Geologic Map of MTM −15032 and −20032 Quadrangles, Western Ladon Basin, Mars

Scientific Investigations Map 3525
Prepared for the National Aeronautics and Space Administration
By: , and 
Edited by: James A. Skinner

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Abstract

Our mapping efforts focused on the geomorphic terrains and geologic units contained within Mars Transverse Mercator (MTM) −15032 and −20032 quadrangles. These two quadrangles are located along the west side of Ladon basin and span lat −12.5° N. to −22.5° N. and long 325° E. to 330° E. The western part of Ladon basin and its bounding basin ring structures to the west preserved features that help to understand the long history of drainage across the Margaritifer Terra region of Mars. Our geologic map provides new insight into the extent of aqueous activity across western Ladon basin and the adjoining highlands, which includes the northern part of Ladon Valles, Arda Valles, numerous small valleys in the western highlands, and light-toned layered deposits associated with these fluvial features. The Mars Odyssey Thermal Emission Imaging System (THEMIS) infrared (IR) daytime mosaic (100 meters per pixel) was used as the primary base map. We constructed the geologic map of western Ladon basin at 1:1,000,000 scale. We identified 20 geologic units in the map area, which we divided into the following groups: crater units; volcanic units; chaotic units; basin fill units; crater, valley, and channel units; and plateau and highlands units.

We observed the following sequence of events: (1) formation of Ladon and Holden impact basins in the middle Noachian, producing a mountainous unit; (2) landscape degradation and infilling during the Late Noachian to Late Hesperian forming terra units; (3) formation of Ladon Valles in the Late Noachian to Early Hesperian by catastrophic flooding, producing channel units; (4) accumulation of sediments in the Late Noachian to Early Amazonian, forming basin fill units; (5) formation of a smooth crater fill unit during the Early to Late Hesperian; (6) deposition during the Late Hesperian to Early Amazonian, creating light-toned layered units within Ladon Valles, Ladon basin, and other smaller valley networks along the western uplands, as well as formation of a light-toned unit along some crater floors; (7) formation a of chaotic unit in the Early to Middle Amazonian, formation of alluvial fans in the Early Amazonian, and eruption of a volcanic unit in the Middle Amazonian; and (8) formation of craters throughout the geologic history of the map region.

Suggested Citation

Weitz, C.M., Wilson, S.A., Grant, J.A., and Irwin, R.P., III, 2025, Geologic map of MTM −15032 and −20032 quadrangles, western Ladon basin, Mars: U.S. Geological Survey Scientific Investigations Map 3525, pamphlet 14 p., 1 sheet, scale 1:1,000,000, https://doi.org/10.3133/sim3525.

ISSN: 2329-132X (online)

ISSN: 2329-1311 (print)

Table of Contents

  • Introduction
  • Physiography and Background
  • Base Map and Data
  • Methodology
  • Age Determinations
  • Geologic Summary
Publication type Report
Publication Subtype USGS Numbered Series
Title Geologic map of MTM −15032 and −20032 quadrangles, western Ladon basin, Mars
Series title Scientific Investigations Map
Series number 3525
DOI 10.3133/sim3525
Year Published 2025
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Astrogeology Science Center
Description Pamphlet: iv, 14 p.; 1 Sheet: 37.02 x 40.03 inches; Read Me: Metadata: Spatial Data
Other Geospatial Mars
Online Only (Y/N) N
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details