Changes

===Early(?)-Middle Jurassic===

===Early(?)-Middle Jurassic===

Very little is known about the pre-Late Jurassic history of the island except that the lower part of the San Cayetano clastics might be Lower Jurassic (163 Ma; [[:file:St58OverviewFG25.JPG|Figure 5]]). The San Cayetano must have been deposited over an initially [[rift]]ing [[basement]] that probably included fragments of continental crust as well as basaltic flows. This is supported by the sub-Neocomian [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?gID=00000000073 granodioritic] [[klippe]]n of La Rana, Tres Guanos, and Rancho Veloz and the occurrences of the El Sabalo and Nueva Maria [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?Term=tholeiite tholeitic basalt]s underlying the sedimentary section of the northern Rosario belt and Cifuentes* belt of the Sierra de Camajan.

Very little is known about the pre-Late Jurassic history of the island except that the lower part of the San Cayetano clastics might be Lower Jurassic (163 Ma; [[:file:St58OverviewFG25.JPG|Figure 5]]). The San Cayetano must have been deposited over an initially [[rift]]ing [[basement]] that probably included fragments of continental crust as well as [http://geology.com/rocks/basalt.shtml basaltic] flows. This is supported by the sub-Neocomian [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?gID=00000000073 granodioritic] [[klippe]]n of La Rana, Tres Guanos, and Rancho Veloz and the occurrences of the El Sabalo and Nueva Maria [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?Term=tholeiite tholeitic basalt]s underlying the sedimentary section of the northern Rosario belt and Cifuentes* belt of the Sierra de Camajan.

It can also be assumed that, prior to the deposition of the Upper Jurassic rocks, a large area of basement was exposed to the northwest, extending from Florida's Sarasota arch to the Maya Mountains. The nature of this basement is generally unknown, but it must have been of [http://geology.about.com/od/more_igrocks/a/granite.htm granitic] to [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?gID=00000000073 granodioritic] composition as indicated by the [[Arkose|arkosic]] nature of the San Cayetano Formation. In south Florida, several wells have penetrated an undifferentiated Jurassic–Triassic volcanic section and Paleozoic granite. The basement must also have included Paleozoic sediments known to outcrop in the Maya Mountains, present as fragments in San Cayetano conglomerates, and, perhaps, as exotics in the Cayo Coco Formation. The bulk of the San Cayetano Formation accumulated south of this basement high.

It can also be assumed that, prior to the deposition of the Upper Jurassic rocks, a large area of basement was exposed to the northwest, extending from Florida's Sarasota arch to the Maya Mountains. The nature of this basement is generally unknown, but it must have been of [http://geology.about.com/od/more_igrocks/a/granite.htm granitic] to [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?gID=00000000073 granodioritic] composition as indicated by the [[Arkose|arkosic]] nature of the San Cayetano Formation. In south Florida, several wells have penetrated an undifferentiated Jurassic–Triassic volcanic section and Paleozoic granite. The basement must also have included Paleozoic sediments known to outcrop in the Maya Mountains, present as fragments in San Cayetano conglomerates, and, perhaps, as exotics in the Cayo Coco Formation. The bulk of the San Cayetano Formation accumulated south of this basement high.