I dusted off a used Geology-101 textbook, that's
not too old [circa:1996], and found that it
still listed the three basic geologic forms
I learned about in high-school [years and years ago].

> Igneous

> Sedimentary

> Metamorphic.

Now, with planetary science having attained the maturity
it now has, are there any additions to those three?

My view [opinion] is...is that...

[1] A large asteroid/comet impact will generate limited/local igneous rock within or near the formed impact crater

[2] The impact shockwave [if it's large enough] will deform sedimentary layers, converting it into "metamorphic rock forms" near the impact zone.

[3] And descending & settling asteroidal/cometary dust may
[depending on the frequency of impacts in the area] form nearby "sedimentary-type" layers over a long period of time.
Agree?

By the way, Dr. Blackwell, what do you think of my revised
and refined crude calculations for the newly-discovered
NEO "asteroid-pair" 1994 KW4?

My calculations indicated that the larger asteroidal body of that 'asteroid' pair [diameter: 1200 meters], orbited by the smaller body [orbital radius: 2200 meters] over a period of 16 hours, may have a bulk density of a little over 1000kg/m^3...

Is that density value too low for even a "rubble pile"
asteroid?....I would think it might be a "burnt-out" comet
nuclei with abundant frozen water still mingled with the "rock/dirt rubble".

Jacob