Amethyst and silver mines at the shore of the White Sea.

Fractured and hydrothermally altered reddish sandstones host stockwork amethyst mineralization in proximity to a graben-bounding regional fault.

Within the deposit, eight sectors (stockworks) have been identified; these consist of quartz, barite, and fluorite veins and extend for approximately 3 km. According to N.I. Frishman, the sequence of formation for these hydrothermal bodies is as follows: Stage 1—crystallization of early fluorite; Stage 2—formation of quartz, comprising several substages (early high-temperature (>400°C), "amethyst" (200–300°C), and low-temperature (160°C and below, involving quartz redeposition)); Stage 3—crystallization of barite and late generations of fluorite. Furthermore, within workings III, large blocks (1.5–2 m in diameter) were discovered; these consist primarily of coarse-crystalline calcite with minor amounts of fluorite and barite, as well as fragments of sandstones from the Terskaya Formation. Low-grade copper mineralization was detected in workings III and VII, represented by chalcocite, covellite, and malachite developed after them. The copper minerals are localized in areas characterized by the development of late vein quartz. Within the scheme proposed by N.I. Frishman, the crystallization of calcite and copper minerals most likely occurred during Stage 3. Calcite blocks with pinkish-violet fluorite and fragments of red sandstones (a) and characteristic copper mineralization (covellite (b), malachite (c)) of the Cape Korabl’ deposit. In 2021, new hydrothermal formations – hematite veins and breccias – were described for the first time in the area of the Cape Korabl’ deposit. Hematite veins and breccias are exposed in the intertidal zone and are confined to two fracture systems in the red-bedded sandstones of the Terek Formation: northeastern and sublatitudinal. The veins form clusters, less commonly represented by individual bodies, and have a thickness of 2 to 20 cm and a length of 2 to 15 meters. Brecciation zones,
consisting of angular sandstone fragments ranging from 1 to 10 cm in size and hematite cement, are developed near the vein clusters and have visible outcrop areas of approximately 1–2 m2. Hematite veins and breccias are often intersected by quartz veinlets. Furthermore, in some parts of the veins and breccias, miarolitic voids filled with quartz brushes can be observed. The bulk of the veins consists almost entirely of fine-crystalline, platy hematite ranging in size from 5 to 50 μm. In isolated areas, fractures or voids can be observed; these are filled with larger-sized platy hematite. Occurrences of barite and rare-earth minerals—predominantly monazite — may also be associated with these same voids. Closer to the contact with the host sandstones, fragments of quartz, potassium feldspar, and—to a lesser extent—albite, apatite, zircon, and titanomagnetite are found within the hematite matrix.

Other Regions, Features and Areas containing this locality

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