ation of carbonate minerals collected from the northern Altiplano suggest that the Central Andes were rapidly uplifted during the last 10 million years. Authors Robin R. Canavan and colleagues present new evidence from the Puna Plateau, the southern-most portion of the Central Andean Plateau, using hydrogen isotopes from volcanic ash deposited over the last 36 million years. Interpreting this geochemical data with regards to an atmospheric model that describes how isotopes vary with elevation, their results indicate that the Puna Plateau was already about 4 km high by 36 million years ago. Integrating the Puna Plateau and Altiplano data suggests a much more complex uplift history for the Central Andean Plateau than previously thought.
Asynchronous response of marine-terminating outlet glaciers during deglaciation of the Fennoscandian Ice Sheet
Chris R. Stokes et al., Department of Geography, Durham University, Science Site, South Road, Durham DH1 3LE, UK. Published online 31 Mar. 2014; http://dx.doi.org/10.1130/G35299.1.
Recent studies show that marine-terminating outlet glaciers (e.g., in Greenland) are thinning, retreating and contributing to sea-level rise. This behavior has been linked to atmospheric and oceanic warming, but non-climatic factors such as the depth of their fjords, can also influence the rate of retreat, and there is uncertainty about which of these factors is most important. Moreover, observations are restricted to the last few decades, making it difficult to separate short-term variability from longer-term trends. This new study by Chris R. Stokes and colleagues uses radiocarbon dating and moraines to reconstruct the retreat of outlet glaciers during deglaciation of the Scandinavian Ice Sheet between 18,000 and 10,000 years ago. Interestingly, retreat rates averaged over several millennia (~30 m/yr) are less than half those observed on Page: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Related biology news :1
. New from Geology: Fossils, earthquakes, gold, and sea-bed landslides2
. Geology covers Mars, the Moon, anthropogenic lead poisoning, earthquake hazards, and more3
. Geological Society of Americas top journal, Geology, begins 2014 with 10 new articles4
. New geology research explores intriguing questions5
. Offshore pockmarks, Wax Lake Delta, Cabo de Gata, the Siberian Traps: Geology covers the world6
. Geology tracks eruptions, earthquakes, erosion, extinctions & more7
. New in GEOLOGY: Gems, Darwin, Mars, Hemp, Snowball Earth, a Siberian Impact Crater, and More8
. Geology covers multiple disciplines and substantial territory in Aprils new postings9
. The Geological Society of America Journal Geology: Dynamic geoscience10
. New Geology study raises questions about long-held theories of human evolution11
. GEOLOGY starts 2013 with 25 new articles posted online ahead of print