From shallow-water carbonate ramp to hemipelagic deep-marine carbonate deposition: Part 2. Sirogojno (Klisura quarry) - the reference section of the Middle to Late Anisian Bulog sedimentary succession in the Inner Dinarides (SW Serbia)

Abstract

The Middle to Late Anisian sedimentary succession preserved in the Klisura quarry in Sirogojno (Zlatibor Mt., SW Serbia) preserves the most complete deepening depositional history in the Inner Dinarides in Serbia. In this section, extensional tectonic movements that took place in connection with the Neo-Tethys break-up are reflected in the exceptional well-preserved record of the depositional history. The Pelsonian Ravni Formation at the base of the section is dissected by two generations of neptunian dikes formed in A) the late Pelsonian, and B) the late Illyrian. Above the late Pelsonian drowning unconformity a deepening trend of the depositional environment is mirrored by the litho- and microfacies characteristics of the more than 21 meter thick red nodular limestones of the Bulog Formation. Periods of starvation with deposition of Fossillagerstatten beds and hardgrounds mark characteristic changes in deposition. Two phases of distinct tectonic motions result in unconformities and a stepwise deepening of the depositional realm. The first and major unconformity is the drowning surface on the top of the Ravni Carbonate Ramp which led to the nearly total demise of shallow-water carbonate production, i.e. the change in deposition from shallow- to deepwater limestones. The second phase of tectonic motions is expressed by the formation of an angular unconformity after a phase of starvation in the basin. No Bulog Limestone section in the Dinarides, even not in the type region near Sarajevo, preserves all these characteristic sedimentological features as preserved in the Klisura quarry section in Sirogojno. Therefore this section is proposed to be the reference section for the sedimentological evolution and depositional environment reconstruction of the Bulog Formation in the Inner Dinarides, located in SW Serbia.