The North Andes Plate or North Andes Block is a small tectonic plate (microplate) located in the northern Andes. It is squeezed between the faster moving South American Plate and the Nazca Plate to the southwest. Due to the subduction of the Coiba and Malpelo plates, this area is very prone to volcanic and seismic activity, with many historical earthquakes.
Image: Coiba & Malpelo Plates and major seismic faults of Colombia
Image: Blakey 120Ma COL
Image: Blakey 065Ma COL
The Llanos Basin or Eastern Llanos Basin is a major sedimentary basin of 96,000 square kilometres (37,000 sq mi) in northeastern Colombia. The onshore foreland on Mesozoic rift basin covers the departments of Arauca, Casanare and Meta and parts of eastern Boyacá and Cundinamarca, western Guainía, northern Guaviare and southeasternmost Norte de Santander. The northern boundary is formed by the border with Venezuela, where the basin grades into the Barinas-Apure Basin.
Rivers of the Llanos Basin
Ariarí River
Coiba & Malpelo Plates
The Cerros de Mavecure in Guainía are a remnant of the Proterozoic basement underlying the Llanos Basin