In contrast, Rainer and Thomas usually followed a specific direction until almost out of sight, then they would return and start off again in a slightly diverging direction – a tactic that Andi and I had dubbed the ‘Bartoschewitz-fan”. Another difference was their search speed, which was significantly higher than the usual, slightly faster than walking pace that we others applied. On the other hand, they often stopped and searched a selected zone on foot. Statistically, per car and unit time, all three approaches lead to an almost identical number of finds and recovered weight. Although this may sound perplexing, it was obvious that in total only the distance and surface covered counted, and that was almost the same for all three crews.
For the afternoon, Andi and I decided to expand our gridding in a northern direction along the borders of the Gart Aouirtefou. Orientation was easy, as we just had to keep the inselberg visible in our mirrors behind us in the southeast.
Unfortunately, after another two hours of searching, we reached an area where the light-coloured limestone gravel was littered with a particularly black variant of fist-sized silcrete fragments. These were dark brown to black remains of a duricrust composed of dissolved and resolidified silica that had formed during arid conditions in the Tertiary. The abundance of this particularly annoying type of pseudometeoritic debris rendered the visual recognition of any potential meteorites that may have been hidden among the black fields almost impossible.
In the hope of a better search ground elsewhere we abandoned our track and instead decided to return to the spot of our first find. From there we would circumnavigate the valley counter clockwise. With the sun beginning to lower in the west this would give us a good field of view ahead and to the right for the best part of this course.
Another two hours later we reached the northern tip of the valley and we were now again facing the blinding sun ahead in the west. Below us, at the foot of the 60-feet cliff lay the valley floor with its treacherous fields of bottomless fech fech. In the east the terrain gently dipped towards the towering dunes of the Draá Afrafir, which could be seen looming at the horizon less then ten miles away.
With limited options at hand we made a choice to take the shortest way back to our rendezvous point and that meant getting down into the valley at our feet and subsequently crossing the Grart Aouirtefou. Together we scouted for a passage down the cliffs and after some walking along the edge we found a natural ramp that, with some good will, could be considered navigable. ‘Might be tricky though” Andi commented at the sight of the narrow slope.
I was equally uneasy, and to increase our chances we rolled some larger rocks out of the way before I carefully steered the car down the steep slope. ‘Wow!’ it came from Andi, ‘piece of cake’ I smiled back with newly gained confidence. Then, for a while, we slowly rolled southwards across the Aouirtefou towards our meeting point, looking out for meteorites on our way.