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The oldest rocks in the shield consist of Archean Imataca Complex, composed of a quartz-feldspar gneiss and subordinate mafic gneiss. The Guri Fault marks the southern boundary of the complex. South of that fault are Early Proterozoic rocks consisting of the metavolcanic Pastora Supergroup and the granitic plutonic Supamo Complex.
The northern Guiana Shield, including Guyana is separated from Southern Guiana Shield by ENE to NE trending Tumbes /Guayaquil - Tacutu Tectonic Lineament. This is a major regional pre-Cambrian shear zone / mega-shear which is believed to have been re-activated several times.
The North Rupununi is situated on the Guiana Shield, precambrian rock with a complex geology that includes plutonic, volcanic, metamorphic and sedimentary rocks and various rifting, uplifting, sedimentation and erosion events.
Guyana belongs to the Guiana Shield, a massif extending north of the Amazon, between the Andes Mountains and the Atlantic, made up of Precambrian rocks dated to between 2.7 and 3.5 billion years ago. The shield consists of several geological units: the southern peneplain, the Inini synclinorium, the central granite massifs and the northern ...
The Guiana Shield occupies the southern region of the Orinoco River and the northern region of the Amazon River, between the plains of Colombia and Venezuela and the Atlantic Ocean. It covers the whole south of Venezuela and the south of the Orinoco. It has the oldest rocks in the country. There are archaic rocks with more than 3,000 million years.
The Cerros de Mavicuri are three hills, located in eastern Colombia, 50 km (31 mi) south of the city of Inírida on the Inírida River.Geologically, the mountains are part of the Guiana Shield.
Baltic Shield, part of the East European Craton; Fennoscandian Shield, the exposed Northwestern part of the Baltic Shield in Norway, Sweden and Finland (3.1 Ga) Karelian Craton, part of the Fennoscandian Shield in Southeast Finland and Karelia Russia, (3.4 Ga) Kola Craton, part of the Fennoscandian Shield, Kola Peninsula, Northwest Russia
Most rocks in Suriname date to the Precambrian. These crystalline basement rocks consists of granitoid and acid volcanic rocks with enclaves of predominantly low-grade metamorphic, geosynclinal rocks in the Marowijne area and of probably considerably older rocks in the Falawatra group of the Bakhuisgebirge and the Coronie area.