Ambergris Cay Limestone

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Ambergris Caye Limestone is a limestone - geological formation in Belize . The fossils contained come from the Neogene era .

distribution

The Ambergris Caye Limestone is the main type of rock on the island of the same name Ambergris Caye . The limestone formations also extend on the mainland far inland to the west and south, up to the metamorphic rocks of the Maya Mountains . The name-giving island forms the edge of a fault that goes back to the displacement of the Caribbean plate compared to the North American plate .

Emergence

In geological drilling in search of oil in the 1960s, the rocks were examined to a depth of 2500 m. About 300-130 million years ago the Caye was still firmly connected to the mainland of today's Belize. In the period from 130 to approx. 1.6 million years, the Caye was apparently covered by a shallow sea, similar to how it is again today.

At that time, the Maya Mountains were the only land mass nearby. The flat southern end of Glover's Atoll merged imperceptibly into the Caribbean plate as the two plates slid past each other. During this time, the underlying layers of Ambergris Caye were formed from Cretaceous and Tertiary limestones that were formed from shell fractures and reef debris, similar to what happens again today.

Glaciers moved across the continents in the Pleistocene , between 1.6 million and 10,000 years ago. As they increased, sea levels fell and the limestones and reefs of the Caye were exposed to erosion and karstification . During this time the numerous caves and sinkholes (sinkholes / cenotes) were created. As the glaciers melted, the sea level rose and new limestone deposits formed. A total of four sea level drops and rises were detected for Ambergris Caye. The youngest rocks on the Caye, such as Reef (Rocky) Point , are around 125,000 years old and were lifted from the sea around 6,000 years ago while the sea level rose to its present level.

The Maya began to process the limestones for lime extraction.

Individual evidence

  1. ↑ ambergiscaye.com geological studies of Sal Mazzullo.
  2. ^ SJ Mazzullo; CS teal; Elizabeth Graham: Mineralogic and Crystallographic Evidence of Lime Processing, Santa Cruz Maya Site (Classic to Postclassic), Ambergris Caye, Belize.

literature

  • Geological Survey (US): Bibliography of North American Geology, 1967. (1267 edition of Geological Survey Bulletin) US Department of the Interior, Geological Survey; Washington, DC, 1949. (Ohio State University Digitized July 1, 2016.)
  • Robin GC Bathurst: Carbonate Sediments and Their Diagenesis. (Developments in Sedimentology; Vol. 12) Elsevier 1972. ISBN 0080869238 , 9780080869230

Web links