress states on faults remains challenging because current borehole methods are rarely applicable to damaged fault zone rocks. We applied neutron texture

Diamonds are witnesses of processes that have operated in Earth's mantle over more than 3 b.y. Essential to our understanding of these processes is the determination of diamond crystallization ages. These cannot be directly determined on diamond, but they can be calculated using radiogenic isotopic systematics of suitable minerals included in a diamond. This method relies on the assumption that the

Resource pulses, occasional events of ephemeral resource superabundance, represent a fundamental mechanism by which energy, nutrients, and biomass are transported across ecotones. They are widespread in extant ecosystems; however, little is known about their deep-time record. We report the earliest-known mayfly swarm from the Early Jurassic Xiwan biota of southern China. Our taphonomic and sedimentological

The earliest evidence of wildfire is documented from two localities: the early mid-Silurian Pen-y-lan Mudstone, Rumney, Wales (UK), and the late Silurian Winnica Formation, Winnica, Poland. Nematophytes dominate both charcoal assemblages. Reflectance data indicate low-temperature fires with localized intense conditions. Fire temperatures are greater in the older and less evolved assemblage. These charcoal

Channel planform patterns arise from internal dynamics of sediment transport and fluid flow in rivers and are affected by external controls such as valley confinement. Understanding whether these channel patterns are preserved in the rock record has critical implications for our ability to constrain past environmental conditions. Rivers are preserved as channel belts, which are one of the most ubiquitous

Breadcrust bombs are pyroclasts displaying fractured, dense surfaces enveloping expanded interiors, and are associated with Vulcanian explosions. We document pyroclasts from the 2008–2009 CE eruption of Chaitén (Chile) that are internally as well as externally breadcrusted. The pyroclasts are cut by intersecting micrometer-to millimeter-thick tuffisites with dense glassy walls, which grade into strongly

The San Andreas fault (California, USA) is near vertical at shallow (<10 km) depth. Geophysical surveys along the San Andreas fault reveal that, at depths of 10–20 km, it dips ~50–70° to the southwest near the Western Transverse Ranges and dips northeast in the San Gorgonio region. We investigate the possible origin of along-strike geometric variations of the fault using a three-dimensional thermomechanical

Flood dynamics in low-relief landscapes control the lateral exchange of water and sediment between a river and its floodplain. Locations where these exchanges occur for any given river discharge depend on local bank elevations, which in turn depend on the type of landform present immediately adjacent to the river channel. Our analysis separated landforms bordering a river into six categories: levee

Hydrothermal veins and altered feldspar are evidence for fluid circulation in granitic rocks in the continental crust. The hydrothermal alteration of feldspar affects the deformation behavior of granitoids, especially if it occurs before orogeny. Geochronology can establish the timing of fluid circulation to determine if this fluid-driven alteration plays a role in crustal deformation. Although existing

In this study, we use data from the SEISConn seismic experiment to calculate Sp receiver functions in order to characterize the geometry of upper-mantle structure beneath southern New England (northeastern United States). We image robust negative-velocity-gradient discontinuities beneath southern New England that we interpret as corresponding to the lithosphere-asthenosphere boundary (LAB) and identify

The Emeishan large igneous province (LIP), southwestern China and northern Vietnam, is thought to have been a potential driver for the biotic crises and paleoclimate changes around the Guadalupian-Lopingian boundary (GLB; Permian), but the lack of high-precision radiometric dates to constrain the duration and eruption rates of the volcanism has limited the assessment of their relationship. We present

There is broad consensus that tectonic and magmatic processes play a role in the evolution of life and the composition of the atmosphere. Tectonic and magmatic processes provide a suite of bio-essential nutrients that are carried into the hydrosphere through sedimentary processes. Tectonic processes facilitate the subsequent recycling and concentration of these nutrients for continued biospheric utilization

The architecture of a mush-dominated plumbing system in active volcanic areas conditions the magma pathways feeding eruptions. Open-system processes along these pathways and the associated time scales are directly related to monitoring data and eruptive behavior. Despite crystal mush–dominated systems being common in active volcanoes, previous studies have not focused on the integration of data from

Three intervals of glaciomarine diamictites with extensive glendonites in middle to upper Permian sediments were found in the Kobyume River, southern Verkhoyanie, Russia. The successions are biostratigraphically constrained as middle to upper Permian. The middle Permian diamictite horizons extend over a large area with a lateral distance of >1000 km. The upper Permian diamictites developed only locally

The Southern Hemisphere westerly wind belt (SHWW) is a major feature of Southern Hemisphere, midlatitude climate that is closely linked with the sequestration and release of CO2 in the Southern Ocean. Past changes in the strength and position of this wind belt are poorly resolved, particularly across the Pleistocene-Holocene transition, a time period associated with fluctuations in atmospheric temperatures

It remains unclear whether waning of the volcanic degassing CO2 source or enhancement of the mafic (Ca, Mg-silicate) weathering CO2 sink, or both, caused global cooling leading to the Ordovician greenhouse–icehouse transition. We present a uniquely age-constrained and integrated Middle–Late Ordovician (470–450 Ma) continental weathering isotopic proxy data set (87Sr/86Sr and εNd(t)) from carbonate

The fine structure and thermal state of >200-km-thick cratonic lithosphere remain poorly explored because of insufficient sampling and uncertainties in pressure (P) and temperature (T) estimates. We report exceptionally detailed thermal and compositional profiles of the continental lithospheric mantle (CLM) in the Siberian craton based on petrographic, in situ chemical, and P-T data for 92 new garnet

Sexual reproduction represents a fundamental aspect of animal biology, but the diversity of reproductive strategies among early Paleozoic metazoans remains obscure. Direct evidence of reproductive strategies comes from exceptionally preserved egg masses in Cambrian and Ordovician euarthropods such as waptiids and trilobites, but anatomical or behavioral adaptations for mating in these taxa are all

Time averaging of fossil assemblages determines temporal precision of paleoecological and geochronological inferences. Taxonomic differences in intrinsic skeletal durability are expected to produce temporal mismatch between co-occurring species, but the importance of this effect is difficult to assess due to lack of direct estimates of time averaging for many higher taxa. Moreover, burial below the

The evolution of oxygenic photosynthesis fundamentally altered the global environment, but the history of this metabolism prior to the Great Oxidation Event (GOE) at ca. 2.4 Ga remains unclear. Increasing evidence suggests that non-marine microbial mats served as localized “oxygen oases” for hundreds of millions of years before the GOE, though direct examination of redox proxies in Archean lacustrine

It is widely thought that oceanic subduction can trigger cratonic keel delamination, but the southwestern Yangtze craton (SYC; southwestern China) lost its lower keel during Cenozoic continental collision. The upper mantle beneath the thinned SYC contains its incompletely delaminated keel, which has high-velocity seismic anomalies. Combining geophysical observations with the geochemistry of Eocene

Primary fluid inclusions in bedded halite from the 830-m.y.-old Browne Formation of central Australia contain organic solids and liquids, as documented with transmitted light and ultraviolet–visible (UV-vis) petrography. These objects are consistent in size, shape, and fluorescent response with cells of prokaryotes and eukaryotes and with organic compounds. This discovery shows that microorganisms

Glacial isostatic adjustment (GIA) imparts geographic variability in the amplitude and timing of local sea-level (LSL) change arising from glacial-interglacial oscillations relative to a global mean signal (eustasy). We modeled how GIA manifests in the stratigraphic record across four shelf-perpendicular transects moving progressively more distal to the Quaternary North American ice complex, subject

Subduction of lithospheric plates at convergent margins leads to transport of materials once close to or at the surface of Earth to great depths. Some of them later return to the surface by magmatism or degassing, whereas others end up being stored in the mantle for long periods of time. The fate of carbon-bearing minerals in subduction is of particular interest because they can arbitrate the long-term

A catastrophic last interglacial Laurentide outburst (LILO) event approximately 125,000 years ago (125 ka) may have contributed to abrupt climate change during the last interglacial. It has been proposed that this event was an analog of the Holocene 8.2 ka event. We characterize in detail the (1) provenance, (2) timing, and (3) delivery mechanism of a layer of red sediments deposited across much of