 |
|
University of Miami scientist uncovers miscalculation in geological undersea record
September 11, 2008New study by Peter K. Swart published in PNAS compares 13C/12C records from carbonate platforms in 3 ocean basins
VIRGINIA KEY, Fla. -- The precise timing of the origin of life on Earth and the changes in life during the past 4.5 billion years has been a subject of great controversy for the past century. The principal indicator of the amount of organic carbon produced by biological activity traditionally used is the ratio of the less abundant isotope of carbon, 13C, to the more abundant isotope, 12C. As plants preferentially incorporate 12C, during periods of high production of organic material the 13C/12C ratio of carbonate material becomes elevated. Using this principle, the history of organic material has been interpreted by geologists using the 13C/12C ratio of carbonates and organics, wherever these materials can be sampled and dated.
While this idea appears to be sound over the last 150 million years or so, prior to this time there are no open oceanic sediment records which record the 13C/12C ratio, and therefore, geologists are forced to use materials associated with carbonate platforms or epicontinental seas. In order to test whether platform-associated sediments are related to the global carbon cycle, a paper by University of Miami Professor Dr. Peter K. Swart appears in the Proceedings of the National Academy of Sciences. This paper examines changes over the past 10 million years at sites off the Bahamas (Atlantic Ocean), the Maldives (Indian Ocean), and Great Barrier Reef (Pacific Ocean). The variations in the 13C/12C ratio are synchronous at all of the sites studied, but are unrelated to the global change in the 13C/12C ratio.
It appears that records related to carbonate platforms which are often used throughout the early history of the Earth are not good recorders of the 13C/12C ratio in the open oceans. Hence, the work presented suggests that assumptions made previously about changes in the 13C/12C ratios of carbonate sediments in the geological record are incorrect.
"This study is a major step in terms of rethinking how geologists interpret variations in the 13C/12C ratio throughout Earth's history. If the approach does not work over the past 10 million years, then why would it work during older time periods?" said Swart. "As a consequence of our findings, changes in 13C/12C records need to be reevaluated, conclusions regarding changes in the reservoirs of carbon will have to be reassessed, and some of the widely-held ideas regarding the elevation of CO2 during specific periods of the Earth's geological history will have to be adjusted."
University of Miami Rosenstiel School of Marine & Atmospheric Science
It appears that records related to carbonate platforms which are often used throughout the early history of the Earth are not good recorders of the 13C/12C ratio in the open oceans. Hence, the work presented suggests that assumptions made previously about changes in the 13C/12C ratios of carbonate sediments in the geological record are incorrect.
"This study is a major step in terms of rethinking how geologists interpret variations in the 13C/12C ratio throughout Earth's history. If the approach does not work over the past 10 million years, then why would it work during older time periods?" said Swart. "As a consequence of our findings, changes in 13C/12C records need to be reevaluated, conclusions regarding changes in the reservoirs of carbon will have to be reassessed, and some of the widely-held ideas regarding the elevation of CO2 during specific periods of the Earth's geological history will have to be adjusted."
University of Miami Rosenstiel School of Marine & Atmospheric Science
Geological Current Events and Geological News RSSBurying the greenhouse gas
To prevent global warming, researchers and policymakers are exploring a variety of options to significantly cut the amount of carbon dioxide that reaches the atmosphere.
Acid Soils in Slovakia Tell Somber Tale
Increasing levels of nitrogen deposition associated with industry and agriculture can drive soils toward a toxic level of acidification, reducing plant growth and polluting surface waters, according to a new study published online in Nature Geoscience.
A new approach in tsunami-early warning
The newly implemented Tsunami Early Warning System for the Indian Ocean, GITEWS, goes into operation today and with this, the system enters its final phase of optimisation.
Paleontologists doubt 'dinosaur dance floor'
A group of paleontologists visited the northern Arizona wilderness site nicknamed a "dinosaur dance floor" and concluded there were no dinosaur tracks there, only a dense collection of unusual potholes eroded in the sandstone.
Seismic response to natural gas anomalies in crystalline rocks
The research done at the Chinese Academy of Geological Sciences has shown that after geochemical experiments, the porosity of crystalline rocks in the middle crust increases sharply due to water-rock interaction.
Research around the North Pole
The German research vessel Polarstern has returned today to Bremerhaven from the Arctic Sea. It has cruised as the first research vessel ever both the Northeast and the Northwest Passages and thereby circled the North Pole.
Pesticide Concentrations Decreasing
The widespread use of pesticides across the United States has been in practice for decades, with little knowledge of the long-term effects on the nation's groundwater.
MU Scientist Uses Tracer to Predict Ancient Ocean Circulation
Even though the Cretaceous Period ended more than 65 million years ago, clues remain about how the ocean water circulated at that time.
21st century detective work reveals how ancient rock got off to a hot start
A new technique using X-rays has enabled scientists to play 'detective' and solve the debate about the origins of a three billion year old rock fragment.
Researchers uncover world's oldest fossil impression of a flying insect
While paleontologists may scour remote, exotic places in search of prehistoric specimens, Tufts researchers have found what they believe to be the world's oldest whole-body fossil impression of a flying insect in a wooded field behind a strip mall in North Attleboro, Mass.
More Geological Current Events and Geological News Articles
 | Dictionary of Geological Terms: Third Edition (Rocks, Minerals and Gemstones) From Aa toZweikanter, this popular dictionary has now been revised and updated. This edition includes over 1,000 new terms plus:-accurate definitions without technical jargon-many word origins-hyphenation and pronunciation guide-commonly used abbreviations-a geologic time and life chartThe definitions in this book are drawn largely from the autoritative 36,000-term Glossary Of Geology, to which... |
 | The Mapping of Geological Structures by K. R. McClay The Mapping of Geological Structures Ken McClay Department of Geology, Royal Holloway University of London, UK Detailed mapping and analysis of the structural features of rocks enable the 3D geometry of their structures to be reconstructed. The resulting evidence of the stresses and movement patterns which rocks have undergone indicates the processes by which they were formed, and allows... |
 | The Geological Time Table, package of 10 charts, Sixth Edition 'The colorful previous editions of the Geological Time Table have been immensely popular with scientists, professors, and students alike. The new and revised sixth edition provides practicing geologists, archaeologists, and Earth historians with a succinct source of reference to stratigraphy and chronostratigraphy. It provides easy access to numerical ages, including the stratigraphic... |
| Rock Formations and Unusual Geological Structures: Exploring the Earth's Surface (The Changing Earth) by Jon Erickson | |
 | Applied Subsurface Geological Mapping with Structural Methods (2nd Edition) (Chemical Engineering) by Daniel J. Tearpock, Richard E. Bischke Applied Subsurface Geological Mapping, With Structural Methods, 2nd Edition is the practical, up-to-the-minute guide to the use of subsurface interpretation, mapping, and structural techniques in the search for oil and gas resources. Two of the industry's leading consultants present systematic coverage of the field's key principles and newest advances, offering guidance that is valuable for both... |
| The Geological History of New Zealand and Its Life by C.A. Fleming | |
| The Geological Interpretation of Well Logs by M.H. Rider | |
 | Geological Approaches to Coral Reef Ecology (Ecological Studies) Coral reefs around the world are sustaining massive damage at an alarming rate. Geological Approaches to Coral Reef Ecology provides a uniquely historical perspective on the destruction—through both natural and human processes—of coral reef ecosystems. Chapters applying the principles of geophysics, paleontology, geochemistry, and physical and chemical oceanography supply novel insights into... |
| Geological Perspectives of Global Climate Change (AAPG Studies in Geology) (Aapg Studies in Geology) Access a broad range of paleoclimatic studies. Current debates regarding potential maninduced modification of climate make this volume especially timely. * Introductory sections address the major and minor physical controls, or drivers, that affect Earth's climate. * Several chapters describe the naturally occurring range of variation of climatic conditions and illustrate past changes in global... | |
 | The Bible, Rocks and Time: Geological Evidence for the Age of the Earth by Davis A. Young, Ralph F. Stearley s the Earth relatively young or very old? We've all heard the controversy. The consensus regarding the age of the Earth, based on the best geological evidence, is that it is billions of years old. But many Christians believe that the Bible teaches the Earth is only a few thousand years old at best. What are we to make of this discrepancy? Geologists Davis Young and Ralph Stearley tackle this... |
| © 2008 BrightSurf.com |