The continuing past five million years steady increase in the amount of sediment deposits, which ha

The continuing past five million years steady increase in the amount of sediment deposits, which has been assumed by many geoscientists, does not exist. This is the key finding that Jane Willenbring and Friedhelm von Blanckenburg now published by the German Research Centre for Geosciences ro membrane GFZ. The world watched four-fold increase in sedimentation is a pure observation artifact, all based on hypotheses must now be subject to review.
Erosion by water and ice and the chemical weathering of rocks of the earth's surface from wear mountains over millions of years. The eroded rock is carried away by rivers and glaciers and is found in the sediment of the oceans and the continents around large mountains again. The global measurement of the thickness of sedimentary ro membrane layers in the past had actually done the result that the amount of sediment that was deposited per time segment ro membrane worldwide in the last five million years ago, has multiplied continuously. To produce this excess sediment, would actually erode the mountains with as higher speed.
Hypotheses for the origin of this phenomenon assumed a stronger global mountain growth and consequently increased erosion effects. It could also have been the other way around: the mountains had long existed before with high relief, but only an environmental shift such as that which led to the ice age about 3 million years ago, has eroded the mountains faster and they subsequently let rise faster again by relieving the weight. However, none of these hypotheses could explain satisfactorily so far.
They only lead to a further paradox that also have not been able to solve geoscientists. Reconstructions of past concentrations of the greenhouse gas carbon dioxide in the atmosphere with indirect chemical and biological methods showed that this varies for over 10 million years to about the value that had the atmosphere even before the start of the current rapid increase in CO2 concentration. However, the erosion to the world, as well as the decomposition of rock must increase as well. However, this consumes about the carbonic acid contained ro membrane in the rain constantly small amounts of atmospheric carbon dioxide. Strictly speaking, this consumption is just as great as the delivery of this gas to the atmosphere by volcanoes. Over millions of years the nature thereby stabilizing the greenhouse effect of the atmosphere and thus the temperature. ro membrane But would the removal of CO2 multiplied by the high weathering, the atmosphere contained today hardly appreciable amounts of this greenhouse gas. This would result in an extremely cold earth on which all the water would be frozen.
The GFZ scientists now solved this riddle. They noted that the increase in sedimentation ro membrane rate is an artifact of the observations: the more precise look geologists, they discover the more sediment deposition. And in the recent geological past can better look into it as in the story a long time ago, because sediment survived not always the geological change. The older it is, the less is supplied. So apparently increases ro membrane the geological sedimentation, the younger geological time and the shorter the period of observation. The phenomenon of increase in sedimentation is therefore not real, but merely ro membrane reflects the sediment preservation.
In support of this interpretation lead Willenbring and Blanckenburg now geochemical measurements in certain ocean sediments. Into centimeter-thick iron-manganese crusts that grow deep in the ocean over millions extremely slow, is in the form of variable concentrations of metals the information ro membrane on the entry of substances into the oceans in the past. The two researchers used the isotope of mass 9 of the rare element beryllium to determine the amount of sediment that is entered via rivers into the oceans. Had the erosion ro membrane caused by increased sedimentation, we would find in the younger layers of these crusts more of this beryllium-9.
Willenbring used to verify this effect and Blanckenburg additionally also the very rare isotope beryllium-10th This is produced in the atmosphere by cosmic rays in always the same amounts and is supplied via the precipitation the oceans. While the iron-manganese crusts grow, the beryllium-10 is const