JSC-08559

NASA TECIiMCAL IMEhdORAwDUM NASA TIIEI X-58108 February 1974

THE MENDELEEV CRATER CHAIN:

A DESCRIPTION AND DISCUSSION OF ORIGIN

NATIONAL AERONAUTICS AND SPACE ADMINISTRAmdN

LYNDON B. JOHNSON SPACE CENTER

HOUSTON, TEXAS 77058

https://ntrs.nasa.gov/search.jsp?R=19740010379 2020-05-17T03:37:47+00:00Z

NASA TM X-58108

THE MENDELEEV CRATER CHAIN:

A DESCRIPTION AND DISCUSSION OF ORIGIN

Dean Eppler Lockheed Electronics Company, Inc.

Houston, Texas 77058

Grant Heiken

Hodston, Texas 77058 Lyndon B. Johnson Space Center

THE M E N D E W CRATER CHAIN:

A D3SCRIPTiON AND DISCUSSION OF OFUGIN

By Dean Eppler' and G r a n t Heiken Lyndon B. Johnson Space Center

SUMMARY

The Mendeleev c r a t e r chain formed on a l i n e a r weakness i n t h e l u n a r c rus t t h a t may have or iginated before the formation of Mendeleev Crater. l i n e s of evidence seem t o ind ica te an endogenetic or ig in : t h e symmetrical dmbbel l pa t te rn , and t h e lack of a "bird's foot" pa t t e rn and other morphological fea tures of secondary impact craters. may be t h e result of an explosive volcanic event taking place along a f a u l t subjected t o d i f f e r ing degrees of stress.

Several t h e l i n e a r t rend,

The dumbbell pa t te rn

INTRODUCTION

This study was based on photographs f r o a Lunar Orbiter I and panoramic and metric mapping cameras car r ied on t h e Apollo 16 command module. long c r a t e r chain w a s se lec ted f o r study because of i t s well-developed dumbbell shape and i ts s t ra ightness . o r ig in of t h e chain and any possible re la t ionships t o Mendeleev Crater and luna r tec tonic pa t te rns . Crater Chains 1.

A 113-kilometer-

The object ive of t h e study was t o determine t h e

This work w a s performed under NASA pro jec t S-255 (Lunar

GEOLOGY OF rm MENDELEEV CRATER AREA

Mendeleev Creter, 274 by 380 kilometers, i s located i n t h e lunar highlands a t longitude 1 4 1 O E , l a t i t u d e 7' N. numerous c r a t e r s i n a l l s tages of degradation ( f i g . 1).

The surrounding t e r r a i n is composed of

The c r a t e r f loor i s p a r t l y f i l l e d with material t h a t m a y have been pa r t ly melted during the impact event. Within t h e c r a t e r , t he re i s a var ia t ion in topography from smooth, marelike t o hummoclqr t o mountainous. co~forms t o t h a t proposed by Beds ( r e f . 1) i n a hypothesis f o r large-scale i q a c t s i n to a th i ck c rus t .

This var ia t ion

%ockheed Electronics Company, Inc. , Houston, Tex.

The western w a l l of Mendeleev has well-developed slump s t ruc tu res . s ive smooth slump deposi ts w i t h low c ra t e r density occurring along t h i s f l oo r / w a l l contact ind ica te some recent slumping. These,deposits p a r t l y embay one 20-kilometer c r a t e r and contain f resh , light-haloed impact c r a t e r s i e s s than 330 meters i n diameter. Slumping of t he other walls does not appear as w e l l developed o r as recent as t h a t of t he western w a l l . This d i f fe rence may be because of the masking e f f e c t s of e j e c t a from the c r a t e r Schuster, wnich breaches the eas te rn w a l l of Mendeleev.

Exten-

DESCRIPTION OF THE CHAIN

The 113-kilometer-long Mendeleev chain has a dumbball shape with one o r Crater more l a rge c r a t e r s a t t h e ends, joined by a l i n e of smaller c ra t e r s .

r i m s are general ly low o r absent, except where influenced by va r i a t ions in pre-crater-chain topography. The inner walls of most c r a t e r s are smooth. The craters are bowl shaped except f o r several smaller c r a t e r s t h a t are conical because of mass wastin4 off t he c r a t e r w a l l s . covers t he inner w a l l . and masks any s t ruc tu re o r layer ing t h a t might be present . There are no v i s i b l e blocks i n the c ra t e r s o r on t h e surrounding f loo r of Mendeleev ( f i g . 21.

A Xne-grained r ego i i th probably

The chain, trending N 25' E , i s o f f se t l a t e r a l l y 3.6 kilometers between Craters rmge i n diameter from 1 . 2 t o c r a t e r s 18 and 19 ( f i g s . 3 and 4) .

9 . 3 kilometers, with t h e l a rges t number occurring i n the 2- t o 3-kilometer range ( t a b l e I ) .

Superposit ional re la t ionships and c r a t e r dens i t ies ind ica te t h a t t h e c r a t e r

Lack of overla?ping deposi ts chain i n Mendeleev i s younger than t h e features t h a t surround it and probably represents t h e youngest event on the c r a t e r f loor . within individual c r a t e r groups and between adjacent c r a t e r s and t h e near ly iden t i ca l s t a t e of degradation within the chain ind ica te t h a t all the c r a t e r s may have formed contemporaneously.

Approximately 150 kilgmeters southwest of Mendeleev Crater i s another s t r a i g h t , dumbbell-shaped chain o f c r a t e r s t h a t i s 177 kilometers long. This chain t rends N 45' W across the center of a degraded, subdued c r a t e r approxi- mately 180 kilometers i n diameter.

DISCUSSION OF O R I G I N

The Mendeleev chain appears t o represent a volcanic event t h a t occurred some time after the c ra te r ing event which produced Mendeleev Crater. several olservat ions t h a t support t h i s theory. The primary evidence f o r endo- genet ic o r ig in i s t h e symmetrical dumbbell a r d the extreme l i n e a r t rend , which i s more pronounced than would be expected f o r secondary impact c r a t e r s . i n t e r i o r s of t h e c ra t e r s appear t o be mantled with fine-grained regol i th t h a t could be in te rpre ted as e j e c t a from an explosive volcanic event. Similar

There a r e

The

deposits observed around the margins of several craters within the chain give tne area a smooth, mantled appearance. f r m the crater margins.

These deposits are not visible away

Another argument against secondary origin is lack of the characterist ic "bird's-foot" Fattern and other morphologicel features of secondary craters ( ref . 2). Also, there i s nc fresh, nearby impact large enough t o produce a chain of secondaries of this magnitude. i s further evidence of a nonimpact origin.

The lack of additional secondary chains

The l inear weakness along which the Mendeleev chain developed may have been E. fault that w a s par t of the "lmar grid system" (ref. 3). trend of the chain, which i s neither radial nor concentric t o Mendeleev, is the test evidence for this observation. No structure that is both straight and non- radial t o the center of h p a c t appears t o be associated with the cratering proc- esses. impact that formed Mendeleev, thus emphasizing that the chain i s not contempo- reneous with Mendeleev.

The northeastern

The age of the chain is younger than the structures associated with the

The reason for the dumbbell shape is unresolved. The formetion of cmtral upl i f t pu l l s material away from the flanks of the crater toward the center (ref. 4). This process would lead t o tensional stress in t he rock around the edge of the crater f loor and compression i n the central upl i f t . asymmetric orientation of the preexisting fault with respect t o t h e center of cratering, the fault would be subdected t o differing degrees of stress. a subsequent episode of explosive volcanism, the result ing different ia l s t ra in mey have produced varying resistance t o magma invasion along the fault and produced the crater s ize patterns observed.

Because of the

During

c0ncLus10lvs

Relative ages determined by comparing the degree of degradation of craters in the Mendeleev crater chain with that of Mendeleev Crater indicate t h a t the chain is younger. It mey have formed on a l inear weakness in the lunar crust that originated before the formation of Mendeleev Crater. symmetrical dumbbell pattern, and the lack of a "bird's foot" pattern and other morphological features of secondary impact craters imlicate an endogene5ic origin. occurred along a fault which has been different ia l ly stressed.

The l inear t rend , the

The dumbbell pattern m v be the result of a volcanic event t ha t

Lyndon B. Johnson Space Center national Aeronautics and Space Administration

Houston, Texas, February 4, 1974 646-03-01-00-72

3

1. Beds, C. S . : Crustal Thickness and the Forms of Impact Craters. J. Geophys. Res., vol. 76, no. 23, 1971, ppe 558605595.

2 . Oberbeck, V. R . ; and Morrison, R. E.: The Secondary Crater Herringbone Pattern. Science Conference (Houston, Tex.?, Mar. 5-8, 1973), pp. 570-571.

Lunar Science IV (Abs. of papers presented at the Fourth Lunar

3. Short, Io. M.: Planetary Geology. Prentice-Hall, 1974.

4. Howard, Keith A.; Offield, T e r r y W . ; and Wilshire, H. G . : Structure of Sierra Madera, Texas, as a Guide t o Central Peaks of Lunar Craters. Soc. Am. Bull., vol. 83, no. 9, Sept. 1972, pp. 2795-2808.

Geol.

4

Crater n u b e r -

1

2

3

L

5

6

1

e 9

10

11

12

1 3

l b

15

16

18

19

20

21

22

23

2b

25

-

Clreulu; bal-abaped

Circular; conical

Xrcular; bwl-shaped

Clrcuhr; bovl-ahaped

C l r c u L r ; bwl - sbped

Circular; bal-shaped

Clreular; bwl-shaped

C l r c u l a r ; bov1-shapd

1rrwu e l l i p t i c a l ; bowl-shaped

C i r e u l u ; bwl-nhapd

I r r w u subdued; bwl-shaped

Circular; bwl-shaped

C l r c u l u ; awl-shaped

C l r e u l u ; bowl-sbapd to conical

Clrcular; boul-shaped

Irrepllar mold; s teep sided; conical

Defaud olold; 501rl- n b p d t o modemtely COUlC.1

Clrcular; bowl-aha@

Truncated c l r cu la r ; bwl-shaped

Thin po l~gona l ; a h a l l a

Truncated circular. bwl-shaped

Irregular ovold; conical

3.2

L.0

h.6

3.2

2 .0

2.8

1.6

2.2

2.2

2.4

2.b

1.2

2.b

2.b

2.0

2.0

5.6

L.O

2.8

5 . 2

3.2

3.6

3.6

9.3

LOV

Lou 011 Y . s t m side; slop. uphil l l n to crater eJseta on eastern n l d e

LOV

Lou

llisb on ueatera aide; lw a

S m e - 6

remalnlng sldss

Lou

Lav to moderately steep; nrin v i t h local t-w

Lou

Lou t o m d e r r t e u r i a ; win v i t h lad w w a p w

very l W

Lav

Lov

Lor

Indls t lnct

Lw

Lou

Moderate t o hlgh

F l a p

llme

none

none

lone

lone

none

None

None

lone

-11; Ss l t I J rounded

lone

F la t

None

-11; f l a t

Sone

lone

lone

lone

lone

lone

lone

None

lone i none

c-ta

h y be a t r i p l e t v l th 3 d k ; h0Uev.r. wall betweem 2 .pd 3 l a .I)

'lant m e r o f doublet v i t h h; lw u8ll In betreen

b e M 3

lot p u t of 3 and h

hiab M rlm

doublet

h e dcpth M 7

W l e r than 6 but v i t h equivalent depth

ti. h e l e t v u l a t i o n duc to aubfloor structure

5- l l gh t p t c h n In in t e r io r -11 d w to =s nstlw

Decpcr than U; u. 1Ut p t c b e r trend ln to 12

ippara to slope Into 11; shrllonr than 11; some l l gb t p t c h e s

Streaks o f mass-uuted a t e r l a l from 13 and rlm o f l b

Shallower than 13

M n t l l n e u n t a related t o US wasting In walls

Dullower. mre bwl- shaped than 15

:oaleaced doublet next r l m unit; p t c h e s of lw crater denslty uni t a iould rim

Rim Msked because Crn- ter Is on s l o p of r l m m1t; posnlbly coalesced t r l p l r t

Long ax16 of omld pu- a l l r l t o l o w axis of chain

soar l i a r t o Dlam pmtches on lnner d l

ne.brr of t r i p l e t v ~ t h

9 u e M 22

23 and 2!4

S U O M 22

One Impact on rim. r i n Crater h u s c a l l o p d us l l r v i th s a e u . a vasting

5

Csm - fresh slvmp deposits with low crater density

Cc - impact craters Ccf - floor material of impact craters

Ccc - chain craters

Ec - impact crater

Ecf - crater floor; flat, high crater density

lcwm - crater wall of Mendeleev

Inn

Itm

- flooded floor ridge material; line denotes ridge crest

- terrace material; forms flat, highly cratered terraces in Inn

Imf - floor material of Mendeleev

Explanat ion

Csc - secondary craters

Csl - slide material from Inn; partly f i l ls some craters

Esm - slumped crater walls

Eeh - hummocky ejecta

IC - impact crater

lsrd - shallbw rimless collapse depress ions

N-

U 0 10

km

sm

Dm

- slump material; age tmcertaiti

- material of low, domal hills, age uncertain - 7 Ridge in Eeh unit

Fault; ball on downthrown side + Shallow trough1 ike rilles

€3 Crater rim - Contact

Figure 3.- Geologic map of a portion of Mendeleet- Crater, compiled from Ap0110 16 metric and panoramic photographs.

8

0 Fl

E 3

0

NASA-JSC 9