It's probably close to averaging a cozy 0 F (255 K) at no greater than
10 meters deep, and it shouldn't have any problems reaching 70 F (day
or night) at 100 km deep or possibly as shallow as 10 km (depending on
the core energy). The R-factor of lunar regolith (lose basalt rock
and loads of crystal dry dust that’s at minimum 10 meters deep) is
none too shabby, and otherwise the geothermal conductance and/or heat
transfer coefficient (aka geothermal gradient) of its paramagnetic
basalt crust of 3.5 g/cm3 density shouldn't be significantly any
different than here on Earth, except that our terrestrial basalt isn't
nearly as paramagnetic or much less offering carbonado, and the core
heat of Earth being 7000+ K as opposed to only 1000 K of our moon.
Supposedly there is only a wee little bit of lunar granite to deal
with, but the samples thus far are inconsistent in their composition.

A new interpretation is that all-inclusively the geothermal outflux of
Earth (including geothermal vents and volcanic contributions) is
getting rid of roughly 128 mw/m2, whereas our moon is supposedly only
getting rid of as little as 16 mw/m2 (an 8th as much).

http://en.wikipedia.org/wiki/Geothermal_gradient
“Geothermal gradient is the rate of increasing temperature with
respect to increasing depth in the Earth's interior.”

The "Igneous Petrology" of our moon and Venus should each be unique
and considerably different than Earth.

“The composition of igneous rocks and minerals can be determined via a
variety of methods of varying ease, cost, and complexity. The simplest
method is observation of hand samples with the naked eye and/or with a
hand lens. This can be used to gauge the general mineralogical
composition of the rock, which gives an insight into the composition.”

Unfortunately, the rocks returned from our moon were entirely similar
to those of terrestrial rocks. Of course there’s all sorts of actual
paramagnetic basalt moon rock to be found on Earth, because there
should be at least a thousand teratonnes of it, whereas naturally most
of which ended up in oceans and otherwise as having meteor and obvious
melt indications that are entirely quite different than local volcanic
spewed basalts.

“A more precise but still relatively inexpensive way to identify
minerals (and thereby the bulk chemical composition of the rock) with
a petrographic microscope. These microscopes have polarizing plates,
filters, and a conoscopic lens that allow the user to measure a large
number of crystallographic properties.”

Contributor “Wretch Fossil” actually has a very good “petrographic
microscope” and multiple resources plus talent of interpreting such to
go along with it. Sadly this technology and its expertise of
interpreting is being ignored by those of authority that do not want
outsiders having a public say about anything. So, once again, it
really doesn’t matter whatever level of modern applied technology and
expertise we have to offer, because it’s only going to be topic/author
stalked and systematically trashed by those of Usenet/newsgroup
authority that have multiple mainstream issues at risk.

TBMs cutting their tunnels into the interior of our moon should prove
both interesting and rewarding in terms of extracting rare and
valuable elements, not to mention creating the very cozy and safe
habitat potential that’s opened up for multiple uses. Unfortunately
this method can not be applied on such a geodynamically active planet
like Venus that has such a thin crust and way more primordial core
energy outflux of perhaps 20.5 w/m2 as contributing way more
geothermal energy than any other planet or moon has to offer, although
older and cooler planets or any number of their moons (except for Io
that’s averaging 2 w/m2) should be somewhat similar to terraforming
the cozy interior of our moon.
http://www.mps.mpg.de/solar-system-s...olcanism_5.pdf

http://commercialspace.pbworks.com/f/Public+ILN.pdf

The likely two thirds (6.6e17~6.6e18 tonnes) worth of lose surface
basalt rock and dust including whatever 4+ billion years worth of
accumulated deposits, as remaining crystal dry on the naked surface of
our physically dark moon (not including the other good third portion
as having been dislodged and deposited on Earth) is a direct result of
the thousands of significant impacts, and especially as a result of
whatever created its South polar crater of 2500 km diameter, that
which all by itself should have contributed a minimum of 3e17 m3 or
possibly a maximum contribution of 1e18 m3 if including the planet
sized impactor contributions. Given the limited surface area of the
moon as being 3.8e13 m2 doesn’t exactly allow all that much surface
area for accommodating such volume of lose crater made fallout, and
perhaps due to much of its own basalt metallicity making its density
worth on average 3.5 tonnes/m3 unless offset by loads of accumulated
carbon buckyballs. In that kind of hard vacuum, there really
shouldn’t be all that much porosity to any of its solidified basalt or
carbonado.

Liquefied basalt as returning fallout from such truly horrific impacts
that should have extensively solidified and possibly fused upon
contact with the relatively cool basalt surface, as such should have
been quite obvious and highly distinctive if such exposed lunar
bedrock samples had been return to Earth. Sadly, no such samples or
even unique meteorites ever materialized from our NASA/Apollo era,
that found our naked moon as instead so unusually reflective and UV, X-
ray and gamma inert as well as hardly the least bit dusty, and what
little crystal dry dust there was seemed to offer terrific surface
tension and clumping for their footing and traction like no place
else.

Even taking the utmost conservative swag-estimate of 3.8e16 m3 worth
of lose rock, debris and accumulated dust, is still suggesting an
average surface depth of one km, which of course our Apollo era found
no such indications, as though that moon is relatively new to us. Of
course, if that moon had created our Arctic ocean basin as of 11,712
years ago, would actually explain quite a bit.

How’s that for a worthy topic of terraforming the innards of our naked
moon that’s practically dust free and mostly solid as any rock
according to our Apollo wizards?