Editing Chicxulub crater (section)

==Morphology==
[[File:Chicxulub schematic section.png|thumb|Schematic cross-section over the Chicxulub impact structure|alt=see caption]]
The form and structure ([[geomorphology]]) of the Chicxulub crater is known mainly from geophysical data. It has a well-defined concentric multi-ring structure. The outermost ring was identified using seismic reflection data. It is up to {{convert|130|km|sp=us}} from the crater center, and is a ring of [[normal fault]]s, throwing down towards the crater center, marking the outer limit of significant [[crust (geology)|crustal]] deformation. This makes it one of the three largest impact structures on Earth.<ref name="Morgan_etal_1997">{{Cite journal |last1=Morgan |first1=J.|author1-link= Joanna Morgan |last2=Warner |first2=M. |last3=the Chicxulub Working Group |last4=Brittan |first4=J. |last5=Buffler |first5=R. |last6=Camargo |first6=A. |last7=Christeson |first7=G. |last8=Denton |first8=P. |last9=Hildebrand |first9=A. |last10=Hobbs |first10=R. |last11=Macintyre |first11=H. |year=1997 |title=Size and morphology of the Chicxulub impact crater |s2cid=4398542|journal=Nature |volume=390 |pages=472–476 |doi=10.1038/37291 |last12=Mackenzie |first12=G. |last13=Maguire |first13=P. |last14=Marin |first14=L. |last15=Nakamura |first15=Y. |last16=Pilkington |first16=M. |last17=Sharpton |first17=V. |last18=Snyder |first18=D. |last19=Suarez |first19=G. |last20=Trejo |first20=A.|display-authors=3|issue=6659 |bibcode=1997Natur.390..472M }}</ref><ref name="Melosh_2001"/> Moving toward the center, the next ring is the main crater rim, also known as the "inner rim," which correlates with a ring of [[cenote]]s onshore and a major circular [[Bouguer anomaly|Bouguer gravity gradient anomaly]].<ref name="Gulick_etal_2008"/><ref name="Hildebrand_etal_1995">{{Cite journal |last1=Hildebrand |first1=A. |last2=Pilkington |first2=M. |last3=Conors |first3=M. |last4=Ortiz-Aleman |first4=C. |last5=Chavez |first5=R.E. |year=1995 |title=Size and structure of the Chicxulub crater revealed by horizontal gravity gradients and cenotes |journal=Nature |volume=376 |issue=6539 |pages=415–417 |doi=10.1038/376415a0|bibcode=1995Natur.376..415H |s2cid=4250257}}</ref> This ring has a radius that varies between {{convert|70|and|85|km|sp=us}}.<ref name="Gulick_etal_2013"/> The next inner ring structure is the peak ring. The area between the inner rim and peak ring is described as the "terrace zone", characterized by a series of [[fault block]]s defined by normal [[Fault (geology)|faults]] dipping towards the crater center, sometimes referred to as "slump blocks". The peak ring is about 80&nbsp;km in diameter and of variable height, {{convert|400|to|600|m|sp=us}} above the base of the crater in the west and northwest and {{convert|200|to|300|m|sp=us}} in the north, northeast, and east.<ref name="Gulick_etal_2013"/> The central part of the crater lies above a zone where the [[Earth's mantle|mantle]] was uplifted such that the [[Mohorovičić discontinuity]] is shallower by about {{convert|1|–|2|km|sp=us}} compared to regional values.<ref name="Gulick_etal_2013"/><ref name="Melosh_2001">{{Cite journal |last=Melosh |first=J. |year=2001 |title=Deep down at Chicxulub |journal=Nature |volume=414 |issue=6866 |pages=861–862 |doi=10.1038/414861a|pmid=11780048 |s2cid=33062203 }}</ref>

The ring structures are best developed to the south, west and northwest, becoming more indistinct towards the north and northeast of the structure. This is interpreted to be a result of variable water depth at the time of impact, with less well-defined rings resulting from the areas with water depths significantly deeper than {{convert|100|m|sp=us}}.<ref name="Gulick_etal_2008"/>