Element mobility patterns record organic ligands in soils on early Earth

Alexander Neaman, Jon Chorover, Susan Louise Brantley

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

Considerable mobilization of Fe without mobilization of Al in Precambrian paleosols has been documented and attributed to either anoxic- or ligand-promoted dissolution. To elucidate these mechanisms, basalt was dissolved under oxic and anoxic conditions with and without citrate, and the mobility of several elements was analyzed. The extent of release of Fe and P was minor (in citrate-free conditions) or considerable (with citrate) regardless of oxygen pressure. Release of Al was minor in all cases, whereas release of Cu was minor (in anoxic conditions) or considerable (in oxic conditions). Release of Cu was enhanced by citrate. In comparison, in the weathered surface of two of the oldest-known basalt-derived paleosols-the Mount Roe (2.76 Ga) and the Hekpoort (2.25 Ga)-Fe and P were considerably depleted and Al retained, consistent with the presence of organic ligands. Cu, retained in the Mount Roe paleosol but considerably mobilized in the Hekpoort paleosol, documents formation under an anoxic atmosphere and an oxic atmosphere, respectively, as inferred by others on the basis of Fe mobility. The immobility of Al in both paleosols is consistent with formation under conditions in which the annual volume of rainwater was lower than the topsoil pore volume. Mobilization of P in such paleosols developed under low-rainfall conditions provides a new proxy for identification of ligands secreted by terrestrial organisms on early Earth.

Original languageEnglish (US)
Pages (from-to)117-120
Number of pages4
JournalGeology
Volume33
Issue number2
DOIs
StatePublished - Feb 1 2005

Fingerprint

element mobility
early Earth
paleosol
ligand
mobilization
soil
anoxic conditions
basalt
atmosphere
oxic conditions
rainwater
topsoil
Precambrian
dissolution
oxygen
rainfall

All Science Journal Classification (ASJC) codes

  • Geology

Cite this

Neaman, Alexander ; Chorover, Jon ; Brantley, Susan Louise. / Element mobility patterns record organic ligands in soils on early Earth. In: Geology. 2005 ; Vol. 33, No. 2. pp. 117-120.
@article{a8ec0eacbd0b455d96e1246c59128318,
title = "Element mobility patterns record organic ligands in soils on early Earth",
abstract = "Considerable mobilization of Fe without mobilization of Al in Precambrian paleosols has been documented and attributed to either anoxic- or ligand-promoted dissolution. To elucidate these mechanisms, basalt was dissolved under oxic and anoxic conditions with and without citrate, and the mobility of several elements was analyzed. The extent of release of Fe and P was minor (in citrate-free conditions) or considerable (with citrate) regardless of oxygen pressure. Release of Al was minor in all cases, whereas release of Cu was minor (in anoxic conditions) or considerable (in oxic conditions). Release of Cu was enhanced by citrate. In comparison, in the weathered surface of two of the oldest-known basalt-derived paleosols-the Mount Roe (2.76 Ga) and the Hekpoort (2.25 Ga)-Fe and P were considerably depleted and Al retained, consistent with the presence of organic ligands. Cu, retained in the Mount Roe paleosol but considerably mobilized in the Hekpoort paleosol, documents formation under an anoxic atmosphere and an oxic atmosphere, respectively, as inferred by others on the basis of Fe mobility. The immobility of Al in both paleosols is consistent with formation under conditions in which the annual volume of rainwater was lower than the topsoil pore volume. Mobilization of P in such paleosols developed under low-rainfall conditions provides a new proxy for identification of ligands secreted by terrestrial organisms on early Earth.",
author = "Alexander Neaman and Jon Chorover and Brantley, {Susan Louise}",
year = "2005",
month = "2",
day = "1",
doi = "10.1130/G20687.1",
language = "English (US)",
volume = "33",
pages = "117--120",
journal = "Geology",
issn = "0091-7613",
publisher = "Geological Society of America",
number = "2",

}

Element mobility patterns record organic ligands in soils on early Earth. / Neaman, Alexander; Chorover, Jon; Brantley, Susan Louise.

In: Geology, Vol. 33, No. 2, 01.02.2005, p. 117-120.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Element mobility patterns record organic ligands in soils on early Earth

AU - Neaman, Alexander

AU - Chorover, Jon

AU - Brantley, Susan Louise

PY - 2005/2/1

Y1 - 2005/2/1

N2 - Considerable mobilization of Fe without mobilization of Al in Precambrian paleosols has been documented and attributed to either anoxic- or ligand-promoted dissolution. To elucidate these mechanisms, basalt was dissolved under oxic and anoxic conditions with and without citrate, and the mobility of several elements was analyzed. The extent of release of Fe and P was minor (in citrate-free conditions) or considerable (with citrate) regardless of oxygen pressure. Release of Al was minor in all cases, whereas release of Cu was minor (in anoxic conditions) or considerable (in oxic conditions). Release of Cu was enhanced by citrate. In comparison, in the weathered surface of two of the oldest-known basalt-derived paleosols-the Mount Roe (2.76 Ga) and the Hekpoort (2.25 Ga)-Fe and P were considerably depleted and Al retained, consistent with the presence of organic ligands. Cu, retained in the Mount Roe paleosol but considerably mobilized in the Hekpoort paleosol, documents formation under an anoxic atmosphere and an oxic atmosphere, respectively, as inferred by others on the basis of Fe mobility. The immobility of Al in both paleosols is consistent with formation under conditions in which the annual volume of rainwater was lower than the topsoil pore volume. Mobilization of P in such paleosols developed under low-rainfall conditions provides a new proxy for identification of ligands secreted by terrestrial organisms on early Earth.

AB - Considerable mobilization of Fe without mobilization of Al in Precambrian paleosols has been documented and attributed to either anoxic- or ligand-promoted dissolution. To elucidate these mechanisms, basalt was dissolved under oxic and anoxic conditions with and without citrate, and the mobility of several elements was analyzed. The extent of release of Fe and P was minor (in citrate-free conditions) or considerable (with citrate) regardless of oxygen pressure. Release of Al was minor in all cases, whereas release of Cu was minor (in anoxic conditions) or considerable (in oxic conditions). Release of Cu was enhanced by citrate. In comparison, in the weathered surface of two of the oldest-known basalt-derived paleosols-the Mount Roe (2.76 Ga) and the Hekpoort (2.25 Ga)-Fe and P were considerably depleted and Al retained, consistent with the presence of organic ligands. Cu, retained in the Mount Roe paleosol but considerably mobilized in the Hekpoort paleosol, documents formation under an anoxic atmosphere and an oxic atmosphere, respectively, as inferred by others on the basis of Fe mobility. The immobility of Al in both paleosols is consistent with formation under conditions in which the annual volume of rainwater was lower than the topsoil pore volume. Mobilization of P in such paleosols developed under low-rainfall conditions provides a new proxy for identification of ligands secreted by terrestrial organisms on early Earth.

UR - http://www.scopus.com/inward/record.url?scp=13944284509&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=13944284509&partnerID=8YFLogxK

U2 - 10.1130/G20687.1

DO - 10.1130/G20687.1

M3 - Article

VL - 33

SP - 117

EP - 120

JO - Geology

JF - Geology

SN - 0091-7613

IS - 2

ER -