1980LPSC...11.2347C

Abstract-A

and transient used approximation

tures

ward

explosion

ameter

flap

a

final

transient

same

the

basalts,

ejecting

equivalent

material,

are

in must

crater. that

tional of

the

the

structural Grieve

to their

Cratering

geometry

The

craters

the

gravity

interpret

Imbrium

Z-model

rotates

3.0

excavation

apparent

to

of

excavation

be

and

diameter,

growth

excavation

shallow

for

associated

Thus,

©

for

impact

determined

calculate

reduced

mantle

crater

structural

moves

(1979)

outward-driven

craters.

Lunar

of

impacts.

transient

volume

independent

at

both

distinct

Lunar

Maxwell information

basin

all

flow

and

the

basin

crater.

for

depths

depth,

and

cavities,

the

material.

D1c,

sizes.

downward

by

explosion

and

rim

cavity

to

has theoretical

The

several

fields

is

above

flow

The

and

explosion

factors

by

from

rim

transient

stage

geology

have

but

melt

compatible

Down-driven

of

Planetary

Z-model of

and,

Consequently,

assuming

model

recently

Planetary

model

and

whose uplifts

the

was

imply

excavation

the

The

the

the

portions.

maximum

important

expansion

fields:

Proc.

and and

of in

of

about

and

transient

geometrically

depth

original

~700

depths

transient

craters

the

observed cratering

two

flow

flow

shapes

of

that

cratering

for

impact

Lunar impact

with

outward

Institute

ejecta

that

case

Institute,

Printed

to

re-emphasized

field

terrestrial

fields

km,

Ejected

comparison

of the

material,

thickness

both

depths

crater

Planet.

Steven

three,

and

the

excavation

ground

may

INTRODUCTION

crater

lunar

Implications

depend

of

the

craters,

flows.

crater.

paucity

is

or

in

lunar

deposits.

simple proportional

match flow

craters.

observed

to

therefore

volumes the

excavation

similar

attain

near

Sci.

•

structures,

respectively.

3303

of

basin

material

divides

form

stages

United

Provided

surface

including

on

Formation

field

excavation

Conj.

estimates

The

Kent

crust

of

and

one

2347

the

with

impact bowl-shaped

NASA

depths

diameters

hinge

excavation

(except

the

lunar

States

!Ith

originating of

in inferred

observed

of

excavation

effective

material

Such

originates

to

the

Considerable

experimental

impact

growth

excavation, from

walls

cavity

and

Croft

the

streamline

(1980),

a by

of

of

form

are

mantle

Road

In

of

central

of

structures

near

America

very

necessity

the

innermost

to

the

to

-IOX

for

lunar crater

a

similar

a

of

p.

in

the

and

the

cavities

craters,

is

of

depths-of-burst

data

embody

hinge

be

I,

NASA

2347-2378.

0.1

at

model

from

the

near

Z-model

the

materals

cavity

-0.

the

Houston,

"cone"

a

structural

non-zero

explosion

geometry, lunar

geologic

the

the

the

reasonable

well

hinge

transient

flow

to

and

I

excavation

about

the

an

rings.

about

D1c,

Astrophysics

are

final

diameter

local

of

the and

effort

formation

and

for

excavation

is

center

field

excavation flow

field

on

sample

radii,

of

inferred

a

which

important

or

Texas

or

depths-of-burst

necessary transient

units,

rim

values

one-half

the craters

are

crustal

shallow,

coherent

crater

the

field,

into

data

near

about

transient

first-order

has

of

cavity

of

ejection

uplift.

lunar

geometrically

the

77058

flow).

ejected

such

petrography

the

collection,

to

of

one streamline

from

cavity

and

and

thickness

gone

Data

one-third

the

crater

coherent

qualitative

exhibit

highly-shocked

surface

Z

basin

if

crater

projectile

as

predicted

between

displaces

the

This

depth

quantitative

angles,

model

impact

to

and

System

which

the

into

has

and

have

transient

diameter

obtain

propor-

implies

around

shapes

depths similar

down-

before

of

ejecta

of

maria

been

and

fea-

and and

the

has

for

the the

2.5

the

di-

by

an

of 1980LPSC...11.2347C 2348 numerical ical tering of indicated the field and A explosion formation 1967; cratering, flow cratering et is field 1980; modified Crater The by short tremely zone behind ejected comparatively impact. Briefly, heated in low-pressure, to complex lengthy by craters, A few discussed. The crater al., its crater excavation particles Bjork properties geology first fields simplified model are immediately high-pressure Orphal O'Keefe calculations short © calculations 1979; by cratering formation the from cratering Lunar the or Rarefactions high flow particle formation compared flow in two formation craters. simulation i.e., predicted the S. et are primary craters the duration. high is of set Roddy K. the et al. passage field and stages pressure fields. first of the derived stage large-deformation little and craters. analytical calculations Croft al., in flow crater pressure motions shock (1967) flow Planetary around in In are cratering model in carried described. motion phase, shock Ahrens, so by 1980) with material that occurs et explosions of the Third, have weak field In of extremely propagating stage. that the that al., is impact behind waves, and the following may contrast, to the field "shock occurring have to description Institute been phase flow a to may by there materials. 1980; actual specific flow is primary and under longer The 1978a; low explosion movement Kreyenhagen Cratering later help Second, an proposed and observations field yielded target the be modeled or the complex, field, levels, is modification are Orphal impact processed" inertial bridge craters. discussions, • the stages explosion cratering the from thought impacts characterized primary very Orphal, model predictions crater Provided shock. few and of cratering has low-pressure a systematics or "detaching" or flow late free to modified the or numerically of systematic et impact. points flow projectile for examined Last, been but ejection of The and describe explosion crater may al., flow by gap to shock 1977; in crater fields during surfaces the stage as often the the the of evaluate derivable preponderance flow described Schuster implications 1980; between of phase, the be depth Virtually by NASA form formation target general Bryan cratering in formation created contact occurs is materials limited divided the by conditions particle both aggregate phase an the and particle characterized that Austin quickly of of the Astrophysics and high-pressure expanding the primary the material from et (1977), are origin by properties Maxwell's impact ultimately during all is geologist between to by a process al., into (e.g., of physics applicability Maxwell (1977) movements based (e.g., modification movements characterized described et material the the of of features reduce the of of al., 1978; three shock particle among paths this earliest and fractured Austin lunar modified the Data region explosion Bjork on by in phenomena of of in 1980). (1977). produces phase, phase ultimately very explosion Thomsen (possibly) the pressures relatively cratering cratering the stages: System of from followed in samples others. motion during during stages of et et of crater stage. phys- detail field. Cra- large flow by flow al., al., and due but the ex- the for or a a a 1980LPSC...11.2347C other of crater. the coherent particles hypervelocity (1968) ward in and developed the the R for a the features described lead Z velocity all ground (Orphal, development hemispheric (Maxwell, sumption field that surface of ability depth times, problematical, applicable and ~ 2. measure 1.08 1. 3. The concave-upward = individual = Z-model cratering times near-surface nature cratering ground Seifert, Austin to the of The a/R Flow Particles 4 from and © below on projectile Z-model, Consequently, of particle and near plane a 6 a Lunar explosions, projectile's with of model in 2 1977). can a of where the radial , by of and the 1977), below at km/sec plane. near-surface of where to constant et the 1974; flow the growth constant flow the ground the cratering flow particle and very Gault increasing of and basis impact al. be follow the free nearly described paths despite of projectile explosions diameter Z ground velocity, they however, but ( stage, the Planetary (1980) Orphal, explicitly deposition The crater stage R early strength = impact surface. arcuate of EDOZ) momentum of et thus a, is that provides ground independent 3. craters paths final a will the flow assumption observations the al. its the which constant of and If of explosion radial times surface, surface, formation by are the (Op). 1977). Institute properties and R, (1968). of a be great the transient crater was near-surface radial paths fields vary of evaluated, A during Maxwell Z found and of plane stationary aluminum in application found of a they aluminum provided: distance. quantitative the the is Subsequent an generalized good has sand The utility. from particles Z-model Z and with not distance in can dimensions, Values ballistic • crater of inverted cratered flow can is called by impact are Provided dissipated. cavity in response of Z-model of first consistent incompressible. incompressibility and 2) in be Z an Thomsen relation be assumed and the streamlines on the Thomsen the explosions, field, the on = 1) deduced formation of of the others order average constructed. to from trajectories below (Orphal, clay, cratering description calculations 2 the development ejecta from flow clay quantitative model surface by Z laboratory. the represent excavation near is to and showed the for origin The to approximation derived with the and Z-model (Maxwell, to impact rarefactions field et numerical the NASA from the for the flap realistic et is Z Cratering be similar are al. effective depth 1977), the move found was applied the al. of determines ground vertical determine the final after constant, (Maxwell, of the that and A obtained, theory (1979) Astrophysics by carried from They so the stage, descriptions conservation (1979) and particle given qualitative to whole of Thomsen to with angle that impact computed crater. called the 1973, spallation the simulations flow flow impact the late three the propagating origin final plane found downward was to or particles expression out the by evolution respect investigated the of how fields effective flow empirical field a including enough 1977; observation, the motion 1977). Z-model, cratering Therefore, real assumptions: Data structures equivalent to ejection, Z-model Gault of flow is craters et that description flow much of individual change is below at flow, of given flow al. Maxwell System traveled of to at The or several field axis in energy during during down- center of (1980) et for paths fields near- some each early 2349 near later field time flow was a was was and the the al. the as- by of of to at R is to if a 1980LPSC...11.2347C 2350 flow deeper crater 2) flow increased tion constant concept Therefore, particle field of gested imply while model. of cept suspect. ejecta explosives. explosion diameter impacting projectile experimental alent impact pact cm in time flow Oberbeck cm diameters EDOZ plume sults field) Oberbeck's density away There the holding quartz a is long. © field field of of are fields and along velocity depth-of-burst imply between the from very that Lunar reached earliest plume that development into flow stationary The incompressibility of ratios. movements of embodied However, EDOZ could is S. for By as crater Z data sand throughout craters for a identical Thomsen (1971) when a nearly the streamlines the streamlines ~1.0 Oberbeck's also K. the that and constant fields at (1971) Z found impact and comparison, characteristics, explosions a stages and impact ~½ given observation These Croft dominant be early using parameter, large Planetary target. grows the the in evidence DP to Z in equal streamlines viewed in target in final because dry impact results, by the (EDOB) in fixed craters. depth dry and et in general. of in EDOB a, times, range crater a results the and space from depth. Thomsen al. is Both crater his constant cannot sand Z, projectile criteria to dimensions, Institute sand and qualitative subsurface in entire still explosion composition. still at the of (1979) one EDOZ that paper that crater of however, two volume in a particularly However, ~½ imply of impacts early viewpoints targets the and of for Oberbeck flow. energies, at is and valid. experimentally holds equivalent particular, be Z of impact an impact calculation, ways: still • varying Z, explosive to that ~70-90% bears subsurface is flow et diameter, Provided flow equivalent well Z time that Accordingly, effective EDOZ nearly craters spatial approximately as deformation after at a during The al. vary to the determines reasonable 1) fields an field craters nearly Austin craters ~2 explosion impact represented Holsapple determine (1971) values (1979) the imply depths-of-burst for cylindrical result which spherical smoothly equivalence show by final center features km/sec, when of flow may the despite EDOZ and probably deformation. the center implies craters determined the the produced produced et velocities, a lies forced may dimensions that NASA cratering Z field. significant be quantitative Z departure the (both al. flow is quantitative the same ejected the remained (1980) constant generally projectile between an of fixed near with significant by during of projectiles a (1980) explosive included that have shape Astrophysics EDOB's the unphysical fields oversimplified changes criterion. EDOZ flow a direct relation by a to one the at constant particle and volume. EDOB early-time flow used series It physical early find determine from aluminum implies differences ~1.0 for are nearly 0.5 near of same can projectile predictions diameter. increased crater target results approximation center differences to stage, EDOZ used of continuously that both the as most and of times, Holsapple's Dp, a be Data of movements move increase one impact The energy a, the constant constant; that equal meaning streamlines. the shown dimensions, to 0.63 impact were a 2 description theory of was like Z, System projectiles the hence EDOB generally projectile diameter. projectile projectile variation = Thus it until in assump- the the steadily may EDOZ energy craters is ± impact moved 1.0 equiv- as ~0.68 in ejecta in from con- flow sug- flow 0.02 a,Z and the the im- or, for the the for for DP re- be a, in of 1980LPSC...11.2347C et The vation. physical Z uplifts process freshly cratering These tion tering very etc.) final from diameter Z, sons: about as interchangeably. vention maximum explosion infer transient ejection 1 a drawn the relations moment 1978, position simple from ground with velocity. ranges. model) It al. the EDOZ :3 significance angles, is transient complex apparent from increasing the the have (1979), parabolic 1979b). I) spatial © flow suggested growing derived derived equal and formed Appendix surface suggested as of justification Lunar Ballistic velocities of the point Therefore, (Da) centered are crater flow. crater craters extension discussed geologic crater flow taken complex field a ejected Austin in available velocity relations, constant The crater phenomenon, and for crater of The crater from expressions are void Fig. center, transient of (e.g., range. field is that In ranges impact, formation. and A Planetary simple place. terms at by are the determined the ultimate evidence volumes, gives et and this for because terrestrial of a I at ~1.0 above, after is the may Dence laboratory field see in highest for Z, volumes al. Maxwell sums especially The the the the probably the Qualitative transient the are The (bowl-shaped) the paper, parallels crater but mathematical EDOZ (1980), DP large Institute Dence all be of transient ballistic center use describe final in and final utility of The ejection directly spirit et that beneath not cratering-related maximum expected ratio a near the impact their by of Ye, terrestrial lll. constant growing profile. however, by impact ranges temporal at apparent Oberbeck flow final slightly the crater et a between spirit of the • of of (1977). the ranges comparison presumably of distances Yu initial Provided cavity, al., flow primarily the velocities a proportional the da:Da any craters insights field apparent the incipient and first-order expressions craters of to craters depths Even of and crater. 1977; target flow Z-model larger field approximate impact a ranges of the Dence crater relations; yield apparent particles the on Vt (1971), first-order where ratio by transient particles over is though field. modifications indicated transient 1 a results it the spatial features Settle is are of decrease surface explosive of crater ~ 1 ~ :3. crater than coarse At provides are typically at of craters. (1973) :5 excavation, approximation. NASA half model centered the to and spatial for Craterinu the the This the passing simple and depth two the and the the of at ca\'ity relationships approximation, Figure transient the particle is center, to Holsapple model surface quantitative Astrophysics transient original crater in and with the increasingly 2) predictions the important usage flow approximate apparent apparent square in Head, apparent by 1:5 Fig. (da) most crater at (slumping, through studies nature. flow Dence are observed increasing 1 simplification of and (Pike, field and arbitrary streamlines, is and shows follows cavity I, to ground frequently the observations fields 1979), of craters defined To (1980) profile consider structural decay (the the radius Data radius their stages crater for of Only et the information impact with the 1977; understand large a the an Thomsen is lll. void rebound, apparent constant two constant System the they distance EDOZ. provide surface, ejection ballistic original of defined and impact rapidly spatial obser- as super- radius of (1977) of in Croft initial ejec- for used both con- 2351 of of cra- rea- rim the the the are the on of a a a 1980LPSC...11.2347C originate velocities, ranges ranges a The it initially hinge streamline surface ejecta; innermost through boundary streamlines 2352 hinge ...... C Cl. w Cl!: minimum C is apparent © 0.5 hinge 1.0 ence permanent Fig. perposed simple about Lunar particle are are particles particle near the I. along between S. monotonically in position and of large crater streamlines A final initial and (the which K. that the on the 1.0 scale the because, structural surface Planetary with a Croft a profile. clear due initially range the crater four particles flow parabolic position streamline drawing the of transient the to ejecta field shown rim Ye the (Ivanov, field; (heavy particles as their center Institute minimum decreasing. on of is 1:3.3 uplift, is of ejected uplifted 0.5 labeled the and streamlines streamlines flap seen the large that particles in ejected depth/diameter RADIAL whose final dashed and • 1976; Fig. hinge rotates initially in Provided extends final at initial craters. Y Ve original Fig. 1 Consequently, volume; a 2 of (horizontal final Killian particle given in initially lines range. passes Z a (Maxwell, DISTANCE/Ra below 2, far ranges, Fig. by 0 back ranges it = ratio Yu surface, surface in the from is 2.71 and This 1) is (stippled through hatched on the translated Fig. NASA transient defined to are there Maxwell Germain, are the 1977). streamlines particle hinge the between range 1) thrown which zone) Astrophysics zone) large crater the is represent cavity 0.5 EDOZ. as 2=2.71 Z-model The a streamlines by from is is the initial is surface due position the 1977). the out the the and center defined streamline hinge above the volume volume surface to The flow flow of a Data position a typical From high crater particle the fundamental whose field streamline. becomes here field uppermost System are differ- of 1.0 the crater particles ejection the su- passing 1:5 Fig. driven center of as to hinge with final the the the as 1, a 1980LPSC...11.2347C passing final The transient volume cavation As tions below of primarily that because ing by seen apparent uncovered seen, The the ...... :c t- C) :c w displacement seen simultaneously C the apparent -0.5 initial to implies of zone rim even structural Fig. excavation © 0.5 by fundamental through incompressibility of volume 0 Lunar no be in cavity. uplift crater. crater, 2. downward 0 the is space momentarily, during material position Fig. A significantly driven that as rim surface scale craters. and of indicated. The the 1, Ra, uplift. of cavity, bounded along Planetary all the the diagram along this division is ground target excavation of and because material defined and excavated modification transient 0.5 Therefore, Material streamlines the volume The during shallower de outward all steady illustrating Institute materials, above (with surface hinge structure of streamlines. in by (as ejected streamlines, the crater the the cavity of into or the axisymmetric following into seen by particle • hatched space the phase than uncovered flow cratering inside of the Provided 1.0 possible this the is the translation RADIUS/Ra during the is transient in formed field purely the an hinge is zone But of original volume Ra walls Fig. becomes Dence equal distinct complex by transient process, crater is into exception the is zone from crater the of 2) a ejected. rotation ejected. in and volume spatial transient HINGE excavation 1.5 of ground all ejected NASA part is CraterinK et depths from formation wall. floor also the space craters), material al. because Material crater is by of Astrophysics construct of indicated. POINT pushed Under apparent (1977), crater of both surface, excavation and central greater the is flow the cavity and below defined particles along the which originated volume down-driven into the hinge 2.0 transient who fields assumptions peak which even than a radius the and transient Data structural is streamlines streamline. into in recognized and ejected as important the materials are bounded the System Fig. is the the from crater. in of depth never mov- final 2 por- part 2.5 and 1 the 35 ex- is a 3 1980LPSC...11.2347C 2354 are Ejected and driven discontinuous the Fig. particles smaller ejected and duces Particles Down-driven material Down-driven 1960; 2: absent cross-section material relative consists along crater. stratigraphy. erable carried crater Excavation Particles between (Vu compressibility closely a surface. the placed Direct Prior Orderly 500 The entire reversed: original Gault, © Kieffer + 1 Stoffler implies ton Lunar streamlines to the Vt) material: in volume evidence Consequently, at within material ejected shearing later by spaced to immediately of streamlines are initially remain detonation, an cratered TNT S. various translates flow inverted the the 1979; Cavity a (1974) and ground K. primarily exceedingly and Comparison important Relative through small Particles et the portions flow of center particles of Planetary Crofi streamlines, explosion and inside for al., Settle, farther land in that material, distances Shape material area, and transient level stratigraphy into volume streamline the directly immediately the below 1975). vertical the of diverge thrown on the movement Roddy the secondary initially including shape of Institute 1980). experience the from at flow. thin crater crater top cone crater crater, of along AV, h ejecta the the the crater Particles radial of the transient into flow beyond of columns (1978) and layer of the Pre-cratering In flow, EDOZ material materials range denoted near • center with observed initially floor. and a the the the below Provided between particular, spatial shows field to crater intercept due structural drag that an are excavation streamlines interior ground retain the a in where the crater (peak blanket. flat to containing of predictions equivalent The the the from by thoroughly and nevertheless characteristics are shallower center, the crater hinge by ejection. flow, in floor neighboring their the hinge the fallout spatial the of the wall. "smeared of zero form rim this pre-shot ejecta volume shallow the the shaded zone NASA whole and center On streamlines and cavity unexcavated and uplift. and streamline, will (GZ). a Under volume, numbered stippled final positions layer particles. Material with fallout mixed. blankets the planets central to initially ballistic Astrophysics retains be of inner layers positions area is out" form are This streamlines, of apparent transient Figure field defined provided true the down-driven the field layer AV, thrown bounded face peak intersect to is the with of in will that This assumptions (e.g., marker direct deep the ejected paths data of illustrated line ejected the in is 3, continuous of which of Data crater the by (Roddy, lead original crater are Fig. pushed atmospheres, a reversal by particles the farther the marker cone Shoemaker, indicated stratigraphy Shoemaker particularly north-south by System and "cone" the cans to Snowball, otherwise 1), transient transient particles blankets (Schultz material the wall, consid- ground in down- moves which above direct 1976). of than were pro- cans Fig. and two are in- in of is 1980LPSC...11.2347C that represent points designate asymmetry, apparent cavity. the regular columns tions by either complex, profile ably tering slightly - - :::c: ..... B:i 0 5 E Less 10 Z a 11 post-shot 6 9 7 8 were SOUTH (from excavation ejecta; Fig. marker reflecting of 50 © flow in side of intervals Streamlines the asymmetric direct = Lunar 3. at crater the the especially cans recovered cans Jones, 2.71 Cross-section cans during marker cans. depths provide 40 the in final crater and cavity evidence complex never represented radius found situ flow observed 1976) from Cans Planetary apparent the considerably cans 30 profiles excavation evidence for and in after floor field. represented provide the recovered. of excavation of in the in Z late-stage is of ~41 Snowball by the surface excavation the predicted and the Institute 20 region = In shallower crater a open direct m ejecta 2.5, detonation. floor of central particular, walls, by cavity. are shallower circles target an The down measure stage. of is . solid by 10 • 2.71, modifications and shown RADIUS Provided also unexcavated blanket the the cavity than thus down-driven area data remained circles Open walls in Z-model. central and shown of a each 0 Marker showing for the than defining are number corresponds in by were in after circles 2.9 (m) comparison. situ excavation in the column, the from the in peak the 10 not passing recovered pre-shot central excavation cans Cratering NASA the Fig. Snowball points depths cone crater of designate Jones directly (see detonation, cans were 3. thus 20 Astrophysics well positions floor of 0 through cone The after cavity. Jones, below Though of flow (1976). cavity. crater gaps in shallow originally with cans and related cans the final 30 the of fields of the walls. The in 1976), Curves shot that the material. numbered are excavated Filled thus there Data central crater recovered the excavation material to in extremely final 40 measured Data predicted placed columns System are the presum- defining the NORTH is circles is 2355 some three posi- The also cra- on 50 at in in 1980LPSC...11.2347C 2356 oriented driven layers impact with by crater diameter sand by comminuted The shocked section are impact impact. in terials portions - .... :::c: LLI C 0.. Kilometer-sized E u Fig. deep thin characteristics © shallow going an layers fused Fig. from 0 5 Lunar are that by cone stratigraphy, craters of 4, apparent The layers and drilling of in 4. ~3.8 the the S. lined sand DLG in but from ...... may Cross-section and their the material. SAND SHOCKED pre-impact origin K. top remnants fused and flow grains" are km) is of Planetary with Croft be original three surface 420. that diameter provided respective fused, progressively GRAINS field represented of parallel simple sand is interpreted thinness, extremely layers consists the As underlain these stratigraphy. + are of model. to Institute FUSED grains. (pre-impact) 5 noted the relatively DLG have interior. terrestrial of also by to remnants of colored remnants and ~28 RADIAL those DLG highly by been as thin Hence 420 by by well Because • Deepest less down-driven position Provided Stoffler cm a the adapted The unshocked ejected. remnants predicted shocked thin separated 420, layers, near shocked impacts stratigraphic DLG (Stoffler the (exaggeratedly DISTANCE exposed must remnants grains layer an from 10 the et The by remnants as 420 and . implying al. the experimental ~1-~•:·.,·.:-:1-: lining of have point also for shaded of material Stoffler material breccia from thinned cone et in NASA (1975), the melt, are al., • down-driven the .. :-': appear of originated sequence of (cm) top are =t:-" layer other material. too l't is Astrophysics remnants remnants the . impact, a 1975). thick) ::-.·:. lens which the on (Robertson three al. inferred distinct ~- thin labeled , inner ... the !- ejected impact (1965). to floor 15 of ••••• layer Figure upraised in ,, to layers of of the have It near Brent ••• central wall "shocked ••• are turn be the to and mode red-yellow-blue • has Data Only PLAIN preserved crater and designated differentiated be top highly the and deep 4 of of .. rim. is walls Crater been •.• System is grains the the the three of displaced underlain cone •· and point a Grieve, in seated origin. down- cross- found shock crater of target sand (rim pre- ma- 20 the as of 1980LPSC...11.2347C layers tigraphic of point distance in terial were rates nature, shocked layers this been that suggest 1977; drilled closely layer tings meteoritic report notes bedrock bearing in conino layers: of material. is layer. radial Volumes position shock), of and The which existant model Drilling a situ not impact ejecta the crater. similar layered Grieve, total to reported originally of of 168 Grieve a movement © cannot precisely are position The the is apparent in is breccia layer glass and corresponds reconstruct sandstone, a layer, impact and Lunar silica layers was from for as markers, of similar only given to Thus similar the volume at imply fragments analogous iron excavation layers exact Barringer the monotonic fractured large target. 198 of plus Meteor 1977). finally et be and central (excluding flour, for in the lens in very are by of much at melted fragments al., known, shock made. to m improbably and deduced origin Planetary a lateral West meteorite impact of predicted the so Meteor point Eq. very below and the manner initial Robertson of reached. white less 1977; to highly Crater to positive to below closer portion (as bedrock question 3e pressure Meteor radial and However, decrease Hawk the as suggests be but the similar of and extent rim craters, quoted in ranges the and Institute Dence Crater by between down-driven nickel-iron analogous description shocked shocked impact spherules drill for which gives Appendix properties to uplift less extent The high identification present of Grieve fine Lake, (low and Crater the to marks the of attenutation of the holes of the and et fractured the there because evidence description • "silica those impact and the no point permits rocks Grieve excavation depths shock shock), Provided of material al., layers Canada, crater. silica decrease discussed crater to (highly et meteoritic (Shoemaker, in spherules A. correcting in fused the of of appears cone replacing in 1977). of al. of flour" Fig. the Accurate the Kieffer's pressures, either features shocked of flour (1977) at Fig. of for the sandstone impact. that uniform by Shoemaker floor). (1977) rate at rock crater material. shocked), pre-impact and of Brent. remnant 5 137-207 the of Crustal cavity a the use immediately by 1. to (Shoemaker appear material to erosion surrounded material similar of for shock NASA note layers Lonar and The Cratering be base with Barringer Hager, consist to material center measurements (1971) The the of 1960) shock slump, Figure suggesting by a was explain assumed meteorite layers Dence that thinness, rocks m Astrophysics in pressure layers silica crude of (1960) increasing highly-shocked of qualitative has Lake, positions the in was including in the extend class deformation found the uniform 1953) of flow extrapolation the etc.) at 5 below by removed constant and 14 at (Hager, flour in same is found. similarly back series et breccia the Brent and India. silica fields Brent glass of lb pressure a with DLG that highly are and al. reports until Kieffer, to of scale of the Data origin (intermediate shocked the depth composition stratigraphic lines Brett the to almost (1977) roughly of (Robertson these the flour the increasing silica (from Below 1953) Z, signifi:;ant lack lens meteorite unaltered the 420, from System 28 shocked shocked shocked shocked layer drawing volume finding EDOZ of of of of decay layers (1968) 1974), point holes deep layer have stra- 2 note flour non- also cut- ma- Co- and 35 the the the the the the at 7

1980LPSC...11.2347C

uplift, uplift,

2358 2358

fields fields

field field

explosion explosion

diameters diameters

volumes volumes amounts amounts

and and

0.0 0.0

to to

state state

al., al.,

the the

(Bryan (Bryan forming forming

of of

-

-

:I: :I:

C C D.. D..

I-

w w

E E

be be

appropriate appropriate

for for

surface. surface.

EDOZ. EDOZ.

© ©

200 200

1975), 1975),

can can

flow flow

Fig. Fig.

Shoemaker Shoemaker

Restored Restored

Coconino Coconino

M upper upper

section section

at at

Lunar Lunar

0 0

bulking, bulking,

-0 -0

0 0

Prairie Prairie

et et

depths depths

these these

(Moenkopi), (Moenkopi),

be be

of of

5. 5.

of of

S.K.Croft S.K.Croft

given given

crater crater

field field

al., al.,

yields yields

right right

Scale Scale

and and

made made

Meteor Meteor

the the

Normalized Normalized

The The

pre-erosion pre-erosion

that that

in in

craters craters

Flat, Flat,

1978; 1978;

(1960), (1960),

extension extension

for for

EDOZ EDOZ

of of

Planetary Planetary

etc., etc., in in

ejecta, ejecta,

average average

the the

(Table (Table

values values

EDOZ EDOZ

a a

using using

approximately approximately

100 100

the the

most most

constant constant

K

brecciated brecciated

Crater Crater

which which

0 0

Roddy Roddy

Brett Brett

has has

tables, tables,

(Kaibab), (Kaibab),

is is

profile profile

cross-section cross-section

of of

in in

of of

or or

Eq. Eq.

3) 3)

Institute Institute

ejecta ejecta

of of

~2.8 ~2.8

= =

(1968), (1968),

the the

not not

EDOZ EDOZ

Fig. Fig.

are are

sufficient sufficient

was was

the the

(Table (Table

0.031 0.031

3e, 3e,

Z, Z,

is is

et et

200 200

breccia breccia

material. material.

and and

dotted dotted

RADIAL RADIAL

and and

been been

for for

used used

EDOZ EDOZ

volumes volumes

al., al.,

ejected ejected

6c. 6c.

formed formed

Roddy Roddy

the the

• •

projectile projectile

one one

C

for for

Da Da

Provided Provided

of of

Meteor Meteor

1), 1),

0 0

lens lens

1980) 1980)

The The

ejecta ejecta

line. line.

here. here.

carried carried

(Coconino). (Coconino).

Meteor Meteor

probing probing

Drawing Drawing

Meteor Meteor projectile projectile

for for

et et

DLG DLG

DISTANCE DISTANCE

model model

is is

volume, volume,

by by

Pre-impact Pre-impact

al. al.

of of

300 300

implied implied

an an

and and

both both

If If

volume volume

by by

Crater Crater

(1975) (1975)

the the

a a

diameters diameters

Crater. Crater.

estimated estimated

out. out.

the the

compiled compiled

spherical spherical

420 420

the the

Crater Crater

quantitatively quantitatively

of of

~0.8 ~0.8

three three

craters. craters.

The The

diameter, diameter,

and and

NASA NASA

an an

indication indication

the the

stratigraphic stratigraphic

values values

(m} (m}

(Table (Table

Consequently, Consequently,

Current Current

and and

(Ye), (Ye),

tight tight

estimate estimate

Roddy Roddy

cm cm

400 400

craters craters

contact contact

and and

upraised upraised

from from

AVERAGE AVERAGE

of~ of~

Astrophysics Astrophysics

Prairie Prairie

charge charge

wavy wavy

EDOZ EDOZ

for for

the the

of of

2), 2),

profile profile

DLG DLG

RESTORED RESTORED

PROFILE PROFILE

(1978). (1978).

data data

30 30

which which

between between

DLG DLG

discussed discussed

Z Z

horizons horizons

apparent apparent

represents represents

are are

line line

and and

of of

m m

CROSS-SECTION CROSS-SECTION

Flat, Flat,

in in

of of

for for

rim rim

is is

420 420

for for

was was

500 500

the the

plotted plotted

in in

top top

Hager Hager

for for

TNT TNT

the the

only only

420 420

Data Data

the the

the the

Kaibab Kaibab

Meteor Meteor

to to

were were

are are

Z Z

and and

solid solid

chosen chosen

the the

Prairie Prairie

extreme extreme

radius radius

correct correct

of of

(Stoffler (Stoffler

in in

labeled labeled

System System

(1953), (1953),

flow flow

the the

the the

resting resting

on on

apparent apparent

••• •••

assumed assumed

line. line.

~2.5 ~2.5

the the

the the

and and

curves curves steady steady

600 600

Crater Crater

ejecta ejecta

fields fields

to to

(Ra), (Ra),

flow flow

flow flow

Flat Flat

for for

for for

on on

be be et et 1980LPSC...11.2347C

for

Coconino Toroweap

the the

Kaibab

Yellow Dv)

DLG

of a (1975). Supai

Red

Blue Moenkopi

Da

in (~176

sediment

removing

Layer

27.5

new

c Layer

b

a

a

b

the

Roddy

(cm)

Apparent

Symbol

Data

Yu Layer

the

curve

EDOZ

estimated

©

permanently

cm

model

includes

420.

Lunar

Meteor

are

layer

3

bulking

ct

).

depths

Mm:

for

al.

Depth

of

taken

As

{ 0 { {

\

{

{

{ {0.9

for

depth

Depth

---

0.0

da

2.7

90

1.8 and

88.5

(-30 310

170

the

volumes

(1975).

8.5

1

5.55

EDOZ

adopted

an

(cm)

=

by

in

±

Meteor

Crater

me

uplifted

Planetary

directly

(cm)

restored

±

million

m),

breccia

of 2

(m)

example

Bryan

2

displaced

plus

of

from

=

(Yu)

cubic

uplifted

or

flow

lens

Crater

crater

Depth/Ra

thickness

0.084

Depth/Ra

Table

Institute

0.065 0.131 0.196

Total

d

0.0

et estimated

Total 0.017

0.184 0.633

0.0

0.181

120

Roddy

0

and

Table

of

2.5

(-10

(cm)

meters.

crater

field al.

m

dimensions

the

sand

1.

ejected

Dais

assuming

(1978).

2.

m,

Meteor

(1978).

of

A.

A.

would

uncertainty

•

volume,

DLG from

in

fallout

B.

B.

Croft,

Individual

Provided

Individual

Yct

48.7

77.5 21.7

rim

R(Hinge)/Ra

included volumes

Yct

Whole

Whole

Ve/Ra

1252 6.4

0.7

473

652

0.384

127

Displaced

data

(displaced)

Crater

(Croft,

420

For

(cm

(-255

1.14

Mm'

layer

be

1980).

the

equals

data

3

and

3

Crater

Crater

)

1 ~2.5.

by (Y

this

b

Layers

Layers

data

(-IO

center

cm

1980)

in

in

0

cross-sections

the

).

summarya.

volumes

present

3

-Yu

)

Z

Values

Fig.

EDOZ,

summarya

---

-255

Ye/Vu

plus m,

-2.3lb

NASA

and

encountered

105

115

Yu

Ye/Ra:l

-

-

35

0.519

of

Roddy,

Cratering

(cm

6c.

volume

14.5

differ

11.3

(uplift)

depth

ofYct,

0.1

3

OMm:i

(Y

flow

.1

3

Astrophysics

)

ct)

This

the

of

slightly

are

1978),

(

Yu,

is

in

-

DLG

R(Hinge)/Ra

estimated

flow

defined

120

crater

near

curve

Ye

Ye

and

---

45.6

using

63.0

Ve/Vu

10.4

-997

plus

1.20

0.6

6.4

from

5.24

537

368

m)

(cm:i)

(

420

92

fields

ejected)

Ye

the

Data

due

Mm:

depth

equal

plus

approximates

are

ejected in

this

to

85

1

Stoffler

value

System

derived

thickness

acquired

to

compaction

method,

m ( m

the

volumes

~V/Ye

~Y/Vc

0.825

0.835

0.102

1.000

0.09

0.54 0.37

2359

~2.5

of

ct

sums

from

al.

by

Z

of 1980LPSC...11.2347C 2360 2) Hinge by Numerical in as estimated rim where of in Depths mation as predicted priate Limits sisting any). samples to section motion, the illustrated a measuring to © the function The radii Lunar da de 52.5 33.3 34.8 43.8 erometers R(Hinge)/Ra Da Ya radius Range inverted the three EDOZ of of on of c a ct e b apparent from Jones Normalized Rooke Averages Roddy excavation layers by 4 for S. orientation Rh ± ± ± ± the mere analysis a of of (Ru), and 0.08 0.69 0.28 0.75 craters K. hinge Average the in in DLG 30.5 the of Appendix (1970). depth layer curves were (1977a). et in Planetary Fig. Croft Fig. that presence m YelR! Z al. calculated radius m. the radius radius located. to of for 420 are (1972). maximumct 7, 3 can 2. of of Ra ejecta in rim will the 0.36 2.57 4.67 0.90 Table Ratios Height excavation the given vs. (Fig. stratigraphic Institute = was A be Fig. of This measured of from uplifts limit 28 4.4 be 61 6.25 ll,100m 1.18 ± ± ± ± indicated Z distinguished same the 3. flap. A. samples from samples m, a 0.04 0.21 0.70 0.09 ma 4), (hu), radius relations. ma in 6a. Prairie present data of function m Dimensions of the innermost B. • the Meteor of the Because m The 3 values excavation Provided given c Transient apparent is can the from Flat appropriate slightly that horizons hinge in implied by of type be crater Y Ye/R/ Ytc Ye 1.242 Ys 1.565 1.191 1.874 Crater and of the the the by Normalized Sauer 1 Z the radius by u layers smaller Uplift point set (settled) (ejecta) radius (Ya+Y1u+Ys) (transient Ru/Ra EDOZ and illustrated composition, Volumes the ratio final data ejecta ± ± ± ± extends hinge changes on (1970). values 0.025 0.003 0.010 0.027 for (Fig. NASA EDOZ. table than of summary. 1, to craters apparent of the to uplift) the point blanket 2, in the the the 5) apparent into profile Astrophysics and of from and in Fig. average original and apparent hinge Figure Z formed Fig. shown layer color, plotted 3, along crater direct are 6c. and Prairie radius but 0.013 0.092 0.167 0.032 apparent 2 radius 3 similar 6a ground which using Hinge texture, fallout in Data as in 27,300 not hu/Ra 13,000 radius is in on 9,400 (Ra)a 0.46 6,800 ± ± ± ± shows Fig. Flat shown, targets 0.001 0.008 an 0.025 0.003 the (Rh crater accel- System from the the m:lb ffi:l m' radii m:Jb to approxi- surface, layer 2 uplifted (Fig. of 33 etc. in appro- model Rh/Ra is those layer each con- then Fig. still are If, (if 9) 1980LPSC...11.2347C ...... :I: 01:: Q. I- w C C 0.5 © and between Fig. depths Fig. Lunar 0 (C) 6. 7. Theoretical of Schematic ejecta 2.5 and excavation --- and r7Z" > Planetary ·- ii C Cl)IC"')O volumes 2.9 Cl:: Cl:: C diagram dependence - for 1.2 1.0 1.3 1.1 .4 for .6 .2 .8 0 - 2.0 ----~-----.------.------. flows on i,c;_ Institute craters ___ illustrating Z and producing of in (A) • EDOZ. __. layered 2.5 Provided ____ 0.5 normalized spatial the Data targets. R/R craters. relations by EDOZ=0.084 z shown 0 ...... , 3.0 the hinge ____ NASA • • used PRAIRIE METEOR DLG from radii, Cratering in 420 Astrophysics LAYER craters (8) technique __... FLAT 3.5 CRATER / 0.0 depths __ / / flow indicate / 4 / _. LAYER of for fields 1.0 Data excavation estimating Z values System 2 2361 1980LPSC...11.2347C 4 2362 narrow. apparent) and the the will from The the ejected cavity 7, in model sets An Fig. then shape excavation thickness upper be predicted and levels. Fig. difference each VT upper estimate © parameters is found volumes 8. If Lunar at given 8. Meteor V of S. crater If the boundaries, a layer Theoretical Depth 1 given the and /Ve K...... -:: > 1,,,1 the on may and of individual cumulative by depth of Crater 1.0 Croft excavation .9 .8 .7 .3 .6 .5 is lower .2 .4 of may where would .l total the individual depth Planetary the may be the a individual cumulative function indicative surface are will extend hinge depth IV ejected is limits respectively, be 0.05 plot reproduced the layers /VT= be calculated Institute volume cavity fraction layers streamline, of on unless at large. into of layers(~ of ejecta volume, 1 0.1 excavation the are the the is Z, layer can by the of • effect ejected is volume depth thick, EDOZ, the normalized of flow Provided and the DEPTH/R 0.15 excavation small, be V layer Ye, 4 excavation then total of fields 1 CUMULATIVE estimated. plotted , as as of such material down into is a V shown, ejecta excavation Ra, limits 0.2 by 3 the function of 0 2 known are depth. • and~ the Z as a depth EC and as EDOZ=0.031 DLG METEOR volume to properties volume thick layer NASA known. 0.25 on PARAMETERS shown EJECTED cavity 2.4 If of a but Volume 420 the V for the given depth excavation and of 3 CRATER layer if 3 in no Astrophysics originating thickness of the shape the the 2.8, in extended 0.3 VOLUMES for on The Fig. Da and data material, samples depth Fig. streamline case depths respectively. can bottom EDOZ Z. from transient 7) of Value 7, 0.35 at be are depths the shown for of Data DLG shallower that the from of made each known = excavation of of shape. any V, the limits 1 0.031 The System deep. 420 (or layer V ejected layer will in / lower layer. set if final Fig. and the Da on be of If 1, 4 1980LPSC...11.2347C

of

(a The

shapes

a vs.

the the more admittedly volumes excavation inconsistent

and the imately vation absence value given of

That presumably

downward, the crater

Both

ejected Fig.

excavated 38)

of

upper

hole craters. crater sand to

basalt

Silty

ejecta servational

et

1)

cylindrical-shaped

V

The

A

excavation

was

pre-shot

a

DLG

al.

origin

crater,

IV

pristine

1

show

blue

normalized

©

depth

3),

through

data

unique

this

clay + the

to

sharply

layers

depth.

Lunar

blankets

interpret flow

for

rims

found

are

depth

/Ve

a

(Roddy,

30

and

~6.25

of

Head

for

number

V

420

was

layer

in

that

points

with

Meteor

of

cross-section

assumed,

and

m

2

small,

an

cavity

in

in

units

)/Ve

constraint

maintaining

points

confirm

Meteor

would and

confluence Meteor

Fig.

discrete

with

of

the

to

of

~20.9

This

shallower

is

bent

indeed

Table

situ may

atmosphere

the

m

the

layers

et was

silt

of

occur

depth

Planetary

this

excavation

~0.18

pers.

at

Prairie

8.

in

shown

of

depth,

the

but

four

Crater

al.

depths

shape

flaps represents

to

apparent

and

be and

the

correspond

A

3),

Mare

m.

craters

excavation

Crater,

driven

Crater

to the that

the

layers

the

of

comm.),

calculated

on

(1978) they

conic excavation

of estimated

on

normalized

craters:

or Ra

Excavation

sand.

extrapolating

than

mean

of

continuous

Flat

consist

of

Institute

IV

case

silt

in

excavations

underlain

is

a

is

of upper

a

de

the

Crisium.

(d

different

(Settle,

structural

the ejecta the

are

(2)

are

Fig.

similar

upward, not

of in

/Ve

~0.25

material

"split"

and

=

to

GZ

the

used

However,

is

~

depth

excavation

that

0.20 Meteor

Prairie

therefore,

and

2 m 2

the

to

Picard,

collected

cavity

evidenced

inappropriate.

left

of

vs.

2.5

by

•

(Jones,

40 top

8

Z

the

Provided

depth

Ra,

these

various

nearly

by are

of

the

only

1979).

Ra.

stratigraphy A

curves,

contact

depth,

depth

passing

sources

m

of

of

corner

cm),

of

found

but

shelf

for

flaps

north-south

to

magnesium

produces apparent

Flat

a

Crater

or

above

the

excavation

The

number

normalized

Peirce,

the

cavity

none

layer

data

1970)

of

four

DLG

together

1.0

the

to

a

or

~120

The

curves

complete

by

by

in

blue

underlain

of

crater

in

remote

fallout the

of

under

apparent

thin

implying

a

nearly

of

slightly

SE depth the

Ve.

of

the

the

available.

the

Prairie

(Table

curve

craters

showed

of

Fig.

produces

extrapolated

The

Greaves

bottom

lunar

420,

of

layer

m.

a the bottom

NASA

underlay

quadrant

layer

brown

lack

will

ejecta

top

family

If

was estimated was

data

rich

trenches

the in

layer,

of

This

8

Craterinf?

the

of

sensing

depth

clay

extrapolated

Prairie

stratigraphic

through

different

Table

by

depths,

less

1)

than

data

seen

Flat

that

multi-kilometer

be

of

of

excavation

have crater

Astrophysics

the

basalt

of of

points

bottom

and

of

blanket.

The layers

a

implies

and

and

layers

of

any

the

different.

the

layer

than

family

following blue

(Jones,

of

the

provide

vs.

a

in

the

Meteor

4

straight

through

Flat,

penetrated

techniques

depth

DLG

flow

constant

Cleomedes

floor.

breccia

the orange

blue

apparent for

Fig.

the

apparent

data

(Head

for

excavation

normalized

entire

Z-derived

of

half below

of

2,

sand

mare,

comparison.

A

fields

of

available

by

Snowball

each

is

depth

Data fine

sections

etc.

4;

the

clay

1970,

points

420

a

of

For

to

Crater

pre-shot lines

curves

the

the

~6.25

stratigraphy:

sand

i.e.,

examination

possible

et

lens,

crater.

was

be

6.25 excavation

blue

sized

Z, to

The

System

diameters,

bottom

(Table crater

and

extending

example,

al.'s

a

post-shot

to

apparent

Figs.

of

F.

through

medium

approx-

curves.

most

are

outside

EDOZ

surface

driven

cavity

m

m

which

ejecta

in

depth

of

depth

layer.

define

much

in

(from

exca-

Head

lunar

2363

bore

type

The

was

(the

not

the are

ob-

the

the

36,

2).

of

of 1980LPSC...11.2347C 2364 further of the nesium-rich excavated in layer gives subsurface shelf surface valid (LTO) Mare than km provide but layers largest terrestrial mg-rich porosity be stant similar sounder shelf, of excavation depths of Transient cavity. The similar cavation and down-driven et values suggested Z Fig. By Mare others appropriate = Z al. a regular discontinuity is © steady field Swift, 2.7. general = 3, and of Z, for apparent this Crisium where actually Lunar (1978) that coverage of of results: to that crater Data 2.5 found the the chemically layer Crisium. profile. EDOZ projectiles. cavity the sets rim central data Z ~0.09 analysis, impact DLG S. in magnesium-rich basin-wide layering for were for did streamlines, the strongest depth and basalt between the the K. are portion characteristic published rest uplift beneath by on lower derived ~200 EDOZ, DLG observed discussed Meteor penetrate diameter, Planetary Crqft magnesium-rich Note is 420 flow depth discussion and Da does not presented the Andre and floor the of of layer, available distinct the appears and m In (Fig. and lunar excavated. 420, of the excavation the constraints fields ~2.5 that layering explosion mare represent the from to deeper Crater, of as depths comparison, the a the Institute et ~0.17 depths which the upper apparent transient to the western and was the detailed 4) the four radar material al. of and flow of in basalts (Eq. that remarkably down-driven for the this magnesium-rich where layer Z bottom this Fig. basin (1978) large-scale found than done of Da, DLG craters that craters of apparently limits, the the ~3.0 layer craters. radar field sounder • = Greaves 2i did point of on excavation Provided excavation section end depth, 2, 2.8 and cross-section is crater in which in the same top da Snowball for and de, the by came not in under significantly 420 as of the corresponds Appendix sounder for is respectively, have of postulated excavated of the the the because regular. Swift depths The seen experiment passes significantly region. penetrate volume ejecta impact and and and the wall bracket Meteor by Mare which to underlies sounder formation ejecta the penetrated related the layer the for data can magnesium-rich is in Prairie Cleomedes not estimated that pushes assumptions of NASA blankets through Lunar compatible they Crisium, A) same Fig. these of If indicate craters between be less. portions only Crater magnesium-rich the vo!umes suggest excavation because to it extends the experiment the are on primarily accounted (May the the is lie Flat Astrophysics 6b. deeper of values conclusion, lunar lies the Topographic an the assumed layer. subsurface ~0.1 surface the closest depth of formed the and 1.4 the Normalized F, that then are the equal et layer, of below and they some ratio across with of transient craters only crater km of than al., Prairie role a Da layer, predicted to bottom plotted Peirce de incompressibility to for is subsurface hinge the de to are basalts by Data deep de/Ra. (1) the volume craters and (= approximately that 1976). a = the slightly played and the layer. found by the the flow structure Peirce. presence on Orthophoto 0.1 single, lie that and Flat. 0.2 excavation System radii, top crater. flow Swift, and on of of reflection depths depths postulate observed the marginal between of Da Peeples Table by but (2) field Ra) Peirce, the This the for curves of by of larger From Swift fields most mag- mare con- low- with The may that not the rim the the ex- the 1.4 for As of of of of of is 4 1980LPSC...11.2347C gauges with 9 observed original expressions ground transmitted below surface simplified and entire Sufficient material time bility parated sand as ticle 1970; is a a height © coherent observations, and motions and Jones, surface and (1970), explosive. maximum Fig. now "dynamic drawing Lunar half-space. 8 m 8 and zero range ground unit. into 9. space. underlying the velocities streamline rim geology (hu) Cross-section in Sauer accelerometers positions ::c .... C Q.. w through and are 1970; at top a in 20 uplift unit; displacement There 10 the uplift" 10 of of Stippled of transient Planetary 0 depths They derived the surface (1970), the the two points It clay, Roddy, of provided ejecta. i.e., data of and line cratered is the flow, is east the accelerometers. point, meters found zone of and suggested between no is material so PRAIRIE cratered are Institute accelerations in Dashed Prairie (Sauer, on of crater rim 10 position profile and 1976; EAST Roddy material ground reason is section were the estimates available that Z, half ejecta. of uplift. indicate PROFILE Flat curved original Roddy rim (1976). EDOZ, clay, to • of O of placed the 1970) surface that FLAT medium space Provided explosion to and maximum Dotted a 20 4 Prairie Heavy motions region. Assuming depth entire of for lines suspect RANGE of responded the to Half that et 8 is as ground satisfies Appendix at the transient the determine and line al., m. are discussed measured into solid indicated crater by circle the Flat radii of displacement instrumented The were is Prairie (m) the Z Roddy 30 1977) the 8 that inferred volume the line = a at surface compiled m, showing NASA maximum between the to 2. constant left shape in probably 7 transient including is A material to Cratering crater material Flat and streamlines the by assumption et is transient post-shot crater compare for Astrophysics of of size 40 text. from as al. a explosion implied original of the the transient rim the ~20 functions dashed formation and Z, transient (1977) data the can continuous separation uplift. flow present all movements crater region uplifted surface. through location EDOZ and model ground given layers be transient continuous of fields 50 Data achieved integrated line. crater Conservation made. ~ incompressi- was of by uplift surface pre-shot 100 as of Dashed predictions surface System range crater flow of Jones the high- occurred an over Velocity uplifted m in silt (Sauer, Figure crater. at of initial unse- field, from both 2365 (Ru) par- was and and the the the 1980LPSC...11.2347C 2366 for line various measurements sient assumed, crater of a volume volume mates sition. ~27 single Transient volume the ,300 in rim Fig. but derived uplift crater for © (V Fig. Estimates Prairie values between radius.) of uplifts with Lunar 10. m tc) then Vs for S. 3 in the 9. • for Semi-log can (apparent a structural K. are transient (There depth/diameter the (solid and Flat a are the transient ..c of ...... Cl: Croft be C constant :::, 0.001---___._ If, based the 0.01 of rim Planetary 0.4.---r-----,----.---.------r--~-~--. Z 0.1 curves) implied crater. given estimated plot following these may crater are original uplift transient rim on :I: (!) "' .,, .... ,_ z <( w w N :E "'= z w N of II 1.0 Z, uplift shown derived from measured be in only with volumes The EDOZ Institute ratio depth uplifts TC PARABOLIC EDOZ=0.0 dtc also Table considerable Dence from ground 1.2 PARAMETERS same of (V inferred two = __ in crater cratering only suggests of 1 8V1cl(rrDD maximum u), calculated • Fig. 3. present diameter profiles made the . 1.6 1.4 RANGE/R the PROFILES _.__ Provided (1973), 0.2. plus surface The dimensions: _ transient transient TRANSIENT PRAIRIE transient 10. flow from ___._ uncertainty transient that a as estimated apparent and The __ a "settled" field. by from 0 transient =19 and parabolic crater geologic the the V 1.8 crater curves ...._ Dashed 1 crater, FLAT u uplift its m NASA the total on _ Da in crater crater UPLIFT present transient Fig. ___._ in uplift inferred 2.0 with volume is = transient cross-sections curve Astrophysics represent volume dtc, __ this indicated 9 61 indicated theoretical volume and measurements is: 2.2 figure is m, ...... down-slumped an theoretical (Vs) Prairie crater of da uplift crater in the by (Va) because the Data transient equal = Fig. model the volume maximum Flat and 19 transient profile System rim plus 10, dotted m) to along uplift tran- esti- po- the the for is is 1980LPSC...11.2347C zero important hinge each explosion gauges transient flows. of consistency are of The different large in the to target transient mate where uplifted predict Qualitative correlates crater; due ical quantitative 4) much roborations shapes most by produced deed "high" chanics, cavation Meteor However, the excavation are each the proportional to explanation (Sauer, observations of important embody change values radii transient different measured © materials. consistent changing This constant data i.e., initially of excavation these crater positions observed Crater. Lunar of Z crater cavity, crater by craters. the with predictions changes were implies evidence the which result are imply of approximation of the 1970; in features the that and calculated can from the crater transient parameter Z the profile located with Z. the available, Likewise, Z, maximum for and Consequently calculated to plotted with of important Planetary uplift characterizing has cited that are successfully The two given Observed estimated cavity EDOZ that finding in V! the calculated Cooper 27,000 2) for Da profiles implies 13 also motions the several from of a dashed will the the original at near in for a on crater = constant in curves a shape for displaced calculated down-driven Institute flow different deformations flow unique of the 61 m depths results uplifts. for Table qualitative be constant parabolic theoretical explosion and 3 value Range/Ra are values rim that Cooper important m, and curve uplifts predicted discussed the volume preceding predict several ground surface. fields field (Snowball) Sauer' DISCUSSION somewhat, flows of uplift de= Z, 3). to flow • of are still flow-field The of the depths Provided ranges is each of shown EDOZ rim excavation Z, The of while for and Z craters not features found match that s fields values 12 of curves important same calculations close cone depths in = predicted (1977) implications unique EDOZ by a in uplift section Prairie crater. m observed very Sauer the 1.6 and and at 30% could maintaining is the and detail by (0.2 model order flow with of for spacing the over four the of in relative floor the and observations. of vertical The sensitive transient curves shallow Z, Z decrease may hinge Snowball, of flow (1977) Da), Flat rim Further, Fig. uplift crater field values appear impact account NASA CraterinR for here: of and different EDOZ a provides lunar is four volumes and uplift wide uplift for magnitude as of be crater the each field 6 and radius, is to for displacements EDOZ calculated constant that target Astrophysics the to walls structures, data 1) of to rim planetary the and a samples. to volume in the is in for Ytc range flow estimate reasonable data. reasonable the for Z DLG Z. flow crater's calculated could ranges transient corroborate a Ytc reasonably the uplift explanation of points explosion and calculated each material of depth quantitative Departures = nature both also field. .fields excavation, This individual implies Ytc of DLG 18,000 of 420, EDOZ for not (Prairie the cratering Data from feature. energies flow are the and the successfully changes the and impact a These conclusion of rim have first-order of variations variations Brent uplifts predicted parabolic 420 averages transient cratering System approxi- m: velocity well does that field curves. volume several ground the for unique uplifts 3 of Flat). phys- cases • 2367 (Fig. been The The cor- and and and and me- the the the ex- re- for in- by 1980LPSC...11.2347C

2368

processes

In (1977). ture of of sient relevant ground

diameters sient and

EDOZ

crater

of may

the to compares

termined

could vation the

in

placed

uation predicts cavity predicted

point,

center

Meteor profile, the attenuation rim assumed

of

The

Field

2) 3)

1)

ejecta

addition to

rebound

this

division

uplifted

the

downward-displaced

shock

final

values

©

volume

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of

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be

the

rim

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be

Lunar

are

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rates

cavities

of

paper

A can

volume)

The

peculiar

surface.

the

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in

measurements

Crater

defined

highly

pre-displacement to apparent

Ve/Vu

estimated

pre-displacement

and

rates

uplift,

mode

in

an

the

S.

have

by

wave

of

most

contrast

of

volume

its

between be

or

crater

and

rate

excavation

that

depth

of

Fig.

K.

field

and

(Fig.

the

excavation

fallout

the

the

Ve/Vu

relation

re-adjustment

structure.

placed

(Croft,

shocked

of

(Table

both

Planetary

occurred.

Croft

is

of

Because

for

difficult

~

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shape

are

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transient

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11

flow

craters

model

Dence

Ve/Vu~

as

3,

are

crater

1

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Pa

to

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ld)

probably

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the indirectly

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it

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high

between

in

1)

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relevant

of

volumes.

appears

cavity

layers

with

R-

crater.

accord

Institute

to

transient

preparation),

has and

of

floor

the

in

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et

reality

modification

a

The

position

the

and

in

crater

2

position

obtain.

its

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0.3,

,

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al.

rates (Fig.

The

and

of

been

observed

those

DLG

and

the

too

et

The

of

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for

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final

by

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were

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displaced

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to

with

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roughly

•

lower

displaced al.

the

Thus

characterized

excavation

down-driven

great.

and a

shown

geological

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lld),

Provided

the

the

pointed

attenuation depth/diameter

excavation

origin

of

In

the

suggested

420

large

's

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of

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glass-lined

reconstructed

observed

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but

excavation

third

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final

final

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(Croft,

bounds the

field

(Table

The

however,

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crater

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by

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value

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floor

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by

the

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use

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material

apparent crater

apparent

assumption.

Dence

each

the

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center

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craters,

the

cavity

by

than

of

cavity

2).

base

rate

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in

materials.

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values,

because

for by

excavation

cavity

NASA

hinge

shock

Dence

direct

the

preparation),

characterized

figure;

Pike's

Figs.

that

Excavation

are all

cavity

predicted

of

is

ratios,

volumes

the

point

Ve/Vu.

assuming:

similar

of

in

et

(see

crater

not

the

and

accommodating

cratering

a

geologic

craters

discussed the

was

Astrophysics

the

the

zone

cross-section.

al.

observed

distinct

differs

but

pressures

estimates

1,

of

(1967)

et

and

osqety the Consequently,

of

Fig.

coincide

the

excavation

and

transient

morphology

ratio

breccia

to

2,

the

the

to

It

requires

al.

are

the

cavity;

at

and

by

be

3,

is

(implicitly) lowest

field

must

experimentally

cavity

2)

from

indicators

the

bottom,

(unknown)

(1977).

excavation

and

of

relation

excavation

dependent

but equal

and

directly

equal

by

the

depths

Ve/Vu

implies

of

Data in

ejected

lens

measurements

at

surface

crater

be

readjustment

that

Dence

the

the

the 7.

shock

constant

point

C

cavity

the

Excavation

both

to

System

represents

to

The

and

noted

Figure

in

or

for

ratios transient

transient

of

rock

by

the

the

that

of

original

the

defined

volume

Fig.

lowest

extent

cavity

radius

on

cavity origin

of

struc-

shock

atten-

crater

et

exca-

tran-

tran-

floor

floor

total

sum

and

that

dis-

the

de-

the

al.

the

for

Z,

11

11 1980LPSC...11.2347C rim done be Transient further are tios are the diameters geometry the crater crater impact Da the craters The ~0.1 breccia (Dence, final different. volumes slumped significantly of dicted formation off-center. C), in Fig. material rather primary by © and is differences the the illustrates craters are and Lunar Da Dence apparent 11. usually center, by illustrated of crater than excavation excavation lenses excavation Comparison difference in while progressively Dence 1973; to the nature of From Dence and the to EXCAVATION in the estimate implicitly et flow three considered depths less crater the Planetary rock), crater. of the et al. between transient Dence C B et the al. of away between in craters cavity differences -- than al. (1977), depth of cavity center cavities cavity, (1977) the Fig. requiring limited inferred relation and, (1977) the from CAVITY For cavity, Institute et predicted smaller crater transient the the like for that 2. TRANSIENT of larger volume al., are is the complex in assume the The are shock the models between material data respective inappropriate. is so Brent, the point in from assumed 1977). driven walls. transient • approximately that by final than at their normalized wave Provided case the in of CRATER crater of constant is increasing to the the transient craters, Table Meteor displaced deepest downward impact. the apparent the be shapes. Thus attenuation The of deepest to highly apparent "scooped" prediction crater, transient depths by simple be Z, 4, apparent point crater it the the Crater, final EDOZ the the and For point appears rock crater crater shocked equal, rates NASA Craterinf.{ in diameter and of (at craters, and excavation same depth/apparent retained out apparent simple the of crater a flow shown in and of diameter excavation least the central the Astrophysics excavation is diameters but the that the based field layers ~0.2 excavation in others, flow craters, final (Figs. even excavation diameter of the for transient the cone depths excavation (Fig. the depth Da on fields crater apparent cavities of apparent 12A, kilometer-sized cavity at shallower of final are 12d). Data the (Pike, (Pike, the cavity the diameter the shallow of cavity, 8, during because appears near to cavity, flow The pre- apparent System apparent and transient bases complex be is depths depths 1977). crater 1977). 2369 ~0.3 than field ra- as of to of 1980LPSC...11.2347C 2370 by ening of craters. 0.3 indicate However, tent ter of assumed craters, is 420 to results near between has Excavation complex It valid the ~0.1 accounting cones. Da, is with © been is 0.1 of Lunar apparent not noted of These not for and Da. that stratigraphic Da 2.5 to these Snowball' Prairie Cleomedes DLG Swift Greaves the suggested S. Meteor Peircer and Picard field The anomalous, impact both a " unlike c (see e 1 be and ct is K. and Diameter transient Roddy Stoffler Data Crater Roddy Croft that Picard Z-flow depths geological a for 420a results. model valid. geological Planetary Crqft Flatb diameter direct Craterd Fig. simple 3, from these (in uplift the and (1977b) (1977a) F are et which (Settle 6b). preparation) adjusted field, predicted marker transient Croft al. transient complex. crater result explosion Again, nor and Table results Institute and (1975) investigations of Thus, investigations (1979b). apparently -61m -990m -83 it 11.1 15.5 due 19.4 9.7 8.35 the 27.5 and complex for 4. of inward appears depths beds, from m Observed crater collapse the by km solely infer km km km km crater transient cm based • Terrestrial craters Head, Lunar The Provided def constant dividing and the of motions first that craters. Da that depth to on using characterize Craters" depths depths limited model complex by -4.4 -5.8 1.8 1.59 by I.SO 1.58 1.37 1979), appear three the 5.5 = the 170 crater the Craters a by re-orientation model Dence 0.1 of km km km km km Z, of cm ratio m m m compactibility limited of the craters indicated shallow inferred reconstructions In the data Prairie EDOZ but excavation. to of: NASA of craters subsequent of cratering be (1973) Croft are a real in field the d near 0.95 0.95 1.4 1.4 1.4 property simple Table Astrophysics excavation Flat for (layer) flow by (1979b). cratering are depth of and km km km km km data kilometer-sized the circumferential near flow beds craters. fields of 4, between discussion, Dence simple of and excavation the of common 0.3 field transient containing -0.122 -0. -0.094 >0.090 >0.098 >0.086 <0.168 >0.072 Data excavation for flows, depth Peirce the 0.091 target Dais 102 et crater into values 0.2 System theoretical al. of are to Eq. sand Da ejected consis- craters depths simple (1977) short- DLG value shat- most of also and (de) 1 as is Z 1980LPSC...11.2347C be of and primary trast to evidence depth excavating Crater One out Material mates history. equivalent crater crater. on gressively model of of of in transient hence (O'Keefe craters complex da!Da single against one 1980). basins. Basin, proportional diameter 1975), Two favor the excavation basins surface important samples an all down-driven projectile of of depth © of important depth, projectiles depth of shown material Consequently, excavation ratio, significantly as types mentioned Evidence the the Lunar of Z shock; In properties crater origin of rim as origins relation and suggested shallower layers, proportional to ~ other. such subsurface of that-but most of large in during and of growth, of the uplift 2.4 in and at Ahrens, the the diameter restoration of above Orphal, simple the transient Fig. Snowball problem studies of transient cited for Planetary portions. to as important, such For non-proportional rocks to depths water above, lunar data. probably transient less the lunar with at Imbrium by a l DLG a i.e., de previous lc, example, 1978b; in craters Depth as layers least growth transient central cratering 1977) Head on deep than table, changes it mantle favor increasing crater Evidence are the such in theoretical Institute samples and cavity models transient is The the 420 cratering several crater do and used usually Roddy maria a were of because distinct if (e.g., et includes Prairie but of that nadir discussions lunar projectile behavior compressibility, extrapolation affect and on the origin crater al. depth, either flow only disagreed (Settle • in simply used only in with the crater basalts, the Provided growth, projectile craters projectile see (1975), et Z in several calculations surface assumed favor mechanics: Flat in stage slightly the pressures maximum geological al., a of mode ~ dimension lunar which a increasing Settle to and chemistry at manner the few diameter diameter lunar 2.8 Z are 1980), interpret large of that by of on at yields (i.e., of ways, i.e., Head, excavated consequence may surface of for tens in radii, the were suggested excavation that in non-proportional all and the problems have even samples Settle are the diameters similar turn that in excavation NASA evidence and, transient changes Meteor scales be of a diameter Cratering of flow including such Head, excavation if and 1979) the iron nearly so depth range lunar viewed been ~970 kilometers in the show was of as and low. Astrophysics material field-the that during albedo, to spite sand, to maintain discussed (O'Keefe and in projectile Crater depths 1979; of equivalent of crustal of penetrated 2.5 of Dence Head's independent craters have not km penetrations flow of Similarly, lunar the as thickness depth a shape terrestrial the ~50 of < the typical is was counter cratering be for transient growth Whitford-Stark, flow fields and deep. been general the Z not may have apparent a studies final et structure solely Data km, (1979) was in become the and < (if by were uniform al. depth large to behind thought this by proposed: 3.0. flow the any), estimates Evidence be System scooping evidence apparent centered Imbrium or complex virtually 's includes the Ahrens, of of events. paucity related craters craters depth/ paper, stony. (1977) direct is depth about field. lunar scale solid 2371 con- esti- final pro- and and the the 1:3 to 1980LPSC...11.2347C Certainly, 2372 of graphically the the the there thicknesses by excavation controlled craters and cavation analysis craters dispute de!Da Thus growth tion thus the transient have Conversely, correct, considerations Peirce strewn hinge with material. maria before local basins streamlines 1980). Imbrium excavation proportional The Second, sampling gravity flow ejecta EDOZ; proportional association © of the increasingly the crust the streamline. ought basalt Lunar is If and to nature ejecting incompressibility, around to should (see of field: then shape of 1/3 this depth/apparent same The projectile crater general possess the blanket, at S. excavation the by scaling Picard to thickness deep depths cavity. the and relatively and problems, and to Croft, deposits, if is transient K. least innermost actual the ½ 1) of distinction gravity relative the of the provide true, be become Planetary significant flow of maximum Croft diameter 3) the streamline in Therefore, vs. the lack larger the depths with proportional depths 20 literally (Gault The as transient the dominating lunar 1979b), the are transient depths a field non-proportional excavation before excavation km derived cavities of nearer for crater direct scaling or primary diameters shape original apparent theoretical not so impacts, rings Institute surface. obvious diameter of between anything and in of of example, et has depths amounts. and tens relatively of well shapes excavation craters diameter. as origin ejecting consequence ~570 ~600 al., in to of cavity thus from excavation is direct to our the transient role the surface, a the of EDOZ, • validity known, cavity, in cavity up and of 1975), mantle impact constant Further, Provided the ratio to km absolute dimensions else, in support sample are of composition, millions Imbrium the must played origin are determining diameter to Therefore any implications 700 the shallow gravity ejected excavation for growth In independent 20 constant of of deep, except implies it proposed remains of craters but materials the basin flow be km usually mantle the km, is of should by Imbrium collections large impact Z, because by Eq. for of that reduced lunar the Basin the shape in of retains material constant EDOZ field at gravity well then cubic controversy the sizes. the 1 diameter Imbrium NASA multi-ringed proportional basins with size, the which proportionally physical for Z, ai dimensions basin assumed material, be cavity craters for samples. in is are lie into extrapolation cratering even of the of suggested EDOZ craters thickness on material by difficult kilometers this flow diameters If Astrophysics within in and and both with the gravity; derived Z, of are the mantle top streamline factors this and the without for may the is paper reasons impact EDOZ orbital hinge field (e.g., and size the ~0.1 estimates First, of to like formation model, basins ~0.1. the this line the model. growth to flow in everything estimates have by evaluation from material 2) former, except somewhat range the of½ explain up the transient the Whitford-Stark, of on streamline, diameter relatively of Data Dtc, ejecting of spectral all if velocity Dence field description why This is becomes to lunar are same. one lunar proportional then the reasoning possessed crater the streamlines is to System subject dominated of permitting ~ of very increases transfers transient valid obscure. assumes is assump- in ½. value basis IOX of deposit the craters mantle (1976), craters crater, mantle else range. of These maps. of strati- larger terms along small lunar near and ex- the the the for the for of of of in is a 1980LPSC...11.2347C growth growth the up account Consequently, and the mantle sistent (Croft, and Acknowledgments-I under paper Horz Andre Croft Bjork Croft Cooper Brett Austin Croft Bryan Dence Dence The Applied Studies scaling. (R. Mare Center Lunar reconciliation Arizona. p. crustal investigation puter of Institute, Prof. to paper Jeff Terry innermost California 1133-1163. is R. S. constitutes Contract S. B. S. R. J.B., basin C. Lunar M. © M. M. Thomsen, greatly Paper H. simulation Crisium with K. Planet. samples K. of (1968) K. of Merrill 1979a) for structure. into L., by Jackson Lunar G., allows to In R. R. G., F. Proc. (1979b) Houston. (1979a) features (1978) excavation the Burton the Astrophysics, Impact and Kreyenhagen (1973) publishable dimensions. Wolfe Jr. 600-D, (1976) all of at appreciated, No. Thomsen Opaque (abstract). Pergamon, Sci. and]. lmbri11m Meteoroid from and the rings and impact L11nar for Los Planetary that and relevant in reconstruction of Lunar on Impact Proc. NSR Proportional D. R. Dimensional gratefully drawing Conj. Lunar and Notes Planetary p. Sauer hypervelocity extensive orbital Angeles. basin associated J. W., the E., a minerals Planet. (e.g., 179-180. cratering J. 09-051-001 Papike, Consortium, form. Explosion Lunar crater restoration cavities. Craters Cunningham 11th. Cambridge. In Hazard. N.Y. and and K. M., as lunar toward F. Institute observations. Thus the X-ray formation Lunar are N., acknowledge M. 264 Efforts Adler Dence, Planetary discussions Institute Sci. Planet. Ruhl volumes: This in vs. figures analysis eds.), dynamics: the (1977) from and surface drill pp. Craterinr; impact fluorescence an with NASA a with Con_(. non-proportional of is and volume. It S. I. near-Herculean Vol. model by impact REFERENCES p. Wagner operated Centimeters Sci. are cuttings M. (1978) proportional F., model has the Crater-related • 1976; Institute of Planetary Lila Interpretation 1-12. the models 9th, cratering: with 1 E., also CR-757. Provided Material the Orpha! Conf. impact National (J. is also (D. model of Mager Evidence flow and p. constructive no N. A. Peter gratefully from Pergamon, data. Croft, by taking 3931-3964. crater J. Contribution 9th, H. Wood, Lettis structures been postulating D. longer to Science the motions 186 Roddy, field Some growth for and by Aeronautics Meteor Schultz. efforts In Megameters. (1967) p. L., ground for transient by pp. Universities the the 1979b), Gwen L.A. Marc formation 3711-3733. bulking acknowledged. pointed ed.). and can N.Y. preliminary models a inconsistent R. NASA X, reviews during of of Imbrium Crater, Analytical high-magnesium (abstract). The Cratering motions Schultz 0. LSI No. Jr. Crisium: basin-sized Dennis p. Stokes be transient and encouragement the Pepin (1978) 248-250. the of Astrophysics craters of Ph.D. Contr. constructed 421. out by Space Arizona. Space impact based Basin. crater and in Orpha! results ejected general P. Jon St11dy Meteoritics and The in flow A manuscript H. dissertation. No. excavation implications Research with two-dimensional Bryan, a Lunar Administration. for growth R. crater (1980) cratering In Vieit· subsurface on for U.S. fields in previous ()f 267D, B. Interdisciplinary Data lack material lunar helping offered proportional proportional Impact Meteor _ti-om that and Merrill, Dave Geo!. 8, period. Calculational preparation, rims Association p. cavities: System 343-344. University and of for Planetary craters 147-155. is Luna basalt hammer by Roddy, Effects Crater, study Survey lunar crater con- eds.), upper near Proc. 2373 into Fred com- This 24 in A 1980LPSC...11.2347C Jones Jones Oberbeck Gault Dence Hager Grieve Head Head O'Keefe Grieve Maxwell Maxwell Maxwell Kreyenhagen Holsapple 2374 Killian Kieffer O'Keefe O'Keefe Gault May Ivanov Res. Petroleum Sci. J. J. J. Planet. Geophys. the and approach C characteristics geologic impact explosion and and Explosion Research the basins. and In 2829. Mono, Pepin, N.Y. Physics Defense Abbott DNA Results onf. © Shock T. Conference J. occurrence J. G. D. implications R. G. D. R. R. Conf. D. B. Papike, 76, M. R. S. Lunar R. B. W., 11th. W., 3628F. W., J. J. J. and D. D. D. craters B. Baltimore. B. B. H. E., Proc. E., H. Inter. E. G. (abstract). W. V. International, (1953) A. K. A. R., 5732-5749. A. history Atomic D. D. D. to Establishment Metamorphism and Res. cratering Craterinr; Merrill, S. E. Merrill, Merrill, E. Adams A. Settle 6th, Peeples Geologists S. . (1976) S. R. Guest and R. Quaide K. (1971) F., A. This F. (1976) the and and Grieve and and eds.), (1977) (1973) Lunar (1970) Defense K. (1976) 16, Seifert (1971) B. and (1979) on N. (1980) Dence Crater 76, p. of Germain on phenomenology. for of Ahrens Support Ahrens volume. Planetary M., Ahrens Croft Merrill, 341-351. J.E., Mercury Shock 2831-2844. and J.B., impact eds.), eds.), the energy eds.), The In W. 5449-5473. W. p. Mare calculations. Simple the Cratering R. Sci. Prairie (D. Subsurface Laboratory K. The Cratering The and Lunar 43-74. 37, M. J., Lunar Schuster Calif. mound Nuclear L., A. effect depth (1974) Murray Suffield, T. J. McCord L. T. metamorphism p. p. p. Con_{. T. Crisium. Agency, of eds.), 821-857. melts. R., Maxwell considerations. equivalent Stein Morphology and F., Roddy, and Z J. 983-1002. 791-814. 1165-1190. Institute J. S. Flat J. Natural Science 50 Hir;hlands Pergamon, model and of (1978b) of (Meteor (1975) and Robertson and (1977) Modeling (1978a) Oberbeck Flow 7th, Agency, Record: the pp. S. p. J.B., R. layering excavation In simulation In gravity Crater In Alberta, T. Robertson Washington, H. 247-275. In R. S. T., Moon. Impact Impact p. Impact of and depth B., VII, Shock Materials Scaling Pergamon, Late • (1977) 0. Mare (1975) Pergamon, Dzurisin Impact 2947-2965. cratering, Sill Crater), c~f' Pergamon, Provided of Crust, Washington, Processes and ofCraterinr;, N.Y. on in Pieters Crater V. Pepin In p. Canada. Central J. the stage of Maria W. of of and and effects and crater Crisium: R. Pergamon, Impact Review 540-542. P. Ejecta Volume of Geophys. burial P. lunar impact flows Coconino R., p. (1968) DC. (B. and B. cratering D., Arizona, Explosion Prediction Explosion C., crater Explosion N.Y. B. ejection, N.Y. Serenitatis 27-29. by (1977) formation: N.Y. Ward Uplift and from 207 M. R. (1977) samples. for and Study. and and and 276 and DC. the of cratering Close-in The Impact Lunar flows B. Effects French pp. impact N.Y. Res. Malin a Explosion material pp. crater sandstone Zisk Cratering S. experiments-an comparison Lunar NASA a Craters. Merrill, and large 110 Terrestrial View Cratering Cratering Cratering Methods. DASA H., geologic and and Science 80, Proc. cratering Thickness S. the pp. Displacements, M. cratering. (abstract). and with scaling impact and from Phillips Astrophysics the 2444-2460. (1978) ejected Crisium: overturned eds.), C. processes: Cratering Suffield Lunar at Report N. Planetary high effect feature. of (1975) (D. (D. Tech. (D. impact Institute, Luna Meteor on M. on mechanics Regional hypervelocity p. R. of explosives. Proc. from J. J. J. Sci. In the the analytical of Apollo Short, POR 1003-1008. J., 24 Report ejecta Some Memo Roddy, Roddy, Roddy, Papers strength structures: (D. flap. Bull. Crater, As moon. moon. Institute, Conf. and Data major Jordan (R. Lunar Houston. 2115 stratigraphy J. interpreted eds.), comparisons Lunar and and Ejecta. In B. TCAM Amer. 281, Roddy, R. R. System and R. 6th, Presented J. Proc. Phys. lunar Arizona. Impact on Planet. (WT impact Merrill R. Pergamon, structures. concentric 0. 0. 0. Geophys. p. Houston. Principle transient hueristic Defense Sounder p. L., Report Assoc. 87-99. Pepin, Pepin, Pepin, basins Lunar 73-17, 2115). Earth 2805- R. from and Sci. and and and and 0. J. to of 1980LPSC...11.2347C Orpha! Roddy Orpha! Peeples Pike Pike Robertson Roddy Roddy Roddy Roddy Roddy Rooke Roddy Settle Shoemaker Settle Sauer Shoemaker Schultz 8th, generation phys. crater from structural 917. In Institute, Merrill, Planetary Crisium. tering Killpack drilling impact Impact orite impact Pergamon, Arizona. iment deformation mechanics Lunar Proc. Symposium p. J. zona. phys. Soc. Analysis R. R. 3389-3407. Impact Geophys. p. M. F. Pergamon, M. D. D. D. D. A. D. a D. D. D. and D. Mtg., J. Res. J. © W. Res. Lunar Station, depth (D. P.H. International and 3427-3436. craters. sur.ft1ce-tanient M. crater, and with and eds.), (1977) J. L. (1980) J. Lunar (1967) J., J. D., J., J. J., L., T. P. J. J., Houston. Proc. Center, Institute, E. E. initial analogs. J. and (1977b) (1970) and (1977a) 72, ( at (1976) Planetary (1978) N. Ullrich B. 84, Geophys. J. Aug. 1977) Schuster Boyce Explosion Head and Sill Report thickness, in Meyer Borden Sci. (abstract). M. M. Roddy, Res. Meteor Y. p. (1978) Apparent 2099-2106. The and Germany Vicksburg, Schroeter's Explosion transport 7669-7687. the and Proc. Lunar N. crater W. (1960) and Gault 185-246. Calculations Summary Conf. 1974. High-explosive Santa J. Pre-impact Tabular Y. 84, G. Large-scale J. rim Grieve In roll Houston. J. Planetary R., Geological (M. W. Orbital W. Kieffer R. S., Institute, Crater, M., Lunar Res. W., 3081-3096. W., Planet. Cratering Impact dimensions D. 66 of Penetration structural of detonation 6th, (1979) May In Barbara, 0. depth/apparent F., and J. Kreyenhagen (abstract). Cratering Colton the fallback comparisons Sauer pp. Mississippi. Pergamon, E. and Rule R. 83, Lunar of Pepin, Dudash, Larson Sci. p. radar (1974) T. Arizona Snowball explosion Snowball geologic (1979) Prairie cratering of Sci. The A. Institute and 3459-3468. Conway impact Houston. 2621-2644. Congress, W., and F. explosion (D. Conf. Calif. cratering G. F. uplift, evidence and ejecta and on Co1if. role and M., of Guidebook Explosion S. (D. In Atmospheric Ward (1977) the J. W., ed.), Flat N. (abstract). a high and conditions, A., K., Misc. Planetary R. of Lunar 7th, of and Roddy, and orientations diameter layered J. J. diameter, Y. modification • and in 9th, the rim multiring B. S. cratering-I p. A. XX! Roddy, Provided and and explosion analogs velocity Shock Jones ground the for p. H., Paper Merrill, Flynn 284-300. Dial slumping (1972) and p. Cratering 3027-3056. to Orpha! R. lunar Schultz modification Session, medium. 3891-3930. In relation G. crater, Phillips Science effects the physical attenuation 0. depth, Planetary R. A. for motion explosion Creek N-72-9. Lunar meteorites, of Dial by H. subsurface craters: of eds.), 0. Geolo;u Pepin, L. I bowl-shaped, joints, D. DASA in Cratering P. the lunar S. Canada. for Jr. Part on (D. Pepin, U.S. R. volume, the Pack: impact IX, und (1980) H. experiments. (1977) properties, 58 NASA p. Cratering martian of lunar (1975) J., and Science J. modification Comparisons crater. crater 18, (1980) faults at 125-162. Plunetury pp. Army p. qf impact 2377-1 illustrated Jordan and Roddy, Crater layering R. Calculations terrestrial Cratering crater, mechanics p. Meteor 823-825. craters. In and Astrophysics Meteor B. 418-434. impact ejecta R. and central Calculations Impact Proc. XI, Engineer 1. craters. mass-balance energy Merrill, R. flow and B. In Pergamon, R. United in Science walls DASA Crater. p. by Proc. of L., Merrill, emplacement. Operation motions Crater, Lunar of 0. impact Maria Lunar morphology. ejecta uplift, and 833-835. lunar and fields Meteor of calculations, Abbott morphological !cams Waterways at eds.), Pepin, States, Lunar phenomenology. impact DataSystem Information XI, Explosion 37th Meteor of Serenitatis Sci. impact and measurements and eds.), structures. Arizona, N.Y. and calculations. impact Crater, p. p. Prairie 42, E. Lunar and Sci. Ann. Con{. Steinheim Planetary multi-ring structural 678-702. 946-948. cratering J. A., p. J. craters. 1-19. Crater, Exper- 2375 Col?f. R. mete- Geo- 907- Geo- Cra- melt Met. rim- 8th, Flat and and and and Ari- and B. In 1980LPSC...11.2347C Thomsen Stoffler Thomsen Whitford-Stark 2376 defined In expressions a Z ejection sions same continues Assumptions laboratory-scale XI, Conj. into investigation 1148. constant cratering this APPENDIX © SPATIAL quantities (Eqs. p. quartz appendix, D., Lunar Lunar Fig. in 10th, Yi d{ at 1242-1244. J. J. to _____ Fig. the Z, flow Gault M., M., AI. y derived la, -·-----Rg--• i------Ru------•~I S. ___ sand: follow p. b EDOZ and ground and of J. and K. Al. lb, field by Schematic Austin 2741-2756. Austin quantitative (Xm,Ym)_____.. impact (1980) D. impact Distribution Planetary FEATURES Planetary Maxwell Croft and the c Lunar by In with A: E., _.,,,...,, flow were level Maxwell the M. Z M. le The cratering Wedekind MATHEMATICAL cratering an streamlines field and /...... ____/ below); drawing Generalized G., (section suggested G., derivations, ------r- effective and Institute, formulae craters Institute and Planetary and in Ruhl (1973, Seifert the dynamics: b) event J., shock OF defining Schultz 2) of ___ crater S. main streamlines until by are . and and Houston. A. 1977) ae Imbrium Mare • (1974) it '--Arbitrary A F., (abstract). Thomsen Institute, metamorphism derived Provided is total Polkowski text. spallation CONSTANT of P. symbols Schultz Z-Model Early and assumed flow H. for ejecta The Maxwell in originate (1980) surface time (EDOZ) DESCRIPTION OF DESCRIPTION Houston. et outline by In P. used geometry occurs G. al. volumes that: (abstract). Transient the Lunar H., Ro material of The (1975) (1979, in bursts and Geometry ejecta. at NASA for and at a) derivations at, Z, development an and constant selected Seifert flow and (section Experimental or Orpha! 1980). motions. EDOZ EDOZ (d Crater J. In Astrophysics Planetary slightly symbols = streamlines Geophys. Lunar (1974) 0). • The spatial depth. 3) D. in I I I I I I located The -~--I- Proc. parallel FLOW of above, Appendix. L. derivations and used for Science the hypervelocity SELECTED features Such derived (1979) Res. I I I I I I I Lunar near-surface are Data Planetary at are ejecta derivations the depth a 80, FIELD defined illustrated field Calculational XI, System ground of formulae Planet. 4062-4077. of I I I 1 plume a d; p. is angles constant Science impact termed c) by 1146- explo- of level. Sci. in flow and the are the of a 1980LPSC...11.2347C from overlapping the EDOZ, shown and From Eliminating 2. I. Substitution surface 3. Substituting Maximum Strewn/inf' A The The The This apparent Ford= E_j('cta nJ?le vertical Eq. in rectangular © polar angle Y yields is both of Lunar la: = the l'0!11mf's: sets Rs, ejection 0, depth crater Streamline Streamline where Maximum of components distance downward properties: cases Rs for (after result l1 Rg(=Ra) (see Eq. of = and = Ro coordinates of components radius. em= 0°, R,, to 2a, in Fig. at some given and Planetary excm below de= reduce (1 spherical Eq. ground streamline equation 2b, equation axis), and cos- 1) + Y of algebra): From by 2f m atio11, Ra is 2c, sin~) velocity original solving in 1 to reduces l(Z-2)/(Z-1)]. given Maxwell (Z-2)[Z-ul-Z)l(Z-2)/[cos~ and are level: and Eq. are Institute the coordinates: 11 (rect.) (polar) Fig. R, cl,,: (z- depth: used: = rectangular found 2d by: expressions le for 2 ground = along U Ur= )_ tan- By A V to into yields: 0 R and I, Ro Ux UY = spherical = 3 definition, 1 /[cos~ by cb • Jf r aR-Z aR- _ a yields: Seifert ------= = Eq. ~ COSLl tanll plane). Provided = J streamline orthogonal ------. COSu Ur Ur r tan (X 2 Xm X 2 Ym Y R 1 2e, given (Z-2)sine/(l (1 sine cos~ sin~ - = polar = = = (1974) 1 + = = - and de tan (Z-2). R, R, R, horizontal de ta~ sin~) R, R, by + by = - , 2 ( cose(l-cose) sine (1 (R Ll are l-cose) recognizing dr transformation (Z-2)[Z-1]0-Z)/(Z- sinem(l-cosem) U U0 Maxwell Y and the + + 0 (Z-1) 11 = dq.i. m (Orpha!, (z- cos~. (Z-2)] sin~)ll(Z-2)] sin~ + for radial NASA Orpha! 2 Cratering 11 >]. cose) distance cz-z) the and . distance 11 that streamline 'z- Astrophysics 1977): (1977). Seifert 11 21 to + (Z- from e 2 + ) flow d. 2 be: + = J d from d 90° (1974) vertical for fields EDOZ, + Data (c) (b) (a) (e) (d) which fl ford at axis System the e = Rg through = 0. ground = 2377 angle Two Ra, (h) (b) (f) (g) (a) (d) (c) (e) (i) (f) (a) 1980LPSC...11.2347C 2378 The For the bounded the Substituting This For 4. Substituting Ye, where which streamline. above given e e cavity that Now From and = Structurul triangle transient is excavation d axial 0 the is © from equating by: that and = Eqs. the wall R, in the Lunar material 0, by practice is symmetry original fii, of between Eq. result is bounded la, found the into Eq. S. cavity a and pushed = rim and yields right If, la cavity K. line 0, Eq. lh continues found uplift: fi ground from must and Eq. Crr~fi Planetary for is = EDOZ Rs circular by and into la (after arbitrary. 90 volume 3e lg and R line Eq. by = and be To 0 Eq. V + the level we reduces 27T and s1, 3 Maxwell sin8 interated the along rearranging): .:i obtain 4c RS, and solving cone V find: wall, = R Ve and la Institute is and e rearranging ° at streamline 27T = Given :i - the the seen relating - _ [(Z-2)j the the of [(l-cosfi/- 90 to 2rr the (Z+ displacing 0 0 8 Ro J 3 (rr Rg for ground and intersection from base to 90+1> + range, streamline I in R J structural 3 = the I) 8 Ro 8 find _cl_ • ·1 Fig. Ra+ Seifert cos~ R = r are (Z+l) (Z-2) ei Ri 2Ra is Eq. 2 Provided [1 intersection yields: yields: Z+I surface, sinfi Ro and = Rg, given ll hu Ru= = + an equal IA 2 2rr(Z- 4e. and 3 R tan- (1 and Xjsinei. + = s (1974). where 0 (Z+ dr equal - fi, during inll] rim (1 to point + (I Rh Finally, Rh by: height 1 27T dfi the by 3 + be Sino)l/(Z-ZJ Rg, [Xj(Yi-d)J and + 1) by uplift, 2) sin8 Z+I z-2 cos8. sin~) R = volume assumption. sinll{- the the (Xi, (Xi, volumes + I a uplift The the 277 the ·1 . cos'l~ d. d - ( the sum streamline 3 i,rz- R/ 1 - 1 it YJ; sinll Z+I NASA Yi) Therefore: line volumes is as range, (assuming 2 2 90+1> J of > Z+l 0 of ) assumed J we Z-2 Z+I bracketed of indicated 3 ) . ) 3 Ra. Ys1. the ( Astrophysics Solving rotation have: 3 1-cosfi{- -1. Ru, emerges. along and streamline no and that in the by Eq. 3 bulking the of 2 Fig. height material d. de volume It the 3b streamline This Data is with IA. for area further or of latter each of along The compression) uplift, System the in rotation transient assumed shape Fig. between volume, range a hu, given are IA (b) (b) (c) (d) (h) (a) (e) (d) (e) (c) (g) (f) (f) of of of