Dissection of 68001, the bottom section of Apollo 16 double drive tube 68002/68001 has been completed. The core was dissected in 0.5-cm depth increments along three l-cm-thick longitudinal layers (passes) starting at the top of this section and continuing through the length (34. l cm) of the core. Soil from each increment of the first and third passes was separated into coarse and fine fractions using a l-mm sieve. The coarse particles were examined and photo-documented. Samples from the second or chemically pure pass were not sieved or examined in detail.
68001 was extruded on December 14, 1993. The length after extrusion was 34.1 cm; thus the total length of 68002/1 was 61 cm. The color of 68001 varied from 10YR 5/1 to 7/1 on the Munsell Color Scale and several distinct color boundaries were observed during the dissection passes. A void at the top end extended to about 1.5 cm. At 0 to about 9.0 cm was a dark layer, approximately 10YR 5/1. Dark soil breccias and soil clods were abundant and varied from small at the top to larger toward the lower end of this layer of the core. Black fine-grained glassy particles are abundant as well as some glass and anorthosites. From about 9.0 to 12.5 cm is a layer of lighter gray soil (10YR 7/1) characterized by light gray clods/soil breccias which dominate the >l-mm fraction. Anorthosites are rare and small black glassy particles are fairly numerous. At 12.5 cm and continuing to about 15 cm is a darker slightly bluish-gray layer. The >l-mm fraction consists of all coherent particles; they are generally small black glassy pieces, and breccias with a few anorthosites and glass. At about 15 cm the soil becomes a brownish-gray color (10YR 6/1) and is noticeably loose and coarse-grained. >l-mm particles are numerous and all are coherent (no friable soil breccias). A finger of light gray material extends about two thirds of the diameter of the core at about 18.0 - 18.5 cm with obvious mm-sized white fragments occurring. From about 21.5 cm and continuing to the bottom of the core is a lighter-colored zone of soil which is more coherent and whose >l-mm portion is rich in soil breccias (both clods and coherent breccias) and black glassy fine-grained fragments.
A close examination of particles >1-mm from the first and second dissection passes showed that about 81% (by number) of the particles are in the 1-2 mm size range, 18% were 2-4 mm, and 1% were 4-10 mm or >10 mm.
Lithology of the >l-mm fraction was deterrnined by binocular microscopic examination of the particles from the first and second passes and is summarized as follows: 47% are various types of breccias and dusty fragments which were difficult to identify, 37% are black fine-grained glassy fragments, about 10% are white or light gray (anorthositic), 6% are glasses, and <1% are basalts. Among the 20 large or unusual particles >l mm which were given individual sample numbers are soil breccias, black glassy fragments, white fragments, and a small soil clod with a rusty-looking spot. Three samples of about .5g each were taken under red-light conditions from three depths of approximately 10, 20, and 30 cm.
Diagrams for the three dissection passes follow and identify samples splits which are available for allocation. Weights are given in grams and "Bx" is used as an abbreviation for "breccia."