6.2 Compaction Band Zones‌

The photographs in Figure 14 show zones of compaction bands composed of subparallel, closely spaced, single compaction bands in Aztec Sandstone, Valley of Fire State Park, USA. Figure 14a shows a simple zone with a few individual bands. An image of multiple compaction band zones in Figure 14b shows a series of eye structures formed by overlapping neighboring zones with individual zigzag bands inside and outside of the relay zone which is located between and delimited by the main segments of the compaction bands.

Figure 14 – Compaction band zones. a) A narrow band with a few single subparallel bands. b) A well-developed compaction band zone with overlapping bands and their splays. From Aydin and Zhong (2017).

The compaction band zones in Figure 14a and Figure 14b developed by the sequential formation of individual bands adjacent to one another, as schematically reported in the series of diagrams of Figure 15a-d. The simplest case is when adjacent bands sequentially develop parallel to one another (Figure 15a). Adjacent bands may interact with each other, partially overlapping and converging, and either forming eye structures (Figure 15b) or diverging away from the zone (Figure 15c). Figure 15d shows a more complex zone with several zigzag splays or tail bands (further details are provided by: Eichhubl et al., 2010; Liu et al., 2015).

Figure 15 – Schematic diagrams showing compaction band zones: a) subparallel bands; b) converging and overlapping bands forming an eye structure; c) subparallel and diverging bands; and, d) subparallel bands with complex splays.