of the thinner, more distal parts of Alpes Formation of the Imbrium Basin on the Moon. The Odin, like the Alpes, occurs in broad lobes such as those in Odin Planitia beyond the main basin scarp. Odin also mantles the intercrater plains ancient crater materials out to a distance of 1200 km from the main Caloris scarp. The Odin Formation is interpreted as part of the Caloris ejecta sequence, but its mode of origin is less clear than those of certain other Caloris formations. The unit may consist of late-arriving, blocky, coherent ejecta from deep within the Caloris cavity, later partly buried by smooth plains. Odin locally mantles intercrater plains, lineated plains, and intermediate plains materials to a distance of 1,100 km from the Caloris Basin scarp. It is named after Odin Planitia Van Eyck Formation The Van Eyck Formation, which is the most distinctive of the circum-Caloris stratigraphic units, was called the Caloris lineated terrain by Trask and Guest. It is named after the Van Eyck crater. The Van Eyck Formation has a lineated facies and a secondary-crater facies. The lineated facies extends from the Caloris Montes as much as about 1,000 km. It consists of long, hilly ridges and grooves that are subradial to the Caloris Basin and are extensively embayed by smooth plains. The inner boundary of the Van Eyck is generally coincident with the weak outer Caloris scarp. The Van Eyck is similar in morphology but somewhat more degraded than the Fra Mauro Formation around the Imbrium Basin on the Moon; secondary cratering and ballistic deposition of ejecta from Caloris undoubtedly played an important role in its emplacement. It is difficult to define individual secondary craters within the Van Eyck, but at a distance of about one basin diameter, numerous clusters and chains of moderately well preserved craters occur that are interpreted as far-flung Caloris secondary craters. These craters have been included in a separate facies of the Van Eyck Formation because of their regional stratigraphic significance. It is noteworthy that this lineated terrain occurs near the foot of the Caloris Montes, whereas similar units of the Imbrium Basin on the Moon occur farther from the basin rim. Such a difference in extent is to be expected because mercurian gravity is two and a half times greater than lunar gravity, and ejecta would fall closer to its source than ejecta from a similar-size basin on the