Martian Low-Aspect-Ratio Layered Ejecta (LARLE) craters

Distribution, characteristics, and relationship to pedestal craters

Nadine Barlow, Joseph M. Boyce, Carin Cornwall

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Low-Aspect-Ratio Layered Ejecta (LARLE) craters are a unique landform found on Mars. LARLE craters are characterized by a crater and normal layered ejecta pattern surrounded by an extensive but thin outer deposit which terminates in a sinuous, almost flame-like morphology. We have conducted a survey to identify all LARLE craters ≥1-km-diameter within the ±75° latitude zone and to determine their morphologic and morphometric characteristics. The survey reveals 140 LARLE craters, with the majority (91%) located poleward of 40°S and 35°N and all occurring within thick mantles of fine-grained deposits which are likely ice-rich. LARLE craters range in diameter from the cut-off limit of 1. km up to 12.2. km, with 83% being smaller than 5. km. The radius of the outer LARLE deposit displays a linear trend with the crater radius and is greatest at higher polar latitudes. The LARLE deposit ranges in length between 2.56 and 14.81 crater radii in average extent, with maximum length extending up to 21.4 crater radii. The LARLE layer is very sinuous, with lobateness values ranging between 1.45 and 4.35. LARLE craters display a number of characteristics in common with pedestal craters and we propose that pedestal craters are eroded versions of LARLE craters. The distribution and characteristics of the LARLE craters lead us to propose that impact excavation into ice-rich fine-grained deposits produces a dusty base surge cloud (like those produced by explosion craters) that deposits dust and ice particles to create the LARLE layers. Salts emplaced by upward migration of water through the LARLE deposit produce a surficial duricrust layer which protects the deposit from immediate removal by eolian processes.

Original languageEnglish (US)
Pages (from-to)186-200
Number of pages15
JournalIcarus
Volume239
DOIs
StatePublished - Sep 1 2014

Fingerprint

low aspect ratio
ejecta
craters
crater
deposits
ice
radii
distribution
duricrust
landforms
excavation
eolian process

Keywords

  • Cratering
  • Geological processes
  • Impact processes
  • Mars, surface

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Martian Low-Aspect-Ratio Layered Ejecta (LARLE) craters : Distribution, characteristics, and relationship to pedestal craters. / Barlow, Nadine; Boyce, Joseph M.; Cornwall, Carin.

In: Icarus, Vol. 239, 01.09.2014, p. 186-200.

Research output: Contribution to journalArticle

@article{7e5cb0aed8a54e8e8e4bdf5c18edf2c3,
title = "Martian Low-Aspect-Ratio Layered Ejecta (LARLE) craters: Distribution, characteristics, and relationship to pedestal craters",
abstract = "Low-Aspect-Ratio Layered Ejecta (LARLE) craters are a unique landform found on Mars. LARLE craters are characterized by a crater and normal layered ejecta pattern surrounded by an extensive but thin outer deposit which terminates in a sinuous, almost flame-like morphology. We have conducted a survey to identify all LARLE craters ≥1-km-diameter within the ±75° latitude zone and to determine their morphologic and morphometric characteristics. The survey reveals 140 LARLE craters, with the majority (91{\%}) located poleward of 40°S and 35°N and all occurring within thick mantles of fine-grained deposits which are likely ice-rich. LARLE craters range in diameter from the cut-off limit of 1. km up to 12.2. km, with 83{\%} being smaller than 5. km. The radius of the outer LARLE deposit displays a linear trend with the crater radius and is greatest at higher polar latitudes. The LARLE deposit ranges in length between 2.56 and 14.81 crater radii in average extent, with maximum length extending up to 21.4 crater radii. The LARLE layer is very sinuous, with lobateness values ranging between 1.45 and 4.35. LARLE craters display a number of characteristics in common with pedestal craters and we propose that pedestal craters are eroded versions of LARLE craters. The distribution and characteristics of the LARLE craters lead us to propose that impact excavation into ice-rich fine-grained deposits produces a dusty base surge cloud (like those produced by explosion craters) that deposits dust and ice particles to create the LARLE layers. Salts emplaced by upward migration of water through the LARLE deposit produce a surficial duricrust layer which protects the deposit from immediate removal by eolian processes.",
keywords = "Cratering, Geological processes, Impact processes, Mars, surface",
author = "Nadine Barlow and Boyce, {Joseph M.} and Carin Cornwall",
year = "2014",
month = "9",
day = "1",
doi = "10.1016/j.icarus.2014.05.037",
language = "English (US)",
volume = "239",
pages = "186--200",
journal = "Icarus",
issn = "0019-1035",
publisher = "Academic Press Inc.",

}

TY - JOUR

T1 - Martian Low-Aspect-Ratio Layered Ejecta (LARLE) craters

T2 - Distribution, characteristics, and relationship to pedestal craters

AU - Barlow, Nadine

AU - Boyce, Joseph M.

AU - Cornwall, Carin

PY - 2014/9/1

Y1 - 2014/9/1

N2 - Low-Aspect-Ratio Layered Ejecta (LARLE) craters are a unique landform found on Mars. LARLE craters are characterized by a crater and normal layered ejecta pattern surrounded by an extensive but thin outer deposit which terminates in a sinuous, almost flame-like morphology. We have conducted a survey to identify all LARLE craters ≥1-km-diameter within the ±75° latitude zone and to determine their morphologic and morphometric characteristics. The survey reveals 140 LARLE craters, with the majority (91%) located poleward of 40°S and 35°N and all occurring within thick mantles of fine-grained deposits which are likely ice-rich. LARLE craters range in diameter from the cut-off limit of 1. km up to 12.2. km, with 83% being smaller than 5. km. The radius of the outer LARLE deposit displays a linear trend with the crater radius and is greatest at higher polar latitudes. The LARLE deposit ranges in length between 2.56 and 14.81 crater radii in average extent, with maximum length extending up to 21.4 crater radii. The LARLE layer is very sinuous, with lobateness values ranging between 1.45 and 4.35. LARLE craters display a number of characteristics in common with pedestal craters and we propose that pedestal craters are eroded versions of LARLE craters. The distribution and characteristics of the LARLE craters lead us to propose that impact excavation into ice-rich fine-grained deposits produces a dusty base surge cloud (like those produced by explosion craters) that deposits dust and ice particles to create the LARLE layers. Salts emplaced by upward migration of water through the LARLE deposit produce a surficial duricrust layer which protects the deposit from immediate removal by eolian processes.

AB - Low-Aspect-Ratio Layered Ejecta (LARLE) craters are a unique landform found on Mars. LARLE craters are characterized by a crater and normal layered ejecta pattern surrounded by an extensive but thin outer deposit which terminates in a sinuous, almost flame-like morphology. We have conducted a survey to identify all LARLE craters ≥1-km-diameter within the ±75° latitude zone and to determine their morphologic and morphometric characteristics. The survey reveals 140 LARLE craters, with the majority (91%) located poleward of 40°S and 35°N and all occurring within thick mantles of fine-grained deposits which are likely ice-rich. LARLE craters range in diameter from the cut-off limit of 1. km up to 12.2. km, with 83% being smaller than 5. km. The radius of the outer LARLE deposit displays a linear trend with the crater radius and is greatest at higher polar latitudes. The LARLE deposit ranges in length between 2.56 and 14.81 crater radii in average extent, with maximum length extending up to 21.4 crater radii. The LARLE layer is very sinuous, with lobateness values ranging between 1.45 and 4.35. LARLE craters display a number of characteristics in common with pedestal craters and we propose that pedestal craters are eroded versions of LARLE craters. The distribution and characteristics of the LARLE craters lead us to propose that impact excavation into ice-rich fine-grained deposits produces a dusty base surge cloud (like those produced by explosion craters) that deposits dust and ice particles to create the LARLE layers. Salts emplaced by upward migration of water through the LARLE deposit produce a surficial duricrust layer which protects the deposit from immediate removal by eolian processes.

KW - Cratering

KW - Geological processes

KW - Impact processes

KW - Mars, surface

UR - http://www.scopus.com/inward/record.url?scp=84903541774&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84903541774&partnerID=8YFLogxK

U2 - 10.1016/j.icarus.2014.05.037

DO - 10.1016/j.icarus.2014.05.037

M3 - Article

VL - 239

SP - 186

EP - 200

JO - Icarus

JF - Icarus

SN - 0019-1035

ER -