<<

1973LPSC....4..613S Abstract-Poikilitic suites chadacrysts generated The that peritectic, presence hypothesis: silica transport plagioclase pores, in POIKILITic* zation port at about and (5) cients Apennine tic nite, (1972) Poikilitic-the K-KREEP Chadacryst-the Oikocryst-host Relic ler all *Definitions net texture. key abundant phosphate therefore © poikilitic of for or crystals which non-mare in 10% reported to Lunar feldspar lunar solid of Fe partial the allows forming relics composition. (1) oikocrysts. (11) of an and Geology Front. of fishnet appear ROCKS, feldspar The texture state recrystallization. The samples. through of and feldspar. and insulating of crystal melt The Mg and is few 2-4 inclusions, important clasts other Lunar less a more euhedral two high rocks, landing Planetary JEFFREY poikilitic between the texture. pyroxene with to abundance Branch, Delano mm Petrology in virtually and (7) the commonly through Most K phases. poikilitic anorthite which lack have The Science in layer phases Normally over virtually abundant(> soil shape typically Proceedings polymict of low poikilitic texture of TN6 sites, (Supplement textural formed Institute nuclei large L. 70% which pyroxene of et The fractions these Institute, of Ca all between rich, of grains used NASA material. WARNER al. CHARLES all fragments liquid. zoned impact optically pyroxene of texture feldspar with (2) is which to feldspar, smaller rocks in of i.e., rocks with to (1973) 50%) 4, form. terms: Flow Apollo group • the breccias are which a rapidly INTRODUCTION Johnson Geochimica Vol. oikocrysts. 3303 oikocrysts. more The Provided low-K-KREEP liquid. Fourth melted from low Slow is have nucleated. remaining are chadacrysts, indicates continuous crystals Continuous 1, alignment and and also within H. protolith NASA 613 pp. had report refractory of K-KREEP in chill proposed Lunar low cooling augite. Space 613-632 16 (4) all et rocks SIMONDS 4-10 referred a rocks. returned WILLIAM by Cosmochimica (10) lower a (chadacrysts) (8) the calcium Road Preservation Science Apollo poikilitic low melt. The of the is Center, that crystals High that (9) pyroxene The mm oikocrysts. not with through gas than feldspar to K- melting composition NASA melt 1, Wilshire Concentration to A Conference expected KREEP compositional form bearing Houston, temperature composition, pyroxene poikilitic they number fines as higher matrix by 16 C. Houston, Acta) of then fishnet the are growth Astrophysics point chadacrysts. sampling one Apollo by of rocks PHINNEY constitute from The polymict cools feldspar. melt melting plagioclase-olivine-pyroxene distributed for crystallization only of and Texas mineral oikocrysts than are texture. Texas observations holes fragments is subsolidus (- of a more correlation Spur refractory few Jackson possible found 14. late olivine 1200°) 77058 have points breccias localities (6) enclose in 77058 (3) tens Data crystallizing Phinney slowly as Resorbed a Crater the enclosing in Large partition inclusions. or widespread been due of melt than of all System fishnet. support with (1972) plagioclase. olivine many and/or soil. degrees, make due an to non-mare spherical crystalli- except the on found ease poikili- impact olivine et coeffi- to many smal- ilme- the The and this low re- the up al. so of 1973LPSC....4..613S 614 from 66035. 60315 0.5 discussed green observed the ments At feldspar and Gooley oikocrysts. rectangular or of observed mole but smooth sections. and feldspar up linings stonite. (the crystals crysts, chadacrysts. minerals relics lineations the rake Taurus-Littrow to The In In Modes mm parent are have the © oikocrysts) the percent 10% this hand and of make rocks Companion Lunar are small poikilitic referred et long or metallic and in and crest found The plagioclase, a in paper al. including in 65015. spherical rocks, (Table hummocky nearly higher specimen, patches, samples In the up the and with were anorthosite, Scattered (1973) (1~20 is wollastonite smaller point the of a a as recognized. Planetary inter-oikocryst the boulders to rocks similar particles enclosing few which North Also few average noted free region 1) papers chadacrysts (Apollo counts as which mm petrology or 11 0.5-3 615XX, 635XX, 615XX, were olivine, amounts the areas the consist fractures. irregularly a textured throughout of rake 2 proportion Ray weigh ) in Institute few HAND to shocked poikilitic and at between mm projecting in discuss in birefringence include inter-oikocryst the determined abundant 17) this samples Other both on analyses (Station these comments spine!, MODAL may of of long Apollo 4-20 foliated of plus C. SPECIMEN rake spheres several crystals • 13 region Some H. the shaped a mafic to both all Provided not rocks rake which of recognizable TEXTURES general the poikilitic g. accessory SIMONDS 645XX, sample various crystals. and from 11). parts smaller the North MINERALOGY by 16 be Low by poikilitic relics of than patches. samples will rocks, silicates. poikilitic are up of are microprobe rake representative pores lithic display Our PETROGRAPHY region, counting by Stations the of pyroxene classification calcium to et study be and very generally degrees. and rocks pyroxenes the and the crystals work samples al. minerals a poikilitic fragments. 0.4-10 tablet made NASA units minerals millimeter respectively. South a poikilitic 648XX fine These The rocks. matrix. contains are slightly returned 1, indicates 300 are (or No by about grained, up 4, Astrophysics shaped (the mm from region coarser-grained and Massifs. of with or All olivine) rocks of Warner were and classified patches to Chips macroscopic include rocks paler the in chadacrysts), crystals Apollo more across Stations polygonal poikilitic by 5 61156 less diameter. that 13 between meters total plagioclase carefully dense, with are Apollo for green and are up et than Data points poikilitic are iron-nickel and as 16 and al. mottled variability to thin of more vesicles 1, large rocks pigeonites, thick hard, rock (1973) 3 color System 5% vugs. 16 pyroxene foliations 4, a the the The clasts than mm sections selected on clast and will mostly than wolla- up rocks types oiko- same pale- were frag- have pore than with long thin The and and the 13. be of of to in in 5 1973LPSC....4..613S

Table 1. Basic mineralogy of poikilitic rocks.

@ Most Abundant t""' Oikocrysts Other Oikocrysts Mode volume % = and average Oikocryst and average "'1= composition size composition Plag+ Sample Number of Oikocryst mm of Oikocryst Mesostasis Opx Pig Aug Oliv Opaques =Q. "ti - 60315 Orthopyroxene 0.5-1.1 Augite 55 34 NF 4 6 =l'C Wo4 Enso Fs,6 Wo4, En4s Fs11 "'1 61568 Pigeonite 0.3 NF present NF present present present present '-< "ti ..... (Poikilitic ('1) Wos En10 Fs22 ....'"'1 portion only) 0 ::t."'= 0 Olivine 1.5 Pigeonite 68 NF 6 2 22 2 (IQ 61569 '-< =l'C F010 FS24 Wo9 En79 Fs,2 ,...,,0 • 63547 Pigeonite 0.4 NF 67 NF 25 NF 8 1 "ti ,:;>- "'1 W 06 En14 Fs20 0 2.. < 63556 Pigeonite 0.4 NF 68 NF 29 NF 2 1 0 ....Q. l'C W 01 En1, Fs20 Q. 63558 Orthopyroxene 0.6 Augite 56 32 NF 12 2 2 ,:;-°' C" 0 '-< Wo, Ensz Fs,, Wo,9 Enso Fs11 fr. =-l'C 64567 Olivine 0.15 NF 69 NF 10 NF 20 1 Ens, Fs,. -;:;· z '"'1 > 0 rn 64568 Pigeonite 0.5 NF 56 NF 39 1 2 2 (') > Wos En16 Fs,6 "' > 64569 Pigeonite 0.4 NF 57 NF 19 tr. 21 4 "'"'1 0 Wo6 En16 Fs,s "C 64575 Orthopyroxene 0.2 NF 47 43 NF 6 3 2 '-<=- .... W o, En1, Fs2• "'t") "' 64815 Orthopyroxene 0.15 NF 55 34 NF NF 9 2 0 Wo. Enn Fs24 a 64816 Pigeonite 0.4 NF 59 NF 34 NF 4 2 rn '-< Wo6 En10 Fs,s "'l'C 65015 Pigeonite 0.4 NF 61 NF 29 6 1 3 s W 06 Enos FS29 -°'Vt 1973LPSC....4..613S both four to A studied, cium 616 typical were rocks oikocrysts section. (Fig. feldspathic abundant is separate and are 64575 small a be Oikocrysts Abundant The slightly rare slight and © samples pyroxene an 2). somewhat contain like Lunar of number pigeonite overgrowth. In morphology chadacryst olivine areas chadacrysts resorbtion. curvature 65015 discontinuously 61156, basalts rounded Fig. and chadacrysts are irregularly enclose oikocryst of of 1. in Planetary has longer Photomicrograph was dominated the the two pyroxene such phase of with Some nearly of In feldspar are the oikocrysts the (Table 70-90% all than feldspar as is Institute dominant euhedral radii shaped make as comers of encloses samples equant 68415 equant which by is the the 1). grains of C. ilmenite. of of up orthopyroxene have Augite low chadacrysts equant • olivine 63556. curvature H. (Warner and of feldspar the Provided rectangular but oikocryst as the extinguish SIMONDS form calcium feldspar well much anhedral thin (a) one, orthopyroxene oikocrysts The oikocrysts. grains Crossed a defined by tablets et section of the et continuous as corners in pyroxene the varies grains al., al. 0.001-0.005 crystals together 50% seven oikocrysts oikocrysts. with and polarizers, NASA 1973). rectangular less occur area. 0.3-0.5 of are In from of smoothly samples, than Astrophysics oikocrysts oikocrysts the whereas sample network the similar in (b) in Of rock are mm. oikocrysts. uncrossed. 0.04 60315 cross-polarized mm The feldspar 13 shapes; continuous orthopyroxene curving to 60315 The long to mm 64567 poikolitic typical enclosing as if and in those Data rock long. tablet chadacrysts all (Fig. these 63359, the the and System The poikilitic outlines, low found (Fig. Augite in augite augite la, rocks shape many 64569 most tend light thin cal- but b). 3). in in 1973LPSC....4..613S

have

round variation,

chadacrysts

categories:

grains length-width nifi.cation

This sequence

may

©

sequence

indicate

dominantly

with

Lunar

chadacrysts

samples

of

and

length

equant

Fig.

of

and

ratios

shapes

the

estimates

an

does

2.

Planetary

Photomicrograph

intermediate

tabular-shaped

have

amount

to

between

grains

in

is not

width

64815

found

been

Petrology

correlate

Institute

of

with

of

ratios

the 2:

examined

are

to

undercooling

1 length

64815 65015

64816 60315,63558 63556 61569 64568 64569 64567

64575 61568,63547

of

length

percentage

and

exist

of

61156.

of

feldspars

apparently

to

Provided

Apollo

over

5 :

any

least

most

to

using

to

in

(a)

1.

width

16

These

other unpolarized

Crossed

5 :

width

equant

equant

by

poikilitic

prior

with

1,

of

this

the

due

ratio.

and

measured

chadacrysts

estimates

polarizers,

ratios

NASA

criteria:

large

to

to

an

rocks

In

plagioclase

reflected

metamorphism.

intermediate

an

Astrophysics

of

length-width

(b)

attempt

parameter;

are

less

uncrossed.

were

listed

light

than

nucleation.

to

Data

made

category

at

in

quantify

2:

ratios.

however,

450X

Table

63558

System

1,

in

tabular

three

mag-

with

2.

The

this

The

has

617

A

it 1973LPSC....4..613S 618 feldspar greater tation. these and the © Fig. in measurements Lunar Such length the chadacrysts tablets 3. Photomicrographs undercooling, and preferred to width Planetary to be ratios may is (a) orientation viewed that 64815, and Institute have the of only curvature feldspar (b) greater along a 64575, C. strong a • might H. Provided single chadacrysts of their (c) SIMONDS the grain but 63558, allow thin length edges boundaries. by undetected et (d) in the section an al. five 64569, to NASA or anomalously width samples faces. Feldspar (e) of pattern Astrophysics 64567. each sample ratio. showing is the large of One darkest the pref Data proportion difference problem is erred phase. System available, orien- with of 1973LPSC....4..613S

trated

nite, by oikocryst show

tum cavities. patches portions f armalcolite continuous have analyze Most before mesostasis.

0.02 shaped

unlined

of

are

subrounded

maskelinite recognizable

eldspathic

olivine.

a

The

Two

Relics

much

mm

©

lower

separated

grown

exsolution

or

of

near

Lunar

the

regions

and

pores

with

in

across

This of types

the

armalcolite,

region.

more

make

Both

which

0.1

highly

this

optical

is

inter-oikocryst

around with

In

grains

oikocrysts.

and

olivine

areas

rims

a

region

commonly

which

mm

64816

of

by

into

microprobe.

network

between

abundant.

shocked

Planetary

up

lamellae

a

pores the

f

Table

up

chert-like

beads

of

reflectivity only

eldspathic

are

one 5-30%

which

Sample

makes

is

grade

this

feldspar

to

feldspar

iron-nickel,

2. only

granular

side

60315 61568 61569 63547

64569

63556 63558 64567 64568 Petrology 64575 64815 64816 65015

0.015 small

are

surround

and

The

Institute

the

of

concentrated

of

Area

phase

Number

feldspar

Shock

of

region.

in

up

metallic

rutile.

of

Two

concentrated a

texture.

oikocrysts

unshocked

the

region

%

mm

more

size

up

amounts

than

few

the

10-30%

laths

of contains

of

in

inter-oikocryst

features

to

samples,

groups

to

chadacrysts

wide.

round

Small

Provided

from

Apollo

troilite,

crystals

microns

feldspar,

the

0.15

width

<2:1

Fe-Ni.

between

irregular

extend

Some

55

50

30

55

45

70 95

50

20 80 50

10

5

as

of

contain

of

feldspars

inter-oikocryst

Some

0.4

grains

mm

pores

16

ratio.

up

of

the discontinuous

range

in

by

material.

of

project.

60315

poikilitic

phosphates,

The

two

across

to

out

with

to

2:

across

the

which

the

rocks

the

the

vugs

1-5:

of

indicating

40

50

40 40

45 40

40

30

50

30

10 10 of

15

9%

abundant

5

high

ranges

or into

from

NASA

area.

oikocrysts.

inter-oikocryst

plagioclase

the

are

and

mm,

calcium

1

rocks

three

K20

and

In

(Fig.

and

may

are

Plagioclase

K

the

noted:

smaller

numerous

of

64816, rare

They

Astrophysics

and

>

regions

are

opaque

somewhat

region.

and

length

20

20

40

50

85

10

oikocrysts, K-bearing

5:

confined

indicate

lb).

that

remainder

5

5

0 5 0

5 5

feldspar,

phosphate

lamellae

1

polygonal

therefore

consist

unshocked

Most

as

relics

The

feldspar

contain

the

are

little

bands

The

cases

is

area:

bubbles

it

best

Data

ilmenite

have

solely

smaller

characterized

typically

olivine,

is

of

to

of

phases,

which

as

are

ilmenite

sub-ophitic

vugs

relics

a

difficult

oikocrysts

developed

within

System

angular

devitrified

the

the

feldspars

7%

complex

optically

concen-

formed

to

grains

plates

round

are

inter-

up

CaO.

ilme-

have

lath

and

the

the

619

or

to

to

to

in 1973LPSC....4..613S

0\ N 0

@ t""' = Table 3. Relics and FeO-MgO contents of mafic silicates. "'1= Relic Olivine Observed Lithic Partitioning Mean Silicate Q. = Sample Number Present Clast Types Kol-pyx Kaug-pyx FeO/FeO + MgO -"ti =l'C 60315 Present - 1.0 0.24 "'1 61588 Present? clast 4-10 mm across 1.2 - 0.25 '-<..... 61569 Not recognized One poikilitic clast with 1.4 1.0 0.24 sub 5 m grain size ::t."'= 63547 Present No recognizable lithic clasts 1.2 - 0.2 =l'C 63556 Present No recognizable lithic clasts 2.0 - 0.23 n • 63558 Abundant olivine One clast with lathy feldspar 1.9 1.0 0.16 ::i::: "ti "'1 granules of olivine and ilmenite 0 en>-< < uncertain origin s::: ....Q. 0 l'C 64567 None recognized One clast with one olivine grain 1.1 - 0.19 Q. and one plagioclase grain. One Cf.l C" '-< clast with submicron mafics and ..... 10 m plagioclase. The clast =-l'C r- z looks like a meta breccia. >rJ1 64568 One grain One mosaic plagioclase grain 1.2 1.03 0.22 > 64569 Abundant None recognized 1.2 1.03 0.2 > 69575 Abundant olivine None recognized 3.0 0.97 0.26 "'"'1 0 granules of "C uncertain origin '-<=- .... 64815 None recognized None recognized 1.2 - 0.26 "'t") "' 64816 Abundant One barred chondrule with 1.3 - 0.18 0 olivine and plagioclase a 65015 Present One clast with lath shaped - 1.09 0.28 rJ1 '-< plagioclase and olivine "' sl'C 1973LPSC....4..613S The inter-oikocryst lar possibly been mineral texture Mauro the yses 61156, 64567, 61156, aluminous, contact (Table with rocks, tic Note 65015, more coordinates. SiO2 TiO, Al,O3 CaO Na2O MnO MgO FeO P2Os K,O on Whole than the By others. © the abundance of engulfed feldspathic also the Lunar comparison mesostasis 4). and composition of highland between relics (1973a) "poikilitic" relic LSPET 60315 45.61 99.63 17.18 10.41 10.53 13.15 silica, Six .2 0.12 0.12 .6 0.39 0.56 .5 0.22 0.45 0.35 1.27 rock individual that Figure 68415, and and majority Figure pink and of by one area. the Planetary will olivine, major LSPET (1973a) of these 61156 rocks than 99.76 44.65 22.94 a 33 11.52 13.34 the 65015 9.6 0.64 0.11 7.75 rich 4 the spinels with or poikilitic other relict composition later shows 5 of A oikocrysts, but of lithic more the non-analyzed shows rocks basalts, few element from Reid anorthite the all Table LSPET olivine Institute (1973a) Petrology 62235 47.04 93 99.57 99.39 18.69 10.14 be are poikilitic Apollo 9.45 0.11 0.48 0.34 0.41 1.21 olivine poikilitic a fragments of modes WHOLE lithic shown plot unit have Apollo 4. et these also the and Composition grains analyses al. Hubbard • is of liquidus (1973) of 64567 and 21.62 45.69 fragments olivine 16 12.52 et 11.5 found is Provided the of 0.17 7.08 0.72 0.19 0.42 0.07 76315, rocks. Apollo (1972). meta-elastic estimates. RocK to al. all rocks poikilitic 16 and indicated virtually the a is chemistry have in available and breccia in quite chemically grains Hubbard a are 16 diagram 17 which The of CHEMISTRY plot 64815 (1973) 94 99.71 99.41 45.86 17.33 12.05 18 11.63 11.83 by et Rocks the sample, 0.26 .9 0.27 0.29 9.5 0.12 .7 0.52 0.47 1.7 poikilitic poikilitic substantial 17. are crystalline al. the available all rocks only variable inter-oikocryst near on Note are is in rocks, NASA noted whole of of 61156 derived a LSPET (1973b) Table 72435 one 45.76 19.23 11.72 non-poikilitic clearly rocks. and the rocks low the very 0.11 8.7 0.23 1.54 analyzed can that Astrophysics in are, and for olivine plagioclase-olivine of rock textural rocks, are K-KREEP be and fine 3. each with by (1973) 65015 Albee the et 45.6 larger 20.2 99.5 11.9 eight with plotted 9.5 0.3 0.1 0.3 9.9 0.3 believed is 1.4 A al. major grained Walker 64567 rocks area. listed large relics including the thin small differences few (1973b) LSPET 77135 and crystalline poikilitic 46.13 Data 99.67 11.03 18.01 12.63 0.3 9.11 0.53 0.13 0.28 1.54 exceptions element In or on 64567, are boulders. section. in basalt occur et to exceptions, more number addition low System the Fra al. Table Apollo the be LowK (1972) et basaltic Reid 99.17 48.89 17.81 10.94 NA (1972). NA 0.63 Mauro 9.69 9.34 0.42 60315, cotec- 1.45 K above relict. in al. rocks angu- at from anal- most rock The Fra the the 15 621 3. of of to 1973LPSC....4..613S 622 © plotted Fig. (Fo10Fa30). and Fig. Recent spinel-plagioclase Lunar measured 4. 5. Plot on Plot OLIVINE unpublished and liquidus Data on of of Planetary the compositions whole MOLE interpolated from NORMATIVE PYROXENE point cotectic diagram PERCENT OLIVINE rock LSPET experimental counted Institute point major of of compositions Walker (1973a, analyzed should C. modes element • SPIN H. Provided work et 1973b), SPIN SIMONDS SILICA be EL 0 SILICA of al. rocks 0 analysis of moved PLAGIOCLASE (1972) analyzed by EL unanalyzed Hubbard 0 (filled by 0 Walker et towards for the for al. POIKILITIC DEVITRIFIED BRECCIA BASALT ANORTHOSITIC circles). and the 0 NASA Apollo et 0 system D + unanalyzed poikilitic al. + indicates the + (1973), The interpolation feldspar Astrophysics 16 GLASS ANORTHITE silica-anorthite and rocks Albee that l APOLLO rocks. 17 comer 0. 6 17 16 t::,. + rocks. (open ... the et Data about al. is olivine- Data circles) olivine (1973). based System 5%. is 1973LPSC....4..613S average ratio abundance oxides, tic mined Mafic selected samples The Pyroxene rake © gives are Fig. is silicates Lunar mean explains of were outlined. about grains samples, 6. En100 randomly some of The and and analyzed molar iron-rich ranges 20% Olivine were Olivine Planetary the idea olivine and lower FeO/(FeO+ of selected discrepancy. analyzed relicts of compositions pyroxene 61568 data metal by Petrology were the Institute Enso than traversing and are range (Gooley 0 analyzed MINERAL compositions precipitated Fs50 and that 64815 plotted MgO), of • are Provided typically in Apollo calculated indicated a and et iron-magnesium number listed for CHEMISTRY al., on have fl 16 for pyroxenes. 64569 63558 by Ca, poikilitic Fig. 1973; by all 61569 many 0 overlapping on the for of available the Fe 6. Table NASA specific line the Pearce and more. rocks A • The on 64816 whole rake minimum ratios Astrophysics Mg 3, compositions. the grains. and The silicate is sample base in determined rock in all Simonds, oikocrysts of 77 these poikilitic available They 64575 64567 63547 each of ratio analysis Data 30 diagram. rocks. are thus System randomly 1973) rocks from in slightly but poikili- deter- most The and the the 623 1973LPSC....4..613S

This noted. the

olivine appears

624 tightly pyroxene,

The than

zoned ter

plagioclase

Feldspar

Iron-magnesium

widely

There

smaller,

most

feature

©

the

Fig.

The

with

Lunar

smaller

about

composition

to

7. rims.

is

iron-rich

yielding

with

have

cores

lying

Histograms

matrix

cores

is

no

and

matrix

1.0.

best

In

80

80

all

reacted

difference

64567

Planetary

64569

between

of

individual

2-4

feldspars.

values

maximum

developed

olivines

olivine

olivine

shown

partition

An of

An

An

mole

feldspar

with

MOLE

MOLE

MOLE

Institute

90

90

90

the

greater

Area

relics

in

was

in

in

percent

Ka-b

adjacent

rake

values

oikocrysts

in

the

%

composition

%

coefficients

%

Fig.

compositions

of

C.

compared

61569

vary

overlap

than

inter-oikocryst

H.

=

samples

6,

100

100

100

Provided

reported

(FeO~MgO)b

richer

SIMONDS

(

but

Fe~+

in

Fe-Ni

in

1.

in

although

composition

which

In

the

FeO

compositions

(An/An+

were

with

between

by

only

in

80

contrast

~gO 80

64568

et

metal

in

variation 64815

the

enstatitic

al.

the

Table

the

calculated

[J

rJ

one

area.

NASA

there

Ab)

)

An

An

GRAINS

CORES

MATRIX

FELDSPAR

reaction

a

to

most

plagioclase

is

the

MOLE

MOLE

for

over

low

form

90 3.

90

marked

In

is

is

Astrophysics

The

cores

OF

or

K1owCapyx-aug

a

no

FELDSPAR

several

magnesian

calcium

%

%

nearly

GRAINS

slightly

as:

more

RELIC

rim

forsterite

Ko1-1ocapyx

greater

with

of

100

100

is

relic

chadacrysts

a

fayalitic

samples, olivine

the

0.1

heavy

different

Data

pyroxene

grains

values

than

low

full

mm

values

component

System line.

and

range

wide.

calcium

that

olivine.

group

range

scat-

was

and

for

in 1973LPSC....4..613S in plagioclase have detect (oral rich all terns rocks round rock's proximate shown types: separated separate oikocrysts lipses are dimension. contains chadacrysts metamorphic than lathy ple olivine metamorphic Warner rocks Petrogenesis: section crystallization the hypothesis at each relic the The 61569 Five Three 64567 constant © relics than comm.) compositional typical plagioclase described but (Fig. Lunar and in equant in chemical Fourth most oikocrysts. rock; feldspars cores from poikilitic et grains; abundant the outline the and also hypotheses from each the of but al. Augite relics 3a). was the and pyroxene are unusual five chadacrysts' (0.2 within rock. rocks. reports poikilitic grains of 64567 have plagioclase, Three (1973) of basalts. Lunar the oikocryst The one Planetary presented above. six individual zoning and large the (Fig. examples have chemically an mm) in rocks chadacrysts Poikilitic plagioclase individual Sample olivine another each composition The ranges impact have 0.025 a hypotheses sided most average and that for feature Science 3e). relic and few and to Sample depart by Petrology Institute outlines sample the consists olivine is mm the the The and oikocrysts olivine by equant 64575 olivine, are grains percent similar generated plagioclase the convential by polygons pigeonite considered petrogenesis large 1.5 is UNUSUAL Bence margins subophitic across Conference. inter-oikocrysts' texture relics are feldspar shown substantially feldspar 61156 of • (generally the of of mm has oikocrysts. compositions of recognizable are Provided rarely of DISCUSSION to Apollo the grains feldspar spinel, (Fig. most strong several orthopyroxene and et and across. partial any in those is nearly varies characteristic has of olivine microprobe grains (Fig. al. interstitial to SPECIMENS Fig. noted chadacrysts 16 texture tablets 6). the chadacrysts of of sample of by pyroxene (1973) about be and We poikilitic of chadacrysts pattern from melt. 7. discrete 2). the from These The pyroxene, the unzoned. which strongest Plagioclase are and transitional in Most the rims, plagioclase (Fig. Sample suggested lithic NASA poikilitic up the 25) characteristic who olivine systematically The the spot pyroxene except to smaller rocks techniques, to data is oikocrysts of chadacrysts 6). were olivine 0.01-0.015 parts oikocrysts the of fragments. are chemical Astrophysics 0.08 only are concentrated suggest development to 64815 fractional This olivine, are suggest plagioclase oikocrysts chadacrysts spot high texture 65015 larger analyzed. between (Simonds enriched mm which feldspars. (Fig. unfused oikocrysts. smoothly grains variation has on that in which grade and of however, mm and 7). as and more are (0.05 the that their were Data are orthopyroxene An crystallization the in one do The the in materials textural between of in wide, feldspar Many of too relics. et 16 this 64815. completely are smaller are is curving alternative System 64815 mm). maximum basalts anorthite- terrestrial sodium. presented tabular 61569 the The al., mm poikilitic poikilitic between cores small to sample of Bence which other 2 Sam- 1973) rock pat- The The thin two is are the ap- the 625 are el- of of or a 1973LPSC....4..613S poikiloblasts were metamorphism 626 ing rock crystallization developed that the that rock, hypothesis. phases melting. extensively rock mineral 1973, ing lization temperature time precursor ene sorbed, and leaving liquid slowly rapid produced of of maining Thermal "The They the the The The Lack Fe/Mg occurred sanidinite nucleation lithic presented © the and 65015 plagioclase p. diffusion 60315, subsequently to Lunar previously to relic were pyroxene the was reason thermal and 25.) melt use most of the pyroxene history that the fragments. while or partitioning. During subophitic (a Their recrystallized melt substantial fragments and pushed sufficient growing completed the lithic formed in protolith to protolith pyroxene-olivine-plagioclase into occurred the poikilitic facies and probable was to by of for resorbing rock Planetary composition metamorphic history for and melted a nucleated pyroxene low the precipitated,• Albee reequilibration. fragments the minimum, sufficient poikiloblastic ahead metamorphosed melt The 60315." metamorphism grains. by texture. region olivine to Ca-pyroxene undercooling plus correlation rock) at by protolith regions Institute that melt metamorphic et hot with the most crystallization this of forming and al. previously solid between Thus to has melt growing were poikilitic on (Bence we most however, Evidence commented incipient term poikiloblast solid of (1973); C. point. initiate fine, grew, are the • undergone the propose H. rocks of was diffusion. a Provided The of abundantly of state did the components SIMONDS small below olivine-plagioclase euhedral at olivine. sample the et at and rock, bulk pyroxene they then partial rocks texture processes precipitated melting small the not for 3.93 al., were hypothesis which growth oikocrysts; plagioclase number is by (sic) the composition peritectic relatively quickly leaving high crystallize suggest et 1973, partial, b.y. The The a inter-oikocryst was 65015 the melting. plagioclase. al. peritectic originally suggests nucleated. of three grains. to by time NASA metamorphic they through growing (Albee, p. interstitial quickly involving of temperature emphasize few cooled "KREEP" that: was but spinel, 62.) however, point large high continued propose step the Less Astrophysics from The unfused cotectic that with extensive temperature a polymict the Gancarz, pyroxene temperature heated The growth a process pyroxene grains where glassy than some third very a few areas K-rich this abundant poikilitic their that temperatures melt it melt glass to relics line. reached 5% tens enveloped is hypothesis by olivine olivine Data limited with grow. agglutinate subsolidus the .... breccias metamorphic of a (Fig. pushed material and partial then impact held metaclastic During which of as K-bearing System remaining pyroxene permitted texture very We degrees, Chodos, Crystal- mineral 8). was and during pyrox- cooled partial melt- some infer were most is well that dur- was to was The this re- re- re- of in is a 1973LPSC....4..613S now like tallized maining reaches form the lowed that while smaller cooling initial in radiation veloped "patchy remains occurs. the The Poik:ilitic ::, a.. I- I- 0::: 0::: <( w w bulk w © poikilitic 60315 clear. Fig. tion plagioclase-olivine indicates viously and the peritectic Lunar the by settled decrease the amount through before two the when for 8. on the at growing pyroxene relatively cooling composition melt Hypothetical The or the the peritectic change for the and stage the textures where ejecta rocks I I I the formation 77135 the peritectic olivine is KREEP-like Planetary the top rapid in from pyroxene melt cooling in still residual the temperature of slow peritectic have rock" of blanket, melt cotectic cooling about time-temperature composition point. melt liquidous of in of have the a reaches Petrology continued Institute composition the melt. a motion, point. the history available surface compositional liquid described from phase 70% grains. poikilitic The compositions the been point initial melts, the that of may of For and • surrounding more remains reaches with the injection Provided cooling of Apollo is TIME It peritectic indicated. until observed texture diagram to the the melt lower due melt take is melt by feldspathic .... transport an associated it clear melt effectively 16 to reaches in the limit initial as Wager place is by from and pools are poikilitic Dotted a fractions the as to plagioclase starts the point. from peritectic initial material, in associated the at dikes be establishment the NASA change quick silica by the on terrestrial a line leaves expected (1961) compositions on ones the rocks point plagioclase-pyroxene-olivine For radiation the melt indicates peritectic into of the for liquidus Astrophysics chemical in temperature changes the or composition. initial ejecta with liquid melt where opposite at reaction when the plane cooler for igneous the rock. the composition. abundant of insulating in cooling melt of blanket. a impact slower composition, about melt the analyses normal are the basaltic material, side Dashed margin Data with compositions diagram. decrease composi- largely temperature The rocks. cooling of 50% into System melts. olivine liquid The heat crust line Ob- the (Fig. further texture of liquid or space crys- slow flow The The fol- the the 627 de- re- by to 4) 1973LPSC....4..613S from temperature that 628 tion Skaergaard diffusion quickly data are cooling magma poikilitic form unrecrystallized poikilitic pyroxene glassy therefore to plagioclase 66035,2 free feldspar at and of oikocryst Therefore Lofgren the with mineral Evidence crystallized metamorphosed. many sub-solidus width There A (4) (5) (2) (1) (3) terrestrial interpreted pyroxene-olivine-feldspar falls the the of © suggests experimental 650 from reasonable times breccias Lunar The Plagioclase, Plagioclase Flow All projecting crystallizes. poikilitic from Apollo is (Fig. and ratios. within at in texture? Metal-shreibersite (1973) rocks to favoring is grains are more assumed. the poikilitic a Intrusion melts 600°C relic rocks compatible melt. 450° lithic and as alignments larger crystallized 1300 9). that conditions, euhedral 12 plagioclase-pyroxene 14 This on the the which may Planetary refractory produced (Fig. lunar texture The plagioclase separate (Lofgren, (the question The for meta-breccias crystals. clasts. to of crystallization chadacrysts the the melt olivine, "poikilitic wall than rocks contrasts be is one 1100° alignment 7). known temperatures are breccias, tablet melt basis poikilitic, feldspar with the crystallization of was rock This Institute the Pyroxene month. produced melt. contain likely lines feldspar and is, (the These plagioclase than 1973) crystallization result of partial a grains shape fine chemistry" igneous with observation is what result peritectic. are spine!, C. the temperature tablets of (Warner, apparently (McKay protolith heated, similar the Since • and takes H. pores round pores, of the Provided mostly evidence only system is melting of tablets is are of SIMONDS of analyses smaller KREEP rocks coalescence an but equant origin. the the metal at of tablets melts place chadacrysts in range fibrous systematically then or field abundant and a near-liquidus 1972). the components. not euhedral is texture rocks hypothesis necessary by Fe-Ni-P irregularly took to few only et which range compatible with suggesting thermal phosphide plagioclase polygonal poikilitic in the pyroxene, Morrison, Experimental as composition slower in in al. temperatures were spherulites The less defined are NASA rock micrometers place size at to of recorded mineral tablets have expected noted large 61156, near-liquidus than as is bubbles history: up cooling cooling 64567 Astrophysics rocks shaped during The temperatures. plagioclase similar equivalent more were that above. reaction) 1971; to chadacrysts a size been with melts in a and in at month selective in (Gooley in crystallization few are the partial recognized first a as in to least rate anorthite-rich the flow of across, cavities, Chao the excess its Wager poikilitic a to non-tectonically cool a compatible (Simonds, the microns the poikilitic range a Data rocks, the bulk melt. silicates) temperatures. the to to if grains a in rapid melting bulk pores et et much centimeter, continuous removal isothermal obtain of phosphide a and typical suggested System composi- generally shape al., al., of partially that in soils clast drop across. typical of length in rocks inter- more 1973) relict 1973) 1971) from than only dur- and the the the for of of or in of in 1973LPSC....4..613S feldspars tion are olivine imagine largely ing is high reaction amount olivine. ditions indicated tic with expected plete tures smaller cients, not (6) (8) (7) point. much which © grade of nearly Fig. experimental within Lunar detectably The Many High comparison of than crystalline relic olivine of These with a 9. wider for appear by heating The the zoning way metamorphosed oikocrysts isothermal Photomicrograph CaAl-NaSi temperature and compositions FeO/FeO 100°C pyroxene melt melt less overgrowth partially grains. to than Planetary to than is rimmed to produce materials. anorthite crystallization. with of data have slight, those form of crystallization the for Apollo + Diffusion oikocrysts resorbed exchange Petrology the MgO Institute are crystallization pyroxene equilibrated of and olivine-pyroxene-plagioclase low observed only is Crossed breccias of this flow data rich not not partitioning augite calcium shows a reaction foliated of • feldspars of few available of to olivines 14 polarizers, in Provided contain and Apollo from Huebner iron be by feldspar samples. at around percent with no pyroxene chadacrysts olivine Warner expected the of and and Apollo 16 preferred appear between these the (b) by are olivine-pyroxene-plagioclase for what the poikilitic uncrossed. an (Misener, the and Relict magnesium change texture high are fused. the surrounding (1972) orthopyroxene NASA 14 appear at in in to Ross almost and necessary rocks indicating a the compositions olivine. olivine be clast in Only during for Astrophysics peritectic. low (1972) 1972) En/Fs, the to peritectic phases. in relict is universally be in the calcium breccia feldspar. result much therefore recrystallization more the partitioning indicates partially and plagioclase rims core Although poikilitic It Data relative 66035,2. of more (1200°C). is extreme pyroxenes is of These zoned. incomplete in compatible difficult System preserva- the resorbed tempera- 60315 rapid peritec- (a) to coeffi- in rocks relict · com- rims con- The the the 629 of to in is is 1973LPSC....4..613S 630 feldspar poikilitic growth plagioclase pyroxene between residium, with by ahead concentrated rock fewer, plagioclase poikilitic logical lack recrystallization rocks. poikilitic all ene-olivine of comparatively developed could Apollo the and of cluded sufficient these melting unusual equal points large, large Apollo (9) the 64567-This 61569-The 64575-Oikocrysts (11) (10) 61156--The (12) individual the © of the and basalts probability of be Lunar The Confinement consequence should pyroxene. larger, to of 16 including sufficient All The The basalts samples pyroxenes rather relics, the model. the melt rich texture pigeonite grains rocks, are due pyroxene be 16 rocks. oikocrysts crystallization poikilitic peritectic. rocks and growing melt Apollo Apollo poikilitic in crystallized oikocrysts not and in oikocrysts remaining more to also small equant olivine the which, pyroxene with Planetary phosphate rock may seems maintaining described the to a All origin silica of continuous. anorthosites with have inter-oikocryst is larger in of of is equant compositions range reaching 16 rocks extremely resorb pyroxene higher 16 of has indicate This also more otherwise of the rocks feldspar melt crystallization, unlikely oikocrysts along to for small poikilitic the at Institute been rocks have is this melts poorly was oikocrysts relics, than react the and in noted. plot textural-compositional the above. chadacrysts compatible likely some other melting plot normative rock only with the amounts This plagioclase-olivine-pyroxene small substantially melted. a potassium, interface poikilitic were to C. refractory chadacrysts. usual (Delano near are with continued pores fine-grained • developed in produce rocks H. olivines are same to Apollo The near Provided region are about some rock a enough points, SIMONDS permit basically melted, the form the small the initial and smaller It initial of the temperature with have mineralogy. are into rocks et is olivine-plagioclase is olivine. largest olivine by 16 cataclastic 50% is but the oxide because low by only al., rapid portion the different olivine-plagioclase assumed also to more olivine et the compatible The temperature the the crystalline poikilitic the rocks. melt temperature strong the are al. produce allow a than melting 1973; plagioclase-low most liquid final inter-oikocryst NASA a growth known observed large minerals. temperature grains, The of rarely lowest relation small only crystallization. of for oik:ocrysts these compositions. material correlation However, during anorthosites Warner f that the eldspathic simple at Astrophysics extremely oikocrysts point rocks a most those rocks with of as able percentage relatively are the drop; range melting all phases in drop is pyroxene. The FUR peritectic impact. cotectic. phases poikilitic to to with apparently any in explanation slower compositions et compositions olivine-pyroxene- decrease. show due, the cotectic crystallize grow region. for compositions of good and al., calcium which rocks, of lathy combined poikilitic (LSPET, Data to points lower texture small The Slightly restriction all to in all 1973). evidence be of cooling. the around Solid Solid for agreement the System rocks Apollo part, feldspars The analyzed triggered engulfed the are line growing number melting pushed poorly- growth of for pyrox- region with and Since rock, 1973) more state have state have melt total with con- to is any and the the of of of 16 is a a a 1973LPSC....4..613S effects. The rapid unshocked Nature could Moore, those pyroxene feldspar generated to was pattern polymict precipitated. centimeters and metal. olivine liquid grains KREEP melted melt Albee Chao Bence authors 146. by Aeronautics Acknowledgments-A 65015 Apollo Suppl. 16 the the The The the volume (abstract). © sufficiently E. with A. A. Universities cooling be for available Lunar point (C.H.S.) As may (abstract). was C. of protolith of of 2, basic E., L., abundance 11 1972). composition grains. released breccias. T., complete Vol. that yet the partial heat and and Papike protolith all Gancarz feldspars resorbed, grow of and Boreman where across In After than the thesis was highland 1, Space 12 melt composition. gas The loss Lunar Space In pp. to Planetary fluid The J. microbreccias. is abundance a melt from easily A. J., normal Lunar The Visiting represented react portion 797-816. believed olivine+ cooled a Administration. pyroxene of was of variety and J. Sueno J., Research poikilitic indicates the Science-N, temperature for and A., bubbles with and this high types, soil Science-N, established and Petrology with for Institute pyroxene and the Post-doctoral of S., the through Chodos MIT large paper rich an degree The the of and melt to Desbough Association of engulf In flow coalescence texture melting, olivine but texture abundant Press. suggest be that by lithic Proc. more research Delano in poikilitic amounts pp. This of A. • reacted is CONCLUSIONS a it the the alignment solar drop Provided REFERENCES grains of pp. Apollo A. 60--62. gas that the other and Second is paper Fellow G. refractory is to clast partial J. peritectic (1973) pores, is 24-26. under is also that reported W. a A. rich protolith wind of form the the liquid. indicated exclusively grew, The predictable 16 to of composition constitutes phases. (1973) (1971) of at Lunar by a types Sanidinite Contract the the poikilitic remaining The poikilitic and form melting, euhedral the is few Lunar bubbles of components the pyroxene. in only Pyroxene surrounding protolith The The Lunar one Lunar temperature olivine Sci. polymict some NASA this was tens and pyroxene by Science No. petrology Lunar rocks metamorphism Conf., a diversity with paper at result Science associated Science rocks few to feldspar the polymict. NSR presence is melts' Astrophysics of precipitated poikiloblastic and temperatures Therefore form Science was not the Institute, degrees, Geochim. complete soil ( percent was 09-051-001 data of of plagioclase. the Institute form and Institute, could only composition gas-rich greatest shocked of or crystallization done pores and early Institute from of with of relic feldspar. glassy from Houston. the Cosmochim. Data of rocks Apollo produce a which while olivine with the shocked lack feldspar Houston. up and precipitated slow in the Gibson most the lithic soil amount System Contribution an from the pyroxene excess breccias. The to one is unshocked of 16 gas low impact operated moved As National and/or steady grains easily a Sample types these relict Apollo of melt Acta, that of few and and and the 631 K- the of of a 1973LPSC....4..613S 632 Wager Simonds LSPET Pearce McKay Delano Huebner Wilshire Warner Warner Walker Simonds Gooley Gibson Lofgren LSPET Reid Hubbard Phinney Misener Institute, of (abstract). from rake samples (1973) in MIT Skaergaard Apollo 516-520. ples from of of MIT samples. soils. soil. Houston. Houston. Cosmochim. Lunar poikilitic rock three lunar A. © from In L. samples. Press. Press. J. G. D., E. J. R., Apollo In (Lunar M., J. D. Apollo (Lunar Lunar D. W. Lunar G. C.H., H. J. C. Sci. N. 14 types W., L., Proc. Proc. L., R. K. W. Apollo from breccias. Longhi J., S. S. Brett Huston. Trans. Warner C., E., H. G. J., Apollo site. In Simonds and and rocks Conf., Bence (1961) instrusion. and 1972. (1972) and and Sample (1973) Warner rock Acta, Rhodes Warner 17 at and 1973. Sample Lunar 16 Third Third Apollo Proc. P.R., Ross Moore U.S.G.S. Spur (76055 15 J., Morrison Am. Simonds Jackson (abstract). Interdiffusion from J. Planetary 16. types: A. Amer. Geochim. A Metamorphism soils. and Suppl. An Sintering L., Ridley Lunar C.H., Lunar Fourth Preliminary Science-III, and J. Crater. M. J. J. E., note Geophys. Science Preliminary 17. G. Apollo Geol. experimental L., and Hays M., L., (1972) The Papike J. Prof. Meteoritics Warner J. Science. W. E. C. D. 3, and Phinney Simonds on Sci. Gast Sci. 77135). of Lunar In In Cosmochim. Institute D. J. Vol. H., and Mag. role (1972) A., 179, 16 W. the Phinney Phase Sci. Paper Apollo F. Conf., studies Union Conf. Lunar (1972) P. Examination (abstract). (1973) J. hot (1971) I., of (1972) 1, In of J., Examination pp. origin 23-34. 98, W. 273, W., Sci. L. Trans. Inorganic C.H., and plagioclase pp. study relations C. 1, pressing Apollo press. and 185, Geochim. Geochim. (1973) 15 410-412. C., in 353-366. 54, • W. Petrology Bansal Science-IV, Magnetic 395-415. Conf., 428-439. Lunar Experimental H. Brown 623-644. Provided Lunar the of Cameron Acta. and C. and 358. 26 Am. of In SIMONDS system ophitic Crystallization 14 (1973a) Team) pp. gas Lunar plagioclase Gooley of in B. Lofgren Geochim. breccias. R. The in Samples, breccias. Geophys. Cosmochim. Team) In Cosmochim. lunar Fra M., and release properties MIT non-mare W. press. by K. Fe Lunar texture (1973a) Science-IV, Petrology Mauro et Shih pp. R. (1972) stratigraphy petrology and (1973) the 2 Press. G. SiO al. (1973b) (1973) lour. pp. Cosmochim. and Proc. crystal Union. 172-179. E., NASA terrestrial C. 4 Science -M~SiO4. history Preliminary and composition Major and in 149-153. Acta, Petrology Y., thermal Acta, (1972) Geophys. and Mineralogy the Third Preliminary and highland Waeisman mode In morphology. Astrophysics pp. of Suppl. element genesis The of chilled Institute, Suppl. origin Classification press. pyroxenes the The analysis 676-678. Lunar Acta. metal Carnegie of of examination Res. Lunar glass Fra rock 3, the Lunar formation of of and 3, composition olivine H., Vol. In particles examination Sci. Fra two Mauro 2-4 16, Vol. Houston. of types. and In The mode press. at Inst. and Data Science Science 2, Apollo Mauro 5658-5669. mm Conf., "igneous" press. one and the 1. Lunar pp. Nyquist Yearbook of Formation of of Proc. pp. System in soil atmosphere distribution lithification 2029-2040. lunar formation Apollo of Apollo rocks Geochim. 14 Institute, Institute, 797-817. of Science fraction glasses Fourth and of rocks L. lunar sam- and the 71, E. 16 15 16 at