Geologic map of the Fracastorius Quadrangle of the Moon

The multi-ringed Nectaris basin (Hartmann and Kuiper, 1962) dominates the Fracastorius quadrangle. The basin is 840 km across as measured from the outermost ring and lies athwart four quadrangles. Fracastorius, the southeastern quadrangle, straddles the three rings of the basin (fig. 1). In this quadrangle most pre-Imbrian structures and many depositions were formed by the Nectaris impact. Furthermore, the emplacement of many younger deposits was controlled by basin structures and locally by probable multi-ring structures related to the Fecunditatis basin centered northeast of the quadrangle. Other geologic features in the area include diverse mantling deposits and both primary impact craters and secondary impact craters produced by ejecta from distant impacts.