Our introduction to this volume highlights the most important aspects of the geology and evolution of the southern Gulf of Mexico (GoM) and the Northern Caribbean. The onshore orogens of the Mexican and Chiapas fold-and-thrust belts and the Northern Caribbean feature prominently in the book, along with a discussion of the tectonics of the Florida–Bahamas peninsula (Fig. 1 and separate Enclosure maps at the back of this volume, Steel and Davison (2020a, b), show the area covered).
Location map showing the area of interest covered in this volume. Locations of two large fold-out maps provided by Earthmoves Ltd and included at the back of the volume and as a digital pdf version are shown as rectangles.
This is a particularly opportune time to focus on these regions, which have seen a recent surge in geological research and hydrocarbon exploration. Large amounts of high-quality seismic reflection data have been acquired offshore, especially in Mexico, but also in Honduras, Cuba, Jamaica and the Dominican Republic. Deregulation of the Mexican energy sector and the introduction of a series of competitive licence rounds has resulted in a new phase of hydrocarbon exploration drilling which has only just begun. Several major hydrocarbon discoveries have recently been made, foretelling the region's huge future potential. There have not been any offshore wells drilled in the Northern Caribbean in the last four years, to our knowledge.
Improvements in satellite and airborne data acquisition and laboratory analytical techniques have also provided an impetus for the collection of high-quality data which have contributed to a better understanding of the region. More rapid and accurate procedures are now available for isotope dating of magmatic events and sediment provenance (especially using single zircon analysis; Erlich and Pindell 2020; Pindell et al. 2020a; Snedden et al. 2020), denudational events (using fission track and (U/Th)/He dating of apatite and zircon; Gray et al. 2020), deformation events (using illite Ar40–Ar39 dating; Hernández-Vergara et al. 2020) and salt depositional ages (using Sr isotope analysis, Pindell et al. 2019, 2020b, 2020c; Pulham et al. 2019; Snedden and Galloway 2019). Higher resolution satellite altimeter-derived gravity (Sandwell et al. 2014) and aeromagnetic data (Pindell et al. 2016, 2020c) have been collected in the last decade, which have led to a greater understanding of ocean–continent transition zones, extinct and active mid-ocean ridges, transform faults (Pindell et al. 2020c) and active tectonics and geomorphology (e.g. Sun et al. 2020).
The first section of papers in the volume is focussed on the southern GoM. This is followed in the second section by a series of papers with studies on the onshore orogenies of eastern and southern Mexico surrounding the GoM. We discuss the naming of several important tectonic features and basins in Mexico and give our reasoning for the preferred names, in an effort to standardize nomenclature. We also briefly summarize the petroleum elements of the southern GoM. The papers in the last section of the book summarize the complex geology and evolution of the Northern Caribbean, focussing on the characterization of the Caribbean Plate basement and basins formed during the development of the North America–Caribbean plate boundary since the Late Cretaceous.
Tectonic framework
The geology of the southern GoM and Northern Caribbean is the manifestation of complex plate interactions resulting from the breakup of western Equatorial Pangea around 250–170 Ma, and, more specifically, the rifting and breakup of the continental crust of the North and South American plates, including the Yucatán Block. The region is further complicated by subduction and mantle-related processes that resulted in either destruction of pre-existing tectonic elements or uplift and non-deposition. These plate-scale events exerted a dominant control on the tectonostratigraphic development of the associated basins and orogens in the wider region. Figure 2 and Enclosures 1 and 2 compiled by Steel and Davison (2020a, b) summarize the geological elements of the area of interest covered in this volume.
Geological elements map of the Gulf of Mexico (GoM) and the Northern Caribbean showing many of the key basins and tectonic features described. This map has been compiled from the following range of data sources. Antillean Arc Progression is mapped from Pindell and Cossey. Fault systems are mapped from Hernández-Vergara et al. (2020), Leroy et al. (2015), Pindell and Kennan (2009), Rogers and Mann (2007). Note, some of the faults and folds have been simplified to show overall trends. Key for structural features: BB, Belize Basin; CB, Corozal Basin; CC, Chuacús Complex; CFB, Catemaco Fold Belt; CHB, Chicontopec Basin; FPFB, Frey Pedro Fold Belt; FZ, Fault Zone; IOT, Isthmus of Tehuantepec; LP-SJ FZ, Los Pozos–San Juan Fault Zone; LTV, Los Tuxtlas Volcanics; MB, Magiscatzin Basin; PAB, Parras Basin; PB, Petén Basin; PLB, Placetas Belt; PMFS, Polochic–Motagua Fault System; PRVI MICROPLATE, Puerto Rico–Virgin Islands Microplate; SCFB, Sierra de Colón foldbelt; SDLO, Sierra de los Organos; SFB, Sepur Foredeep Basin; TMFS, Tuxtla–Malpaso Fault System; TP, Tuxpan Platform; VF, Veracruz Fault; YC, Yucatán Channel.
The key tectonic elements of this area are the following:
GoM – extensional rift basin with widespread salt deposition on the rifted margins, and floored by oceanic crust in the deep Gulf.
Mexican Fold-and-Thrust Belt – the southern continuation of the North American Cordilleran Orogen.
Oaxaca, Chortis and Yucatán blocks – located on the southern margin of the North American plate which underwent large translations during the Mesozoic and Cenozoic evolution of the GoM.
Greater Antillean Arc and Caribbean Plate – a largely intra-oceanic magmatic arc, fringing the oceanic Caribbean Plate which collided diachronously from west to east with the rifted continental margins of North America (Cuba, Nicaragua Rise–Jamaica, Hispaniola, Puerto Rico–Virgin Islands) and South America (Leeward Antilles, Margarita, Tobago).
Regional geology of the southern GoM and the surrounding orogens
The main geological events of the southern GoM and surrounding orogens are summarized in Figure 3 and discussed in chronological order below.
Geological events chart for the Mexican GoM.
The opening of the GoM
The Precambrian and Paleozoic crystalline basement surrounding the GoM is highly complex. The Florida peninsula and western Bahamas are composed of an amalgam of over 20 different basement blocks with main structural contacts trending ENE to NE (see map in Erlich and Pindell 2020). This strong basement trend has conditioned the orientation of the adjacent rifting in the onshore Triassic basins in South Georgia, and the offshore rifts bordering western Florida (see Fig. 12 of Erlich and Pindell 2020, and Fig. 2). Precambrian to Paleozoic crystalline basement rocks surround the southern GoM area, the Yucatán Peninsula and Campeche Knoll (located on Fig. 2, DSDP, Leg 77, Hole 538A). The curved Jurassic shear zone system allowed the Yucatán block to rotate away from North America, and follows the arcuate crystalline basement outcrop and subsurface trend through eastern Mexico (Fig. 2). This basement trend and adjacent curvilinear shear zones have also controlled many later Cenozoic to Recent events.
Rifting was initiated in the Triassic (c. 240 Ma) in the eastern USA and the GoM (Olsen 1997; Olsen et al. 2005; Withjack et al. 2012). ‘Red bed’ continental rift basins have been drilled along the US margin, where the Eagle Mills Formation in that location at least is dated as Carnian (Figs 2 and 3; Wood and Benson 2000). However, the exact age of the ‘red bed’ sediment infill onshore Mexico (Plomosas Formation in the North, Huizachal Group in the East, Todos Santos Group in the South) is not well dated owing to a lack of age-specific fauna (Mixon et al. 1959; Lawton and Pindell 2017), and our understanding relies heavily on maximum depositional ages from detrital zircon work (e.g. Godínez-Urban et al. 2011). The onshore Triassic rift fill reaches c. 1–3 km in thickness. However, offshore seismic data along the NW Yucatán margin indicate a thick pre-salt, syn-rift and sag basin sequence which can reach up to 8 km, where lacustrine or even marine deposits may be expected (Steier 2018; Hudec and Norton 2019; Davison 2020; Kenning and Mann 2020b; Miranda-Madrigal and Chavez-Cabello 2020; Pindell et al. 2020c). Rifting continued into the Middle to Late Jurassic for some 70 myr, which is an exceptionally long period for active rifting.
The Jurassic salt basin
The GoM is dominated by two major salt basins which were originally deposited as one contiguous basin in the Middle Jurassic (Humphries 1978). Subsequent rifting and opening of the GoM and emplacement of the oceanic crust separated the salt basin into its present two-part configuration (Fig. 2).
The northern salt basin comprises much of the US sector of the GoM, the Mexican Salina Del Bravo and the Perdido Fold Belt which straddles the border between the two countries (Fig. 1). The southeastern Mexican salt basin is referred to herein as the Sureste Basin, the name adopted by the Mexican Comisión Nacional de Hidrocarburos (CNH) and Pemex. The basin or parts of it have previously been named the Cuenca de Campeche (Campeche Basin, after the Bay of Campeche), Cuenca de Salina del Istmo (Isthmian Salt Basin) and simply Cuenca Salina. The northernmost part of the Sureste Basin has also been separately named both the Isthmian Salt Basin and the Yucatán Salt Basin (Hudec et al. 2013), even though there is no geological separation between the main Sureste Basin and this northern area. We prefer to refer to this northern subarea as the Yucatán Salt Basin, as no isthmus is present here (Fig. 1). The shallow-water (<200 m) segment of the Sureste Basin has also been divided into the Pilar, Catemaco, Comalcalco and Macuspana sub-basins, the latter two separated by the Reforma–Akal high, and the onshore Chiapas Basin Foldbelt subareas, among others (Fig. 1).
The original thickness of halite in the Sureste Basin probably approached 4 km in the centre prior to breakup owing to seafloor spreading (Davison 2020), and may have been somewhat greater in the Salina del Bravo where large allochthonous sheets, but not the original salt, reach up to c. 6 km in thickness near to the feeder stems (Hudec et al. 2020). The few Sureste Basin wells that have penetrated the salt have encountered mainly halite, as is the case in the US Louann salt basin area (Fredrich et al. 2007). The main salt basin was probably deposited in a short period of time (<3 myr), as suggested by the apparent paucity of other intervening sedimentary rocks.
Oceanic spreading and formation of oceanic crust in the GoM
Ocean spreading is believed to have started soon after deposition of the Bajocian salt, but there is no absolute dating control on initiation, and continued until the end of the Berriasian c. 140 Ma (Fig. 3; Pindell 1985; Marton and Buffler 1994; Stern and Dickinson 2010). Approximately 700–800 km of ocean crust was formed which has been measured parallel to the transform faults at the westernmost end (Fig. 2). Extinct mid-ocean ridge segments, transform fault offsets and curved fracture zones are now reasonably well imaged using vertical gravity gradient data and seismic data (Sandwell et al. 2014; Lin et al. 2019; Fig. 4). Pindell et al. (2020c) provide more details of ocean spreading history.
Vertical gravity gradient map of the GoM and the Northern Caribbean derived from satellite measurements of ocean topography (dataset of Sandwell et al. 2014).
Jurassic to Upper Cretaceous post-salt sediment deposition (167–65 Ma)
Individual papers on post-rift sedimentation are too numerous to mention here, but Snedden and Galloway (2019) have compiled a milestone synthesis of the majority of new developments on the sedimentology, stratigraphy and palaeogeography of the whole of the GoM. Padilla y Sánchez (2007) and Byron Rodriguez (2011) have also produced regional studies of the Mexican sector of the GoM. A few specific comments are, however, justified here and a summary of the main depositional and tectonic events is presented in Figure 3.
The oldest known sediments deposited on top of the salt are anhydrites, aeolian sandstones and ephemeral fluvial deposits (Bacab Formation), which have not been dated, and these could be any age between 169 and 160 Ma. These are overlain by the Tson anhydrites, limestones and shallow marine sandstones, mudstones and oolitic limestones of the Ek-Balam Formation (Ortuño Álvarez 2014; Snedden et al. 2020), which have been dated by ammonites as Late Oxfordian (c. 160 Ma, Cantú-Chapa 1992, 2009). The overlying Norphlet aeolian sandstones found in the deepwater central and eastern US sector, and the Bacab Formation in the Sureste Basin, are similar facies (Godo 2019; Snedden et al. 2020). The occurrence of aeolian desert dunes and wadi deposits overlying the salt suggests the salt basin was not connected to the global ocean system until the late Oxfordian. The degree of downslope rafting of the Norphlet sandstones on salt is significant (Pilcher et al. 2014), which suggests that these were deposited on a topographic slope with the centre of the basin below global sea-level, so that a Bathonian–early Oxfordian transgressive marine section may overlie the oldest parts of the oceanic crust with the transgression only reaching the proximal basin edges in the late Oxfordian (Pindell et al. 2020b, 2020c).
During the late Jurassic to mid Cretaceous period the GoM slowly subsided owing to thermal cooling and sediment loading. The surrounding onshore areas were presumably low relief and the basin was starved of coarse clastic sediment. Carbonates were deposited on the surrounding shelves and fine-grained sediment in the deepwater (Snedden and Galloway 2019). During the 100 myr period from 165 to 65 Ma only 1–3 km of sediment was deposited in the deep GoM (Salvador 1991; Galloway 2008; Snedden and Galloway 2019). This is a relatively recent realization, as prior to the dating of the ‘mid Cretaceous unconformity’ or ‘Challenger reflector’ as top Cretaceous by Dohmen (2002), this reflector was thought to be around 97 Ma (Buffler et al. 1981; Shaub et al. 1984). Hence, prior to 2002, it was thought that much more sediment had entered the GoM during the Late Cretaceous, and less in the Paleogene. We now know that the GoM remained essentially starved of sediment input until the Chicxulub impact, which in fact caused the Challenger reflector, and after which deposition was permanently altered.
Mexican Fold-and-Thrust belt (c. 93–45 Ma)
The starved slowly subsiding GoM was dramatically changed by several important pulses of Late Cretaceous to Pliocene activity, which caused basin deformation, basin margin uplift and rapid sediment influx. These tectonic events were mainly concentrated in the Mexican sector of the GoM and resulted in the development of the Mexican Fold-and-Thrust Belt (MFTB), Mexican Foreland Basin and the Chiapas Fold-and-Thrust Belt which exerted important influences on the evolution of the Mexican GoM.
The first contractional pulse, now known as the Mexican Orogeny, produced the Mexican Fold-and-Thrust Belt, consisting of the mountain chains of the Sierra Madre Oriental (SMO), and Sierras Juárez and Zongolica in the south (Carrillo-Bravo 1971; Tarango 1973; Fitz-Díaz et al. 2018; Juárez-Arriaga et al. 2019a, b; Fig. 5). Apatite fission track dating of the latest cooling event affecting rocks exposed in the Chiapas Fold Belt, and dating of thrust faults and flexural slip zones in folds, suggests a limited amount of Late Cretaceous to Paleogene deformation may have extended this far south (Abdullin et al. 2018; Hernández-Vergara et al. 2020), although the main phase of compression in Chiapas occurred later in the Miocene.
Simplified sketch map showing the latest stage of development of the Mexican Foreland Basin (MFB) in the late Paleogene. The MFB captured most of the eroded material from the Sierra Madre Oriental and the Mexican cordillera arc and basement terranes further west. Two major channel systems fed coarser-grained sediment into the GoM in the Veracruz Basin and in the Burgos Basin to the north. The central part – the Tampico Misantla Basin – was starved of coarse clastic sediment in Paleogene. Fine-grained deposits were accumulated on this steep transform margin and a series of major mass transport complexes were developed in the deep water which reach up to 3.5 km in thickness (Kenning and Mann 2020a). The two schematized cross-sections (no specific location intended) show (a) the late Paleogene foreland basin which accumulated up to 6 km of clastics and (b) the same cross-section as in (a) after Oligo-Miocene uplift. Uplift of the whole mountain and foreland system is interpreted to have been caused by increased upward force from a shallowing of the subducting Pacific slab (Gray et al. 2020). Sediment then spilled over the foreland bulge into the Tampico–Misantla Basin where up to 6 km of Oligoene to Pliocene sediment was deposited. Uplift also caused an inversion in dip of the basal detachment from a westerly dip to an eastward dip.
Compressive deformation was initiated around 90 Ma in the interior basins of Mexico and the SMO, and the associated thrusts and folds propagated progressively eastward into the frontal part of the SMO and coastal areas of the western Tampico–Misantla Basin by middle Eocene times (44 Ma) (Gray and Lawton 2011; Fitz-Díaz et al. 2014, 2018; Juárez-Arriaga et al. 2019a, b; Gray et al. 2020; Fig. 5). This orogenic event has also been called the Mexican Laramide or Hidalgoan Orogeny (Lawton et al. 2009; Gray and Lawton 2011). Hidalgoan was coined by Guzmán and de Cserna (1963) because the structural style of the MFTB differs from that of the Canadian and US cordilleras. Guzmán and de Cserna (1963) named the orogeny after the Mexican state of Hidalgo that lies to the north of Mexico City, but this is only a small part of the whole orogeny and as such we prefer the names Mexican Orogeny and the Mexican FTB (see Juárez-Arriaga et al. 2019a, b, who adopted these names).
The Mexican Orogen developed in association with the palaeo-Pacific Benioff Zone and could have been created by several different processes; by shallowing of the subducted Pacific slab below the North American plate (Coney and Reynolds 1977; English and Johnston 2004), subduction of a buoyant oceanic plateau (Burke et al. 1978; Livaccari et al. 1981) or an increase in the rate of subduction (Engebretson et al. 1984). The ‘La Posta’-type plutons along the western margin of Mexico indicate that subduction of the Pacific Farallon plate was probably initiated around 100 Ma, slightly before the first subduction-related granitic intrusions dated at 98 Ma (Kimbrough et al. 2001).
The Mexican sierras formed as a result of the Mexican Orogeny and rise to over 3 km in height; these are mainly composed of Cretaceous carbonates, marls and shales (Carrillo-Bravo 1971, and the front cover of this volume). Uplift of the Cretaceous carbonate platforms resulted in important karstification events occurring in the Golden Lane carbonate rim of the Tuxpan Platform, and in the Sureste Basin where some of the breccias in the Cantarell Field resulted from several episodes of Cretaceous karstification, shelf edge collapse and reworking (Aguayo-Camargo 1978, 1998; Horbury et al. 2005; Ruiz et al. 2011; Horbury 2018; Horbury and Ruiz 2019). The Sureste Basin also exhibits a distinct phase of allochthonous salt sheet development in the Eocene, which was probably due to compression at the end of the Mexican Orogeny (Davison 2020).
Mexican Foreland Basin development and GoM Paleogene deposition
The name Mexican Foreland Basin (MFB) was first formalized by Juárez-Arriaga et al. (2019b). The MFB was developed along the eastern front of the MFTB and extends for c. 1700 km from the city of Chihuahua in the north, to the town of Jesus Carranza in Veracruz State in the south. Up to 6 km of siliciclastic sediments were deposited in the basin (e.g. Ortuño-Arzate et al. 2003; Alzaga-Ruiz et al. 2009; Lawton et al. 2009; Juárez-Arriaga et al. 2019b, Fig. 5). The MFB encompasses the Parras, Mayran (name proposed by Gray et al. 2020), Magiscatzin, Tampico–Misantla and Veracruz basins, and follows underlying Jurassic NW trending rifts, which have been identified in both the Magiscatzin and Chicontepec areas (Horbury et al. 2003; Alzaga-Ruiz et al. 2009).
The earliest sediments in the MFB are unnamed marine turbidites that outcrop in the Mesa Central (maximum depositional age from detrital zircons of c. 94–92 Ma; Juárez-Arriaga et al. 2016). The youngest MFB sediments are early and middle Eocene, mostly calcareous turbidite sandstones of the Chicontepec Formation (Vasquez et al. 2014; Cossey et al. 2016; González Díaz et al. 2018; Juárez-Arriaga et al. 2019b; Gray et al. 2020).
The MFB is unusual in that it appears to have been actively contracting at the same time that it was subsiding, and the basin was maintained well below sea-level. Folds and thrusts were developed in the western foreland during rapid marine transgression and accompanying sediment deposition, with relatively little forward propagation of the thrusts into the foreland. As a result, the main foreland basin succession is marine in origin from the basal Soyatal Formation to the uppermost Eocene Chicontepec Formation (Cossey et al. 2016; González Díaz et al. 2018). This anomalous foreland basin development is perhaps best explained by an underlying dynamic pull-down force in the mantle coeval with compression (Fig. 5; Gray et al. 2020).
Sediments were trapped in the MFB west of the Tamaulipas, Tuxpan and Cordoba highs which are located near to the Jurassic East Mexico Transform zone (González Alvarado 1974; Vázquez-Meneses 2005, Fig. 5). These highs have been previously interpreted as foreland bulges by Horbury et al. (2003) and Alzaga-Ruiz et al. (2009). However, we interpret these as earlier features which developed relative relief in the Late Jurassic, as evidenced by onlap of the Zuloaga and Olvido carbonates onto the Tamaulipas Arch (and the others?). Positive elevation persisted into the Cretaceous at the Golden Lane, where the carbonate shelf edge developed around the Tuxpan High in Aptian–Albian times (CNH 2015b), well before the MFB was initiated in the Late Cretaceous.
Paleogene sediment was channeled parallel to the MFB, with palaeocurrents systematically oriented towards the SE in the San Luis de Potosi area (Cuevas Barragan et al. 2016) and the Chicontepec Channel system of the Tampico–Misantla Basin (Cossey et al. 2016; González Díaz et al. 2018). Sedimentary detritus escaped into the offshore Veracruz Basin between the Tuxpan and Cordoba carbonate platforms, and into the southern Veracruz area (future Los Tuxlas volcanic centre) where long-range NNW channels ran out along the frontal western edge of the Sureste salt basin (Fig. 5).
The offshore region east of the Tampico–Misantla Basin, which would become the future site of the Mexican Ridges Fold Belt (MRFB), was shielded by the Tamaulipas Arch from the sediment shed off the MFTB and the basement and volcanic arc terrains further west. However, fine-grained mudstones derived from Cretaceous shales and carbonates were eroded from the eastern side of the Tamaulipas Arch and deposited along this steep transform margin (Fig. 5).
The apatite cooling histories of the frontal eastern parts of the MFTB and the western part of the MFB indicate that it was buried by 4–7 km of sediment, but then rapidly uplifted around 35–40 Ma, with most of the MFB sediment removed, except in the Chicontepec and Veracruz areas (Gray et al. 2020). This later uplift is possibly due to asthenospheric upwelling above a retreating subducted slab (Gray et al. 2020). The large volume of eroded material spilled over the partially eroded Tamaulipas Arch into the Salina del Bravo and Tampico–Misantla Basin in the late Eocene to Miocene.
Eocene to Oligocene gravity tectonics along the East Mexican margin
Tectonic elevation of the Laramide (US) and Mexican orogens during the Paleocene initiated a major increase in sedimentation rate after c. 65 Ma (Galloway 2008; Snedden et al. 2018). The catchment area of the Rio Bravo and Colorado rivers extended to the Rocky Mountains in Colorado (Snedden et al. 2018) and these rivers transported coarse clastic material from across the North American continent into the Burgos Basin and the Salina del Bravo where it was deposited as the Wilcox Formation. In the US sector the Wilcox Formation has been dated from 61.5 to 51.1 Ma (Zarra et al. 2019). Wilcox Formation sandstones evenly blanketed the whole of the Burgos Basin during large-scale progradation of deltas (Echanove Echanove 1986). In the deeper water of the Salina del Bravo and Perdido Fold Belt areas the Wilcox appears as a regionally extensive interval of sub-parallel reflectors. These sandstones constitute the principal target for hydrocarbon exploration in these basins. In the Salina del Bravo and Perdido Fold Belt the Paleogene section can reach more than 2.5 km in thickness (Colmenares 2014).
The rapid deposition of the Wilcox Formation, which began in the Paleocene, caused sediment loading and major seaward-directed salt extrusion in the Salina del Bravo (Pérez Cruz 1992; CNH 2015a; Davison and Cunha 2017; Hudec et al. 2020). However, it was not until the Late Eocene–Early Oligocene (30–35 Ma), some 15–20 myr later, that the salt-detached Perdido Fold Belt developed (Fiduk et al. 1999; Patiño Ruiz et al. 2003). The time lag between end of Wilcox deposition and the formation of the salt-detached Perdido Fold Belt is significant. It has been suggested that the presence of an outer ‘Baha High’ east of the Perdido Fold Belt prevented the salt from flowing seaward onto the oceanic crust (Hudec et al. 2020). These authors attributed the outer high to be an original ‘basement high’ present at the time of salt deposition. Compression continued later into the late Oligocene to early Miocene, when the Lamprea Fold Belt detached on Paleogene shale in front of the southern segment of the Salina del Bravo salt canopy (Salomón-Mora 2013; Vazquez-Garcia 2018).
Paleogene mass transport complexes in the deep water (offshore) Tampico–Misantla Basin
Major Paleogene siliciclastic input occurred throughout the Tampico–Misantla offshore basin where fine-grained clastics dominated, and the thickness of this interval can reach up to 3.5 km (Marcías Zamora 2007). The rapid sediment input along the steep transform margin caused dramatic shelf failures and produced stacked mass transport deposits (MTDs) in the deep water (Kenning and Mann 2020a, Fig. 4). The largest MTD extends to the northern part of the Sureste Basin, an east–west distance greater than 400 km (see Kenning and Mann 2020a, their Fig. 12A).
Miocene to Recent: Mexican Ridges Fold Belt
The deepwater Tampico–Misantla Basin remained undisturbed for some 30 myr until the mid Miocene (c. 15 Ma), when a remarkable series of large coast-parallel extensional growth faults were initiated in the shallow-water part of the basin, (e.g. Faja de Oro Fault). Large shale-cored folds developed downdip of the growth fault system, to produce the Mexican Ridges Fold Belt (MRFB, Buffler et al. 1979; Pew 1982; Vázquez-Meneses 2005). Downslope gravity gliding has continued until the present day, resulting in a seabed which is significantly folded. The folding occurred above a major detachment surface located at or near the base of the Eocene MTDs (Kenning and Mann 2020a).
Le Roy (2007) and Le Roy et al. (2008) suggested that the sudden collapse of the shelf 30 myr after the development of the MFTB was due to the Neogene reactivation and 1–2 km of relief enhancement along the transform fault which borders the GoM, trending 170–150° N (Fig. 2). However, the MRFB can reach up 220 km wide, and the thickness of the pre-kinematic strata above the detachment can be c. 3.5 km. Therefore, it is unlikely that a fold belt of this scale was produced from localized uplift along a transform fault (Gradmann et al. 2009). Local Neogene reactivation would have been insufficient, in isolation, to generate the folding of 3.5 km of normal strength clastic strata as observed in the MRFB. However, when combined with the presence of a weak overpressured detachment and overpressure in the folded strata across the entire fold belt, the observed geometries of the MRFB could be generated. Hence, a much more likely explanation for the time lag is that the Eocene shales only became sufficiently weak and overpressured in the Late Miocene when the underlying Tithonian source rock began to generate gas. The Tithonian source was buried to c. 6 km depth below seabed by mid Miocene times and is predicted to have entered the gas window at this time (authors’ estimate with geothermal gradient of 30°C/km). The gas would then have risen to the hydraulic seal at the base of the MTDs and caused overpressure where the detachment is located.
Miocene: Chiapanecan Orogeny
Subduction-related magmatism commenced in the Miocene in southeastern Oaxaca and southern Chiapas as the Chortis Block moved east and exposed the Tehuantepec and Chiapas regions to subduction for the first time. The introduction of the Cocos Slab beneath Chiapas as the Chortis Block moved east greatly increased the total lithospheric thickness and drove rapid and large uplift and imbrication within the Chiapas Massif, which initiated the Chiapanecan Orogeny (Pindell and Miranda 2011; Graham et al. 2020). The Chiapanecan orogenic event also produced folds and thrusts throughout both the southern half of the Sureste Basin and the Chiapas Fold-and-Thrust Belt (Garcia-Molina 1994; Mora et al. 2007; Mandujano-Velazquez and Keppie 2009; Davison 2020; Graham et al. 2020; Villagomez and Pindell 2020). Maximum contraction occurred in the mid Miocene, which was most concentrated in the southern half of the Sureste Basin and the onshore areas extending from Veracruz to Chiapas states.
Seismic data reveal a culmination of sorts within the Chiapanecan Orogeny. This culmination is represented by a strong erosional unconformity that can be regionally correlated across the southern Sureste Basin, with high-angle sedimentary onlap patterns onto the fold crests associated with this unconformity (Davison 2020). This indicates there was a short intense compressional event in the present-day offshore area, which is estimated to have occurred between 13.8 and 11.6 Ma (Mandujano-Velazquez and Keppie 2009; Shann 2020). This compressional event also produced the main episode of folding and thrusting in the onshore Chiapas Fold-and-Thrust Belt (Graham et al. 2020).
The transcurrent fault systems that facilitated the rotation of the Yucatán block in the Jurassic to early Cretaceous were reactivated in the mid Miocene with the Veracruz, Tuxtla–Malpaso and Grijalva faults and many subsidiary west- to NW-trending faults exhibiting sinistral movement at this time; some movement has continued to the present day (Fig. 2; Meneses-Rocha 1991, 2001; Andreani et al. 2008; Witt et al. 2012; Hernández-Vergara et al. 2020).
Late Miocene–Recent: rejuvenation of the major strike-slip faults, North Chiapas Volcanic Arc
The final tectonic events affecting the onshore Mexican sector of the GoM resulted in late Miocene to Recent sinistral rejuvenation of large strike-slip faults bordering the Oaxaca (or Southern Mexico Block) and Chortis blocks (Fig. 2; Andreani et al. 2008). In addition, important mafic alkaline volcanism occurred during the late Miocene to Recent (7.5–0 Ma) along a zone bordering the GoM in the Tampico–Misantla and Veracruz basins known as the Eastern Alkaline Province (Ferrari et al. 2005). Los Tuxtlas volcanic field in the Veracruz Basin is 80 km long by 50 km wide and volcanism is centred over two parallel strands of the Veracruz Fault that have been mapped through the complex (Fig. 2; Andreani et al. 2008). The volcanic rocks have been dated from 7 Ma to the last historical eruption of San Martin Tuxtla in 1773 AD (Nelson and Gonzalez-Caver 1992; Aguilera-Gómez 1988). These volcanic rocks are interpreted to have formed during transtension along these deep-seated fault strands with magmas derived from the underlying subducted Cocos plate.
The North Chiapas calc-alkaline volcanic arc became active around 2.9 Ma (Mandujano-Velazquez and Keppie 2009). The magmatism was probably associated with significant uplift and denudation, and coincided with the timing of a large influx of sediment into the southern part of the Sureste Basin which caused large-scale evacuation of allochthonous salt sheets and formation of deep mini-basins (Comalcalco Macuspana, and Pescado with up to 4 km of sediment accumulated in the last 2.5 myr (Gomez-Cabrera and Jackson 2009; Ruiz-Osorio 2018; Chavez Valois et al. 2009)).
Chicxulub impact (66 Ma)
A regional review of the GoM would not be complete without mentioning the Chicxulub impact, which had such an important effect on our planet. Since the discovery of the location of the impact crater in northern Yucatán (see Penfield 2019 for a historical account of its discovery, and Hildebrand et al. 1991), there has been great interest in this feature with publications too numerous to mention here. The asteroid impact that caused the Chixcxulub crater occurred at 66.038 ± 0.025/0.049 Ma (Renne et al. 2013), which coincided with the last day of the Mesozoic when more than 60% of all Cretaceous species died out (Schulte et al. 2010). The bolide is estimated to have had a diameter of 10–15 km and created an impact crater c. 110 km in diameter. The calculated impact angle of 45–60° arriving from the NW (Collins et al. 2020) produced a very deep crater (c. 20 km) almost instantaneously (Morgan et al. 2016). Consequently, a large volume of dust and molten material was ejected. The impact locality was covered by thick Cretaceous anhydrite deposits which were vaporized into large volumes of sulfate aerosols, which would have created a very effective block to sunlight (325 ± 130 Gt of sulfur were gasified; Artemieva et al. 2017). This, along with the occurrence of a smoke screen created by numerous mega-wildfires, is postulated to have caused darkness and global cooling for a sufficiently long enough period to cause mass extinction (Gullick et al. 2019). Molten spherules of impact melt up to 1.4 mm in diameter were thrown as far as 1700 km from the crater, with fish choking on them in a lake deposit at the aptly named Hell's Creek in North Dakota (De Palma et al. 2019). Ejected zircons from around the world show a Pan-African age, indicating that the crust of northern Yucatán is similar to that of Florida, but unlike that of southern Yucatán (see Krogh et al. 1993; Erlich and Pindell 2020).
The impact shocked the GoM and surroundings with an energy equivalent to a magnitude 10–11 earthquake and this created the largest known ‘event’ deposit (debris flows and later tsunami deposits) in the world. This event can be correlated across the entire GoM using a bright high-impedance seismic reflector and well data (Sandford et al. 2016). Collapse of the Mesozoic carbonate shelf edge around the GoM produced a widespread carbonate breccia that forms an important portion of the reservoir in most of the giant oil fields reservoired by carbonates in the Sureste Basin. However, not all breccias are associated with the meteorite impact. At the Cantarell Field, in situ carbonates with karstic processes and dolomitization were developed during the Late Cretaceous (Horbury and Ruiz 2019). An iridium-rich ash-fall layer associated with the impact forms the lowermost part of the Paleocene mudstone top seal to the Cantarell Field (Grajales-Nishimura et al. 2000), which has the largest known vertical hydrocarbon column in the world at 2.2 km (Shann 2020).
Hydrocarbon systems of the southern GoM
The widespread presence of the Bajocian salt, Tithonian source rock, Cretaceous carbonate buildups and Cenozoic clastic depositional systems across the Mexican GoM has resulted in many of the basins sharing common elements of their petroleum systems (Fig. 6). However, the Mexican (Late Cretaceous–Eocene) and Chiapanecan (Neogene) orogenies had the greatest impact on the hydrocarbon habitat of these basins. These tectonic events uplifted the Mexican hinterlands, caused karstification and brecciation of the Cretaceous carbonate buildups and delivered Cenozoic clastic sediments into the basin depocentres. These are the two primary present-day reservoir types. The orogenies also indirectly triggered, within the GoM basin, updip gravitational extension, translation and downdip compression with shortening of allochthonous salt canopies and creation of salt-cored fold belts in the Sureste, Burgos and Perdido basins and shale-cored structures of the MRFB. Peak deformation during the Chiapanecan Orogeny occurred in the middle Miocene Serravallian period (Mandujano-Velazquez and Keppie 2009; Shann 2020), resulting in a phase of intense structuration and trap formation in the Sureste Basin. These orogenic events also controlled hydrocarbon maturation and migration at a regional scale.
Summary of the key petroleum systems elements for the basins of the Mexico and southern GoM.
Following the 2013 reform of the Mexican energy sector, subsequent competitive licence rounds have resulted in the drilling of a number of wells (Fig. 7). The current focus of exploration drilling has targeted Miocene to Recent siliciclastic reservoirs within salt-related structures formed during the Chiapanecan Orogeny. However, the ultradeep water Chibu-1 and Max-1 wells reportedly targeted Jurassic (Oxfordian) objectives, and will provide important calibration on the petroleum potential of the northern deepwater area of the Sureste Basin.
Map showing location and publicly reported results of recent exploration/appraisal wells drilled during the period January 2017 to May 2020 in Mexico.
The majority of wells in this first phase of drilling was located with legacy seismic data that was probably inadequate for detailed subsalt imaging. To support the recent exploration effort, 72 000 km2 of wide azimuth, multiclient 3D seismic data were acquired and processed across the offshore Sureste Basin. The combination of modern acquisition and processing technology combined with detailed velocity modelling and re-processing of targeted mini-basins provided enhanced imaging of the subsalt section, which will be a focus for future exploration.
Regional geology of the Northern Caribbean islands, and the Honduras–Nicaraguan Rise
The geology of the Northern Caribbean region is more complex than that of the GoM and its immediate margins. The Caribbean Plate is bounded by structurally complex zones involving microplates rather than discrete plate boundaries (Burke et al. 1978; Tillman and Mann 2020; Fig. 8).
Tectonic framework of the Northern Caribbean. Caribbean Large Igneous Province (CLIP) which is overthickened oceanic crust has been drawn using a combination of work from Reuber et al. (2019), Serrano et al. (2011), Mauffret and Leroy (1997) and Nerlich et al. (2015). Cenozoic Basins/Rifts are mapped from Brandes and Winsemann (2018), Cruz-Orosa et al. (2012), Mann and Burke (1984), Sanchez et al. (2015) and Torrado et al. (2019). Key for structural features: BB, Belize Basin; CB, Corozal Basin; CFB, Catemaco Fold Belt; FPFB, Frey Pedro Fold Belt; FZ, Fault Zone; IOT, Isthmus of Tehuantepec; LP-SJ FZ, Los Pozos–San Juan Fault Zone; LTV, Los Tuxtlas Volcanics; PB, Petén Basin; PLB, Placetas Belt; PMFS, Polochic–Motagua Fault System; PRVI MICROPLATE, Puerto Rico–Virgin Islands Microplate; SCFB, Sierra de Colón Fold Belt; SDLO, Sierra de los Organos; TMFS, Tuxtla–Malpaso Fault System; VF, Veracruz Fault; YC, Yucatán Channel.
The Northern Caribbean region of today has formed as a result of the relative eastward migration of Pacific-derived oceanic lithosphere, led by the Great Caribbean or Greater Antillean Arc, with the partly continental Chortis Block at its trailing end. This multicomponent plate has been engulfed between the originally passive North and South American margins during the westward flight of the Americas from Africa (Pindell et al. 2005; Pindell and Kennan 2009; Figs 8 & 9). The Greater Antillean Arc began to form c. 135 Ma by subduction when there was very little space between the Americas, and comprises igneous and metamorphic rocks of Cretaceous to Eocene age (Rojas-Agramonte et al. 2011). It is now widely accepted that the Caribbean lithosphere and the Antillean Arc migrated from west to east into the Proto-Caribbean gap since the Late Cretaceous (Pindell et al. 1988, 2006; Montgomery and Kerr 2009; Neill et al. 2011; van Benthem et al. 2013; Stanek et al. 2019; Fig. 9). Subduction produced largely intra-oceanic island arc complexes, but some continental basement blocks (e.g. the core of the Chortis Block) were accreted into the Caribbean Plate during collision with the rifted continental margins of North and South America as a consequence of the long-lived migration (Figs 2, 8 & 9).
Late Paleocene (56 Ma) depiction of the allochthonous Caribbean Plate entering the Proto-Caribbean gap between the Americas. Reconstruction is drawn in the Indo-Atlantic hotspot reference frame of Müller et al. (1993). Faint grey geographic lines are present-day coastlines. Label abbreviations: GoM OC, GoM oceanic crust; NR, Nicaragua Rise; CB, Colombian Basin; VB, Venezuelan Basin; J, Jamaica; SH, southern Hispaniola; AR, Aves Ridge; C, Central Cuba; WC, Western Cuba; CR, Cayman Ridge; YB, Yucatán Basin; GB, Grenada Basin (not yet opened); CCB, composite Chortis Block. Heavy grey line, outline of present oceanic crust of Caribbean interior. Circles with G, granite (arc); circles with V, volcanic (arc). Modified after Pindell and Kennan (2009).
The zone of original island arc collision with the North American continental margin was some 3000 km in length extending along the southern Chortis Block (Nicaragua) and continuing northward through eastern Honduras into southeastern Mexico (Chiapas) and Guatemala, along Belize and eastern Yucatán, and across the Florida Straits to the southern flank of the Bahamas (Figs 8 & 9). Central Cuba (part of the frontal arc), the Yucatán Basin (intra-arc basin) and the Cayman Ridge (the remnant island arc) were once part of the mobile Caribbean island arc system, but became part of the North American Plate with the Paleogene advent of the Cayman Trough transcurrent fault system (Figs 2, 8 & 9).
Foreland basins were produced along the northern margin of the collisional zone in Guatemala, Yucatán, Cuba and the Bahamas (e.g. Masaferro et al. 1999). The foreland basins were uplifted, deformed and eroded in Guatemala and the Yucatán, but are still well preserved in northern Cuba and the Bahamas, where up to 4 km of mainly Paleogene sediment are preserved, overlying the original passive Jurassic–Cretaceous continental margin section (Hempton and Barros 1993; Iturralde-Vinent et al. 2008; Pszczółkowski 1999; López Corzo 2015). Several exploration wells have been drilled in the Cuban foreland but with no success. This can probably be attributed to an absence of siliciclastic reservoir rocks, because the Cuban fold-and-thrust belt is composed mainly of arc volcanic rocks, ophiolites and limestones.
The Northern Caribbean Plate interior is dissected by a series of presumed left-lateral strike-slip faults (e.g. Pedro Escarpment, Hess Escarpment), which link northward into an east–west sinistral transcurrent fault zone (Swan Island–Enriquillo–Plantain FZ) passing through Jamaica and Hispaniola (Fig. 8). This fault system is the southernmost of several fault strands associated with the Cayman Trough transform system (Pindell and Barrett 1990; Pindell et al. 2006), which define elongate microplates through Hispaniola and the NE Caribbean. Paleogene to Recent sedimentary basins are preserved along the transform strands through Hispaniola (Gorosabel-Araus et al. 2020; Mann and Pierce 2020; Tillman and Mann 2020). The original Greater Antillean Arc has been offset by the Cayman Trough transform, with an estimated 1100–1200 km of total sinistral movement. This corresponds to the east–west width of the deep Cayman Trough, an oceanic pull-apart basin which opened with a north–south-orientated spreading axis (Fig. 8). However the offset between the Cuban and Hispaniolan arc segments is only 350 km because most of the Cayman offset passed south of the Hispaniolan arc axis (Pindell and Barrett 1990). Several pull-apart basins developed along other strike-slip faults associated with the Cayman Trough system (Burke et al. 1978), such as the Niobe, Patuca, Tela, San Andres Grabens and the Walton Trough (e.g. Jablonski et al. 2010; Fig. 8).
Nature of oceanic crust of the Caribbean Plate
The interior of the Caribbean Plate is floored mainly by Cretaceous oceanic crust. However, some Cenozoic basins have formed within the oceanic crust, and today there are three types of oceanic basement in the Northern Caribbean.
(1) Oceanic Plateau crust
The Colombian and Venezuelan basins cover a large portion of the Caribbean Plate. The upper levels consist predominantly of mafic rocks of the middle to Late Cretaceous Caribbean Large Igneous Province (CLIP; Fig. 8), but it has long been suspected that much of the CLIP is underlain by Early Cretaceous oceanic crust because the better-sampled flanking arc dates back to the Early Cretaceous (Pindell and Dewey 1982). The CLIP crust can reach 25 km in thickness, but there are areas of thinner oceanic crust about which little is known. None of these thinner or CLIP areas feature magnetic stripes or extinct mid-ocean ridges that can be identified in terms of seafloor spreading isochrons, making plate reconstruction difficult (Reuber et al. 2019; Romito and Mann 2020). Marine borehole and outcrop samples (e.g. from southern Haiti) of the plateau basalts show a range of ages from 112 to 68 Ma (Kerr et al. 1997; Sinton et al. 1998; Lapierre et al. 2000; Révillon et al. 2000; Hoernle et al. 2004; Escuder-Viruete et al. 2007; Hastie et al. 2008; Sandoval et al. 2015). The CLIP magmas appear to be intruded into, and to overlie, older oceanic crust (Pindell 2018; Reuber et al. 2019; Serrano et al. 2011; Nerlich et al. 2015).
(2) Areas of oceanic crust formed by intra-arc extension
The Yucatán and Grenada intra-arc basins lie amidst tectonically extended island arc crust (Fig. 2). Both basins have extensionally faulted flanks that produced thinned arc crust with probable oceanic (intra-arc) crust occupying the deepest portions of the basins (Hall and Yeung 1980; Pindell and Dewey 1982; Speed and Westbrook 1984; Rosencrantz 1990; Bird et al. 1993, 1999). The crustal extension and inferred seafloor spreading in both basins is thought to be Paleogene in age, and caused by the geometrical expansion of the two ends of the original Antillean Arc after it had passed through the Yucatán–Colombia constriction of the Proto-Caribbean gap (Pindell and Barrett 1990).
(3) Cayman Trough oceanic crust
The 1100–1200 km-long, but narrow, Cayman Trough is an oceanic pull-apart basin that records less than half of the demonstrable sinistral offset between the North American and Caribbean plates (Figs 2, 8 & 9). Dating of sediments from the deep trough (Perfit and Heezen 1978), magnetic anomaly interpretation (Leroy et al. 2000) and the interpreted timing of motions on the Cayman Trough's fault splays through Hispaniola (Erikson et al. 1990; Pindell and Barrett 1990; Dolan et al. 1991; Gorosabel-Araus et al. 2020; Sun et al. 2020) indicate that the basin has probably opened since the Eocene, after the Greater Antilles Arc had collided with the Bahamas. The rest of the demonstrable North America–Caribbean displacement can be measured from the length of the undulating southern Chortis–southern Yucatán–southern Bahamas suture zone, some 3000 km in length, that had formed diachronously from the Albian to the Eocene (Pindell and Kennan 2009). This is the period when subduction-related magmatism formed most of the Greater Antilles Arc, and when most of the circum-Caribbean HP–LT syn-subduction metamorphic suites found today in the Caribbean frontal suture zone were formed (see summary of chronology in Pindell et al. 2012).
Papers in current volume
The papers in the current volume span a large range of scales and disciplines that contribute significantly to the understanding of this region. Papers can be broadly categorized into three themes:
geological evolution of the basins of the southern Gulf of Mexico;
evolution of the Late Cretaceous to Neogene Mexican orogens;
geological evolution of the basins and crustal elements of the Northern Caribbean, associated with emplacement of the Caribbean Plate and the Greater Antillean Arc.
In section one, Pindell et al. (2020c) present a comprehensive updated synthesis for the reconstruction of western Equatorial Pangaea and the synrift and drift histories of the Gulf of Mexico and surrounding regions, accommodating the recently determined Bajocian rather than Callovian age for salt. This latest model proposes new mechanisms for the emplacement of Mexican continental crust into the ‘Colombian overlap position’ in Pangean reconstructions, and may be used as a regional exploration framework. Erlich and Pindell (2020) have used a new dataset of U–Pb radiometric dating of detrital zircons to support initial extension in the SE GoM beginning in the western Bahamas and offshore western Florida in the Middle Triassic, and progressing into the South Florida Basin by the Early Jurassic. Crustal affinity of the newly described West Florida Terrane suggests a hybrid origin, possessing characteristics shared with the Suwannee Terrane and northern Yucatán Block.
The Oxfordian palaeographic reconstruction outlined by Snedden et al. (2020) is supported by detailed sedimentological analysis, and illustrates that aeolian sandstones of the Bacab Formation, found in the offshore Sureste Basin of Mexico, are coeval to aeolian sandstones of the Norphlet Formation of the northern Gulf of Mexico. Whilst petrographic data demonstrate the similarity of these aeolian sands on the northern and southern GoM, detrital zircon thermochronology demonstrates differing source terranes, with the Bacab formation being derived from the Yucatán Block.
Shann (2020) reviews the hydrocarbon exploration history of the prolific Sureste Basin and summarizes the tectonostratigraphic development of the basin. Fifteen tectonostratigraphic units of Jurassic to Pliocene age are described which record the basin's evolution. The key petroleum system elements of reservoir, source and seals are outlined, and future exploration opportunities are discussed. Davison (2020) summarizes the evolution of salt bodies and related structures in the Sureste Basin and their relation to the Mexican and Chiapanecan orogenies. Salt-related deformation was diapiric in nature until the Eocene, when allochthonous salt sheets developed in response to the propagation of the Mexican fold-and-thrust belt into the Sureste Basin. The more intense mid Miocene Chiapanecan orogeny produced folding and thrusting over a north–south distance of 600 km. These compressive events controlled the source maturation, trap development, fluid migration and accumulation within the Sureste Basin.
The geological evolution and hydrocarbon prospectivity of the Yucatán Margin is addressed in two studies by Kenning and Mann (2020b) and Miranda-Madrigal and Chavez-Cabello (2020). Kenning and Mann present an exploration framework for the northern Yucatán margin in the southern GoM. Stratigraphy, structure, event timing and thermal considerations are integrated to provide a modern synopsis of the margin's petroleum setting. Although it was once believed that this margin had too thin a sedimentary column for hydrocarbon maturation, the new analysis suggests that Neogene–Recent maturation is likely, in keeping with recent mapping of oil seeps along the margin. Miranda-Madrigal and Chavez-Cabello (2020) map and describe the regional geology of a large portion of the southern and central GoM from the northern Yucatán Platform to the eastern Mexican Ridges Foldbelt. Basement type, stratigraphy, structure and palaeogeography through time are documented using a variety of datasets including regional seismic sections. The analysis defines the various play types of the area addressed, providing an exploration framework for this frontier exploration area.
In section two, papers discuss the onshore orogenic belts of Mexico and provide further understanding of the nature and timing of deformation of the margins of the southern GoM, and the resultant uplift, denudation and sediment delivery to the concurrently evolving basinal depocentres.
Gray et al. (2020) have analysed an extensive database of new and existing apatite fission track and apatite and zircon (U–Th)/He data across eastern Mexico to describe the thermo-tectonic evolution of the region with the primary aim of understanding the amount of onshore denudation and the delivery and deposition of sediment to the GoM. The study reveals the Mayran foreland basin of the MFTB (Fig. 5) accumulated large volumes of sediment which was delivered in a northerly direction through the Burgos Basin and into the GoM during the Late Cretaceous and Paleocene. During the Eocene sediment transport changed, when the Mayran Basin was inverted, to a southerly direction through the Tampico Misantla Basin and sediment was redeposited into the southern GoM.
Evolution of the onshore Chiapas region is addressed by Hernández-Vergara et al. (2020), Pindell et al. (2020a) and Graham et al. (2020). The work of Hernández-Vergara et al. (2020) presents illite Ar40–Ar39 and zircon U–Pb radiometric dating of field samples, using the age of illite clay growth in sheared strata to address the long-standing debate over whether or not Laramide-aged tectonic events occurred in the Chiapas Foldbelt of southern Mexico. Indeed, authigenic clay growth during structural deformation appears to be Eocene, despite strata as young as middle Miocene being involved in most folds. Possible explanations for the observations are discussed, providing yet further material for the ongoing debate. Graham et al. (2020) present a series of restored cross-sections from published maps and field studies across the Cuicateco Belt, southern Sierra Madre Oriental and the Chiapas Fold Belt. They decipher the main tectonic controls on regional tectonic evolution of the thrust belts, exerted by changes in the geometry of the subducting Farallon and Cocos Plates. Pindell et al. (2020a) present U–Pb radiometric dating of detrital zircons from field samples of the middle Miocene Nanchital conglomerate in the Chiapas Fold Belt and igneous exposures in the SW Tehuantepec region to propose a sediment source-to-sink model prior to the present uplift of the Chiapas Massif. The study demonstrates that source areas for middle Miocene reservoirs in the southern GoM, possibly including those in the Zama and other recently discovered fields, extended far beyond the Chiapas Massif to the southern Mexican coastal zone and possibly the Chortis Block.
The third section of the volume addresses the complex evolution of the Caribbean, the Greater Antillean Arc, and in particular the transpressional suture zone on the southern margin of the north American plate. Romito and Mann (2020) synthesize a broad array of datasets over much of the Caribbean region to define basement type in relation to Caribbean evolution, burial and structurally driven sediment thickening histories. They also present an assessment of the petroleum habitat upon each basement type. A series of papers focus on the geological evolution and hydrocarbon characteristics of the island of Hispaniola. Sun et al. (2020) use gravity modelling, geomorphology and historical seismicity to investigate the nature of crustal types and associated deformation across the oblique 250 km-wide collisional zone between the Bahamas, the island arc of Hispaniola and the CLIP. Tillman and Mann (2020) review the regional hydrocarbon potential and, in particular, the source rock maturation history of Hispaniola and Puerto Rico, and show that most of the basins are immature for hydrocarbon generation. Mann and Pierce (2020) focus on the development of the Azua Basin in the Dominican Republic and explain the origin of the isolated hydrocarbon occurrences. The oilfields are illustrated with a series of new cross-sections. Gorosabel-Araus et al. (2020) examine and correlate the central and southern onshore basins of Hispaniola with the offshore San Pedro Basin of the Dominican Republic, integrating a large dataset consisting of updated geological mapping and subsurface information. The modelling provides new insights and suggests that suspected Upper Cretaceous source rocks may be locally mature, with Oligocene and Miocene reservoirs sealed by shales which may trap oils generated since the Neogene.
Mitchell (2020) provides a comprehensive summary of lithostratigraphic and biostratigraphic data from outcrop and wells to define the four separate Cretaceous terranes in Jamaica. These data are integrated into a tectonostratigraphic model for the amalgamation of these terranes during their collision with the Greater Antillean Arc in the late Cretaceous to Paleogene.
Footnote on large fold-out maps
Earthmoves Ltd. have produced two large fold out-maps of the Mexican GoM and the Northern Caribbean which are compiled from many different sources and provide a useful background for many of the papers. These are available at the back of the volume, and digital pdf versions are available from the Geological Society website.
Acknowledgements
We would like to thank Bethan Phillips for expertly guiding us through the process of editing this volume which such good grace and patience. Ian Steel is thanked for compiling the map illustrations in Figures 1, 2 and 8. Bob Erlich, Ricardo Padilla y Sánchez, Gary Gray and Edgar Juárez-Arriaga are thanked for their very useful comments that helped improve this paper.
Author contributions
ID: writing – original draft (lead); JP: writing – review & editing (supporting); JH: writing – review & editing (supporting).
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Data availability
There are no new data.
- © 2020 The Author(s). Published by The Geological Society of London
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/licenses/by/4.0/).
References
The basins, orogens and evolution of the southern Gulf of Mexico and Northern Caribbean
