Planet Trek:

Mapping New Worlds


Part II: Concept Introduction: Features

Activity #3 - Surface Processes

The surfaces of all terrestrial worlds are shaped by four essential processes:

Listed below are definitions of the 11 types of surface features you identified in Activity 2, along with 12 other features from the USGS Descriptor of Terms.

Surface Feature
Description
Catena

Chain of craters

Chasma

Deep, elongated, steep-sided depression

Craters

Circular depression

Dorsum

Ridge

Ejecta

Rays of debris from an impact crater

Fluctus

Flow terrain

Fossae

Long, narrow, shallow depression

Labes

Landslide

Lacus

"Lake" - small plain

Lenticula

Small dark spots on Europa

Mare or Maria

"Sea" - large circular plain

Mensae

Flat-topped prominence with cliff-like edges

Mons

Mountains

Reticula

Reticular or netlike pattern on Venus

Rima or Rimae

Fissure

Rupes

Scarp (cliffs produced by faulting or erosion)

Sinus

"Bay" - small plain

Sulcus or Sulci

Subparallel furrows and ridges

Tessera or Tesserae

Tile-like, polygonal terrain

Tholus or Tholi

Small, domical mountain or hill

Undae

Dunes

Vallis or Valles

Valley

Volcano

Mons (mountains) that erupted

Using the description for these terms, decide which type of surface process created each one. List each of the terms in the correct category below to complete the table. Please note that some of these may fit into more than one process!

Volcanism
Impact Craters

Erosion/Volatiles
Tectonics


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