Abstract The great variety of climatic conditions, tidal ranges and wave regimes of South and Central America act on a complex geology and tectonic framework. Many of the rock and cliffed coasts of South America are strongly controlled by the occurrence of extensive Cenozoic and Pleistocene sediments that crop out at the coast. Geology and the different uplift rates are a major factor in the whole coastal geomorphology of South and Central America, and consequently are a very important control of the processes and landforms of rock coasts. This chapter covers several aspects of the rock coast of South and Central America, with special attention to the combination of tectonic movements and Quaternary Pleistocene–Holocene sea-level changes.

Abstract In the last decade, Paleozoic rocks have been recognized as having potential for future resources of oil and gas in several countries around the world. The petroleum potential of the upper Paleozoic strata in northern South America is noteworthy in view of the correlations with hydrocarbon-bearing strata and source rocks in neighboring Brazil and Peru–Bolivia, and the southern United States, for both conventional and unconventional oil and gas reservoirs. In the northern part of South America, specifically in Venezuela and Colombia, the upper Paleozoic stratigraphic record is poorly documented and understood, but the succession there reveals major changes in facies, which can be related to global-scale events. These changes have been described through detailed fieldwork in the Venezuelan Andes, supported by petrographic and geochemical studies. This dataset forms the basis for the interpretation of the potential petroleum systems in this area, along with the available published information. Sedimentation during the Permian occurred on an extensive ramp, which dipped basinward, probably toward the north, toward the open ocean within the foreland basin, which has been named the Mucuchachi Basin (MB). The Permian rocks in the MB extend through Colombia to the west and southwest, where a few sections of limestone and shale with fusulinids occur. The MB may well have been connected to the basins in Peru and Bolivia to the southwest and with those in the Mexican and Guatemala areas to the north, where a similar stratigraphic succession is developed. Elements of the petroleum system for these Permian rocks include the presence of source rocks since values of total organic carbon reach 5% in some shales. However, indicators of thermal maturity suggest an over-mature level. On the other hand, a thermal simulation derived from basin modeling software and clumped isotopes thermometry suggests that strata could have been in the oil and gas window during the Cenozoic. Thus there is the likelihood of hydrocarbons having been expelled upward into stratigraphically younger reservoirs, where fractured fine-grained clastic facies and sandstone horizons could have the potential to provide reservoir rocks. The presence of fine-grained facies with low permeability suggests that these Permian rocks could have the potential to provide a sealing capacity as well as the possibility of being part of stratigraphic traps. In addition, several authors have pointed out potential structural traps in the Barinas–Apure Basin and these could have extended to the western areas of the Los Llanos Basin in Colombia are restricted to the Tachira Graben.

Abstract The Sabinas Basin is located in northeastern Mexico in the states of Coahuila and Nuevo León. Basin fill is composed mainly of Mesozoic marine sediments deposited during long-term subsidence and folded during Late Cretaceous and Paleogene Laramide orogenesis. The origin of the basin is related to a rift associated with the opening of the Gulf of Mexico. More than 5000 m of sedimentary rocks was deposited in the Sabinas Basin. Three supersequences have been defined. The first represents synrift sediments and is composed of conglomerates and evaporites with associated basic igneous rocks. The following supersequence (144–96 m.y.) comprises several higher-frequency cycles represented by carbonate, evaporite, and coastal siliciclastic deposits of extensive platforms on a passive margin. The youngest supersequence (96–39.5 m.y.) consists mainly of regressive, terrigenous clastic facies deposited in a foreland setting. Subsidence was 40% to 70% greater during the initial rift stage than during subsequent depositional stages. Several lateral and vertical facies changes in the basin were controlled by the Coahuila and Tamaulipas basement blocks, as well as other, smaller blocks. Laramide deformation is of the thin-skinned type. Four areas with distinct structural styles are recognized: (1) where Jurassic salt is the regional detachment level; (2) where salt diapirs formed; (3) where deformation was controlled by a basement high northeast of the basin; and (4) where the absence of Jurassic salt resulted in the development of fault-bend folding. Structural shortening calculated for different areas of the basin ranges from 16% to 26%. The critical-wedge model has been used to explain some of the deformational variations in the basin. The structures have natural fractures that provide permeability in the hydrocarbon reservoirs. The Upper Jurassic La Casita Formation is considered to be the main hydrocarbon source. Total-organic-carbon (TOC) values are favorable, and although the formation’s kerogens are mainly type III, they are characterized by a high transformation ratio. In 23 years of exploitation, the Sabinas Basin has produced more than 350 bcf of dry gas. The average daily production rate per well ranges from 0.5 to 2.0 MMCFGD. Geostatistical modeling indicates that the La Gloria, La Casita, and Padilla-Virgen plays could contain total resources of more than 1000 bcf. Furthermore, a coal-degasification play may extend over an area exceeding 1000 km 2 and could contain additional potential resources amounting to 147 bcf of gas. Both of these resources could supply much of the local industry’s methane needs for more than 20 years.