Habitable Planet [this journal has moved to new platform at: https://www.sciltp.com/journals/hp]
IMPORTANT ANNOUNCEMENT: TO FREELY DOWNLOAD PDFS OF ARTICLES AND FOR REGISTRATION AND SUBMISSON OF MANUSCRIPTS, PLEASE GO TO THE JOURNAL’S NEW HOMEPAGE AT: https://www.sciltp.com/journals/hp Habitable Planet is peer reviewed international interdisciplinary open access journal belonging to the International Association for Gondwana Research (IAGR) and the Gondwana Institute for Geology and Environment (GIGE), Japan. The journal aims to promote high quality research publications across diverse fields of Earth and Environmental Sciences covering the history of evolution of planet Earth, resources, hydrosphere, biosphere and atmosphere, particularly focusing on the planet Earth’s habitability. Interdisciplinary topics of natural hazards, environment-related socio-economic issues, and intercultural aspects in the context of sustainability are also considered. The journal also welcomes contributions on studies related to planetary equivalents. The journal aims to promote and disseminate scientific information among researchers, students, academics as well as policy and decision makers with a view to serving the global community. ISSN: 3079-5281 Publisher: International Association for Gondwana Research https://iagrglobal.org/ © International Association for Gondwana Research & Gondwana Institute for Geology and Environment, Japan Journal Headquarters: Kochi University, Kochi 780-8520, Japan E-mail: editorial@habitableplanetjournal.com
International Association for Gondwana Research, Japan
CC Attribution-NonCommercial-NoDerivatives 4.0
Habitable Planet Earth: Secular evolution and sustainable future
The secular evolution of the Earth involved slow, long-term and step-wise changes since its formation, driven by internal processes of differentiation, whole mantle convection and overturn, changes in style of plate tectonics from mobile lid to hot and shallow subduction, and finally to cold and steep subduction of oceanic lithosphere. This was complimented by tectonic activities that resulted in building continents and supercontinents, cleaning up toxic oceans and archiving important metals as mineral deposits, and evolving a life-sustaining atmosphere as well as a nutrient supported environment for the birth and evolution of the biosphere. Planetary evolution, a dynamic process that dictates the formation of planets over time, and sustainability, which deals with protecting the planet without endangering its environment and life, are interrelated aspects. The launch of the new Journal, “Habitable Planet” is aimed at providing an appropriate platform for the scientific community to publish scholarly research on multidisciplinary themes related to the evolution of Earth and challenges on sustainability during current transitional phase of the planet with population explosion, resource depletion, environment degradation, and climate change.
Copyright (c) 2025 © International Association for Gondwana Research & Gondwana Institute for Geology and Environment, Japan https://creativecommons.org/licenses/by-nc-nd/4.0
Laterite formation under tropical weathering: A geochemical characterization
The laterite deposits of the Madayippara in Kannur district, Kerala, is a flat-topped lateritic plateau in Western margin of India. This study employed geochemical techniques—such as CIA and correlation coefficient analysis—to assess relative weathering and lateritization processes across the selected profile. It is observed that SiO2 and Al₂O₃ are the most abundant oxides in the samples. Fe₂O₃ values suggest strong ferruginization (lateritization) in the upper part of the profile and a corresponding depletion in silica, while the bottom layer exhibits lower Fe₂O₃ content and higher silica levels. The degree of lateritization systematically illustrates samples from various depths according to lateritization intensity, with even the lowest sample falling within the weakly lateritized field. The Weathering Index of Parker (WIP) and Chemical Index of Alteration (CIA) suggest intense tropical weathering leading to the formation of laterites associated with gibbsite-rich layers. The correlation coefficient matrix between different major elements indicates a negative correlation between Fe and Si, reflecting a typical trend in high-grade laterites. Mineralogical studies confirmed the presence of kaolinite, gibbsite, goethite, hematite, and quartz typical of mature laterite profiles. These findings highlight the impact of prolonged tropical weathering on the Madayippara landscape and contribute to a better understanding of the region's geological evolution and resource significance. This study also supports in situ field evidence, indicating that the laterites at Madayippara developed over Tertiary sedimentary rocks during the post-Warkalli lateritisation cycle.
Groundwater potential and sustainability in the Indian subcontinent
Understanding regional groundwater characteristics is an important aspect for sustainability. The Indian subcontinent is one of the critical regions because of the high population and rapid developmental activities where the groundwater potential plays a crucial role in meeting the water demands for agriculture, domestic, and industrial purposes. Here we evaluate the characteristics of the major aquifer systems in the Indian subcontinent and divide these into three distinct types viz. sedimentary aquifers comprising 48%, followed by metamorphic crystalline aquifers 32% and igneous crystalline aquifers at 20%. In 2023, India extracted 241.34 BCM of groundwater though all these aquifers, representing approximately 59.26% of the nation's annual extractable groundwater resource. Severe over-exploitation of groundwater is observed in sedimentary aquifers of the Indo-Gangetic alluvial system, notably in Haryana, Punjab, Rajasthan, and Delhi, whereas significant over-exploitation in metamorphic crystalline aquifers is reported of Tamil Nadu and Karnataka, particularly in cities such as Bangalore and Chennai. Nevertheless, most assessment units are categorized as 'safe,' offering ample opportunity for sustainable groundwater development. Our review shows that 87% of India's groundwater is extracted annually primarily for irrigation purposes. We observe substantial disparities in the distribution and extraction of groundwater for irrigation across the country, exacerbated by increasing water shortages linked to rising temperatures. These findings underscore the urgent need for building efficient irrigation systems in mitigating climate-induced threats. Therefore, to align with the UN Sustainable Development Goals (SDG-6,13 and 15) and safeguard India's productive aquifer units, it is essential to implement managed aquifer recharge schemes across the country.
Mount Popa in the Central Dry Zone of Myanmar: From legacy of a volcano to a habitable refugium
Mount Popa is recognized as one of the most significant volcanoes in Myanmar. Conservation initiatives have resulted in extensive forest coverage throughout the Mt. Popa region, which receives comparatively greater precipitation than surrounding towns within the central dry zone. The volcanic activity of Mt. Popa has contributed to notable geological formations, while also serving as a critical biodiversity refuge within an otherwise arid landscape. Additionally, the area has supported successive human populations, whose presence is deeply intertwined with the site’s enduring religious and anthropological significance. Recent seismic activity along the Sagaing Fault has prompted concerns regarding the dormant status of Mt. Popa and underscores the necessity for comprehensive scientific investigation. Given that geopark initiatives integrate research, conservation, and socioeconomic development, robust support from both local and international stakeholders is essential to sustain Mt. Popa as a viable ecological and cultural refugium.
Earth’s habitability in a planetary framework: The Archean rock record
This study briefly synthesizes geochemical and isotopic evidence of co-evolution of Earth’s surface, atmosphere, oceans and biosphere from Hadean to Archean geological records. Impact induced Hadean tectonics, emergence of oceans and the reducing atmosphere created conditions favourable for the initial biological processes. Intense volcano-hydrothermal activity and tectonism were responsible for nutrient supply and circulation, supporting microbial life. Geochemical trends of bio-essential elements such as Fe, Mn, Mo, P, Ni, Co, and U indicate a strong relationship between elemental cycling and early life processes. Archean passive margin sedimentary rocks such as stromatolitic carbonates, banded iron formations (BIFs), Manganese deposits, and carbonaceous shales present in the greenstone belts of Dharwar Craton preserve biosignatures indicating ancient microbial activity under varying redox conditions of early Earth. Higher thermal state of the Archean Earth led to intense volcano-exhalative activity, released Fe-Mn, gold along with other sulphides creating alkaline to acidic, reduced and chemically enriched oceans favouring cyanobacterial growth. Oxygen released due to microbial activity deposited Fe and Mn as oxides at shallow shelves. These processes detoxified the ocean, rendering the planet habitable for the growth and diversification of advanced life forms. Decayed organic matter contributed to the deposition of carbonaceous shales at the deeper ocean with δ13Corg of -38.8‰ to -8‰ VPDB, coinciding with associated BIFs (-28.5‰) and Mn formations (-26.2 to -23.2‰ VPDB) reflecting on significant biological influence. Geological similarities of Mars, Venus with Earth suggest that life supporting conditions may have existed for a short time on these terrestrial planets.
Coralline algae as integral components of shallow-marine ecosystems: Anecdotes of past resilience and future outlook
Coralline red algae are among the major groups of calcified benthic biota thriving in the marine photic zone globally as crustose and erect forms, attached to the substrate or forming free-living nodules (rhodoliths). Coralline algal beds denoting extremely productive habitats cover wide-ranging coastal shelf and upper slope horizons of the Earth but several gaps persist in our understanding of their systematics, productivity, net carbon flux dynamics and inputs to the oceanic carbon cycle. The current review emphasizes on the taxonomy, ecology and distribution of coralline algae in the shallow-marine ecosystems deciphered both in the context of Recent environments and fossil archives. Numerous discrepancies exist particularly in the taxonomy of fossil coralline algae, strongly dependent on morpho-anatomical study approaches. The communities of biologists and palaeontologists worldwide need to manifest a shared knowledge platform and present a viable nomenclature scheme to facilitate summarizing the critical functional traits associated with coralline algae. Persistent occurrence of several coralline genera from the Cretaceous period to the Holocene epoch reflect high-end resilience across multiple extreme events including K-Pg extinction, PETM, EECO and MECO. In view of the ongoing global change phenomena like ocean warming, acidification and adverse sea-level fluctuations, future outlook pertaining to the studies of coralline algae should essentially seek both quantitative and qualitative datasets from diverse domains of the Earth. This should be supplemented with special focus on the response of corallines to past hyperthermals and climate change, when corals perished at large scales compared to the relatively tenacious corallines.
Climatic shifts and floristic responses during India’s tectonic voyage from Gondwana to Asia
Rising atmospheric carbon dioxide (CO₂) levels are profoundly altering Earth's hydrological systems. To contextualize these changes, insights from past warm intervals are essential. This study synthesizes plant-derived proxy records from the Indian subcontinent to reconstruct hydrological patterns from the Late Cretaceous through the Paleogene—a period marked by India's tectonic drift from Gondwanaland to Asia. Results indicate a persistently warm and humid climate with high mean annual precipitation and pronounced seasonal rainfall from the latest Cretaceous into the early Paleocene. Throughout the early to middle Paleogene, including hyperthermal events such as the PETM, ETM2, and MECO, plant assemblages reflect changes in hydrological cycles and biotic turnover. Notably, these intervals saw a rise in deciduous taxa, signaling heightened seasonality and prolonged dry periods despite global warming. The Early Eocene Climatic Optimum (EECO) stands out for its sustained warm and humid conditions that supported stable tropical evergreen rainforests. The long-standing monsoonal regime observed during Late Cretaceous to early Oligocene more closely resembled the present-day Indonesian–Australian Monsoon than the modern South Asian Monsoon, which likely developed following Himalayan uplift in the Neogene. This synthesis highlights the complex interplay between global warming, seasonal precipitation patterns, and vegetation dynamics, reinforcing India's key role in understanding Cenozoic climate–biosphere evolution.
Archean crustal evolution and building of habitable continents: Insights from the Western Dharwar Craton
This contribution presents a comprehensive review synthesis addressing the time frame and processes involved in formation of Archean continental crust, surface environments, oxygenation and microbial activity leading to building the habitable continent in the western Dharwar craton (WDC). The WDC preserve ca. 3600-2600 Ma crustal record comprising TTGs, volcanic-sedimentary greenstones and potassic granites. U-Pb zircon ages and Sm-Nd whole rock isochrons suggest successive stages TTG accretion and greenstone volcanism contribute to episodic continental growth during ca. 3450-3350 Ma, 3300-3200 Ma, ca. 3230-3150 Ma, ca. 3000-2900 Ma, 2700-2600 Ma with crustal reworking ca. 3150 Ma, ca. 3000-2950 Ma, 2600 Ma and ca. 2500 Ma. Elemental and Nd isotope data of ca. 3380-3150 Ma greenstone volcanics reveal their derivation from primitive to deep mantle reservoirs in plume setting whilst ca. 3000-2900 Ma volcanism originated in shallower undepleted mantle caused by asthenosphere upwelling. On the other hand, ca. 2700-2600 Ma volcanics generated by melting of depleted to enriched sources in arc settings. Collision of arcs with eventual slab breakoff leads to generation and emplacement of Chitradurga-Arsikere-Banavara potassic plutons in the basement or in between the volcanic arcs. Redox sensitive elements and isotope biomarkers (FE, N and MIF-S) data on the sedimentary record reveal dominantly anoxic environments during ca. 3400-3000 Ma whilst ca. 3000 Ma onwards a shift from anoxic to minimum oxygen on ocean surface with periodic organic production linked to the microbial activity and oxygenation building of habitable continent few hundred million years prior to GOE.
Thermal coupling mode in mantle-outer core convection predicted from an ultra-high-resolution numerical simulation of two-layer convection with a large viscosity contrast
Previous global mantle seismic tomography analyses have revealed the large-scale horizontal structure of the mantle. On the other hand, the large-scale horizontal structure of the outer core could not be well determined using seismic wave analysis due to its liquid nature. Therefore, at present, numerical simulations are the only method for understanding the large-scale horizontal structure of the outer core. Previous numerical studies on two-layer Rayleigh-Bénard convection with an infinite Prandtl number have shown that the coupling mode between the two layers changes from mechanical coupling to a transitional mode to thermal coupling as the viscosity contrast between the two layers increases. This study presents an ultra-high-resolution numerical simulation of two-layer convection with a viscosity contrast of 104. The effective Rayleigh number of convection in the inner low-viscosity layer is approximately 2 × 1010. A spatiotemporal analysis of convection confirmed a new thermal coupling mode in the two-layer convection, primarily driven by downwelling plumes. When applied to the coupling between the mantle and outer core of Earth's interior, whose geophysical and geochemical structures are considered nearly hemispherical relative to the axis of rotation, this coupling mode effectively cools Earth’s core and releases heat from the interior to the surface.
Decoupling economic growth from energy consumption: Review of global trends and policy implications
As the climate crisis on a global scale worsens, the need to reconcile the growth of the economy and environmental sustainability has become a defining challenge of the 21st century. At the heart of this discourse is decoupling, alleviating the negative footprint impacts of economic activity without endangering development objectives. This review article offers a comprehensive synthesis of global experiences with both relative and absolute decoupling, with a focus on the underlying theoretical foundations, empirical patterns, and policy mechanisms that characterize the pursuit of sustainable growth. Based on cross-country comparisons and detailed case studies, we explore how members of diverse income groups manage the balance between economic development and environmental responsibility. Developed countries now show absolute decoupling more and more, supported by technological innovation, structural economic transformation, and strong policy frameworks. On the other hand, relative decoupling is evident for a middle-income economy because the economy has recorded high growth while making modest gains in energy efficiency and emissions control. Low-income countries, on the other hand, tend to be tightly coupled, dogged by dependence on fossil fuels, weak institutions, and weak access to clean technologies. The review outlines major drivers of climate action, including carbon pricing, investments in renewable energy, urbanization, and quality of governance, along with persistent impediments, like a shortage of infrastructure, policy inertia, and lack of capital. In addition, the article defines new emerging research gaps and highlights the need for sector-specific analysis, behavioral insights, and equitable policy design with just transition in mind.
Distribution of CO2 emissions per capita
Sustainability challenges of mangrove ecosystems in the Anthropocene: Current perspectives and prospects
Mangrove ecosystems, vital coastal habitats, face unprecedented challenges in the Anthropocene due to the interplay of natural and anthropogenic disturbances. Climate change-driven stressors, including sea level rise, altered precipitation regimes, and increased storm intensity, threaten mangrove survival by modifying hydrological and salinity conditions. Additionally, direct human activities such as land conversion, pollution, and unsustainable resource exploitation contribute to habitat degradation and biodiversity loss. These stressors impact mangroves' ability to provide crucial ecosystem services, including carbon sequestration, coastal protection, and habitat for diverse species. Understanding mangrove responses to these threats is essential for developing effective conservation and management strategies. This review synthesizes scientific literature, policy documents, and case studies to explore sustainability challenges in mangrove conservation. A holistic approach integrating ecological, social, and economic factors is necessary to enhance mangrove resilience. Collaborative efforts among scientists, policymakers, and local communities can drive sustainable management practices, ensuring the long-term health of mangrove ecosystems in the face of global environmental change.
Carbonatites complexes and associated REE mineral system: Significance in modern technology
Carbonatites, comprising both intrusive igneous and hypabyssal rocks, are among the major reserves of rare earth elements (REE) on Earth, and are hence critical for modern technology. Major REE minerals in these rocks include bastnaesite, monazite, xenotime, pyrochlore and apatite. REE important military applications, computer displays, sonar, hybrid vehicles, digital cameras, etc. REE mineralization is usually associated with potassic rocks, carbonatite and nephelinitic rocks. In Western Australia, important carbonatite systems include Copperhead, Mt Weld and the Gifford Creek ferrocarbonatite complex. In terms of whole-rock alteration, fenitisation, which occurs in aureoles of carbonatite and alkaline complexes. Associated mineralisation is usually related to alkali metasomatism in anorogenic ring complexes, in which unusual concentrations, apart from REE, contain F, Zr, Ba, Nb, Th, U, Ta and W. Ring complexes of the ijolite-carbonatite association may contain economic amounts of pyrochlore, columbite, cassiterite, monazite and zircon. Pyrochlore generally occurs in sodic metasomatized peralkaline granites. Good examples of REE mineral systems are the Pilanesberg Complex, the Pienaars River Complex and the Lolekop carbonatite complex.
The Sagaing Fault, deadly earthquake and volcanoes in Myanmar: Geodynamic perspectives
The Sagaing Fault is a prominent, right-lateral strike-slip fault that extends approximately 1,400 kilometers through central Myanmar. The Fault is one of the most seismically active fault systems in world, with a history of producing large and devastating earthquakes including recent 7.7 earthquake that struck near Mandalay. Although the primary cause of the earthquake is regarded as being the result of a rupture that occurred along the Sagaing Fault due to the Myanmar plate and Sunda plate sliding horizontally past each other, we here discuss the other geodynamic factors on the deadly nature of the Earthquake. Preparedness in advance is key to staying safe and reducing the damage caused by natural hazards. Ongoing scientific research and regular monitoring are also crucial for spotting early warning signs of natural hazards like earthquakes, landslides, and volcanic eruptions. Given the easy accessibility along the Sagaing Fault and volcanoe area such as the Mt. Popa region, further integrated research combining seismic, volcanological, petrological and tectonic studies is strongly encouraged and highly warranted.
Critical metal deposits in terrestrial and oceanic environments and the Global Energy Transition
Critical metals like rare earth elements (REE), Li, Co, Cu, Ni, and platinum group elements (PGE) are vital requirements for various green technology applications. These metals are essential components in rechargeable batteries, wind turbines, solar panels, electric vehicles, and for strategic applications. In this overview, we present a consolidated account of the different types of critical mineral deposits on land and in the deep oceans is presented here. The terrestrial deposits include various types of magmatic, hydrothermal, and sedimentary archives, which are currently the major sources for these critical minerals. The potential marine mineral deposits include manganese nodules on ocean floor, ferromanganese crust deposits on seamounts, hydrothermal sulphide deposits in the mid-oceanic ridges, phosphorite deposits on the ocean floor along continental margins and submerged mountains, and REY-rich mud representing deep-sea sediment deposits. Currently, exploitation of marine mineral deposits face many challenges including pollution and habitat destruction in the marine environment, as well as climate change, which can negatively impact the environment and the resources. The shift to a low-carbon economy depends on securing a stable supply of these critical metals. While terrestrial mining remains dominant, deep-sea resources must be balanced with environmental protections. Sustainable strategies, including recycling and diversification of supply chains, with emphasis on circular economy, will be the key to ensuring a smooth energy transition. Coupled with supportive policies, technological advancements, and ethical practices, these strategies forge a resilient, low-carbon future.
Soils diversified through geological time with the evolution life on land, from microbes in Archean soils, to fungi and amoebozoa in early Proterozoic soils, and lichens in late Proterozoic soils. Ordovician non-vascular land plants lived in Entisols and Aridisols, but trees created clayey subsurface horizons of Alfisols and Ultisols, and ferruginous horizons of Spodosols. Finally, sod grasslands creating distinctive surface horizons of Mollisols. Organisms can be adapted to particular environments, but also adapted by natural selection to other organisms in coevolutionary pairs, such as grasses and grazers, or trees and termites. Coevolution is notable for creating communities that can change the environment, such as ice ages brought on by evolution of forests and of grasslands. If life can be defined as a system capable of Darwinian evolution by natural selection, the same can also be said of soils. Even before the evolution of life, clay formation in soils that were like carbonaceous chondrite meteorites would have maintained a place in the sun and rain for the formation of more clay. Soils at matric potential for water were like multicellular creatures with tiny reactive centers within menisci of water between grains. They would have been a starter system for entirely organic-based life capable of natural selection with the same aim: hold the ground against erosion.
The Energy Trilemma: An overview of balancing security, sustainability, and affordability
The global energy sector faces a complex challenge in balancing three critical dimensions: energy security, environmental sustainability, and economic affordability—commonly referred to as the energy trilemma. This paper provides a novel review of emerging trends, policies, and technological advancements that address this challenge. It particularly examines the role of top CO₂-emitting countries in navigating the energy trilemma, shedding light on their strategies and potential pathways for achieving a sustainable energy future. Findings demonstrate that these countries have achieved some success in their shift to cleaner energy systems, yet they maintain diverse approaches to policy frameworks, energy systems, and economic programs. Countries deal with specific obstacles because their economic systems combine with their energy reserves and climate agreement responsibilities. China and India remain the world's biggest growing economies, but they must keep their economies expanding while reducing their coal dependence. The United States and Canada hold substantial fossil fuel reserves, yet they must establish a strategy that aligns their home energy security requirements with worldwide climate objectives. Renewable energy development remains vigorous in Germany and Japan, yet their progress is limited by high power costs, affecting their electrical grid stability. Countries with abundant resources, including Russia, Brazil, Indonesia, and Mexico, have not effectively incorporated sustainability into their plans for energy development. The findings underscore the need for integrated policies, increased investments in renewable energy, and international cooperation to achieve a balanced energy transition.
Before the occurrence of the 26 December 2004 mega-tsunami caused by the Mw 9.2 Sumatra earthquake, there was no tsunami warning facility in the Indian Ocean, and one depended on the tsunami advisories being issued by the Pacific Tsunami Warning Center and the Japan Meteorological Agency. Many of these issued advisories were later withdrawn, causing a lot of inconvenience to a large population residing along the east coast of India. From a study of past tsunami sources, we discovered that there are only two areas, which can host tsunamigenic earthquakes in the Indian Ocean. This finding was accepted in the 2nd International Coordination Meeting during 14–16 April 2005 for the Development of an Indian Ocean Tsunami Warning and Mitigation System, held at Grand Baie, Mauritius. This provided the foundation of setting up of the Indian Tsunami Early Warning System (ITEWS). Global network of seismic stations permits determination of the location and the magnitude of the earthquake within 5 minutes or so of its occurrence. If an earthquake has a magnitude ≥7 and if it is located within the two identified tsunamigenic earthquake generating areas, there are chances of generation of a tsunami. However, whether a tsunami has been really generated and what is its magnitude cannot be determined, which is necessary to issue appropriate advisories. This issue was resolved by placing ocean bottom pressure recorders in the immediate vicinity of the two regions capable of hosting a tsunamigenic earthquake.
The four stages of the Sixth Mass Extinction
The Earth stands on the brink of another global biocrisis, commonly dubbed the Sixth Mass Extinction (SME) in reference to the Big Five Phanerozoic mass extinctions that have episodically transformed the biosphere through time. Relative to these earlier extinctions, the present-day biocrisis is unique in being a carbon-release event with a bioevolutionary trigger, i.e., the development of technology to an extent that gives humans near-ubiquitous influence over the Earth’s climatic, environmental, and biospheric systems. Although the SME started slowly and in a punctuated manner, its pace has accelerated sharply in the last 100-200 years and is likely to continue to do so in the future, implying that the peak of the biocrisis may be no more than a few hundred years away. Although not sharply delineated in time, the four stages of the SME are: Stage 1—hunting and overexploitation (~50-0.25 ka); Stage 2—habitat loss (~0.25 ka to present); Stage 3—climate change and alien species invasions (~0.1 ka to the near-future); and Stage 4—ecosystem collapse (middle future). Each of the first three stages were associated with a technological development that initiated and contributed to coeval biodiversity declines, e.g., advances in early human hunting technology (Stage 1), the spread of agriculture and animal husbandry (Stage 2), and industrialization and combustion of fossil fuels (Stage 3). The fourth stage, ecosystem collapse, is unlikely to require another human developmental trigger—rather, it will come about spontaneously in response to widespread, intense degradation of habitats and biotic communities by human pressures.
Environmental dynamics in the tropical tourist beaches of southwestern India
Tropical beaches and adjoining lush green vegetation areas are the preferred choices of recreation-leisure activities. The south-western coast of India is characterized by rainforests meeting serene beach profiles, with many aesthetic beach resorts. Though promoting economic prosperity, proliferation of recreational activities brings in unintended and irreversible adverse impacts to the coastal environment. A systematic documentation of field conditions of coastal environmental-landuse-landcover change, sediment textural properties and environmental dynamics may help assess sustenance of habitability of such popular tourist beaches. Four selected beaches of Kerala State, southwestern India, namely Pozhikkara, Hawa, Lighthouse and Chowara were studied in terms of pristine nature of geomorphology, beach profile, land use-land cover, sediment textural characteristics. The sediment textural characteristics indicate survival of only the medium-coarse sediments, occurrences of heavy minerals in majority of the samples, absence of spatial variability of sediment characteristics and prevalence of platykurtic nature, evidencing the anthropogenic interventions that caused monotony. While the sediments retain their affinity to marine signature, after transformation from fluvial origin, environmental discrimination diagrams show that majority of the studied sediments correspond to turbid-higher energy conditions and affirm the interpretation of anthropogenic impact on sediment texture. These results implicate that the recreational and associated commercial-constructional activities unto the intertidal region have heavily impacted the natural environmental conditions of beach ecosystem that gets further aggravated by flouting of coastal environmental regulations. Sustaining the recreational activity along the popular beach and habitability is under threats that require appropriate remedial-reclamation measures.
Guidelines for testing hypotheses: A case study of episodic crustal production versus supercontinent-linked selective preservation
From a big picture perspective, the major components of scientific research include metaphysics, scientific paradigms, scientific hypotheses, scientific data, and tolerance toward various ideas. Based on these components, six guidelines are established for conducting geological research: awareness of underlying assumptions, development of falsifiable hypotheses, testing hypotheses, tolerance of competing hypotheses, replicating results, and obtaining representative sampling. Using these guidelines, a case study follows, which reviews empirical tests of the episodic crustal production hypothesis and the supercontinent-linked selective preservation hypothesis. The results support the episodic crustal production hypothesis while falsifying two key postulates of the selective preservation hypothesis.
Volcanic rocks of the oceanic crust as habitat for recent to Paleoarchean microbial life: A review
Submarine alteration of basaltic glass in pillow lavas and hyaloclastites result in (1) abiotic palagonite with smooth interface between the fresh and altered glass, and (2) biogenically-produced irregular granular and tubular textures. In the upper oceanic crust, the bio-generated textures are dominant, but become progressively less abundant downwards into the volcanic pile to finally disappear at ca. 500 m depth, contemporaneously with the increase in palagonite alteration. The bio-related granular and tubular alteration structures can be found in originally basaltic glass of pillow lavas dating back to ca. 3.5 Ga, providing information of the earliest life on Earth. Element mapping of these bio-related textures show traces of carbon even in the oldest examples. Further, carbon isotope data of the glassy pillow rims and crystalline material exhibit significantly lower δ13Ccarbonate of the former than the latter. Thus, both the carbon signatures and the C-isotope signatures are consistent with microbial influence during alteration of the basalt glass.