The Azov megablock is one of the old­est tec­ton­ic ele­ments of the south­east­ern part of the Ukrain­ian Shield. Its bound­aries are con­trolled by deep-seat­ed faults and mar­gin­al nor­mal faults that clear­ly sep­a­rate the mas­sif from adja­cent struc­tures.

The Azov megablock is locat­ed in the south­east­ern part of the Ukrain­ian Shield. Its west­ern bound­ary fol­lows the Azov–Pavlohrad deep fault zone, where it bor­ders the mid­dle Dnipro block. These bound­aries are defined by deep tec­ton­ic zones mark­ing the con­tacts between Archean and Pro­tero­zoic struc­tures of the shield. To the north, east, and south, the bound­aries coin­cide with sys­tems of mar­gin­al faults. In the mod­ern tec­ton­ic frame­work, the megablock cor­re­sponds to the Azov mas­sif (a pro­to­con­ti­nent), char­ac­ter­ized pre­dom­i­nant­ly by femic crust approx­i­mate­ly 50 km thick. Sial­ic crust occurs only in the east­ern part, where Pro­tero­zoic intru­sive bod­ies are devel­oped.

In tec­ton­ic terms, the megablock con­sists of two struc­tur­al lev­els:

• Archean (low­er lev­el) — dome-like struc­tures (Kamyshu­vakha and Salty­chany domes), between which syn­forms and green­stone struc­tures are locat­ed.
• Pro­tero­zoic (upper lev­el) — deformed syn­cli­no­ria: the Kor­sak and Cen­tral Azov (Man­gush) syn­cli­no­ria.

Meta­mor­phosed com­plex­es: The Archean sec­tion includes the West Azov series (the Vely­ka Tok­mach­ka and Kainku­lak units), which con­tain iron ore lay­ers. Above it lies the Vovchan­sk unit, char­ac­ter­ized by amphi­bo­lite- to gran­ulite-facies meta­mor­phism. With­in the Mesoarchean, the Sorokyne and Novo­horiv­ka green­stone struc­tures are devel­oped, togeth­er with the Kosivt­si unit con­tain­ing iron ore occur­rences.

The Cen­tral Azov series (Neoarchean) is sub­di­vid­ed into the Tem­riuk and Demi­an­iv­ka for­ma­tions. The lat­ter includes the Kuk­sun­gur, Kor­sak-Mohy­la, and Mohy­la Kami­ana deposits. The Palaeo­pro­tero­zoic suc­ces­sion is rep­re­sent­ed by the Dibro­va, Huli­aipole (con­tain­ing fer­rug­i­nous quartzites), and Sadove for­ma­tions, com­pris­ing a wide vari­ety of schists, mar­bles, and calc-sil­i­cate rocks.

Intru­sive com­plex­es: The Azov megablock includes some of the old­est apo­tonalitic rocks of the Novopavliv­ka com­plex, as well as enderbite–tonalite, Dobropil­lia, Haichur, and Sorokyne com­plex­es. In the Neoarchean, the Shevchenkove com­plex, the Man­gush mafic–ultramafic com­plex, and the Starobo­hdaniv­ka com­plex are devel­oped. In the Pale­o­pro­tero­zoic, the Anadolske, Khli­bo­dariv­ka, Rybinske, and Dubiv­ka gran­i­toids occur; the Khli­bo­dariv­ka and Karatyuk com­plex­es have iso­topic ages of approx­i­mate­ly 2.08–2.03 Ga.

Alka­line com­plex­es: These include the Cherni­hiv com­plex (car­bon­atites and nepheline syen­ites), as well as the Kolar­iv­ka, Oktyabrskyi, Yelanch­nyi, and South Kalchyk com­plex­es, which are asso­ci­at­ed with rare-met­al min­er­al­iza­tion. The Azov and Volo­darske deposits con­tain zir­con, tan­ta­lum, and hafni­um.

Dyke swarms: At the end of the Pale­o­pro­tero­zoic, swarms of dia­base, lam­pro­phyre, por­phyrite, and quartz por­phyry dykes were formed. Major dyke belts include the Kuznetsov–Mykhailivka, Anton–Taram, Pavlopil–Oktyabr, Mal­oy­anysol, Kami­anomo­hy­la, and Yel­y­seiev belts. The iso­topic age of kim­ber­lites (the “Mriya” pipe) is 1950–1955 Ma.