Restoration of plate consumption recorded by Caribbean arc volcanism reveals probable plate movements that led to the emplacement of the proto–Caribbean plate into the present Caribbean region and provided the space necessary to accommodate the rotation of the Yucatán Peninsula concurrent with the opening of the Gulf of Mexico between ca. 170 Ma and 150 Ma. Fault movement of the Yucatán, caused by edge-driven processes, resulted in counterclockwise rotation, as shown by paleomagnetic studies. Restoration of Yucatán rotation necessitates the presence of a paleogeography different from the current distribution of the Greater and Lesser Antilles. During emplacement of the Caribbean plate region, four magmatic belts with distinct ages and different geochemical characteristics are recorded by exposures on islands of the Antilles. The belts distinguish the following segments of Cretaceous and Tertiary magmatic arcs: (1) an Early Cretaceous geochemically primitive island-arc tholeiite suite (PIA/IAT) typically containing distinctive dacite and rhyodacite that formed between Hauterivian and early Albian time (ca. 135–110 Ma); (2) after a hiatus at ca. 105 Ma of ∼10 m.y., a voluminous, more-extensive calc-alkaline magmatic suite, consisting mainly of basaltic andesite, andesite, and locally important dacite, developed beginning in the Cenomanian and continuing into the Campanian (ca. 95–70 Ma); (3) a second (calc-alkaline) suite, spatially restricted relative to the older belts, that consists of volcanic and intrusive rocks, which formed between the early Paleocene and the middle Eocene (ca. 60–45 Ma); and (4) a currently active calc-alkaline suite in the Lesser Antilles typically composed of a basalt-andesite-dacite series that began to develop in the Eocene (ca. 45 Ma). Plate convergence took place along northeastward- or eastward-trending axes during the formation of the Caribbean, which is outlined by the Antillean islands and Central and South America. Movements were facilitated by strike-slip faults, commonly trench-trench transforms, as subducting crust was consumed. Restoration of apparent displacements of at least several hundreds of thousands of kilometers along the inferred lateral faults of the Eocene and younger Cayman set separating Puerto Rico, Hispaniola, and the Oriente Province of southeastern Cuba brings together Eocene volcanic rocks revealing a magmatic domain along the paleo–south-southwestern margin of the Greater Antilles. The transforms along the southern margin of the Caribbean plate are mainly obscured by contractional deformation related to the northward motion of South America as it was thrust over the faulted plate margin. Restoration of the Caribbean plate also translates the Nicaragua Rise westward, thereby revealing a pathway along which Pacific oceanic lithosphere, mainly composed of a large, Late Cretaceous igneous province (Caribbean large igneous province), manifest as an oceanic plateau (Caribbean-Colombian oceanic plateau), converged toward and subducted beneath the southern flank of the Cretaceous Greater Antilles magmatic belt between 65 and 45 Ma. The Eocene arc rocks overlie or abut previously recognized Early and Late Cretaceous subduction-related units. Eocene consumption of Pacific lithosphere ceased with the arrival, collision, and accretion of buoyant lithosphere composed of Caribbean large igneous province. The Greater Antilles formed during Late Cretaceous subduction of Jurassic ocean crust beneath an Early Cretaceous arc formed at the eastern margin of the proto–Pacific plate. Formation of a volcanic edifice above Early Cretaceous arc rocks was followed by plate collision and coupling of the Greater Antilles belt against the Bahama Platform. The most straightforward path of the Greater Antilles into the Caribbean is along northeast-striking transforms, one of which coincided with the eastern margin of the Yucatán Peninsula. The transform appears to link the Motagua suture to the Pinar del Rio Province of western Cuba. To the southeast, the arc was transected by a second transform, perhaps coinciding with the present trace of the Romeral fault in northwestern South America and extending northeast to the eastern terminus of the Virgin Islands. During Late Cretaceous convergence, a segment of the extinct Early Cretaceous arc, developed at the Pacific margin, was carried northeastward.

Warford Ranch is a small “drive-in” shield volcano covering an area of ~2 by 3 km west of Phoenix, and it is accessible from Interstate Highway 8 near Gila Bend, Arizona. The basaltic shield is superposed on silicic lavas, granodiorites, and alluvial deposits and is part of the Sentinel-Arlington volcanic field. Dated at 3.19 Ma, the shield volcano is sufficiently young to preserve the original morphology, but it also shows the effects of moderate weathering, development of desert varnish, and the formation of caliche deposits. Imaged in both color near-infrared (IR) and in thermal infrared multispectral scanner (TIMS) data, these various units afford the opportunity to conduct simple remote-sensing mapping, which can then be field tested. In addition to the lava flows comprising the shield, pyroclastic deposits and dikes are also present. The compact size of the volcano enables the entire feature to be examined in the field in one day. With short introductory discussion, participants of nearly any background can be introduced to the fundamentals of remote sensing, igneous rocks, field methods, and evaluation of the volcanic history of a small volcano.