Radiolarian biostratigraphy of supraophiolitic Cretaceous metalliferous sediments of Cyprus (Perapedhi Formation)

Sedimentary strata related with ophiolites commonly represent high interest for tectonostratigraphic reconstructions. Upper Cretaceous Perapedhi Formation represents lowermost part of sedimentary cover of Troodos Ophiolite Complex, and consists of umbers (sediments enriched by iron and manganese) and cherts with total thickness ranging from few meters up to nearly 50 m. These sediments are characterized only by radiolarians that still need detailed study.
   Best section of Perapedhi Formation is known in the former Mangaleni quarry, Limassol District. Three lithological units can be distinguished in this section: 1 – dark-brown massive umbers (2-20 m), 2 – intercalation of brown umbers and brown radiolarian cherts (6- 10 m), 3 – pink ribbon cherts (up to 6 m). All units are characterized by abundant wellpreserved radiolarian assemblages. According to stratigraphic distribution of radiolarian taxa the following radiolarian zones and subzones can be distinguished in this section:
   1. Alievium superbum Zone, Turonian, Theocoronium subtriquetrus Subzone. First occurrences (FO) of Pseudodictyomitra sp. A and Theocampe cypraea Bragina (middle part of unit 1).
   2-3. Alievium praegallowayi Zone, Coniacian, subdivided into: 2. Multastrum regale Subzone, FO of Archaeospongoprunum bipartitum Pessagno, Annikaella omanensis De Wever (middle part of unit 1 – lower part of unit 2); 3. Microsciadiocapsa quasisutterensis Subzone, FO of: Lipmanium (?) ovalum Bragina (lower part of unit 2).
   4-7. Alievium gallowayi Zone, Santonian – Lowermost Campanian, subdivided to: 4. Quinquecapsularia sp. A Subzone, FO of Theocampe urna (Foreman) (lower – middle part of unit 2); 5. Dorypyle sp. A Subzone, FO of Acanthocircus sp. A, Dictyodedalus sp. A (middle – upper part of unit 2); 6. Multastrum mangaleniense Subzone, FO of Amphipyndax sp. ex gr. A. pseudoconulus (Pessagno) (lower part of unit 3); 7. Bisphaerocephalina (?) amazon Subzone, FO of Dorypyle sp. B, Neosciadiocapsa urquharti Bragina, Theocampe salillum Foreman (middle part of unit 3).
   8. Crucella espartoensis Zone. FO of Dictyomitra koslovae Foreman subsp. B, Heliocryptocapsa sp. B (upper part of unit 3). Therefore the total stratigraphic range of this section is Turonian – Lowermost Campanian
   Another section of Perapedhi Formation was studied near Perapedhi Village, Central Cyprus. It is represented by umbers with recrystallized chert bodies and rare layers of pink padiolarian cherts with total thickness 10 m. These strata yield radiolarian assemblage of Subzone 6 only (Multastrum mangaleniense).
   Therefore, the deposition of metalliferous sediments of Perapedhi Formation was diachronous. In the Mangaleni Section it starts in the Turonian, but in the Perapedhi Section it was considerably later (Santonian). This phenomenon can be interpreted as result of deposition of Perapedhi Formation in isolated small depressions of Troodos Ophiolite Complex that was completely formed in Turonian.