Sol Summary – July 24th

Written by Jon Clarke

Sol 8 (or 88)

Very still overnight, and when we woke we found out why; the fog had
come in and the hab was enveloped in cloud. We could still see the
crater floor though, so the cloud base must have been just below us.
The fog gradually lifted, and when we went on our EVA visibility was
clear for the area we wanted to visit.

For a change there was no wind and no rain, so it was a suited EVA.
Our goal was to sample the limestones that form the rim of the crater.
We climbed Haynes Ridge and found a range of carbonate lithologies,
including stromatolites, burrowed mudstones, megafossil rich units
(stromatoporoids), and horizons rich in skeletal fragments. Sampling
finished we then proceeded to our secondary objectives, which was to
investigate the nature of some large rocks on the sides of the crater
a few km from the station. We descended from the rim and walked down
the sloping sides across block streams and muddy polygonal ground. In
several places we had to take care to step only on the stone polygons
to avoid getting bogged in the softer centres. The boulders were
about the side or shipping containers and proved to be of complex
brecciated limestone formed by the Haughton impact event, excavated
from the bedrock and then emplaced from the crater floor. It was
problem also scattered across the landscape surrounding the crater
too, but that has long been eroded. Exploring these deposits was a
very martian experience, as such impact breccias are common on Mars
and the Moon. Then it was back to the hab to process our data.

We have another birthday, Paul’s. He’s the youngest of our group and
our second geologist. Alex and Anastasiya cooked spaghetti carbonara.
Yusuke made a piñata. Tonight we will also watch a video to celebrate.
Paul’s choice and he’s not telling us what it is! As we have been
preparing to celebrate, the fog has really rolled in, we can’t even
see the crater floor now. So it’s goodnight from a snug and fogbound
FMARS.

Jon Clarke