A so-called light-toned deposit (LTD) in Eastern Noctis Labyrinthus, about 160 km (99.4 miles) north-west of Oudemans crater near Mars’ equator, presents distinctive morphologic characteristics of a glacier, according to new research. Although the glacier is likely relict, the preservation of glacial features opens the possibility that water ice might still be preserved beneath LTD material.
“What we’ve found is not ice, but a salt deposit with the detailed morphologic features of a glacier,” said lead author Dr. Pascal Lee, a planetary scientist with the SETI Institute and the Mars Institute.
“What we think happened here is that salt formed on top of a glacier while preserving the shape of the ice below, down to details like crevasse fields and moraine bands.”
The relict glacier is estimated to be 6 km (3.7 miles) long and up to 4 km (2.5 miles) wide, with a surface elevation ranging from 1.3 to 1.7 km (0.9-1.1 miles).
The presence of volcanic materials blanketing the region hints of how the sulfate salts might have formed and preserved a glacier’s imprint underneath.
When freshly erupted pyroclastic materials come in contact with water ice, sulfate salts like the ones commonly making up Mars’ LTDs may form and build up into a hardened, crusty salt layer.
“This region of Mars has a history of volcanic activity,” said co-author Sourabh Shubham, a graduate student at the University of Maryland.
“And where some of the volcanic materials came in contact with glacier ice, chemical reactions would have taken place at the boundary between the two to form a hardened layer of sulfate salts.”
“This is the most likely explanation for the hydrated and hydroxylated sulfates we observe in this LTD.”
Over time, with erosion removing the blanketing volcanic materials, a crusty layer of sulfates mirroring the glacier ice underneath became exposed, which would explain how a salt deposit is now visible, presenting features unique to glaciers such…
Read the full article here