General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) NASA I echmc,il hiemmandum IWOO 0 Meteor Ablation Spheres From Deep-Sea Sediments M.B. Blanchard, D.E. Brownlee, T.E. Bunch, P.W. Hodge, and F.T. Kyte ( N A 1, 10) AH ATjvvq , ;t ­ i , !,. I [1it 1 F A 14 0: 1 is lit ii I^ Selitt-11111( . 1 11118 si j,I NASA AL -A NASA Technical Memownclun ► 78510 Meteor Ablation Spheres From Deep-Sea Sediments M.B Blanch, d, Ames Rese,uch Center, Mofl. • tt Vivid, California U.E. Brownlee, Calih ►rnia Institute of Technology, Pasadena, Californie T.E. Bunch, Ames Reseatch Center, Moffett Field, .:a11fontid P.W. Hodge, University of Washint'lton, Seattle, Washirniton F.T. Kyte, San Join State Umveisfty, San ,lose, California i AMA N Iliofl,l \e , w I ,wd Ames Research Center t: I \ t f ^^ MIA VOh ABLr IAON SPHI RF S FROM 11F I-T-S A SO 111MF'M", `I. F. It I.1nwII.1t ,I4 Itrowti I eo** l' . I Itun,• It's .111A N. 1. 1.\ c ^' I *NAsA Amv!, K.`::q`.tr%'It l'i'nt or ,j1 Mottt'tt Vic Id .'.1litorn1.l 1 1 I I tol- 111.1 Ill::( it lll i' 1 ' .1 I t 1 of tit., ` 1 1 125 ^^ ► I ! tit vt`t! . lt y of w.I::Il tit t`,ton ..ill .l^^:a.' :^l .Ic ^' I^I11V^'lr• t L \' :.Ill .lose. l'.1111"r11tA ^'"^.'.^ ^—' 1 \cs^1 ',—'^^^ ^^^^,^ / ,^^. fib- ^ ^•' ...r.l i ABSTRACT This paper describes analyses of spheres which were magnetically extracted from mid-Pacific abyssal clays ranging in age from 0 to 500,000 years. The concentration of spheres larger than 200 microns was found to be a few time3 10 ppb. The spheres were readily divided into three groups using their dominant m neralogy. These groups are named iron, glassy, and silicate. Mo:: t of the spheres were formed from particles that completely melted and subsegvently recrystallized as they separated from the parent meteoroid bodies. However, some of the silicate spl.eres contain occasional relict grains of the parent metoroids that did not experience any melting. ► Typically, these relict grains are olivine crystals whose cores are Mg-rich, i !1 ranging from Fo 89-o9 . Commonly the outer rim of these relict grains was altered during heating. Other relict mineral grains include enstatite, ferrous spin,-I., chromite, and pentlandite. The three groups of spheres (iron, glassy, and silicate) may possibly have some genetic significance. It seems reasonable to expect iron-rich spheres to be produced during ablation of iron and metal-rich silicate meteoroids. Metal spheres are probably not produced by ablation of predominantly silicate meteoroids because studies of fusion crusts and laboratory ablated silicate materials have never yielded separate metal spheres, but rather have produced spheres with intergr.own iron oxide and silicate phases. The iron spheres recovered possess identical mineralogy 1 with the fusion crusts of Boguslav^:a, Norfork, and N'Kandhla iron meteorites as well as with the ablation debris created in the laborator y using metallurgical samples of iron and nickel-iron. The combination of several UIt1l^INAi, PAGE I5 2 r )F POOR QUALITY 7_1 ,` I t i 1 ^I iron ox i,it' i , Ii as y s ,Intl N I rtt`t; ,. og t i t` n in i tltt l v I dtt l i spIit'rt`t. I s ctlnv i tit , I iig cvitlt'nt t` tit at'l.lt I ' m t mint tilt- , al l is Ft` - 1'it• I1 Int'tt'Orklids. s ftI Iit s sv ,{I IIt, I-e a atr y c0Its dvr . at.l y unar y Fv - rich t h.ln t ilt` t it'.It v ^+.{thl`rl^r: l'hr y c ollsI-it tit nl. ► l;nt't iIV . Intl a Fe ,; i. ► S: : wIli,`fI IS r al.1t ivvIv law ill tii. I'hia coulhi it. II Ikill Is n I.( I Ikcl y prodile `t1 b y .II`i.it it'll t`1 nit`t.II - rtcll c,ttl` motcttt'a1tl:+. TIle asi l icatc ,I`II%. I F % .11't' unti. , itI, tt'til y der ivt't1 fPant .lhIitt ian of stilly mot voraitl-l. 1'llo al Ivillt`-magilct itt'-t',l.iria Aild cult ide milict.tl .1Ss4'1111,1v%-,v; f avk, u ' I, illy; I it t lio!w sphcrt`:i .irt` IdVIIt I t'.1 I t 0 t Ill t tit` tit'Kt' l' l ti ed 1 11 t lit' 11.1t itr.11 I Its Ia11 t ' rll:tti al AIIc1ltlt'. l l rgut ' II. ,111.1 %Iu%'11 'it'll 1110tV, , I 1tv s .IIti.1t It`It dobrIN treat ctl Ili t lit' I.11t tl r . attlrv. tll,l Inc I t t' tI illt v {` I.illot .11" y &Ill1S( t'.' I Ion t t'tl f 1'01M i tIlc Strato 1111t`rt', lilt l k t', t m{t aaitI t ll ti all.i reI ict I`r.11n:i .11'0 list , tit tat" 'let "I in.I it i iv, t lit` part'llt 1110t ti ara Itl t y {lt`H 1 ar tilt` tii i it'.tt t' Sl, ht`rt';t. Illl I k .II1.1I v-,vs o I, vt r v s t .1 i I 1 . • t`tl s1, itv I- v-I II.IVi' tihaWII t 11.1t I1t`I1VO1.1t i I t' 10111011t .11 r^ t ' IhltlUi.11lt'cti . Irt` SIinII a r to t 'halidr Itc . tl`mid.itice s Alm IN- tit';: at FVI IC ,I.itIIlti I ^iolllltl tIt .1 1t'W I)0rt'" 11t a! t llt' a{'llt'I't 'ti) have itit'Iltlllt ' tl I1111'.lt` rOils 11 t1;11 tt`mporattlrt` Inill01'.11: 1 wh ich Oi tt'll t't • . " 111" .Iti 1.11. 11 I- ct' y tit.1h; ill .1 tlilt'-t;Yaillt`tl i s m.ltt"ix that is ch.Ir :lctt'rI.• cti t'v llll III cl'anti : it'cu1.11 raitlti. 1'hctit' vat.la Were c:llltictl by t'tit• .11t i11 ►; y atat ilt`: It'. !; WAtt`r. Slllitlr) pratltit'atl '. ' y do,'0111- i10:iit it'll Oi IlV,Il'.It t`t1 . Illtl .'t ht'r law t t'1111't 1 .ti tlrt' millo r .11:1 dill illy; .It`1.1t it`ll. lirt'.lutic t.lrl;t`r citstalt. of httJwl .ltitiaci:ltrtt 1,lth f ill y -gi.iiiiod. low t t'i71por.It tire. y al.lt i la-rich m.lt 1't\. t he ah y iallri Calldi.l.lt t`s far 1 t .II, e iit metvoroIds .` t '.ht`tit' Niil.'.Itt' til t llt' rt'N Al " 0 ,'.111) 11,1t' 00IIS i11al1tirit0S \ ..._ - -- - --- - I - -- - --- -^ '— 1+ a A 1. Introduction Over a centu:y ago, Murray and Renard (l] discovered microscopic magnetic spheres in deep-sea sediments. Finding both "stony" and "iron" types, they suggested that the spheres were produced by the melting of meteoroids as they entered the atmosphere. Since their discovery, deep- sea spheres have been subjected to a variety of investigations, but their importance to the science of meteoritics has not been fully recognized. Reviews of much of the early work on the spheres were Liven b y Schmidt [2] and Parkin and Till ,­ 13]. Most of Lite previous work has concentrated on the "iron" spheres which are reasonably well characterized and under- stood; their credibility as extraterrestrial particles is now well. established. Evidence is strong that the "iron" spheres were produced 'ay atmospheric melting of iron meteoroids [4,5). The "stony" spheres i have only been studied by a few investigators [6,7,8], and they are only E now being extensively examined with modern analytical techniques [9,10]. The "stony" particles have not generated much interest because their properties were not understood, and there was no real evidence that Che particles were, indeed, extraterrestrial. The "stony" spheres have been interpreted as droplets produced by ablation of stony meteoroids 16,71 and mistakenl y identified as "rounded bodies in space" not altered by atmospheric entry [8]. In this paper we direct most of our efforts to the "stony" spheres because 0 ey are the least understood and potentially the most interesting. It is the purpose of this paper to show that the "stony" spheres are extraterrestrial and are generated by ablation of parent meteoroids similar to chondritic meteorites. ^11tIGIN AL "0'' 15 '' I OFp(I^R l?l1Al,ICY 4 f The m. ► I or t echnitlut' we hav • used for ident if teat ion anti in c rI,ret at Wit of ah l .