The Yucatán Platform or Yucatán Shelf is a

geologic Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Eart ...

physiographic Physical geography (also known as physiography) is one of the three main branches of geography. Physical geography is the branch of natural science which deals with the processes and patterns in the natural environment such as the atmosphere, h ...

province, and a continental and

carbonate platform A carbonate platform is a sedimentary body which possesses topographic relief, and is composed of autochthonic calcareous deposits. Platform growth is mediated by sessile organisms whose skeletons build up the reef or by organisms (usually microb ...

, in the

Maya Block The Maya Block, also known as the Maya Terrane, Yucatan Block, or YucatanChiapas Block, is a physiographic or geomorphic region and tectonic or crustal block in the southernmost portion of the North American Plate. Extent The Block is com ...

of the southernmost portion of the

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacific ...

. It comprises the Yucatán Peninsula and its

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

, located between the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

and the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

Extent

The Yucatán Platform is commonly defined as the continental platform constituted by the Yucatán Peninsula and its continental shelf. As such, the margins of the continental shelf, or, more particularly, their isobaths or depth contours, are often taken as the platform's submarine limits. Its subaerial limits (on the Yucatán Peninsula) are less precisely fixed. The US Geological Survey have demarcated the limits of the Yucatán Platform. Their British, Belizean, and

Mexican Mexican may refer to: Mexico and its culture *Being related to, from, or connected to the country of Mexico, in North America ** People *** Mexicans, inhabitants of the country Mexico and their descendants *** Mexica, ancient indigenous people ...

counterparts have not defined an equivalent geologic, physiographic, or geomorphic province or region.

Geography

Political

The exposed or peninsular portion of the Yucatán Platform encompasses four

districts of Belize Belize is divided into six districts. __NOTOC__ List See also *Constituencies of Belize *List of municipalities in Belize *List of West Indian First-level Subdivisions *ISO 3166-2:BZ *Commonwealth Local Government Forum, Commonwealth Local Go ...

(i.e., Corozal, Orange Walk, Belize, and Cayo), one department of Guatemala (i.e., Peten), and four

states of Mexico The states of Mexico are first-level administrative territorial entities of the country of Mexico, which is officially named United Mexican States. There are 32 federal entities in Mexico (31 states and the capital, Mexico City, as a separate ent ...

(i.e., Quintana Roo, Yucatán, Campeche, and Tabasco). Its submarine portion encompasses the continental shelf which abuts those of the aforementioned districts with a coast.

Basins

At least three sedimentary basins have been identified in the Yucatán Platform, namely, the Campeche, Yucatán, and PetenCorozal.

Faults

At least six fault systems or zones have been identified in the Yucatán Platform, namely, the Holbox, Hondo, Ticul, Ring of Cenotes, ChemaxCatoche, and La Libertad, with the first four of these considered prominent.

Geology

Formation

The Gulf of Mexico formed during a 7090 million year rifting of Pangaea, which began some 240

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...

, during the

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between Ma and ...

, and ended some 170150 million years ago, during the Middle or Late Jurassic. The subaerially exposed (i.e., peninsular) portion of the platform is thought to have been fully submarine up to some 3010 million years ago.

Layers

Basement

The platform's

crystalline basement In geology, basement and crystalline basement are crystalline rocks lying above the mantle and beneath all other rocks and sediments. They are sometimes exposed at the surface, but often they are buried under miles of rock and sediment. The baseme ...

is composed mainly of

Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

Palaeozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and '' ...

granodiorite rocks. It starts at a depth of some in the centre-point of the platform's exposed or peninsular portion, but steeps down towards the platform's eastern and northwestern extremes, starting at a depth of in the latter point.

Cover

The platform's sedimentary cover is composed mainly of carbonates and evaporites formed during or after the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

. It forms one of the largest deposits of carbonate minerals on Earth, with a depth range of .

Notes

Citations

References

# # # # # # # # # # # # # # # # # # # # # {{authority control Geology of North America Geology of the Atlantic Ocean Geology of Belize Geology of Guatemala Geology of Mexico Geomorphology#Physiographic divisions Physiographic divisions