Results 21 to 30 of about 17,614 (181)

SQUID-SIMS is a useful approach to uncover primary signals in the Archean sulfur cycle [PDF]

open access: yes, 2014
The Agouron Institute and National Aeronautic and Space Administration Exobiology Award NNX09AM91G supported this work.Many aspects of Earth's early sulfur cycle, from the origin of mass-anomalous fractionations to the degree of biological participation,
Guan, Yunbin   +14 more
core   +1 more source

Transfer functions used to interpret Archean paleosols.

open access: yes, 2023
Transfer functions used to interpret Archean paleosols.
Mark D. Schmitz (2843513)   +1 more
core   +1 more source

Creating Continents: Archean Cratons Tell the Story [PDF]

open access: yes, 2023
The record of the first two billion years of Earth’s history (the Archean) is notoriously incomplete, yet crust of this age is present on every continent.
Carol Frost   +9 more
core   +1 more source

The Sedimentary Origin of Black and White Banded Cherts of the Buck Reef, Barberton, South Africa

open access: yesGeosciences, 2019
The Buck Reef is a 250−400 m thick sequence of banded black and white (B&W) cherts deposited ca. 3416 Ma ago in a shallow basin. We provide field, petrological and geochemical constraints on the chert-forming process and the origin of the ...
Morgane Ledevin   +4 more
doaj   +1 more source

2200 million years of crustal evolution: The Baltic Shield [PDF]

open access: yesBulletin of the Geological Society of Finland, 1986
The crustal history of the Baltic shield is interpreted in the light of the plate tectonic concept. Five tectonic cycles, each characterized by special lithological and structural features, are distinguished: The Early Archean (> 2900 Ma), the Late ...
G. Gaál
doaj   +1 more source

Drilling for the Archean Roots of Life and Tectonic Earth in the Barberton Mountains [PDF]

open access: yesScientific Drilling, 2009
In the Barberton Scientific Drilling Program (BSDP) we successfully completed three drill holes in 2008 across strategically selected rock formations in the early Archean Barberton Greenstone Belt, South Africa.
Nicola McLoughlin   +3 more
doaj   +1 more source

The Abundance and Behavior of Viruses in Ancient Seawater and Modern Iron-rich Environments [PDF]

open access: yes, 2011
The proclivity of silica for ferric hydroxide sorption sites allows for an Archean iron cycle involving iron-silica co-precipitation and deposition of banded iron formations (BIF).
Liu, Hanna Ken-Yuin
core   +1 more source

Chemical composition (wt %) of Archean paleosols by XRF.

open access: yes, 2023
Chemical composition (wt %) of Archean paleosols by XRF.
Mark D. Schmitz (2843513)   +1 more
core   +1 more source

Archean crust-mantle geodynamic regimes: A review

open access: yesGeosystems and Geoenvironment, 2022
The crust-mantle dynamic system of the formation and evolution of the early Earth crust is a frontier field in current Earth Science. This paper mainly introduces the popular dynamic models, comprising the stagnant-lid, mantle plume, sagduction, dripping,
Shuwen Liu   +7 more
doaj   +1 more source

Rare-earth elements in the Archean iron formation and associated schists in Ukkolanvaara, Ilomantsi, SE Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1977
This study describes the La, Ce, Nd, Sm, Eu, Tb, Yb and Lu concentrations in six iron-formation rocks (Fetot >> 15 %), four ferriferous schists (Fetot ~ 10—15 %) and two schist interbeds of the Archean Ukkolanvaara iron formation, as well as in seven ...
K. Laajoki, S. Lavikainen
doaj   +1 more source

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