Olivine settling in cosmic spherules during atmospheric deceleration: An indicator of the orbital eccentricity of interplanetary dust
File(s)Genge_et_al-2016-Geophysical_Research_Letters.pdf (1.44 MB)
Published version
Author(s)
Genge, MJ
Suttle, M
Van Ginneken, M
Type
Journal Article
Abstract
A new type of cosmic spherule is reported with textures suggesting settling of olivine during atmospheric deceleration. Numerical simulations of entry heating reveal that relict forsterite, which survives melting, can settle over the 1-2s of flight at high entry angles and entry velocities up to 16 km s-1. Enhanced crystallisation of phenocrysts by heterogeneous nucleation on accumulated relict forsterites is the most likely origin of the observed cumulate textures in cosmic spherules. Such textures in cosmic spherules reveal interplanetary dust with higher encounter velocity with the Earth that correspond to orbital eccentricities >0.3. The relative abundance of cumulate spherules suggests 14% of ordinary chondrite-related, S(IV)-type asteroid dust over the last 800 kyr had relatively high orbital eccentricity owing to secular and planetary perturbations. The textures of cosmic spherules collected from sediments can therefore be used to trace dust orbital variations with time which may influence terrestrial climate.
Date Issued
2016-10-19
Date Acceptance
2016-09-28
Citation
Geophysical Research Letters, 2016, 43 (20), pp.10646-10653
ISSN
1944-8007
Publisher
American Geophysical Union
Start Page
10646
End Page
10653
Journal / Book Title
Geophysical Research Letters
Volume
43
Issue
20
Copyright Statement
©2016. The Authors.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Grant Number
ST/M003167/1
ST/N000803/1
Subjects
Science & Technology
Physical Sciences
Geosciences, Multidisciplinary
Geology
cosmic spherules
ANTARCTIC MICROMETEORITES
EARTHS ATMOSPHERE
ASTEROID DUST
COLLECTION
MODEL
ICE
METEORITES
LIQUIDS
MELTS
Meteorology & Atmospheric Sciences
MD Multidisciplinary
Publication Status
Published