Abstract Numerous geoscientists have proposed and evaluated many conceptually distinct models for the evolution of the Caribbean region since 1930 (Fig. 1). From these, seven predominant interpretations of Caribbean crustal generation and modification have emerged: (1) sea-floor spreading, involving mid-ocean rifting, tectonic convergence, subduction, and back-arc spreading (for examples, see Pindell and Barrett, this volume); (2) basification of continental crust (Skvor, 1969); (3) lateral shear and transverse extension with attenuation, a variation on plate-tectonic theory (Ball and Harrison, 1969); (4) in situ orthogeosynclinal crustal evolution (Khudoley and Meyerhoff, 1971; Meyerhoff and Meyerhoff, 1972), a process classically associated with the tectogene hypothesis; (5) magmatic crustal thickening, related to magmatic-arc emplacement near subduction zones, to "hot-spot" magmatism (Officer and others, 1957; Duncan and Hargraves, 1984), to basaltic intrusion (Burke and others, 1984), and to flood-plateau basaltic volcanism (Donnelly, 1973; Donnelly and others, this volume); (6) tectonic crustal thickening and crustal accretion: processes in which tectonites are formed, assembled, or reassembled at convergent plate margins into masses reaching continental thickness (MacDonald, 1972a, b); (7) another process, involving thermal contraction and attendant mantle surges, is described by Morris, Meyerhoff, and others in this volume. Most of these processes lead to three genetically distinct types of crust (Ewing and Press, 1955; this paper): (1) oceanic, (2) continental, and (3) accretionary. Physical and genetic aspects of these crustal types are discussed below. Crust that cannot be readily assigned to one of these classes is, temporarily at least, categorized as indeterminate. Knowledge of Caribbean crustal evolution has emerged

Abstract The northern Andes in Colombia form three great ranges, the Cordilleras Oriental, Central, and Occidental (Fig. 1). Other ranges include the Sierra Nevada de Santa Marta, Guajira Peninsular ranges, and physiographic extensions of the Cordillera Oriental northeast into Venezuela, including the Sierra de Perijá and the Cordillera de Mérida (Venezuelan Andes). The present physiographic expression is the result of Tertiary (Neogene) uplift. The Cordillera Occidental is underlain by deformed oceanic crust, perhaps allochthonous as judged from the low metamorphic grade of Mesozoic rocks in the north (see chapter by Escalante, this volume; Duque-Caro, 1990); most of the Cordillera Central, Cordillera Oriental, Sierra de Perijá, and Cordillera de Mérida are underlain by continental crust. The Sierra Nevada de Santa Marta and ranges on the Guajira Peninsula are probably underlain by both types of crust, and oceanic segments on the north sides are probably allochthonous. In the following summary of the regional geology, the main mountain ranges will be described from east to west. The Sierra Nevada de Santa Marta, Guajira ranges, and sedimentary basins will be discussed last. Some of the generalized descriptions are modified from Case and others (1984). Geologic maps by Bellizzia and others (1976), Arango C. and others (1976), Mart×n F. (1978), Case and Holcombe (1980), Etayo-Serna and others (1983, 1986), and Case and others (1984) provide a regional framework for this summary. Bürgl (1961,1973), Irving (1975), Etayo-Serna and others (1983, 1986) and González and others (1988) provided very useful syntheses of the pre-1960 to 1970 literature for

The greater Caribbean region has been divided into more than 100 geologic provinces, some of which are tectonostratigraphic terranes or suspect terranes as defined by Coney, Jones, and Monger (1980). The principal criteria for distinguishing provinces are groups of rocks that differ from their immediate neighbors with respect to: (1) rock lithology, thickness, and age, (2) structural style, (3) presence or absence of outcropping igneous rocks, (4) degree of metamorphism, (5) physiographic expression, (6) nature of crust, and other characteristics. Many of the provinces thus identified are bordered by known major faults, including suture and transform zones; other provinces are bordered by unexposed or cryptic faults; and still other boundaries are drawn on the basis of major changes in rock facies, and so are not boundaries of tectonostratigraphic terranes. Paleomagnetic data, far from complete in the region, indicate that many of the provinces have experienced large tectonic translations and rotations. Colors and patterns have been used on the map in an attempt to portray provinces that appear to be geologically similar in rock type and age, and style and age of principal deformation. For example, Neogene accretionary prisms of the Lesser Antilles, North Caribbean, South Caribbean, North Panama, and Pacific margin deformed belts are shown by the same color, with slight variations in pattern to indicate apparent structural differences between the deformed belts. Many provinces defined here can be further subdivided on the basis of existing information, and many changes will be required as new data accumulate.

Abstract The Caribbean region has been an attractive area of the world since Columbus rediscovered it in 1492. In colonial times the Caribbean was an area of settlement, economic exploitation, and intense competition between the powerful nations of Spain, England, France, and Holland. Geological interest in the region, in a sense, started with the search for gold, silver, and precious stones, and the quest for the sources of the El Dorado legend. Many accounts of exploration during the conquest not only mention fabulous mines but also describe volcanoes, thermal springs, and the effects of earthquakes. It was only natural that in the initial days of modern geology the region should be intriguing to earth scientists. Thus, geologic accounts appear in the writings of such naturalists as von Humboldt, Karsten, De La Beche, Montessus de Ballore, and others. Within a global context, the first attempt to portray the geology of the region was by Suess in 1885. In the early part of the 20th century, scientific interest, and the construction of the Panama Canal and exploration for oil greatly advanced geologic knowledge of the region. Many European scientists worked in the Caribbean during their Wanderjahren. Much of this knowledge was masterfully summarized by Schuchert (1935), and for the Central American part by Sapper (1937). Until that time, scientific contributions were mostly by geologists residing in countries outside the region; only a few indigenous geologists conducted Caribbean research, but some of their contributions were outstanding. Long-range scientific programs were initiated shortly before World War II by Utrecht and Princeton Universities, but the work of both institutions was interrupted during the war years.