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最新研究发现,在云开地块北缘陆川县石窝镇—北流市清水口镇一带的“云开岩群”中出露一系列变质基性火山岩,该火山岩总体呈北东向带状分布,主要岩性为斜长角闪岩和斜长角闪片麻岩,局部岩石中还夹有少量呈透镜状、布丁状或似层状产出的石榴辉石岩、透辉石岩、透辉角闪石岩、角闪石岩、(含石榴)斜长角闪岩、角闪绿帘石岩、石榴阳起石岩、石榴斜长辉石岩等。地球化学研究表明,其为典型的大洋拉斑玄武岩(MORB型玄武岩)。斜长角闪岩的锆石SHRIMP法喷发成岩年龄为(1462±28)Ma,表明其可能代表该区消失了的古洋壳岩石,是四堡期洋壳蛇绿岩的组成部分。
The latest study found that a series of metamorphic basement volcanic rocks are exposed in the “Yunkai Group” in Shikou Town, Beiliu City, Shikou Town, Luchuan County, the northern margin of the Yunkai Block. The volcanic rocks are generally distributed in the NE direction , The main lithology is amphibolite and amphibolite gneiss, part of the rock is still a small number of lens-like, pudding-like or layered-like garnet pyroxene, diopside, through Hornblende amphiboles, amphibole rocks, (including pomegranate) amphibolites, hornblende Epimedium, pomegranate rock, pomegranate plagioclase pyroxene and so on. Geochemical studies show that it is a typical oceanic rock basalt (MORB type basalt). The zircon SHRIMP eruption age of amphibolite is (1462 ± 28) Ma, which indicates that it may represent the paleo-oceanic crust that disappeared in this area and is a component of the four-stage marine oceanic ophiolite.