A record of ancient tectonic stress on Mars
Sets of ridges and troughs some 1000 km north of the giant Olympus Mons volcano contain a record of the intense tectonic stresses and strains experienced in the Acheron Fossae region on Mars 3.7–3.9 billion years ago.
Acheron Fossae is part of a network of fractures that radiates from the Tharsis 'bulge' some 1000 km to the south, home to the largest volcanoes on Mars. As the Tharsis region swelled with hot material rising from deep inside Mars as the volcanoes formed, it stretched and pulled apart the crust along lines of weakness over a wide area.
The pattern of cross-cutting faults seen in various places in Acheron Fossae implies the region experienced stresses from different directions over time, suggesting a complex history.
Acheron Fossae has been likened to Earth's continental rift systems. Major rift zones on Earth are associated with plate tectonics, such as mid-ocean ridges that are spreading apart.
|This context image shows part of Acheron Fossae on Mars imaged by
Mars Express |
on 4 May 2016 during orbit 15641 (outlined by the large white box)
[Credit: NASA MGS MOLA Science Team]
Source: European Space Agency [November 03, 2016]