Oxfordian–Berriasian Stratigraphy of the North American Paleomargin in Western Cuba<subtitle>Constraints for the Geological History of the Proto-Caribbean and the Early Gulf of Mexico</subtitle>

Abstract

M any models that attempt to interpret the regional geology of the Caribbean-Gulf of Mexico area share the handicap of paying little attention to precise data from Cuba despite its location at the North American-proto-Caribbean paleoboundary. The North American Mesozoic paleomargin crops out along northern Cuba, an area where many wells have encountered Jurassic and Lower Cretaceous rocks. In this chapter, we present a stratigraphic interpretation of the North American passive continental paleomargin recognized in the Guaniguanico mountains (western Cuba) and identify the main geological events recorded in their Oxfordian to Berriasian sections. We correlate these sections with other Mesozoic passive paleomargin sections in Cuba, including the Escambray and Isle of Youth metamorphic terranes. These sections and those in the southeastern Gulf of Mexico record early stages of the disintegration of Pangea in Mesoamerica and the early development of the southeastern Gulf of Mexico and westernmost Tethys (proto-Caribbean). In all, two main sequences can be distinguished: (1) a lower terrigenous one and (2) an upper marine carbonate sequence. The transition from terrigenous to carbonate sedimentation occured during the late middle Oxfordian in western Cuba (and possibly in the Escambray mountains of central Cuba). In Placetas zone of central Cuba, the terrigenous-carbonate transition spans from Kimmeridgian to Berriasian. Transgression occurred close to the Kimmeridgian-Tithonian 20

New species of lower Tithonian macroconchiateHybonoticerasfrom Mexico and the co-occurrence ofMazapilitesandHybonoticerasin the Mexico-Caribbean area

“…Fossiliferous horizons of reference in western Cuba were reported from: (1) well-stratified gray-black limestones, with occasional fine clayey intercalations from the El Americano Member of the Guasasa Formation in Sierra de Los Órganos, which represents Tithonian to early Berriasian outer-shelf-to-upper-slope deposition; and (2) well-bedded and commonly laminated black mudstones to wackestones, with occasional intercalations of shales and siltstones, and laminated shales and marls upward, from the La Zarza Member of the Artemisa Formation in Sierra del Rosario, which are interpreted as outer ramp deposits deepening throughout younger Tithonian times. Thus, analogous paleoenvironmental conditions during the same time interval can be interpreted for both areas (Cobiella-Reguera and Olóriz, 2009, and references therein).…”