The nature of magmatism in the Fiolent Cape area, Southwestern Crimea

Abstract

This article concerns novel data for the chemical composition (rare earth and trace elements) of igneous rocks that developed in the central part of the Fiolent Cape. The possible geodynamic settings of magmatism are discussed.

Ophiolite association of Cape Fiolent (western part of the Mountainous Crimea) – the upper age constraint according to the U-Pb isotope dating of plagiorhyolites (Monakh Cliff)

“…In [27,28] present some material (petrographic, petro-and geochemical) characteristics of plagiorhyolites from the Fiolent-Heraclea area. Plagiorhyolites are indistinctly porphyritic light greenish-grey rocks.…”

“…Its stratigraphic section begins with a gently dipping terrigenous-argillaceous-carbonate sequence of the Sarmatian (Middle Miocene) regional stage of the Peri-Thetic Region [23], corresponding to the upper parts of the Serrovalian and Tartonian stages [24]. This sequence, with a pronounced structural unconformity, overlies weathered and deeply eroded heterogeneous igneous formations, usually attributed to the Middle Jurassic [18] and combined [25][26][27][28][29] into the ophiolite association of Cape Fiolent.…”

“…4. Apoperidotite serpentinites, gabbroids, basalts, dolerites, and plagiorhyolites exposed in coastal rocks in the area of Cape Fiolent [25][26][27][28][29] and, moreover, penetrated by boreholes on the Heraclea Plateau [18] (Fiolent-Heraclea igneous area). Attempts to obtain the U-Pb isotopic age from three zircon crystals from a dolerite dike in the centre of the exposed part of the Fiolent-Heraclea area using SHRIMP-II gave estimates of 1771±28 Ma [18].…”

“…Fiolent-Heraclea igneous area. Igneous formations of the Fiolent-Heraclea area are known in the literature as: 1) heterogeneous and diverse (from rhyolites to mafic rocks) igneous formations that compose the so-called Heraclean volcano-tectonic structure [36]; 2) ophiolite association of Cape Fiolent or ophiolites of the Heraclea Peninsula [25][26][27][28][29]. These formations are exposed in steep (reaching a height of 200 m to the east of Cape Fiolent) coastal cliffs of the southern part of the Heraclea Peninsula (Fig.…”

“…In the work by E.E.Shnyukova [18], the part of the field of igneous formations distribution in the Fiolent-Heraclea area exposed in the coastal band is divided into a series of areas, within which igneous rocks were formed during separate stages of magmatic activity. The works [25][26][27][28][29] developed ideas according to which the igneous formations of the Fiolent-Heraclea area, together with associated rocks, form an ophiolite association.…”