The importance of being cited - p563

doi:10.1038/ngeo305

The world of published science has become crowded and confusing. Impact factors provide rough and ready guidance, as long as they are understood in context.

Full Text - The importance of being cited | PDF (171 KB) - The importance of being cited

Mercury redux - p564

Moritz Heimpel & Konstantin Kabin

doi:10.1038/ngeo297

In January 2008, 33 years after Mariner 10 flew past the solar system's innermost planet, MESSENGER crossed Mercury's magnetosphere. Ancient volcanoes, contractional faults, and a rich soup of exospheric ions give clues to Mercury's structure and dynamical evolution.

Full Text - Mercury redux | PDF (273 KB) - Mercury redux

Deep time travel - p567

Neil D. L. Clark reviews Fossils Alive! New Walks in an Old Field by Nigel H. Trewin

doi:10.1038/ngeo293

Full Text - Deep time travel | PDF (108 KB) - Deep time travel

Forests on Greenland, Titan's atmosphere and more - p568

doi:10.1038/ngeo303

Full Text - Forests on Greenland, Titan's atmosphere and more | PDF (192 KB) - Forests on Greenland, Titan's atmosphere and more

Soil science: The Arctic carbon count - pp569 - 570

Christian Beer

doi:10.1038/ngeo292

Despite its potential importance in a warming world, the organic carbon content of Arctic soils has escaped robust quantification. A closer look at the North American sector suggests that much more carbon is stored in these high northern grounds than previously thought.

Full Text - Soil scienceThe Arctic carbon count | PDF (147 KB) - Soil scienceThe Arctic carbon count

Subject Category: Atmospheric science

Climate science: A tale of two ice sheets - pp570 - 572

Mark Siddall & Michael R. Kaplan

doi:10.1038/ngeo286

The vast Laurentide ice sheet once covered the northern reaches of the American continent. A combination of geological data and climate simulations suggests that it dwindled faster than has been projected for Greenland's ice over the next century.

Full Text - Climate scienceA tale of two ice sheets | PDF (150 KB) - Climate scienceA tale of two ice sheets

Subject Category: Climate science

Volcanology: Throwing mud - pp572 - 573

Debi Kilb

doi:10.1038/ngeo299

The causes of the catastrophic eruption of the Lusi mud volcano in Indonesia are hotly debated. Data from a nearby exploration well and a new look at the stress regime suggest that drilling operations, and not an earthquake set the eruption off.

Full Text - VolcanologyThrowing mud | PDF (415 KB) - VolcanologyThrowing mud

Subject Category: Volcanology, mineralogy and petrology

Planetary science: Shackleton grows older - p573

Ninad Bondre

doi:10.1038/ngeo300

Full Text - Planetary scienceShackleton grows older | PDF (299 KB) - Planetary scienceShackleton grows older

Subject Category: Planetary science

Geodynamics: A tale of a trail - pp574 - 575

Richard G. Gordon

doi:10.1038/ngeo295

A mantle plume origin for the Samoan hotspot has been contested because the ages along its putative trail did not seem to increase monotonically. New dates from the island of Savai'i resolve the controversy and favour a plume origin.

Full Text - GeodynamicsA tale of a trail | PDF (223 KB) - GeodynamicsA tale of a trail

Subject Category: Structural geology, tectonics and geodynamics

Oceanography: Cycling coloured carbon - pp575 - 576

Paula Coble

doi:10.1038/ngeo294

The fate of dissolved organic carbon in the ocean interior is poorly constrained. Fluorescence measurements illuminate the relative roles of in situ production and riverine input of at least the coloured carbon fraction.

Full Text - OceanographyCycling coloured carbon | PDF (140 KB) - OceanographyCycling coloured carbon

Subject Category: Oceanography

Palaeoceanography: Bloom without fertilizer - pp576 - 578

Mitchell Lyle

doi:10.1038/ngeo287

Iron has been shown to stimulate productivity in certain areas of the modern ocean. However, it was not the primary driver of carbon burial in the equatorial Pacific Ocean for the past 10 million years.

Full Text - PalaeoceanographyBloom without fertilizer | PDF (227 KB) - PalaeoceanographyBloom without fertilizer

Subject Category: Palaeoclimate and palaeoceanography

Production of bio-refractory fluorescent dissolved organic matter in the ocean interior - pp579 - 582

Youhei Yamashita & Eiichiro Tanoue

doi:10.1038/ngeo279

Dissolved organic matter in the ocean constitutes one of the largest pools of reduced carbon on the Earth's surface. An analysis of observations from the Pacific Ocean shows that as organic matter is oxidized biologically, fluorescent dissolved organic matter is produced in situ in the ocean interior and is resistant to biological degradation on centennial to millennial timescales.

First Paragraph - | Full Text - Production of bio-refractory fluorescent dissolved organic matter in the ocean interior | PDF (626 KB) - Production of bio-refractory fluorescent dissolved organic matter in the ocean interior | Supplementary information

Subject Categories: Biogeochemistry | Oceanography

See also: News and Views by Coble

Riverine organic matter and nutrients in southeast Alaska affected by glacial coverage - pp583 - 587

Eran Hood & Durelle Scott

doi:10.1038/ngeo280

Dissolved organic matter and nutrients from high-latitude coastal watersheds stimulate microbial activity and primary productivity in near-shore ecosystems. A survey of southeast Alaskan watersheds suggests that the extent of glacial coverage may control the release of these nutrients to rivers and ultimately the oceans.

First Paragraph - | Full Text - Riverine organic matter and nutrients in southeast Alaska affected by glacial coverage | PDF (753 KB) - Riverine organic matter and nutrients in southeast Alaska affected by glacial coverage

Subject Categories: Biogeochemistry | Climate science

Community dynamics of anaerobic bacteria in deep petroleum reservoirs - pp588 - 591

Christian Hallmann, Lorenz Schwark & Kliti Grice

doi:10.1038/ngeo260

The nature, activity and metabolism of microbes that inhabit the deep subsurface environment are a matter of ongoing debate. The analysis of oil samples from three different basins in South America, central Europe and the Middle East indicates the presence of intact phospholipids and suggests that indigenous bacteria inhabit petroleum reservoirs in sediment depths of up to 2,000 m.

First Paragraph - | Full Text - Community dynamics of anaerobic bacteria in deep petroleum reservoirs | PDF (305 KB) - Community dynamics of anaerobic bacteria in deep petroleum reservoirs | Supplementary information

Subject Category: Biogeochemistry

Plant spore walls as a record of long-term changes in ultraviolet-B radiation - pp592 - 596

Barry H. Lomax, Wesley T. Fraser, Mark A. Sephton, Terry V. Callaghan, Stephen Self, Michael Harfoot, John A. Pyle, Charles H. Wellman & David J. Beerling

doi:10.1038/ngeo278

Determining stratospheric ozone levels from before instrumental records began has proved difficult. Measurements of the chemical composition of plant spore walls suggest that ultraviolet-B-absorbing compounds have the potential to act as a proxy for past changes in ultraviolet-B radiation and stratospheric ozone.

First Paragraph - | Full Text - Plant spore walls as a record of long-term changes in ultraviolet-B radiation | PDF (465 KB) - Plant spore walls as a record of long-term changes in ultraviolet-B radiation | Supplementary information

Subject Categories: Atmospheric science | Biogeochemistry | Climate science | Palaeoclimate and palaeoceanography

See also: related Backstory

The isotopic signature of the global riverine molybdenum flux and anoxia in the ancient oceans - pp597 - 600

C. Archer & D. Vance

doi:10.1038/ngeo282

Despite important biological and biogeochemical consequences of extensive ocean anoxic events, their identification is controversial. The marine isotope geochemistry of molybdenum can help quantify the past oxygenation state of the ocean if the riverine input of Mo isotopes is known. Analysis of a set of rivers that account for 28% of global river runoff suggests more variable Mo isotopic ratios in rivers that are also isotopically enriched in the heavy isotopes, suggesting near-total anoxia in the Proterozoic ocean and during Mesozoic ocean anoxic events.

First Paragraph - | Full Text - The isotopic signature of the global riverine molybdenum flux and anoxia in the ancient oceans | PDF (256 KB) - The isotopic signature of the global riverine molybdenum flux and anoxia in the ancient oceans | Supplementary information

Subject Categories: Biogeochemistry | Palaeoclimate and palaeoceanography

See also: related Backstory

Persistent summer expansion of the Atlantic Warm Pool during glacial abrupt cold events - pp601 - 605

Martin Ziegler, Dirk Nürnberg, Cyrus Karas, Ralf Tiedemann & Lucas J. Lourens

doi:10.1038/ngeo277

In the high latitudes, abrupt cooling events are thought to control mainly the winter temperatures, thereby increasing seasonality. Sea surface temperature reconstructions from the Gulf of Mexico suggest that over the past 300,000 years these events also enhanced seasonality in tropical regions.

First Paragraph - | Full Text - Persistent summer expansion of the Atlantic Warm Pool during glacial abrupt cold events | PDF (924 KB) - Persistent summer expansion of the Atlantic Warm Pool during glacial abrupt cold events | Supplementary information

Subject Category: Palaeoclimate and palaeoceanography

Synchronous basin-wide formation and redox-controlled preservation of a Mediterranean sapropel - pp606 - 610

Gert J. De Lange, John Thomson, Anja Reitz, Caroline P. Slomp, M. Speranza Principato, Elisabetta Erba & Cesare Corselli

doi:10.1038/ngeo283

Organic-rich sedimentary units called sapropels have formed repeatedly in the eastern Mediterranean Sea, but the mechanisms leading to the formation of these shale beds are still under debate. The analysis of a suite of sediment cores covering the Eastern Mediterranean basin reveals that across the entire basin preservation of sapropel S1 was different in characteristics above and below 1,800 m depth, which is a result of different redox conditions.

First Paragraph - | Full Text - Synchronous basin-wide formation and redox-controlled preservation of a Mediterranean sapropel | PDF (367 KB) - Synchronous basin-wide formation and redox-controlled preservation of a Mediterranean sapropel | Supplementary information

Subject Categories: Biogeochemistry | Palaeoclimate and palaeoceanography

Large heat and fluid fluxes driven through mid-plate outcrops on ocean crust - pp611 - 614

M. Hutnak, A. T. Fisher, R. Harris, C. Stein, K. Wang, G. Spinelli, M. Schindler, H. Villinger & E. Silver

doi:10.1038/ngeo264

Geophysical data for the Cocos Plate sea floor suggest that basement outcrops along mid-ocean ridge flanks can discharge very large quantities of heat and fluid. This is indicative of high crustal permeability at the regional scale.

First Paragraph - | Full Text - Large heat and fluid fluxes driven through mid-plate outcrops on ocean crust | PDF (734 KB) - Large heat and fluid fluxes driven through mid-plate outcrops on ocean crust | Supplementary information

Subject Categories: Oceanography | Structural geology, tectonics and geodynamics

High stocks of soil organic carbon in the North American Arctic region - pp615 - 619

Chien-Lu Ping, Gary J. Michaelson, Mark T. Jorgenson, John M. Kimble, Howard Epstein, Vladimir E. Romanovsky & Donald A. Walker

doi:10.1038/ngeo284

The Arctic soil organic-carbon pool is poorly constrained. Measurements of soil organic carbon in the North American Arctic reveal that the carbon store in this region is larger than previous estimates suggest, and highly dependent on landscape type.

Abstract - | Full Text - High stocks of soil organic carbon in the North American Arctic region | PDF (758 KB) - High stocks of soil organic carbon in the North American Arctic region | Supplementary information

Subject Categories: Biogeochemistry | Climate science

See also: News and Views by Beer | related Backstory

Rapid early Holocene deglaciation of the Laurentide ice sheet - pp620 - 624

Anders E. Carlson, Allegra N. LeGrande, Delia W. Oppo, Rosemarie E. Came, Gavin A. Schmidt, Faron S. Anslow, Joseph M. Licciardi & Elizabeth A. Obbink

doi:10.1038/ngeo285

The demise of the Laurentide ice sheet during the early Holocene epoch allows rates of ice sheet decay under natural conditions to be assessed. Analysis of terrestrial and marine records of the deglaciation along with a climate model reveal two periods of rapid melting during the final retreat of this ice sheet, with rates of sea level rise of up to 1.3 cm per year.

Abstract - | Full Text - Rapid early Holocene deglaciation of the Laurentide ice sheet | PDF (642 KB) - Rapid early Holocene deglaciation of the Laurentide ice sheet | Supplementary information

Subject Categories: Climate science | Cryospheric science | Palaeoclimate and palaeoceanography

See also: News and Views by Siddall & Kaplan

Re-evaluating plume-induced uplift in the Emeishan large igneous province - pp625 - 629

Ingrid Ukstins Peate & Scott Edward Bryan

doi:10.1038/ngeo281

Thick alluvial fan sediments from the core of the Emeishan Large Igneous Province have been considered as critical field evidence in support of plume-induced pre-volcanic doming and uplift. These sediments are now reinterpreted as mafic hydromagmatic deposits emplaced at sea level, precluding dynamic pre-volcanic uplift as predicted by mantle plume models.

Abstract - | Full Text - Re-evaluating plume-induced uplift in the Emeishan large igneous province | PDF (1,198 KB) - Re-evaluating plume-induced uplift in the Emeishan large igneous province | Supplementary information

Subject Categories: Structural geology, tectonics and geodynamics | Volcanology, mineralogy and petrology

See also: related Backstory

Geochemical evidence for enhanced fluid flux due to overlapping subducting plates - p630

Hitomi Nakamura, Hikaru Iwamori & Jun-Ichi Kimura

doi:10.1038/ngeo290

Full Text - Geochemical evidence for enhanced fluid flux due to overlapping subducting plates | PDF (76 KB) - Geochemical evidence for enhanced fluid flux due to overlapping subducting plates

Digging the Arctic - p634

doi:10.1038/ngeo296

Chien-Lu Ping and his colleagues got their plane stuck in a runway of melting seasonal frost during their survey of North American soil organic carbon pools.

Full Text - Digging the Arctic | PDF (218 KB) - Digging the Arctic

In search of molybdenum - pE14

doi:10.1038/ngeo291

Corey Archer and colleagues sailed into the wilds of Sweden and the Amazon to collect river water and the trace metal isotopes it carried.

Full Text - In search of molybdenum | PDF (243 KB) - In search of molybdenum

Heading to the herbarium - pE15

doi:10.1038/ngeo301

A trip to the British Antarctic Survey herbarium in Cambridge marked the beginning of a journey into the Earth's ultraviolet-B history for Barry Lomax and colleagues.

Full Text - Heading to the herbarium | PDF (202 KB) - Heading to the herbarium

Serendipity in Sichuan - pE16

doi:10.1038/ngeo304

Research opportunities can present themselves at the most unexpected times. When Ingrid Ukstins Peate and Scott Bryan went on a conference field trip in China, they didn't expect to steer previous geological interpretations in a new direction.

Full Text - Serendipity in Sichuan | PDF (236 KB) - Serendipity in Sichuan