88 D24. Stratigraphy (Posters)

Sunday, 22 October 2017
9:00 AM - 5:30 PM
Halls 4EF

JURASSIC & CRETACEOUS BOUNDARY AN UNCONFORMITY IN NORTH & SOUTH AMERICA: FAR FROM RHETORIC, CLOSER TO REALITY

Paper number: 88-11
Program: Technical Sessions
Time: 9:00 AM – 5:30 PM

Authors

Abstract

The stratigraphic connection between Early Cretaceous rocks (i.e. Potomac Group & Potomac Formation) over late Jurassic named the Newark SuperGroup along the Eastern area of the US; it can represent an unconformity suggested by several authors. The methodology of the research is literature review and field trips for several years with a great picture support.

According to a literature review realized by the USGS regarding as a summary of more than 100 papers since the 19thCentury, this summary tried to solve several problems about Stratigraphic Nomenclature in the US but not solved clearly the issue about relationship of the boundary between Triassic-Jurassic and Cretaceous.

Based on diverse personal field trips in both North and South America an own hypothesis appeared about TriassicJurassic- Cretaceous boundary in different areas is an unconformity.

As a result of this study, all geological formations described by different scientists in areas where the Newark Supergroup appears covered by Cretaceous rocks along South Caroline, North Caroline, Maryland, Delaware, Virginia, New Jersey, New York, Connecticut, and New Hampshire where the boundary relation as unconformity is suggested more than evidenced.

It is thinkable to conclude that equivalent ideas from many scientists, whom announced a Hiatus disturbing a normal geological processes of continuous regular sedimentation. Unfortunately, they do not explained in detail or demonstrate all the phenomena occurred. However, in South America the author found vestiges of flat Cretaceous layers over high dipping Jura-Triassic. These evidences could confirm an unconformity between Jurassic rocks of the La Quinta (vertical faults), Girón, and Saldaña Formations under flat Cretaceous continental and marine sedimentary strata. Other similar evidences by geological literature appeared in eastern Canada, Durango-Mexico, Andean Peru, and La Quinta Formation in Venezuela.

As recommendations, it is a need to prepare a geophysical and drill program along areas of the Eastern of US. It will be ambitious and rigorous, containing stratigraphic information in order to recover drilling cores of the Newark Supergroup and/or Potomac Group including Potomac, Raritan, Patapsco, and Patuxent Formations.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-297704

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