ISS030-E-254011 Click the photo number to access all resolutions available and the database record.
Originally called Tindouf, the 3.5-kilometer wide crater (image center) has been heavily eroded since its formation; however, its circular morphology is highlighted by exposures of older sedimentary rock layers that form roughly northwest to southeast-trending ridgelines. From the vantage point of an astronaut on the International Space Station, the impact crater is clearly visible with a magnifying camera lens.
A geologist interpreting this image to build a geological history of the region would conclude that the Ouarkziz crater is younger than the sedimentary rocks, as the rock layers had to be already present for the meteor to hit them. Likewise, a stream channel is visible cutting across the center of the structure, indicating that the channel formed after the impact had occurred. This Principal of Cross-Cutting Relationships, usually attributed to the 19th century geologist Charles Lyell, is a basic logic tool used by geologists to build relative sequence and history of events when investigating a region.
