AS15-1010(M)

Figure 67

 Click here for larger NASA image
 Click here for lunar chart showing location

This area is east of that covered in figures 65 and 66; the large crater is Lambert. Here also lava flows of more than one age are present. A sinuous band of smooth, sparsely cratered mare extends northeastward through the center of the picture. It is most certainly a young lava flow and contrasts strongly with the much more densely cratered older mare southeast of the dashed line marking the contact between the two. The western boundary of the young lava flow clearly laps upon and embays the blanket of ejecta deposits surrounding Lambert. Many radial ridges of ejecta and radial grooves or chains of secondary craters radiating outward from Lambert are faintly visible beneath the younger flow near its western boundary. These relationships prove that the younger flow postdates the formation of the crater. Many clusters of secondary craters from craters other than Lambert are present. The shape, orientation, and freshness of some (indicated by arrows) lead us to believe they were probably formed by ejecta from Copernicus, which lies 360 km further south. They are present on the older mare, on the ejecta from Lambert, and elsewhere around this area. However, none is present on the younger flow. If this observation is supported by further study, the younger flow must postdate even the crater Copernicus, and thus be younger than any other extensive lava flow recognized to date.
 -H.M.