Primordial Krypton in the Terrestrial Mantle Is Not Solar

نویسندگان

  • G. Holland
  • C. J. Ballen
  • M. Cassidy
چکیده

Introduction: Noble gases are key tracers for the origin of volatiles in the terrestrial planets and of interaction between mantle reservoirs and the atmosphere. General consensus is that material accreting in the solar nebula and nebula gases from the Sun itself were incorporated into the terrestrial planets, providing a starting point for models of planetary evolution. However, the isotopic signatures of these accretion processes are often masked by air contamination and therefore deviations from air may be <1%, requiring high precision measurements. Typically, oceanic basalts, continental diamonds and xenoliths have provided the noble gas data for the mantle. Our current work focuses a suite of samples from individual wells that extract almost pure (>99%) CO2 from beneath New Mexico, USA. These well gases are sourced from deep within the sub-continental lithospheric mantle (SCLM) and have been shown to contain magmatic volatiles retained from the earliest stages of planetary formation [1]. Uniquely, these gases provide essentially unlimited amounts of sample for high precision measurements which, coupled with improved instrument precision from the new generation of noble gas mass spectrometers, allows us to investigate accretionary processes.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

What CO2 well gases tell us about the origin of noble gases in the mantle and their relationship to the atmosphere.

Study of commercially produced volcanic CO2 gas associated with the Colorado Plateau, USA, has revealed substantial new information about the noble gas isotopic composition and elemental abundance pattern of the mantle. Combined with published data from mid-ocean ridge basalts, it is now clear that the convecting mantle has a maximum (20)Ne/(22)Ne isotopic composition, indistinguishable from th...

متن کامل

Solar Noble Gases in Enstatite Chondrites and Implications for the Formation of the Terrestrial Planets

Introduction: In a companion abstract [1], we report evidence for tiny amounts of most likely primordial noble gases with solar-like elemental and isotopic composition admixed to Q-type primordial noble gases in an E chondrite. Here, we discuss possible implications of this finding for terrestrial planet formation. The genetic relation of the noble gases in planetary bodies to those in the Sun,...

متن کامل

Late Impacts and the Origins of the Atmospheres on Venus, Earth, and Mars

Introduction. Diverse origins of terrestrial planet atmospheres are inferred from differences in the noble gas abundances and isotope ratios observed on Venus, Earth, and Mars [e.g., 1, 2]. Models for the origin of terrestrial atmospheres typically require an intricate sequence of events, including substantial loss and isotopic fractionation of solar nebula gases, outgassed mantle volatiles, an...

متن کامل

ar X iv : a st ro - p h / 03 06 60 5 v 1 2 8 Ju n 20 03 The Dual Origin of the Terrestrial Atmosphere

The origin of the terrestrial atmosphere is one of the most puzzling enigmas in the planetary sciences. It is suggested here that two sources contributed to its formation, fractionated nebular gases and accreted cometary volatiles. During terrestrial growth, a transient gas envelope was fractionated from nebular composition. This transient atmosphere was mixed with cometary material. The fracti...

متن کامل

The Accretionary Origin of Noble Gases in the Earth’s Mantle

Introduction: An outstanding problem in the Earth and planetary sciences is the source and mechanism by which the Earth-like planets accreted their highly volatile elements. Unlike highly refractory elements, which preserve close to solar proportions in even quite evolved meteorites and the inner planets, moderately refractory and more volatile elements are depleted relative to the highly refra...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2009