A Pyroxenite Dike? of Stunning Textural Beauty: An Unexpected Geological Occurrence from Türkiye

Türkiye hosts a wide variety of natural landscapes and geological features and is therefore a region worthy of investigation. Owing especially to its active volcanic areas, it has been the subject of numerous scientific studies. Within the scope of this study, a zone in the Malatya–Pütürge–Kayadere area was investigated. The region is widely characterized by ophiolitic stratigraphic units and alteration zones, representing remnants of the Neo-Tethys Ocean formed between the African–Arabian and Eurasian plates during the Mesozoic tectonic evolution of the region.
An unusual internal structure exhibiting distinctive formation characteristics was identified during microscopic examination of a drill core sample from the Malatya–Pütürge–Kayadere area. Since no surface occurrence of this unit has been documented to date, the material was accessed at undersurface levels through drilling and investigated using optical microscopy, whole-rock geochemical analyses (XRF, XRD), and electron microscopy.
The rock is characterized by dendritic, platy, and radial micro-textures composed of pyroxene frameworks. Although these microstructures were initially thought to be conodont- or graptolite-like fossils, their occurrence within a matrix composed of amorphous volcanic glass indicates that they represent mineral forms crystallized in this distinctive manner. The aphanitic textured rock locally contains gas cavities infilled with zeolites and carbonates. Minor amounts of olivine grains are also present. Based on its mineralogical and textural characteristics, the rock is classified as a pyroxenite dike. Such examples are scarce globally, and no comparable study has been documented from Türkiye to date.
SEM analyses have confirmed that the crystalline phases are pyroxenes, displaying weak compositional zoning with Mg-rich cores and Fe-rich rims. Major oxide chemical analyses, normalized to 100 wt.%, indicate values of SiO₂ 42.5 wt.%, Fe₂O₃ 13.1 wt.%, MgO 13.2 wt.%, Al₂O₃ 14.9 wt.%, CaO 9.2 wt.%, K₂O 1.4 wt.%, TiO₂ 0.8 wt.%, and Na₂O 0.7 wt.%. This study presents the preliminary results of investigations on an interpreted ultramafic dike, while future studies aim to constrain its formation conditions, stratigraphic affiliation, and genetic interpretation.