Earth History Research Articles

The History of Earth and Life: Escape Room for High School Students

Introduction: This study investigates how different teaching strategies influence students’ learning outcomes and engagement. Objective: The primary aim is to evaluate the knowledge and motivation of students in the first year of high school (17 years old), before and after participating in an escape room activity on the History of the Earth and Life. Methodology: The research involved 50 students, divided into a control group that received traditional lectures and an experimental group that participated in a gamified experience. Pre- and post-intervention assessments were conducted to measure knowledge acquisition, and motivation was assessed through a survey. Statistical analyses, including ANOVA, were performed to compare the effectiveness of both teaching methods. Results: The study shows significant statistical differences between the two strategies, demonstrating a notable increase in learning through gamification (F(1, 48) = 21; p < 0.001). Additionally, students in the experimental group perceived the methodology as more engaging, highlighting its dynamic, interactive, and motivating nature. Conclusions: The findings suggest that incorporating interactive and dynamic learning experiences can foster deeper engagement with the content.

Optimized J2 Recovery for Multi‐Decadal Geophysical Studies

AbstractThe time history of the Earth's dynamic oblateness, or , is a unique climate data record, with its estimation from satellite laser ranging (SLR) tracking data beginning in 1976. Due to its impact on variations in length of day (LOD), the long‐term time series is frequently applied to LOD studies and their contributions, which include tidal friction, glacial isostatic adjustment, ice melt, sea level change, and the angular momentum exchange between the fluid outer core and the mantle. Previous studies demonstrated that the accurate recovery of requires the use of time variable gravity models from GRACE when processing the SLR tracking data. However, no reliable models exist prior to GRACE's 2002 launch, calling into to question the accuracy and utility of the pre‐GRACE estimates. Here we present a new approach to accurately recover without gravity modeling, resulting in the first fully consistent long‐term solution for climate studies.

Earth's Deep‐Time Geodynamic Evolution Recorded by Hafnium Isotope Perturbations

AbstractInteractions between Earth's mantle and crust have shaped the planet's evolution through deep time. Hafnium (Hf) isotopes provide a unique fingerprint of magma sources, enabling the tracking of the crucial interaction zone in the upper mantle evolution through more than four billion years of Earth's history. However, previous studies have relied on a combination of evolved and juvenile zircons, making it challenging to distinguish the genuine evolution of mantle properties. Here, we present a global compilation of Hf isotopic analyses of zircons from juvenile crust to track the upper mantle's evolution throughout Earth's history. By employing Singular Spectrum Analysis and Wavelet Analysis for time series, we decompose the complex Hf isotopic evolution curves and determine the respective periods and interpretations of each component. Our analysis reveals a complex and dynamic evolution of the upper mantle, with distinct periods of stability and upheaval. We show that the upper mantle has undergone periodic perturbations through mixing with crustal materials since Earth's formation, primarily caused by plate subduction and weakly influenced by mantle convective cycles. Hf isotopes reveal vigorous mantle convection that propelled plate tectonics during the Hadean, along with numerous supercontinent cycles that originated in the early Mesoarchean and a notable shift in subduction modes during the Neoproterozoic. This Hf isotope survey provides new insights into Earth's tectonic machinery, advancing our understanding of the planet's geological history.

Tropical Atlantic Temperature and Hydrologic Change During the Paleocene‐Eocene Thermal Maximum

AbstractThe Paleocene‐Eocene Thermal Maximum (PETM, ∼56 million years ago) is among the best‐studied climatic warming events in Earth history and is often compared to projected anthropogenic climate change. The PETM is characterized by a rapid negative carbon isotope excursion and global temperature increase of 4–5°C, accompanied by changes in spatial patterns of evaporation and precipitation in the global hydrologic cycle. Recent climate model reconstructions suggest a regionally complex and non‐linear response of one important aspect of global hydrology: enhanced moisture flux from the low‐latitude ocean. In this study, we use the elemental and stable isotope geochemistry of surface‐dwelling planktic foraminifera from a low‐latitude Atlantic deep‐sea sedimentary record (IODP Site 1258) to quantify changes in sea‐surface temperature (SST) and salinity. Foraminiferal Mg/Ca and δ18O values are interpreted with a Bayesian forward proxy system model to reconstruct how SST and salinity changed over the PETM at this site. These temperature and salinity reconstructions are then compared to recent climate model simulations of Eocene warming. Our reconstructions indicate °C of warming, in excellent agreement with estimates from other tropical locations and modeled PETM warmth. The regional change in salinity is not as straightforward, demonstrating a slight decrease at extreme pCO2 forcing (a reversal of the modeled sense of change under moderate pCO2 forcing) in both model and proxy reconstructions. The cause of this non‐linear response is unclear but may relate to increased South American continental runoff or shifts in the Inter‐Tropical Convergence Zone.

Geochemical data of Al-rich diopside pyroxenites from the Premosello mantle peridotite massif, Ivrea-Verbano Zone, Southern Alps.

Geochemical data of Al-rich diopside pyroxenites from the Premosello mantle peridotite massif, Ivrea-Verbano Zone, Southern Alps.

Tentzel and the elephant in the room. Inconsistencies in the history of nature and history of humans (not) being discussed when ‘fossils’ were found in Thuringia in 1695

ABSTRACT In 1695 the fossils of a woodland elephant were excavated in Burgtonna (Thuringia). This article deals with the debate between Gotha’s court historiographer Wilhelm Ernst Tentzel (1659–1707), who interpreted the discovery as the remains of an elephant, and the collegium medicum of Gotha, that insisted that it was a lusus naturae. The debate, in which scholars throughout Europe soon became involved, is paradigmatic for the social, professional, epistemological and religious frames that determined what around 1700 one could say and think about the history of the earth and the role humans played in it. While Tentzel, as a specialist in human history, proved that the findings of fossilized exotic animals could not be explained by human intervention and argued for the Deluge as an agent of transport, for some of his correspondents inconsistencies between human history and the history of Nature emerged at this point, and time itself became an issue. The study emphasizes the importance of regional historiography for the understanding of nature as well as the transformation of history of Nature into natural history.

Computational capacity of life in relation to the universe.

As physical systems, all life in the universe processes information according to physical laws. Estimates for the computational capacity of living systems generally assume that the fundamental information-processing unit is the Hodgkin-Huxley neuron, thereby excluding aneural organisms. Assuming the laws of quantum mechanics, the relativistic speed limit set by light, a universe at critical mass-energy density, and a recent experimental demonstration of single-photon superradiance in cytoskeletal protein fibers at thermal equilibrium, it is conjectured that the number of elementary logical operations that can have been performed by all eukaryotic life in the history of Earth, which is shown to be approximately equal to the ratio of the age of the universe to the Planck time, is about the square root of the number by the entire observable universe from the beginning. The existence of ultraviolet-excited [Formula: see text] states in these protein fibers, operating within two orders of magnitude of the Margolus-Levitin speed limit, motivates state-of-the-art performance comparisons with contemporary quantum computers.

Tectonics and Surface Environments on Early Earth.

The mode of tectonics that governed early Earth is controversial. This makes it challenging to infer surface environments relevant to the origin of life. The majority of the literature published in the past two decades was inclined to favor the appearance of plate tectonics sometime around the mid-Archean (∼3 Ga), with the operation of stagnant lid convection (or its variants) dominant in the earlier part of Earth's history. However, the available and increasing geological record from early Earth is actually equivocal, and there is no theoretical basis to prefer stagnant lid convection over plate tectonics. In fact, such a delayed onset of plate tectonics would inhibit the emergence of life in the Archean, let alone in the Hadean. On the contrary, rapid plate tectonics in the early Hadean, enabled by the fractional crystallization of a magma ocean, could quickly transform inclement young Earth into a habitable planet, with formation of multiple surface environments potentially conducive to abiogenesis.

Lipid hydrogen isotope compositions primarily reflect growth water in the model archaeon Sulfolobus acidocaldarius.

The stable hydrogen isotope composition (δ2H) of lipid biomarkers can track environmental processes and remain stable over geologically relevant time scales, enabling studies of past climate, hydrology, and ecology. Most research has focused on lipids from the domain Eukarya (e.g., plant waxes, long-chain alkanes), and the potential of prokaryotic lipid biomarkers from the domain Archaea to offer unique insights into environments not captured by eukaryotic lipids remains unclear. Here, we investigate the H-isotope composition of biphytanes in Sulfolobus acidocaldarius, a model thermoacidophile and obligate heterotroph. We conducted a series of experiments that varied temperature, pH, shaking rate, electron acceptor availability, or electron donor flux. From these experiments, we quantified the lipid/water H-isotope fractionation (2εL/W) values for core biphytane chains derived from tetraether lipids. The 2εL/W values are consistently negative (-230‰ to -180‰) and are relatively invariant across all experiments despite a 20-fold change in doubling times and a twofold change in lipid cyclization. The magnitude and relative invariance of 2εL/W values are consistent with studies on other heterotrophic archaea and suggest archaeal lipids may be faithful recorders of the δ2H composition of growth water. Our study highlights the potential of archaeal lipid δ2H values as a hydrological proxy, offering new insights into environments where traditional proxies, such as plant-derived lipids, are not available, including extreme environments and extraterrestrial settings.IMPORTANCEReconstructing past climates is crucial for understanding Earth's environmental history and its responses to changing conditions. This study examines Sulfolobus acidocaldarius, a thermoacidophilic archaeon that thrives in extreme environments like hot springs. These microorganisms incorporate hydrogen water in the growth environment into membrane lipids, creating hydrogen isotope signatures that can reflect hydroclimate conditions. Our findings show that these hydrogen isotope ratios remain consistent even under varying temperatures, pH, oxygen levels, and electron donor fluxes, indicating a stable fractionation between lipids and water. This invariance suggests that S. acidocaldarius lipids could serve as a robust proxy for reconstructing ancient water H-isotope values, especially in extreme environments where traditional proxies, such as plant waxes, are absent. This research has broader implications for planetary-scale reconstructions, including potential applications in studying past climates on other planets, such as Mars, where similar microorganisms may have existed in hydrothermal conditions.

Miocene marine calcite concretions: a collaboration of microbial and inorganic processes?

ABSTRACT Late Miocene and early Pliocene mixed siliciclastic and carbonate deposits of the Cibao Basin, Dominican Republic, contain concretions cemented by low-magnesium calcite. These late Cenozoic concretion-bearing deposits have not been extensively altered or deeply buried and thus provide an opportunity to study a relatively young occurrence. Marine concretions are a feature of organic-rich siliciclastic shelves and basins, especially during certain times in Earth history. These pervasively cemented rocks can form low-porosity flow baffles, can be relatively fast acoustically, and are mechanically strong as they form near the seafloor and very early in their burial history. Preservation of soft grains, organic remains, and delicate fossils is exceptional in most concretions, due to an early, extensive pore-filling precipitation of small crystals (10–30 μm) of low-Mg calcite. This early cement allows concretions to preserve original grain structure in compaction-prone, mud-rich lithofacies. Stable carbon and oxygen isotope values of Miocene concretion calcite cement (δ13C = −10 to −35‰: δ18O = −2 to −5‰) are consistent with precipitation in pore water where alkalinity was generated by microbial processes. In addition to the long-recognized role of microbial sulfate reduction (δ13C values −5 to −25‰), our data suggest that anaerobic oxidation of methane (δ13C more negative than −25‰) may also contribute to an increase of alkalinity and may initiate precipitation. We favor a diffusion-based setting to supply sulfate and calcium ions. In order to facilitate precipitation of low-Mg calcite, a reduction of the Mg/Ca ratio of the pore fluids is needed to limit the inhibitory effect of Mg2+. One mechanism might be the absorption of Mg2+ by clay minerals such as chlorite, a clay common in the Cibao Basin and in many marine siliciclastic sediments. These concretions are thus a collaborative product of cementation from both microbial-induced and inorganic processes. We classify concretions as “stratigraphic” or “isolated” endmembers based on whether they form an extensive stratigraphic horizon, or occur individually, respectively. Most stratigraphic concretions mark the top boundary of their depositional cycle (meter scale), and are consistent with conditions needed for their formation (organic matter, low rate of deposition for sufficient diffusion and cement precipitation). Initial observations on the stratigraphic distribution of concretions from two depositional sequences (Cercado Formation, late Miocene, and Gurabo Formation, early Pliocene) indicate they cluster within the basal Cercado sequence and lower parasequences of the Gurabo sequence.

Bedding Surfaces: True Substrates and Earth's Historical Archive – An Introduction

Bedding surfaces are innate components of the fabric of sedimentary successions and define the beds that they bound. However, despite their ubiquity across many sedimentary strata and their use and description in a huge variety of geological studies, the importance and diversity of these stratal phenomena can frequently be overlooked and ill-defined. In this introductory text, a brief review of the history of understanding of bedding surfaces is presented: from the 17 th century origins of the lithological use of the word ‘bed’ to recent advances such as the isolation and use of true substrates, as bedding surfaces that archive the ancient interface between substrate and air/water. The open questions and contradictions that persist in our understanding of bedding planes, and their utility in interpreting Earth history, are summarized and provide the springboard for introducing the diverse papers in this volume. Together, the papers collected here shed new light on these familiar phenomena from several angles, including sedimentological and stratigraphic discussions of the divergent origins and meanings of different types of siliciclastic and carbonate bedding surfaces, details of practical considerations when using bedding surface signatures in palaeontological and ichnological studies, and a series of case studies illustrating how bedding surfaces (and particularly true substrates) can inform palaeoenvironmental reconstructions.

Terrestrialization: toward a shared framework for ecosystem evolution

Abstract The Paleozoic evolution of a complex terrestrial biota has been among the most important events in Earth history. Here, we synthesize paleontological and neontological information across the different threads of the biota—including microbial life, fungi, animals, and plants—addressing discrepancies between the fossil record and time-calibrated molecular phylogenies. Four fundamental patterns are emphasized: (1) Most terrestrial animal lineages consist of diminutive inhabitants of soil and litter, with the soil fauna exhibiting remarkable continuity between the Paleozoic and present. (2) Faunal evolution tracks the ecological opportunities afforded by the evolution of the land flora. Flora and fauna alike were initially confined to the thin interface between soil and air, but animals explored both flight and burrowing as vascular plant size increased to encompass tree stature and deep rooting. (3) Skewed nutrient ratios of land plants present a fundamental challenge for animals that are accommodated through contrasting size-based dietary strategies. Detritivory and cell-by-cell herbivory are the diets most readily available for primary consumers but impose limits on the largest possible body sizes; only with subsequent evolution of herbivory in insects and then vertebrates could the dramatic increases in size in the Permian and Mesozoic have been achieved. (4) A second pulse of animal terrestrializations is apparent in the Cretaceous and Cenozoic that might be attributed to increased terrestrial productivity associated with angiosperm evolution. However, environmental changes to nutrient availability earlier in the Mesozoic prevent an unambiguous causal attribution, and the pulse may just be an artifact of our modern vantage point.

Determination of KGa‐1b and SHCa‐1 Δ′17O and δ18O via Laser Fluorination of Lithium Fluoride Clay Pellets

ABSTRACTRationaleStable oxygen isotope measurements in silicate clays, such as smectite and kaolinite, provide crucial information for understanding Earth's climate history and environmental changes. Despite a growing interest in the oxygen isotope analysis of silicate clays and clay‐rich sediments, there lacks a consensus on the preparation and standardization of clay mineral samples. To improve the accuracy and interlaboratory comparisons of clay isotope measurements, especially those involving laser fluorination techniques, newly established kaolinite and smectite oxygen isotope standards are much needed.MethodsWe employed conventional nickel bomb fluorination combined with dual‐inlet isotope ratio mass spectrometry to establish precise δ18O and Δ′17O values for leached clay reference materials KGa‐1b and SHCa‐1, a kaolinite and a hectorite/smectite, respectively. We further measured leached KGa‐1b and SHCa‐1 pressed into pellets with a lithium fluoride as a binding agent for the laser fluorination method, allowing us to test the reproducibility between methods and utilize a standard laser chamber drift correction scheme.ResultsThe laser fluorination technique yielded highly precise and reproducible δ18O and Δ′17O measurements for the KGa‐1b and SHCa‐1, aligning with bomb values of δ18O. This confirms the method's reliability and comparability to conventional isotope measurement techniques while also stressing the importance of proper sample preparation and laser chamber drift corrections.ConclusionsThis study demonstrates that laser fluorination is an effective method for accurately measuring the stable oxygen isotope composition of silicate clays or clay‐rich sediments when corrected with known silicate clay standards. These methods offer a valuable methodology for future research and applications that will significantly improve our understanding of past climate and environmental conditions.

Geography Education and Earth Science: Bridging Concepts in Chinese High School Teaching

The teaching of earth science in Chinese senior high school geography has faced significant challenges, particularly in the compulsory module “The History of the Earth.” Despite being part of the 2019 curriculum reform, current teaching practices often fail to emphasize the geographical nature of the subject, instead treating it as a mix of geology, biology, and historical facts. This paper addresses this challenge by proposing a framework that maintains a geographical focus while teaching earth science concepts. The framework consists of three integrated approaches. First, it introduces a structured method for teaching geological time through an “Eon → Era → Period → Year” progression, helping students build a comprehensive understanding of temporal scales from a geographical perspective. Second, it demonstrates how to effectively use the “Trade Space for Time” method alongside stratigraphic analysis, enabling students to connect spatial and temporal aspects of geographical phenomena. Third, it develops geographical thinking by following the logical pathway of “Fossil → Biology → Environment,” ensuring that biological evidence is interpreted within a geographical context. For successful implementation, the paper recommends two key strategies: managing interdisciplinary content while maintaining geography’s core focus, and emphasizing geographical characteristics throughout specific teaching content. This approach ensures that “The History of the Earth” fulfills its role in developing students’ geographical literacy while contributing to their broader understanding of earth science within China’s senior high school curriculum.

The paleoenvironmental and biological significance of marine carbonate depositional surfaces

Carbonate rocks form a substantial part of the ancient geological record, yet their reliability as archives of past environments and ecosystems has been questioned because of diagenetic alteration. This study investigates the potential of carbonate depositional surfaces—irregular or planar interfaces formed at the sediment-water or sediment-air boundary during deposition—to serve as records of ancient environments and ecosystems. These surfaces, commonly preserved in carbonate strata, provide valuable insights into sedimentary processes and ecosystems over varying timescales. Some carbonate depositional surfaces have the same features as siliciclastic examples, such as desiccation cracks, ripples, dunes, and surfaces with trace and body fossils. Surfaces offer a glimpse into ordinary day-to-day deposition, such as ripples moving with the tide, or mudcracks forming on an exposed tidal flat. Other depositional surfaces are unique to carbonate sediment, including hardgrounds, tepees, beachrock, reefs, and microbialites. These surfaces represent cemented and/or condensed intervals of deposition, preserving significant differences in the duration of exposure and environmental conditions. Sedimentary factors, original mineralogy, biological and ocean chemical changes over Earth history, and tectonic/burial history all impact the likelihood of preserving carbonate depositional surfaces.

Earth's magnetic field and its relationship to the origin of life, evolution and planetary habitability.

Earth's magnetic field history can provide insight into why life was able to originate and evolve on our planet, and how habitability has been maintained. The magnetism of minute magnetic inclusions in zircons indicates that the geomagnetic field is at least 4.2 billion years old, corresponding with genetic estimates for the age of the last universal common ancestor. The early establishment of the field would have provided shielding from solar and cosmic radiation, fostering environments for life to develop. The field was also likely important for preserving Earth's water, essential for life as we know it. Between 3.9 and ca.3.4 billion years ago, zircon magnetism suggests latitudinal stasis of different ancestral terrains, and stagnant lid tectonics. These data also indicate that the solid Earth was stable with respect to the spin axis, consistent with the absence of plate tectonic driving forces. Moreover, these data point to the existence of low-latitude continental nuclei with equable climate locales that could have supported early life. Near the end of the Precambrian (0.591 to 0.565 billion years ago), the dynamo nearly collapsed, but growth of the inner core during earliest Cambrian times renewed the magnetic field and shielding, helping to prevent drying of the planet. Before this renewal, the ultra-weak magnetic shielding may have had an unexpected effect on evolution. The extremely weak field could have allowed enhanced hydrogen escape to space, leading to increased oxygenation of the atmosphere and oceans. In this way, Earth's magnetic field may have assisted the radiation of the macroscopic and mobile animals of the Ediacara fauna. Whether the Ediacara fauna are genetically related to modern life is a matter of debate, but if so, magnetospheric control on atmospheric composition may have led to an acceleration in evolution that ultimately resulted in the emergence of intelligent life.

"The Earth is Alive": Attributing Agency to the Earth Causes Moral Concern for the Environment and Biocentric Attitudes.

Do people need to attribute agency to nature to morally care for it? The answer to this question has significant implications for our understanding of social cognitive effects on moral judgment. Despite its relevance during an environmental crisis, surprisingly little is known about the answer. Across two studies, we explored whether attributing agency to nonhuman natural entities like the Earth has a causal influence on environmental moral concern and intrinsic valuing of nature (biocentrism). In Study 1, we used an experimental design, assigning U.S. urban adults to one of three videos about the history of Earth's ecosystems. Two of them described the Earth as an agent: either as a thoughtful person (psychological) or as a living animal (vitalist). The third described the Earth as a nonagentic object (control). Participants in either agentic condition showed greater environmental moral concern and biocentrism than participants in the nonagentic condition. In Study 2, we examined whether-absent any agency cues-a scientifically informative video about Earth's history would prompt environmental moral concern and have a greater effect than watching awe-inspiring depictions of the Earth or learning irrelevant information in a control condition. No significant differences were found. However, patterning with Study 1, individuals' tendencies to attribute mind to the Earth predicted environmental moral reasoning. Carefully invoked, vitalist agency attributions-which deviate less from scientific understandings of the Earth than psychological ones-can mobilize conservationist attitudes among U.S. adults. Overall, our results suggest that agentic attributions of life are required to engage significant moral concern.

Trace fossils from the Meishucun section of South China: revisiting ichnotaxonomy, behavioural diversification and ecosystem engineering from a key Ediacaran–Cambrian succession

AbstractThe Ediacaran–Cambrian transition was a time of profound geobiological revolution and sedimentary change in Earth's history, including arguably the most dramatic evolutionary radiation and a remarkable biotic replacement. The complex feedback between diversification of metazoans and their ecological interactions, especially after the extinction of the latest Ediacaran biota, is still debated. Here, we systematically studied the trace fossil content of the Ediacaran–Cambrian succession from the Meishucun section of South China. A total of 20 ichnogenera comprising 31 ichnospecies have been identified in the succession. The occurrence of Treptichnus pedum in the Lower Phosphate of the Zhongyicun Member reinforces the importance of this ichnotaxon as an indicator of the Ediacaran–Cambrian boundary. Our critical review of the trace fossil record of this key succession shows that increases in ichnodiversity, ichnodisparity, degree of bioturbation, and bioturbation depth were accompanied by increases in modes of life and ecosystem engineering throughout the early Cambrian. The dramatic and stepped increased in ichnodiversity and ichnodisparity in the Ediacaran–Cambrian transition, from simple trace fossil morphologies in the Ediacaran to complex branching in the Fortunian, and finally horizontal looping trails and suspension feeding burrows in Cambrian Stage 2, paralleled the shift from the Cambrian information revolution to the agronomic revolution. The dramatic hike in bioturbation intensity and depth that occurred during Cambrian Stage 2 may have resulted in an increase in bioirrigation levels and was conducive to a further deepening of the redox discontinuity surface.

Shallow vs. Deep subduction in Earth history: Contrasting regimes of water recycling into the mantle

Shallow vs. Deep subduction in Earth history: Contrasting regimes of water recycling into the mantle

Persistence of davemaoite at lower-mantle conditions

The lower mantle occupies over half of Earth’s volume, and accordingly, its mineralogy is crucial in determining the structure and dynamics of Earth. Davemaoite, the calcium silicate perovskite, was believed to coexist with bridgmanite in the lower mantle and is considered essential for understanding the chemical evolution and dynamics of Earth’s lower mantle. However, the presence of davemaoite is challenged due to the potential for high calcium silicate solubility in bridgmanite. Here we use an ultrahigh-pressure multi-anvil technique to show experimentally that the calcium solubility in bridgmanite is insufficient to eliminate davemaoite under mantle conditions, including typical mantle pressure, temperature and chemical compositions. We conclude that davemaoite has been stable in Earth’s lower mantle since its formation. Due to the limited calcium solubility in bridgmanite, davemaoite-enriched domains are expected at the core–mantle boundary. These domains could serve as the principal reservoir for incompatible elements in the lower mantle and may be the source for some ocean island basalts. Furthermore, our study offers an explanation for the observed large low-shear-wave-velocity provinces at the bottom of the lower mantle. These provinces may consist of davemaoite-enriched materials crystallized from basal magma ocean in early Earth history.