The Apollo 17 drill core - Modal petrology and glass chemistry /sections 70007, 70008, 70009/

On the basis of modal petrography the upper, mare basalt-rich portion of the Apollo 17 drill core (sections 70007, 70008, 70009) can be subdivided into three major stratigraphic units. The lower unit (a) falls within 70007, is relatively mature, and contains evidence of an increase in highland component and decrease of mare component within the lower approximately 8 cm. The middle unit (b) is coarse-grained and relatively immature; this unit has the highest concentration of mare basalt lithic and mineral fragments and mare orange/black glasses. The top unit (c) falls within 70009 and is relatively mature. Within these three sections of the drill core, there are compositional clusters of glass beads that correspond to high Ti subfloor basalt (orange/black glass), anorthositic gabbro (clear glass), and a new very low Ti (VLT) mare basalt (yellow/green glass).