Pallasite paleomagnetism: Quiescence of a core dynamo

نویسندگان

  • Claire I.O. Nichols
  • James F.J. Bryson
  • Florian Kronast
  • Francis Nimmo
  • Richard J. Harrison
چکیده

a Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, United Kingdom b Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA c Centro Universitario de la Defensa, Ctra. de Huesca s/n, E-50090 Zaragoza, Spain d Instituto de Ciencia de Materiales de Aragón, CSIC—Universidad de Zaragoza, Pedro Cerbuna 12, E-50009 Zaragoza, Spain e Helmholtz Zentrum Berlin, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, Berlin 12489, Germany f Department of Earth Sciences, University of California Santa Cruz, CA 95064, USA

برای دانلود 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

Evidence for a dynamo in the main group pallasite parent body.

Understanding the origin of pallasites, stony-iron meteorites made mainly of olivine crystals and FeNi metal, has been a vexing problem since their discovery. Here, we show that pallasite olivines host minute magnetic inclusions that have favorable magnetic recording properties. Our paleointensity measurements indicate strong paleomagnetic fields, suggesting dynamo action in the pallasite paren...

متن کامل

Energetics of Asteroid Dynamos and the Role of Compositional Convection

Introduction It has recently been argued that the observed paleomagnetism of angrite meteorites is most likely due to an early dynamo on the angrite parent body [1]. On Earth and other large silicate bodies, dynamo activity is thought to be sustained by a combination of thermal and compositional buoyancy [2]. Here I will argue that compositional buoyancy, if present, overwhelmingly dominates th...

متن کامل

شواهد بافتی وجود شرایط دینامیکی در حین و پس از تبلور گنایس‌های دیناموماگماتیک قلعه‌دژ، ازنا

The dynamo-magmatic gneisses of Azna have a mylonitic texture characterized by large retortshape porphyroclasts or augen of feldspars, around which a more ductile, medium to fine-grained matrix of white-mica (phengitic muscovite), biotite, quartz and feldspar is deflected. The structure is named core-and-mantle structure.  Feldspars behave in both plastic and brittle fashion. Evidence of strain...

متن کامل

Lifetime of the solar nebula constrained by meteorite paleomagnetism.

A key stage in planet formation is the evolution of a gaseous and magnetized solar nebula. However, the lifetime of the nebular magnetic field and nebula are poorly constrained. We present paleomagnetic analyses of volcanic angrites demonstrating that they formed in a near-zero magnetic field (<0.6 microtesla) at 4563.5 ± 0.1 million years ago, ~3.8 million years after solar system formation. T...

متن کامل

Spherical Oscillatory alpha2 Dynamo Induced by Magnetic Coupling between a Fluid Shell and an Inner Electrically Conducting Core: Relevance to the Solar Dynamo.

A two-layer spherical alpha2 dynamo model consisting of an inner electrically conducting core (magnetic diffusivity lambdai and radius ri) with alpha=0 surrounded by an electrically conducting spherical shell (magnetic diffusivity lambdao and radius ro) with a constant alpha is shown to exhibit oscillatory behavior for values of beta=lambdai&solm0;lambdao and ri&solm0;ro relevant to the solar d...

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

برای دانلود 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

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2016