From The rover’s Blog: The plan was to image three rocks the MAHLI camera during that sol :-

1. Bedrock target “La Tranquita” - It’s not that target as that was brushed with the rover’s DRT.
2. A plate-like rock formation, target named “Aqua Dulce.”
3. A target with more complex rock structures dubbed “Paposo” I believe this is the small target in that MAHLI I posted earlier.

As for its composition it is too early to tell. This is a near record elevation for the rover having climbed since landing 2012, so these are new (to the rover) rock types. The orbital data from the satellites suggested that this region is filled with sedimentary rocks a little over 3 billion years old and that the 'Boxwork Structures the rover is now exploring has large mineral filled fractures that created by mineral rich ground waters, the rover team are currently investigating the rocks to obtain the ground truth, and comparing it with the orbital data.

Here’s the extract from the blog for the afternoon of sol 4608 - "Curiosity’s arm will reach out to brush the dust from the bedrock target “La Tranquita,” then observe it with the MAHLI microscopic imager and APXS. MAHLI and APXS will also investigate plate-like rock formations at target “Aqua Dulce.” A third target with more complex rock structures dubbed “Paposo,” after a natural monument along the Pacific Coast of northern Chile, will be imaged only by MAHLI. The next morning will include another targeted science block. Curiosity will then drive away toward the next viewpoint in the boxwork terrain of Mars.