Editing Chicxulub crater (section)

===Pre-impact geology===
[[File:Chicxulub Wharf Yucatan Mexico.jpg|thumb|alt=An image of a boardwalk over a body of water. A sign says "Chicxulub Puerto Mexico"| The center of the crater is near [[Chicxulub Puerto]].|right]]
[[File:Chicxulub Puerto.jpg|right|thumb|[[Stele|Stela]] in the main square of Chicxulub Puerto commemorating the impact]]
Before the impact, the geology of the [[Yucatán Platform|Yucatán area]], sometimes referred to as the "target rocks", consisted of a sequence of mainly Cretaceous limestones, overlying [[red bed]]s of uncertain age above an unconformity with the dominantly granitic [[basement (geology)|basement]]. The basement forms part of the [[Maya Block]] and information about its makeup and age in the Yucatán area has come only from drilling results around the Chicxulub crater and the analysis of basement material found as part of the ejecta at more distant K–Pg boundary sites. The Maya block is one of a group of crustal blocks found at the edge of the [[Gondwana]] continent. [[Zircon]] ages are consistent with the presence of an underlying [[Grenvillian orogeny|Grenville]] age crust, with large amounts of late [[Ediacaran]] [[Volcanic arc|arc]]-related [[igneous rock]]s, interpreted to have formed in the [[Pan-African orogeny]]. Late [[Paleozoic]] [[granitoid]]s (the distinctive "pink granite") were found in the peak ring borehole M0077A, with an estimated age of 326 ± 5 million years ago ([[Carboniferous]]). These have an [[adakite|adakitic]] composition and are interpreted to represent the effects of [[slab detachment]] during the [[Ouachita orogeny|Marathon-Ouachita orogeny]], part of the collision between [[Laurentia]] and Gondwana that created the [[Pangaea]] [[supercontinent]].<ref name="Zhao_etal_2020">{{Cite journal |last1=Zhao |first1=J. |last2=Xiao |first2=L. |last3=Gulick |first3=S.P.S. |last4=Morgan |first4=J.V.|author4-link= Joanna Morgan |last5=Kring |first5=D. |last6=Urrutia-Fucugauchi |first6=J. |last7=Schmeider |first7=M. |last8=de Graaf |first8=S.J. |last9=Wittmann |first9=A. |last10=Ross |first10=C.R. |last11=Claeys |first11=P. |last12=Pickersgill|first12=A.|last13=Kaskes|first13=P.|last14=Goderis|first14=S.|last15=Rasmussen|first15=C.|last16=Vajda|first16=V.|last17=Ferrière|first17=L.|last18=Fiegnon|first18=J.-G.|last19=Yamagucho|first19=K.|display-authors=3|year=2020 |title=Geochemistry, geochronology and petrogenesis of Maya Block granitoids and dykes from the Chicxulub Impact Crater, Gulf of México: Implications for the assembly of Pangea |journal=Gondwana Research |volume=82 |pages=128–150 |doi=10.1016/j.gr.2019.12.003|bibcode=2020GondR..82..128Z |s2cid= 214359672|url=https://biblio.vub.ac.be/vubirfiles/78237141/Zhao_etal_accepted.pdf }}</ref>

Red beds of variable thickness, up to {{convert|115|m|sp=us}}, overlay the granitic basement, particularly in the southern part of the area. These continental [[clastic rock]]s are thought to be of [[Triassic]]-to-Jurassic age, although they may extend into the [[Lower Cretaceous]]. The lower part of the Lower Cretaceous sequence consists of [[Dolomite (rock)|dolomite]] with interbedded anhydrite and gypsum, with the upper part being limestone, with dolomite and anhydrite in part. The thickness of the Lower Cretaceous varies from {{convert|750|m|sp=us}} up to {{convert|1675|m|sp=us}} in the boreholes. The [[Upper Cretaceous]] sequence is mainly platform limestone, with [[marl]] and interbedded anhydrite. It varies in thickness from {{convert|600|m|sp=us}} up to {{convert|1200|m|sp=us}}. There is evidence for a Cretaceous basin within the Yucatán area that has been named the Yucatán Trough, running approximately south–north, widening northwards, explaining the observed thickness variations.<ref name="Guzman_Hidalgo_etal_2021">{{Cite journal |last1=Guzmán-Hidalgo |first1=E. |last2=Grajales-Nishimura |first2=J.M. |last3=Eberli |first3=G.P. |last4=Aguayo-Camargo |first4=J.E. |last5=Urrutia-Fucugauchi |first5=J. |last6=Pérez-Cruze |first6=L. |display-authors=3|year=2021 |title=Seismic stratigraphic evidence of a pre-impact basin in the Yucatán Platform: morphology of the Chicxulub crater and K/Pg boundary deposits |journal=Marine Geology |volume=441 |page=106594 |doi=10.1016/j.margeo.2021.106594|bibcode=2021MGeol.44106594G |s2cid=238783773}}</ref>