Microfossil and strontium isotope chronology used to identify the controls of Miocene reefs and related facies in NW Cyprus

Abstract

The existing chronostratigraphic framework in NW Cyprus of two-phase, Early and Late Miocene reef and associated facies development is tested and improved using a combination of calcareous nannofossil, benthic and planktic foraminiferal, and also Sr isotope dating. Following localised Late Oligocene neritic carbonate deposition (e.g. benthic foraminiferal shoals), reefs and related facies (Terra Member) began to develop c. 24 Ma (Aquitanian) and terminated c. 16 Ma (end-Burdigalian). Early Miocene reef and marginal facies were then extensively redeposited as multiple debris-flow deposits until c. 13.7 Ma, influenced by a combination of global sea-level fall (related to growth of the East Antarctic Ice Sheet) and local- to regional-scale tectonics. Reef growth and related deposition resumed (Koronia Member) c. 9.1 Ma (Tortonian), then terminated by c. 6.1 Ma (mid-Messinian), followed by the Messinian salinity crisis. Neritic accumulation in NW Cyprus began earlier (Late Oligocene), than in southern Cyprus (Early Miocene). The Early Miocene reefs developed on a c. N-S-trending structural high in the west (Akamas Peninsula area) whereas the Late Miocene reefs developed on both flanks of the neotectonic Polis graben. The two-phase reef development is mirrored in SE Cyprus and in some other Mediterranean areas; e.g. S Turkey, Israel, Italy, S Spain.Supplementary material: GPS Locations of dated samples, the Sr isotope method and the samples examined for planktic foraminifera biostratigraphy are available at https://doi.org/10.6084/m9.figshare.c.5205315.

Microfacies evidence for the evolution of Miocene coral-reef environments in Cyprus

“…1C). In addition, the Koronia Member is also exposed on both the east and the west flanks of the Polis graben (Follows et al, 1996;Cannings et al, 2021;E. Balmer, unpublished data) (Fig.…”

“…The Terra Member is exposed in the Cape Greco area as relatively well preserved build-ups and related shallowwater facies (Follows and Robertson, 1990;Follows, 1992;Follows and Robertson, 1996). In contrast, in western Cyprus the Terra Member almost entirely consist of talus deposits that sedimented on an older and irregular substratum (Cannings et al, 2021;E. Balmer, unpublished data).…”

“…Relatively little new information on these shallow-water carbonates has been published during the intervening years. Recently, understanding of the lower and upper Miocene reefs in the northwest of Cyprus has improved based on a combination of calcareous nannofossils, planktic foraminifera, large benthic foraminifera (LBF) biostratigraphy and strontium isotopic dating of associated hemipelagic facies (Cannings et al, 2021). In this paper, we build on and extend the previous research by providing a detailed microfacies analysis of the lower and upper Miocene coralreefs and related facies, focusing on LBF and calcareous algae.…”

“…1). Reefs and related shallow-water carbonate facies occur in several different tectonic settings, in different parts of the island, facilitating insights into the potential controls of reef formation, including local to global sea-level change, tectonics and other environmental factors (Follows, 1992;Eaton and Robertson, 1993;Cannings et al, 2021). The geological framework and the geometries of Miocene reefs and related facies of Cyprus were largely established in the 1990s, based on field mapping, facies analysis, petrographic and isotopic studies (Follows, 1990(Follows, , 1992Follows and Robertson, 1990;Follows et al, 1996) (Fig.…”

Sedimentary response to current and nutrient regime rearrangement in the Eastern Mediterranean Realm during the early to middle Miocene (southwestern Cyprus)

“…On the Mamonia Terrain, the formation of these shallow water regions was attributed to local highs which formed atop large thrust faults related to uplift of the Troodos Massif and the continued collision of Cyprus and the Eratosthenes block to the south (Follows et al, 1996;Papadimitriou et al, 2018). However, the specific mechanism is debated, with some arguing for a horst and graben structure (Balmer et al, 2019;Cannings et al, 2021), whereas others call for blind thrusts (Papadimitriou et al, 2018) to generate the highs the reefs developed on. The former would result in steep slopes while the latter in gentler slopes with piggyback basins.…”