Geologist lingo:

• Coring - Drilling in order to acquire a “core sample”, in this case for return to Earth (hopefully). Often proves difficult, on every planet we’ve tried it.
• Conglomerate - Sedimentary rock that contains rounded pebbles surrounded by finer-grained stuff (e.g. mud, sand), like raisins sprinkled in dough. Not surprising to find these where a river flowed, naturally.
• Delta fan - the flattish “platform” of sediment dumped by a river entering a larger, calmer body of water.
• Vug - Small cavity inside a rock, as distinct from a mineral vein (which are long, narrow, and filled in). Can be created by a variety of causes. Sometimes filled in later, by agents such as flowing groundwater.