A team of researchers at the Lawrence Livermore National Laboratory (LLNL) have inferred the evolution of the topography of the red planet by analyzing an early Martian meteorite. The scientists have discovered the earliest known red planet meteorite which dates back to near about 4.4 billion years ago.
This meteorite known as the Northwest Africa (NWA) 7034 lies under the category of a breccia, which means it consists of many different rocks of the crust that were mixed and sintered long back. This is said to be the only specimen from the red planet that has a composition, which represents the average crust of the planet. The researchers involved in the study got unique clues about the oldest crust of the red planet.
As part of the study, the team of researchers applied several radioisotopic dating methods on the meteorite. The researchers drew the conclusion that the split in between the red planet’s densely cantered Southern Highlands and the smoother Northern Lowlands had evolved way before the evolution of the NWA 7034. These observations of the new study were published in the Science Advances journal on 23rd May.
The lead author of the study, Bill Cassata, a cosmochemist at the Lawrence Livermore National Laboratory said in a statement, “If the Martian crustal dichotomy formed as a result of a giant impact, and available data and modeling suggest this is likely, the history of NWA 7034 requires that it formed very early in the planet’s history, before 4.4 billion years ago.”
On the basis of the collaboration of the radioisotopic estimations with the previously published information, the involved team of researchers pointed out that all of the crustal rocks within the NWA 7034 meteorite breccia were laid out in the “source terrain” around 4.4 billion years ago. Further, the study results highlighted that the “source terrain” faced the process of metamorphism for a long duration along with a huge “plume-fed volcanic center” from near about 1.7 – 1.3 billion year ago. The study also brought to light that the rocks came together near about two hundred million years ago.
The co-author of the study, Caroline Smith, who is the head of the Earth Sciences Collections, said, “This multi-disciplinary study, combining both traditional and innovative geochemical techniques has provided us with some exciting new insights into the timings of major processes that shaped young Mars.”
The main author Cassata, highlighting the importance of the study, said, “This study demonstrates that multiple radioisotopic dating systems that are reset by different metamorphic processes can be used to tease out the thermal history of a sample over billions of years.”