Continental Drift Research Articles

Oriental freshwater mussels arose in East Gondwana and arrived to Asia on the Indian Plate and Burma Terrane

Freshwater mussels cannot spread through oceanic barriers and represent a suitable model to test the continental drift patterns. Here, we reconstruct the diversification of Oriental freshwater mussels (Unionidae) and revise their taxonomy. We show that the Indian Subcontinent harbors a rather taxonomically poor fauna, containing 25 freshwater mussel species from one subfamily (Parreysiinae). This subfamily most likely originated in East Gondwana in the Jurassic and its representatives arrived to Asia on two Gondwanan fragments (Indian Plate and Burma Terrane). We propose that the Burma Terrane was connected with the Indian Plate through the Greater India up to the terminal Cretaceous. Later on, during the entire Paleogene epoch, these blocks have served as isolated evolutionary hotspots for freshwater mussels. The Burma Terrane collided with mainland Asia in the Late Eocene, leading to the origin of the Mekong’s Indochinellini radiation. Our findings indicate that the Burma Terrane had played a major role as a Gondwanan “biotic ferry” alongside with the Indian Plate.

Premature rejection in science: The case of the Younger Dryas Impact Hypothesis.

The progress of science has sometimes been unjustifiably delayed by the premature rejection of a hypothesis for which substantial evidence existed and which later achieved consensus. Continental drift, meteorite impact cratering, and anthropogenic global warming are examples from the first half of the twentieth century. This article presents evidence that the Younger Dryas Impact Hypothesis (YDIH) is a twenty-first century case.The hypothesis proposes that the airburst or impact of a comet ∼12,850 years ago caused the ensuing ∼1200-year-long Younger Dryas (YD) cool period and contributed to the extinction of the Pleistocene megafauna in the Western Hemisphere and the disappearance of the Clovis Paleo-Indian culture. Soon after publication, a few scientists reported that they were unable to replicate the critical evidence and the scientific community at large came to reject the hypothesis. By today, however, many independent studies have reproduced that evidence at dozens of YD sites. This article examines why scientists so readily accepted the early false claims of irreproducibility and what lessons the premature rejection of the YDIH holds for science.

Pre-Historic Intra-Continental Africa-India Proximity Series on the Vedic-Period-Earth Viewed from Alfred Wegener’s Pro-Universals

This paper has chosen its platform on which Alfred Wegener had advanced his fast-track research-method as a German Professor looking at many proproximity universals in geographic locations nurtured by the Cosmic Nature‟s identical species inhabiting the Earth / Vedic Soil from the beginning of prehistoric times. The Professor must have been ignited by the Nature‟s configured terrestrial fauna and flora with remnants of material-life-objects facilitated by occurrences of fossil organisms which are the geologically altered remains and/or conceptacles of once-living organisms before and after the separation of the Continental rocks, say, not man-made at all . His Excellency Alfred Wegener came up driving home his down-to-Earth hypothesis of prefixed „Continental Drift‟ as one of the pro-Universals akin to a mathematical lemma with deemed-proof in light of the paleontological wonders , say again, not man-made at all but of his times. Yet, fossils of identical plants and animals were taken as the pro-Universals by Wegener (1880-1930), while inspired by ancestral Indo-European settlers belonging twined to Germans‟ Vedic roots of Indo-European language family as pioneers of Vedic-Research since 1846 AD on Rig-Veda by Rudolph von Roth (1821-1895) and Max Mueller (1823-1900) known as the Veda Vyasa of the Kali Yuga.

A statistics and physics-based tropical cyclone full track model for catastrophe risk modeling

Catastrophe (CAT) risk modeling of perils such as typhoon and earthquake has become a prevailing practice in the insurance and reinsurance industry. The event generation model is the key component of the CAT modeling. In this paper, a physics-based tropical cyclone (TC) full track model is introduced to model typhoons events in the western North Pacific basin. At the same time, a comprehensive test of the model is presented from the perspective of CAT risk modeling for insurance and reinsurance applications. The full track model includes the genesis, track, intensity, and landing models. Driven by the global environmental circulations, the model employs the advection and beta drift theory in atmospheric dynamics to model the track of typhoons. The proposed model is novel in the way of modeling the genesis of TCs with three-dimension kernel distributions in space and time. This enables the simulation of seasonal characteristics of TCs. By generating 10,000-year TC events, we comprehensively test the model from the standpoint of CAT insurance and reinsurance applications. The typhoon hazard model and the generated events can serve as the inputs for assessing the typhoon risk and insured loss caused by winds, rains, floods, and storm surges.

Tides and Volcanoes: A Historical Perspective

In this paper, we examine the origins and the history of the hypothesis for an influence of tidal forces on volcanic activity. We believe that exploring this subject through a historical perspective may help geoscientists gain new insights in a field of research so closely connected with the contemporary scientific debate and often erroneously considered as a totally separated niche topic. The idea of an influence of the Moon and Sun on magmatic processes dates back to the Hellenistic world. However, it was only since the late 19thcentury, with the establishment of volcano observatories at Mt. Etna and Vesuvius allowing a systematic collection of observations with modern methods, that the “tidal controversy” opened one of the longest and most important debates in Earth Science. At the beginning of the 20thcentury, the controversy assumed a much more general significance, as the debate around the tidal influence on volcanism developed around the formulation of the first modern theories on the origins of volcanism, the structure of the Earth’s interior and the mechanisms for continental drift. During the same period, the first experimental evidence for the existence of the Earth tides by Hecker (Beobachtungen an Horizontalpendeln über die Deformation des Erdkörpers unter dem Einfluss von Sonne und MondVeröffentlichung des Königl, 1907, 32), and the Chamberlin–Moulton planetesimal hypothesis (proposed in 1905 by geologist Thomas Chrowder Chamberlin and astronomer Forest Ray Moulton) about the “tidal” origin of the Solar System, influenced and stimulated new researches on volcano-tides interactions, such as the first description of the “lava tide” at the Kilauea volcano by Thomas Augustus Jaggar in 1924. Surprisingly, this phase of gradual acceptance of the tidal hypothesis was followed by a period of lapse between 1930 to late 1960. A new era of stimulating and interesting speculations opened at the beginning of the seventies of the 20thcentury thanks to the discovery of the moonquakes revealed by the Apollo Lunar Surface Experiment Package. A few years later, in 1979, the intense volcanism on the Jupiter’s moon Io, discovered by the Voyager 1 mission, was explained by the tidal heating produced by the Io’s orbital eccentricity. In the last part of the paper, we discuss the major advances over the last decades and the new frontiers of this research topic, which traditionally bears on interdisciplinary contributions (e.g., from geosciences, physics, astronomy). We conclude that the present-day debate around the environmental crisis, characterized by a large collection of interconnected variables, stimulated a new field of research around the complex mechanisms of mutual interactions among orbital factors, Milankovitch Cycles, climate changes and volcanism.

Cenozoic tectono-sedimentary evolution of the northern Turkana Depression (East African Rift System) and its significance for continental rifts

Rifting is an emblematic facet of continental drift and its early stage (i.e., stretching phase) is pivotal to be fully characterized and understood because it then conditions all subsequent stages of the break-up cycle. Although the final architectures of rifted margins have been extensively documented and discussed over the past decades from a wide range of examples and from multiple surface and sub-surface data, the complete evolution of the stretching phase itself remains mostly illustrated from analogue and numerical models and more rarely from real case studies and field evidences. The northern Turkana Depression (Cenozoic East African Rift System) stands as a key natural example to investigate every stage of the evolution of a stretching phase, as it provides almost ∼30 Ma of rift evolution from its initiation to present-day. In this study, we combine field analyses and seismic reflection data to characterize every stage of this tectono-sedimentary evolution, with a focus on the, rarely observed, surface rupture initiation and tectonic decay. In particular, we show rifting initiates with the reactivation of non-optimal inherited structures, progresses with their abandonment during the development of long and wide grabens or half-grabens, and locally terminates with the development of a post-tectonic flexural sag, synchronously to the migration of the locus of brittle deformation to an adjacent area where starts a similar cycle. Our observations allow us to nuance commonly accepted generic rift evolution models, and to discuss possible geodynamic controls on fault evolution and strain migration. We propose a field-based alternate conceptual evolution model for rift systems sharing common characteristics with the northern Turkana Depression such as abundant inherited basement structures, thin and hot lithosphere and a low to moderate magmatism.

Methods and algorithm for calculating the focal parameters of a hollow conical electron beam in high-voltage glow discharge electron guns with a focusing magnetic lens

The algorithm is considered for calculating the focal distance of a hollow conical electron beam generated by high-voltage glow discharge electron guns with magnetic focusing of the beam in the drift region, as well as a method for calculating the diameter of the focal ring and its thickness for such a beam. The proposed algorithm is based on the theory of electron drift in the field of a focusing magnetic lens and is designed using the methods of discrete mathematics and the minimax analysis. The obtained simulation results made it possible to establish the influence of the magnetic lens current on the focal diameter of a hollow conical electron beam and on its focal ring thickness. It is shown that the change in the focal parameters of a hollow conical electron beam can be effectively provided through the regulation of the magnetic lens current.

Trøndelag Platform and Halten–Dønna Terraces Composite Tectono-Sedimentary Element, Norwegian Rifted Margin, Norwegian Sea

Abstract The Trøndelag Platform and Halten–Dønna Terraces occupy a central part of the Norwegian Sea rifted continental margin off the mid-Norway coast. The margin is expected to hold 4500 Mboe of undiscovered oil equivalents and represents an economically important Arctic province. The geological evolution of the area is closely linked to processes involving the Caledonian Orogeny and subsequent plate tectonic reorganizations, multiphase rifting, continental drift and glaciations across the northern hemisphere. In this chapter we review the geology of the Trøndelag Platform and Halten–Dønna Terraces Composite Tectono-Sedimentary Element based on published data and results of Equinor ASA in-house studies. Three new structural elements are defined for the first time: the Leka fault complex, the Vikna high and the Sula basin.

A plate-tectonics based neighborhood search optimizer and its application for fault monitoring in IoT systems

Plate tectonics is a scientific theory that describes large scale motions of plates in Earth’s lithosphere. This paper presents a new optimization technique inspired by the tectonic forces that drive continental drift: Plate Tectonics based Neighborhood Search Optimization (PBO). The proposed evolutionary algorithm simulates tectonic forces on different points of the plate using nearest neighborhood search to exploit local information available in the objective function’s gradients while simultaneously exploring for better solutions throughout the search space. PBO is a versatile algorithm whose behavior can be altered in accordance to domain specific requirements on the objective function. Such tuning can lead to higher accuracy and faster convergence rate than other optimization algorithms. According to the CEC 2018 benchmark, it performs better than other top-performing evolutionary optimization methods in the CEC 2018 special session in all dimensions (D) where D= 10, 30, 50, and 100. It is resistant to getting stuck at local-minima due to increased sampling density of stable points even in vanishingly small gradients. This property, along with its customizability in search behavior, make it a compelling choice for adaptation in industrial uses such as those in mechanical engineering, communication, and aviation. Towards the end, this paper discusses and adapts PBO for application in one such industrial domain: Fault Monitoring in IoT systems. It also compares the results with other evolutionary algorithms like, GA, ACO, PSO, Simulated Annealing, etc. From the results, it can be seen that PBO outperforms other contemporary algorithms for the same application on standard datasets of different sizes.

Need for the Determination of the Nigerian Fault Lines

Earthquakes and Tremors are Tectonic activities traced to Crustal Motions with roots in the Continental Drift Theory. These activities occur mostly at Plate Boundaries and along or close to Fault Lines. Nigeria was erroneously considered aseismic in the past, but studies have shown that Nigeria was never aseismic as information on different Tremors and Earthquakes abound. The recent occurrences of Tremors in Abuja, the Nation’s Capital, call for a serious attention towards the definition of the Nigerian Fault Lines. An attempt towards the determination of the Fault Lines is made, using the Non-Geodetic and Geodetic Methods. The Non-Geodetic Method Seeks to connect the Epicenters of different Earthquakes and Tremors on record, in order to present a possible set of Fault Lines. Three Fault Lines, The Western Nigeria Fault Line, the Mid Nigeria Fault Line and the Eastern Nigeria Fault Lines were proposed. The Geodetic Method adopted the use of archived GNSS data from the Nigerian CORS stations between 2012 and 2014. Fourteen sites, ABUZ, BKFP, GCCT, CLBR, FPNO, FUTA, FUTY, GEMB, HUKP, MDGR, OSGF, RUST, ULAG and UNEC, were used for this experiment, and ten IGS stations, DEAR, ABPO, RAMO, DARK, MELI, ASCG, MOIU, ZAMB, NOT1, BHR4, were used for Network Stabilization in the experiment conducted with the GAMIT/GLOBK Software. The Mean Horizontal Velocity of Nigeria for the period was 22.5625±0.32583mm/yr East, 18.93±0.23417mm/yr North, found to agree with Bawa, Ojigi and Dodo (2018) and Altamimi et al (2011). The Analysis of the Position Solution, showed that stations along a particular line, share similar direction of motion, which agrees with the Non-Geodetic Proposal. It was recommended that in order to adequately and accurately determine the Fault System in Nigeria, about three times the existing number of CORS Stations must be established, and their data made readily available to researchers. Keywords: Earthquakes, Tremors, Fault Lines, GAMIT/GLOBK DOI: 10.7176/JEES/11-10-05 Publication date: October 31 st 2021

New Caenis Species (Insecta: Ephemeroptera: Caenidae) from Angola, Okavango and Zambezi River Basins

Nine new species of Caenis from Angola are described herein: Caenis wegeneriana sp. n. (imago), Caenis angolensis sp. n. (imago and larva), Caenis branchiata sp. n. (larva), Caenis filappendicessp.n.(imago),Caenisulesisp.n.(larva),Caeniscubangosp.n.(larva),Caenisarmata sp. n. (imago), Caenis brevispinata sp. n. (imago), and Caenis gallocristata sp. n. (imago). The relationship between the newly described species and other known African species is discussed. The vicariant biogeographic affiliation of Caenis wegeneriana to a related species group in South America, separated by continental drift, is considered. A key to the male imagoes is provided, including Caenis antelucana Malzacher, 1990, Caenis brevipes Kimmins, 1956, Caenis douglasi Malzacher, 1993 and Caenis jinjana Kimmins, 1956, which have previously been recorded in the Cunene River, along the shared border with Namibia.

Provenance and Paleoenvironmental Studies of Cretaceous African and South American Kaolins: Similarities and Differences

The African and South American continents are of great interest in continental drift studies. Hence, this study assesses the possible correlations in the provenance and paleoenvironment of selected Cretaceous Nigerian and Cameroonian (in Africa), and Argentine and Brazilian (in South America) kaolins through an analysis of their mineralogical and geochemical characteristics. On the basis of their mineralogical composition, the Nigerian Lakiri and Brazilian soft Capim River kaolins are predominantly characterised as pure kaolins, whereas the kaolins from Cameroon (except for Yatchika) and Argentina are mainly considered as sandy kaolins. The present study revealed that the Brazilian soft Capim River kaolin had the highest kaolinite structural order, whilst the Argentine Santa Cruz kaolin had the least. The kaolins from Nigeria, Cameroon, and Argentina were dominated by subhedral to anhedral kaolinite crystals relative to the Brazilian kaolin, which possess more euhedral kaolinite crystals. The kaolins were formed by the intense weathering of intermediate to felsic rocks under anoxic conditions, which is consistent with the structural framework of the basins. The average paleotemperatures obtained for the kaolins (except for the one from Santa Cruz) indicates that the paleoweathering took place under tropical climates.

Correspondence between South African geologist Alex L. du Toit and Birbal Sahni concerning Gondwana Palaeobotany (1925–1944)

Birbal Sahni (1891-1949) was well known as the first Indian palaeobotanist, and he established the Institute that was named after him, now the Birbal Sahni Institute of Palaeosciences. Alexander L. du Toit (1878-1948) was the most famous South African geologist, known internationally for advocating the idea of Continental Drift, and for his work on Gondwana geology and palaeobotany. Du Toit was introduced to Sahni by Albert Seward, who was Sahni’s mentor at Cambridge University. They started a correspondence in 1925, involving the exchange of papers, books, and samples, which lasted at least until 1944. Du Toit and Sahni met in 1938 at the Indian Science Congress in Calcutta. Their preserved letters deal with the palaeobotany, correlations, and age of the Rajmahal beds, and later with the palynological investigations of Karoo Dwyka samples sent by du Toit to Sahni, which were worked on by D. D. Pant, who had been a student of Sahni. This correspondence reveals in detail just how these geoscientists involved with problems of Gondwana palaeogeography tackled these questions in spite of the long distances, and slow communications of the time. Information, especially that published in local journals, was disseminated by means of sending reprints, proof copies, and sometimes by handwritten lists of fossils. Although, initially, Sahni had obtained South African and Australian fossil material through the British Museum in London, he later obtained South African samples specially collected for him by du Toit. Samples were also exchanged between South Africa, England, India and Australia.

Under the Radar: Institutional Drift and Non‐Strategic Institutional Change

AbstractAlthough researchers have acknowledged that not all institutional change results from the intentional efforts of relatively reflexive actors, we lack an explanation of how mundane interactions between actors can result in non‐strategic institutional change. To address this, we advance the theory of institutional drift that reveals how the practice deviation(s) that occur between interaction partners in an institutional order, transformed into tolerable deviations by the self and others, can lead to the non‐strategic transformation of that institutional order. Our framework extends the interactionist perspective in organizational institutionalism by showing how interpersonal interactions are animated and constrained by people’s passionate attachment to the fundamental sacred ideals, or ethos, underlying institutional orders. It is this connection with ethos that animates the interactional processes tied to both maintaining and disrupting institutions.

INTERPRETAÇÃO SÍSMICA E MODELAGEM 3D ESTRUTURAL NA BACIA DE BARREIRINHAS (MARANHÃO, BRASIL)

Discoveries of hydrocarbons in the basins of the African Equatorial Margin and Guinea Gulf stimulated the exploratory interest in the basins of the Brazilian Equatorial Margin, for being together before the Continental Drift. This interest emerges because both African and South American equatorial margin are considered analogous. The Barreirinhas Basin is a member of the Brazilian equatorial margin. The objective of this work is to present the results obtained through the seismic interpretation and structural 3D modeling, in the context of gravitational tectonics, in an area covered by 3D seismic data, in the Barreirinhas Basin. The compressional domain of an extensive-compressive system was mapped. In this study, were identified reverse faults, thrust faults and fault-related folding like fault-bend and fault-propagation fold that can be accompanied by backthrust features in deep to ultra-deep waters. The 3D structural model allowed the representation of the geometric variations present in the study area. The new information will be important for the identification and evaluation of structures with greater potential for hydrocarbon accumulations and can help in future studies to characterize the reservoir, contributing to the evolution of knowledge of the equatorial margin, especially in the Barreirinhas Basin.

An Antigenic Thrift-Based Approach to Influenza Vaccine Design.

The antigenic drift theory states that influenza evolves via the gradual accumulation of mutations, decreasing a host’s immune protection against previous strains. Influenza vaccines are designed accordingly, under the premise of antigenic drift. However, a paradox exists at the centre of influenza research. If influenza evolved primarily through mutation in multiple epitopes, multiple influenza strains should co-circulate. Such a multitude of strains would render influenza vaccines quickly inefficacious. Instead, a single or limited number of strains dominate circulation each influenza season. Unless additional constraints are placed on the evolution of influenza, antigenic drift does not adequately explain these observations. Here, we explore the constraints placed on antigenic drift and a competing theory of influenza evolution – antigenic thrift. In contrast to antigenic drift, antigenic thrift states that immune selection targets epitopes of limited variability, which constrain the variability of the virus. We explain the implications of antigenic drift and antigenic thrift and explore their current and potential uses in the context of influenza vaccine design.

Applying Humboldt's holistic perspective in China's sustainability

Alexander von Humboldt, was a great German geobotanist, educator and naturalist who greatly influenced science and humanities for more than two hundred years. In addition to scientific contributions (such as the understanding of vegetation distribution, the concepts of isotherm and pressure contours, and the initial concept of continental drift theory), he firmly believed in the concept of the interconnection of everything and the methodological approach of a holistic perspective to development, which has significance in achieving the UN Sustainable Development Goals, because they include both synergy and trade-offs among these goals. China has undergone tremendous changes since its reform and opening up in 1978 and now faces severe challenges in sustainable development. The scientific methods applied by Chinese scientists in sustainability fulfil the Humboldtian holistic perspective of nature. Here I provide four successful cases and their significant implications for addressing the increasingly severe water shortage, biological conservation, and conflicts between human well-being and land. The four examples discussed in this article are enlightened to establish a strong, just, and influential government and require empirical research to implement sustainable development plans. I believe that it's vital to encourage and supervise public participation for a successful program; for example, the participants should not be restricted to project executors, i.e., farmers or workers, but also students and scientists. Eradicating poverty must be prioritized, and well-being is the ultimate goal for sustainable development. This review article provides an extremely valuable reference for other developing or even developed countries to address sustainability challenges.

Deciphering paleogeography from orogenic architecture: Constructing orogens in a future supercontinent as thought experiment

Orogens that form at convergent plate boundaries typically consist of accreted rock units that form an incomplete archive of subducted oceanic and continental lithosphere, as well as of deformed lithosphere of the former upper plate. Reading the construction of orogenic architecture forms the key to decipher the pre-orogenic paleogeographic distribution of oceans and continents, as well as bathymetric and topographic features that existed thereon such as igneous plateaus, seamounts, microcontinents, or magmatic arcs. Current classification schemes of orogens divide between settings associated with termination of subduction [continent-continent collision, continent-ocean collision (obduction)] and with ongoing subduction (accretionary orogenesis), alongside intraplate orogens. Perceived diagnostic features for such classifications, particularly of collisional orogenesis, hinge on dynamic interpretations linking downgoing plate paleogeography to upper plate deformation, plate motion changes, or magmatism. Here, we show, however, that Mesozoic-Cenozoic orogens that undergo collision almost all defy these proposed diagnostic features and behave as accretionary orogens instead. To reconstruct paleogeography of subducted and upper plates, we therefore propose an alternative approach to navigating through orogenic architecture: subducted plate units comprise nappes (or mélanges) with Ocean Plate Stratigraphy (OPS) and Continental Plate Stratigraphy (CPS) stripped from their now-subducted or otherwise underthrust lower crustal and mantle lithospheric underpinnings. Upper plate deformation and paleogeography respond to the competition between absolute motions of the upper plate and the subducting slab. Our navigation approach through orogenic architecture aims to avoid <i>a priori</i> dynamic interpretations that link downgoing plate paleogeography to deformation or magmatic responses in the upper plate, to provide an independent basis for geodynamic analysis. From our analysis we identify ‘rules of orogenesis9 that link the rules of rigid plate tectonics with the reality of plate deformation. We use these rules for a thought experiment, in which we predict orogenic architecture that will result from subducting the present-day Indian Ocean and colliding the Somali, Madagascar, and Indian margins using a published continental drift scenario for a future supercontinent as basis. We illustrate that our inferred rules (of thumb) generate orogenic architecture that is analogous to elements of modern orogens, unlocking the well-known modern geography as inspiration for developing testable hypotheses that aid interpreting paleogeography from orogens that formed since the birth of plate tectonics.

Celebrating Women in Paleobotany: A Tribute to Edith L. Taylor—Introduction and Dedication

Celebrating Women in Paleobotany: A Tribute to Edith L. Taylor—Introduction and Dedication

Paleosols and weathering leading up to Snowball Earth in central Australia

The Cryogenian Period (717–635 Ma), or ‘Snowball Earth’, was an unusually cool period of Earth history when glaciers extended to low latitudes. Past ideas on causes of this widespread glaciation include increased consumption of atmospheric carbon dioxide by silicate weathering due to continental drift into tropical paleolatitudes, or by voluminous, easily weathered volcanic tuffs. Alternatively, carbon sequestration from the atmosphere may have been intensified by advances in biomass on land or at sea. These hypotheses are tested with a new study of red siltstones of the Johnnys Creek Formation (785–717 Ma) in central Australia, where paleosols have long been recognised. Although these dolomitic red siltstones look like shales, they lack lamination. Instead, they have the massive bedding and grainsize distribution of dolomitic and calcareous loess, which precede tillites of the Areyonga Formation. Paleomagnetic studies indicate little drift from a paleolatitude of 26.2° during accumulation of the Johnnys Creek Formation. Nor does the Johnnys Creek Formation contain easily weathered volcanic ash, only local basalt flows. Paleoproductivity of the paleosols increases up section, as estimated in ppm soil CO2 from depth in paleosols to gypsic (By) and then calcic (Bk) horizons. Deepening and intensification of soil respiration reflects greater terrestrial carbon sequestration, and increased chemical weathering up section, and both would have drawn down atmospheric CO2. Comparable transition from gypsic to calcic soils in modern deserts reflects change from cyanobacterial-gypsic to fungal–algal calcic ecosystems. Snowball Earth glaciation may have been induced by evolutionary advances to eukaryotic and multicellular life on land, in the same way as Ordovician glaciation was induced by land plants, Permo-Carboniferous glaciation by trees, and Pleistocene glaciation by grasslands. KEY POINTS Johnnys Creek Formation of central Australia has paleosols dated 785–717 Ma. Little drift from paleolatitude 26.2°, and no volcanic ash, only local basalt flows. Paleosol paleoproductivity and depth of weathering increased steadily up section. Glaciation may have been induced by eukaryotic and multicellular life on land.