Results 71 to 80 of about 5,545 (213)

Subterranean environments contribute to three‐quarters of classified ecosystem services

open access: yesBiological Reviews, Volume 101, Issue 3, Page 1582-1605, June 2026.
ABSTRACT Beneath the Earth's surface lies a network of interconnected caves, voids, and systems of fissures forming in rocks of sedimentary, igneous, or metamorphic origin. Although largely inaccessible to humans, this hidden realm supports and regulates services critical to ecological health and human well‐being.
Stefano Mammola   +30 more
wiley   +1 more source

Predicting Nitrogen Isotope Fractionation in Nitrate Deposition on Early Mars

open access: yesJournal of Geophysical Research: Planets, Volume 131, Issue 6, June 2026.
Abstract Noachian and early Hesperian Mars were likely warm and wet, with an atmosphere abundant in molecular nitrogen. The recent discovery of nitrate deposits in the Yellowknife Bay mudstones at Gale Crater confirm the existence of nitrogen oxides (NOX) on Noachian Mars. The processes responsible for the production of these nitrates would fractionate
J. Shawcross   +4 more
wiley   +1 more source

Unveiling microbial preservation under hyperacidic and oxidizing conditions in the Oligocene Rio Tinto deposit

open access: yesScientific Reports, 2021
The preservation of biosignatures on Mars is largely associated with extensive deposits of clays formed under mild early Noachian conditions (> 3.9 Ga). They were followed by widespread precipitation of acidic sulfates considered adverse for biomolecule ...
David C. Fernández-Remolar   +8 more
doaj   +1 more source

Detection of Biosignatures Using Raman Spectroscopy

open access: yes, 2018
International audienceRaman spectroscopy is particularly suited for the study of biosignatures: it is able to detect both organic and mineral phases, is very sensitive to carbonaceous matter and biogenic pigments, and can be used in the field and for ...
Frédéric Foucher, Foucher, Frédéric
core   +1 more source

Microbially generated ferruginous crusts: A potential biosignature of continental input in coastal settings

open access: yesSedimentology, Volume 73, Issue 4, Page 1225-1243, June 2026.
ABSTRACT Thin ferruginous sandy crusts are common on top of sandstone beds in the Early Permian post‐glacial deposits of the Paraná Basin in southern Brazil. These crusts usually preserve wrinkle structures, suggesting that they might be a product of microbial mediation.
Patrícia Weschenfelder   +2 more
wiley   +1 more source

Detecting signs of life in biotic–abiotic mixtures using pyrolysis–gas chromatography–mass spectrometry and machine learning

open access: yesFrontiers in Astronomy and Space Sciences
Biosignature detection is at the forefront of modern astrobiology and paleobiology research. Previous studies have demonstrated that machine learning models trained on data from pyrolysis–gas chromatography–mass spectrometry (py–GC–MS) can distinguish ...
Emersyn Slaughter   +10 more
doaj   +1 more source

Increased Stability in Carbon Isotope Records Reflects Emerging Complexity of the Biosphere

open access: yesFrontiers in Earth Science, 2019
Preference for certain stable isotopes (isotope fractionation) during enzyme-mediated reactions is a universal aspect of life. For instance, carbon isotopes are fractionated during anabolic (e.g., photosynthate production) and catabolic (e.g ...
Martin Schobben, Bas van de Schootbrugge
doaj   +1 more source

Development of Holocene lacustrine microbialites on the Iberian Peninsula: Insights into environmental and depositional controls using X‐ray CT and petrography

open access: yesSedimentology, Volume 73, Issue 4, Page 1148-1184, June 2026.
ABSTRACT Microbial mats and microbialites are common in modern and ancient saline lacustrine environments and are highly responsive to biological and environmental factors. As such, they represent important sources of high‐resolution environmental data across a wide range of geological time. Nonetheless, interpretation of fossil mats is non‐trivial due
Connor Doyle   +6 more
wiley   +1 more source

Assessing the utility of trace and rare earth elements as biosignatures in microbial iron oxyhydroxides

open access: yesFrontiers in Earth Science, 2015
Microbial iron oxyhydroxides are common deposits in natural waters, recent sediments and mine drainage systems and often contain significant accumulations of trace and rare earth elements (TREE). TREE patterns are widely used to characterize minerals and
Christine eHeim   +7 more
doaj   +1 more source

Detectability of Surface Biosignatures for Directly Imaged Rocky Exoplanets

open access: yes
Modeling the detection of life has never been more opportune. With next-generation space telescopes, such as the currently developing Habitable Worlds Observatory (HWO) concept, we will begin to characterize rocky exoplanets potentially similar to Earth.
Borges, Schuyler R.   +2 more
core   +1 more source

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