The Podil­lian megablock (also known as the Dniester–Bug megablock) is locat­ed south of the Volyn megablock and is one of the old­est tec­ton­ic struc­tures of the Ukrain­ian Shield. Its con­fig­u­ra­tion is com­plex due to bor­der­ing deep fault sys­tems: the Teteriv and Andrushiv­ka faults to the north, and the Bru­syliv, Shpykiv, Obod­niv, and Talne faults to the south and east. Its west­ern bound­ary coin­cides with the mar­gin­al fault sys­tem of the shield.

The megablock is char­ac­ter­ized by a thick femic-type crust (45–60 km, reach­ing up to 65 km in the south) and is con­sid­ered a clas­sic region of charnock­i­toid devel­op­ment. The old­est for­ma­tions of the Podil­lian block belong to the Azov–Dnister domain and include gran­uli­tized units of the Dniester–Bug series togeth­er with the ultra­m­eta­mor­phic Haiv­o­ron com­plex, which form dome-like struc­tures.

With­in the Dniester–Bug series, the Tyvriv, Hnivань, Pavliv­ka, Berezny­na, and Zele­na Lev­a­da units are dis­tin­guished. The old­est is the Tyvriv unit (zir­con ages approx­i­mate­ly 3.65 bil­lion years), rep­re­sent­ed by pyrox­ene crys­talline schists and ender­bite gneiss­es. The oth­er units have iso­topic ages rang­ing from 2.6 to 2.5 bil­lion years. Most occur as xeno­liths with­in tec­ton­ic blocks sur­round­ed by rocks of the Haiv­o­ron com­plex.

The Haiv­o­ron com­plex is rep­re­sent­ed by ender­bits, charnock­ites and dior­ite rocks that have under­gone region­al meta­mor­phism in sev­er­al stages: gran­ulite (~3.2 bil­lion), amphi­bo­lite (~2.8 bil­lion) and local (~2.0 bil­lion).

The Lityn com­plex (age 2815 ± 35 mil­lion years) is formed from ender­bites, dior­ite-charnokites and oth­er deep rocks that are part of the Dnieper. Togeth­er with Azov-Dni­ester, these com­plex­es form dome-shaped struc­tures.

Neoar­chaean supracrustal sequences of the Pobuzhzhia region are grouped into the Bug series, which forms syn­cli­nal struc­tures of north­west­ern strike (for exam­ple, the Khashchuvato–Zavallia and Kap­i­taniv­ka struc­tures). The series is sub­di­vid­ed into the Kosharo–Oleksandrivka for­ma­tion (high-alu­mi­na sil­li­man­ite gneiss­es) and the Khashchuvato–Zavallia For­ma­tion (mar­bles, calc-sil­i­cate rocks, graphite gneiss­es, and fer­rug­i­nous quartzites).

The Zaval­lia ore field with­in the Khashchuvato–Zavallia for­ma­tion is an impor­tant source of graphite and has been exploit­ed since the begin­ning of the 20th cen­tu­ry. The thick­ness of the ore-bear­ing sequence reach­es 1,110 m.

At the con­di­tion­al lev­el of the Bug series, the Cap­tain-Derynyukhin intru­sive com­plex was iden­ti­fied, rep­re­sent­ed by hyper­b­a­sites (ser­pen­tinites, dunites, peri­dotites) con­tain­ing chromite ores and nick­el (Cap­tain deposit).

The Pobuzhzhia ultra­m­eta­mor­phic com­plex (Palaeo­pro­tero­zoic) is com­posed of leu­co­crat­ic gran­ites, charnock­ites, and biotite migmatites con­tain­ing cordierite and hyper­s­thene (approx­i­mate­ly 2.5 Ga in age).

The Berdy­chiv com­plex (2200–2060 mil­lion years): pink gran­ites with blue quartz, ender­bites, migmatites (vin­nit­sites), charnokites.

The Proskuriv alka­line com­plex com­pris­es syen­ites, ijo­lites, melteig­ites, and pyrox­en­ites. In the Meso­pro­tero­zoic, Khmil­nyk aplite–pegmatite gran­ites and tour­ma­line-bear­ing gran­ites (Yanyshiv­ka type) appeared.

The Khmil­nyk dyke belt formed dur­ing the Meso- and Neo­pro­tero­zoic and con­sists of maf­ic rocks (dia­bas­es and gab­bro-dia­bas­es) as well as fel­sic rocks (gran­ite por­phyries and quartz por­phyries).

Acti­va­tion of the block dur­ing the Palaeo­pro­tero­zoic was accom­pa­nied by deep meta­mor­phism, ana­tex­is, and crustal thick­en­ing, like­ly relat­ed to the sub­duc­tion of north­ern Palaeo­pro­tero­zoic struc­tures beneath Archean ter­ranes.