This region covers that part of the northwestern far side between the East Limb, past the 180° meridian, all the way to 150° west longitude. It covers from 20° north to 60° north latitude.
This area is entirely covered with craters of all sizes and a few basins. The upper layers of the surface have been deposited by ejecta from several basins. Most recently, the Hum-boldtianum Basin and the Moscoviense Basin (Figure 9.1) arrived in the Nectarian Period, the time range when most of the large craters struck as well. In the pre-Nectarian era, Freundlich-Sharanov and Birkoff left their deposits. Below those layers is a layer from the South Pole-Aitken Basin that is at least 100 m thick.
The proposed Near Side Megabasin would have deposited the foundation layer of ejecta over most of this region. The rim of the Near Side Megabasin runs along the 130° east meridian. Its ejecta blanket covers all the Northwestern Far Side Region east of the rim.
The deep layers of ejecta material that have been reworked by going through the impact process repeatedly have resulted in a surface that is very uniform in element composition. Except for Mare Moscoviense, there are only a few small patches of mare material.
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