Geology of Colombia ocean invaded the area which is exposed in Colombia's Andean zone, as subterranean volcanic eruptions in the western part of the country spouted lava. In the Triassic Period of the 186-million-year-long Mesozoic Era, which began 252 million years ago, the sea that occupied the Andean zone separated into two parts after the Cordillera Central rose. Large layers of sedimentary rock were deposited during the Jurassic Period, which ended with great igneous activity. During the Cretaceous Period, the sea to the east of the Cordillera Central extended to Putumayo region in the south, while subterranean volcanic activity continued to the west
Gulf Keystone Petroleum is notably one of the largest Super Giant oilfields discovered in the last 50 years. Shaikan was declared a commercial discovery on August 1, 2012 following a five-well appraisal program. Initially independent estimates place the gross oil-in-place (OIP) volume at 13.7 billion barrels (P50) potentially making it one of the largest oilfields discovered in Iraqi Kurdistan. The oilfield covers an area of some , and comprises a series of limestone reservoirs stacked upon each other. These reservoirs encompass a very long period of geological time, from the Cretaceous which ended some 65 million years ago to the Triassic, which began