Earth science concepts and applications

EARTH SCIENCE: THE SCULPTING of the EARTH'S CRUST

The objective of this work is to review the article entitled: "Magma P.I. 'Unearths Clues to How Earth's Crust Was Sculpted" published December 14, 2007 online the website 'Science Daily'.

The article entitled: "Magma P.I. 'Unearths Clues to How Earth's Crust Was Sculpted" published online the Science Daily website December 14, 2007 relates the work of John Hopkins University geologist Bruce Marsh who is stated to have "challenged the century-old concept that the Earth's outer layer formed when crystal-free molten rock called magma oozed to the surface from giant subterranean chambers hidden beneath volcanoes." (Science Daily, 2007)

MARSH'S THEORY

Bruce Marsh has posited that the "deep-seated plumbing underneath volcanoes" is actually comprised of a system that is extensive in nature of "smaller sheet-like chambers vertically connected with each other and transporting a crystal laden 'magnetic mush' to the surface" and is a theory that is becoming accepted widely among scientists. This type of system has been termed a "magmatic mush column" and said to exist "beneath all of the world's major volcanic centers. It is held by Marsh that these channels, instead of simply transporting the magma and crystals needed in formation of the surface of the Earth involves a process in which the magma is pushed up through the earth and in doing so the earth's crust became fractured creating a type of "template" which guides erosion and sculpting that occurs in formation of "a series of valleys and mountain ranges..." (Science Daily, 2007)

II. TIMELINE of MARSH'S THEORY

Marsh holds that the functions he describes, at least in the region of Antarctica, "date back at least 180 million years to the time when the continents split apart. He points out that this observation brings together the usually disparate study of deep-seated magmatic processes and land-surface evolution." (Science Daily, 2007) Marsh's study has been conducted in McMurdo's Dry Valleys which is stated to be ideal for the study of these systems "because it was eroded into its present form millions of years ago and has, unlike the rest of the Earth's surface undergone very little subsequent erosion." (Science Daily, 2007) George Denton, of the University of Maine and David Marchant of Boston University term this region to be "a relic landscape, since it is the single place on the face of the earth."..that looks almost exactly as it did millions of years ago. The delicacy of the landscape in the Dry Valleys has preserved for us an unusually rich collection of geological evidence of the processes that formed this terrain." (Science Daily, 2007)