Transient fluvial incision and active surface uplift in the Woodlark Rift of Eastern Papua New Guinea

Mar 28, 2012

The Woodlark Rift off-shore of eastern Papua New Guinea is the fastest extending continental crust on Earth.

In the center of the rift, the D'Entrecasteaux Islands exceed elevations of 2,500 meters and include the youngest ultrahigh-pressure rocks on Earth, which were transported from more than 90 km deep since rifting began about eight million years ago.

Even though the Woodlark Rift presents an unparalleled view into the processes that govern the rifting of , little is known about the history and spatial pattern of vertical motions over the past million years.

Over this time, plate motions have changed significantly, with extension and rock uplift possibly migrating from the center of the rift to its southern margin on the Papuan Peninsula.

In order to better understand the mechanisms that have brought deeply exhumed rocks to Earth's surface, a community of earth scientists has been working to understand the history and pattern of vertical rock motions within the Woodlark Rift.

In this study, Scott Miller and colleagues present data about the lengthwise elevations of rivers draining the D'Entrecasteaux Islands and the Papuan Peninsula.

These rivers are gauges that adjust their slopes in response to mountain-building processes, such that their profile shapes record patterns in the amount and history of rock uplift and, hence, .

These river profiles indicate that the islands and the peninsula have increased in mean elevation, likely over the past few hundred thousand years.

This study is part of a growing body of work that suggests that profound rock uplift continues to the present day in both the D'Entrecasteaux Islands and the Papuan Peninsula, driven by continental extension and upwelling, buoyant mantle.

Explore further: Clean air: Fewer sources for self-cleaning

More information: Scott R. Miller et al., Dept. of Earth Sciences, 204 Heroy Geology Laboratory, Syracuse University, Syracuse, New York 13244, USA. Lithosphere. Posted online 25 Jan. 2012; print issue: April 2012; doi: 10.1130/L135.1

Provided by Geological Society of America

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Formation of the Gulf of Corinth rift, Greece

Dec 22, 2009

A study of the structure and evolution of the Gulf of Corinth rift in central Greece will increase scientific understanding of rifted margin development and the tectonic mechanisms underlying seafloor spreading ...

Geologists correct a rift in Africa

Mar 26, 2012

The huge changes in the Earth's crust that influenced human evolution are being redefined, according to research published today in Nature Geoscience.

New insights into volcanic activity on the ocean floor

Jun 16, 2010

New research reveals that when two parts of the Earth's crust break apart, this does not always cause massive volcanic eruptions. The study, published today in the journal Nature, explains why some parts ...

Recommended for you

Clean air: Fewer sources for self-cleaning

1 hour ago

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

There's something ancient in the icebox

1 hour ago

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Image: Grand Canyon geology lessons on view

8 hours ago

The Grand Canyon in northern Arizona is a favorite for astronauts shooting photos from the International Space Station, as well as one of the best-known tourist attractions in the world. The steep walls of ...

First radar vision for Copernicus

8 hours ago

Launched on 3 April, ESA's Sentinel-1A satellite has already delivered its first radar images of Earth. They offer a tantalising glimpse of the kind of operational imagery that this new mission will provide ...

User comments : 0

More news stories

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

Turning off depression in the brain

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Is Parkinson's an autoimmune disease?

The cause of neuronal death in Parkinson's disease is still unknown, but a new study proposes that neurons may be mistaken for foreign invaders and killed by the person's own immune system, similar to the ...