Description and Objectives

Cuba, the largest island in the Greater Antilles (Fig. 1), is key to understanding the interactions between the North American, South American, and Caribbean plates during the Jurassic-Paleogene period (180–45 Myr), as well as the origin of the Caribbean plate. The island contains Mesozoic-Cenozoic fragments of both the Caribbean plate (arc volcanics and intrusives, ophiolites, and mélanges with high-pressure metamorphic blocks) and the North American plate (subducted passive margin and non-subducted units of the Bahamas Platform and Maya/Yucatan margin). This makes Cuba an exceptional example of arc-continental margin “soft collision.” The island is also ideal for studying subduction initiation, mature subduction, arc development, and how arcs and terrane accretion contribute to continental crust growth.

Despite its geographical proximity to the United States, Cuba has remained understudied by U.S. geoscientists for over half a century due to political barriers. This Thompson Field Forum aims to renew scientific exchange by bringing together experts to discuss recent findings by Cuban and international researchers. It will serve as a platform to revitalize collaboration among Cuban, U.S., and international geoscientists, highlighting exciting research opportunities in Cuba and the broader Caribbean region.

We will visit key localities in western and central Cuba to study the following:

• North American/Yucatan continental passive margin and basin sections
• Ophiolite complexes and serpentinite mélanges
• Cretaceous Arc and Meta-Arc Complexes
• The metamorphic Caribeana terrane (Escambray Massif)

Agenda

The seven-day Thompson Field Forum will begin in Havana, Cuba, and then travel to Pinar del Rio in western Cuba. For the first two days, the group will visit localities around Viñales (a UNESCO World Heritage Site). The group will then move to central Cuba for a traverse across the Cuban orogenic belt, spending three nights in Santa Clara and one in Trinidad (another UNESCO World Heritage Site and one of the best-preserved colonial cities in the Caribbean).

April is typically dry, with temperatures ranging from 26-32°C. No special fitness is required, and outcrops will be easily accessible from the road.

Day 1 (April 12)

Arrival in Viñales by 11 a.m. Overview of the Viñales valley and introduction to the geology of western Cuba. Visits include Late Jurassic (Oxfordian)-Early Cretaceous exposures transitioning from shallow marine to basinal carbonate and chert facies (Jagua-Guasasa Fms.), and deformed Jurassic siliciclastic deposits.

Day 2 (April 13)

Examination of the K-Pg boundary and transition from continental margin into foreland sedimentation, Mid Jurassic and Cretaceous basinal protocaribbean deposits, and ophiolites.

Day 3 (April 14)

Travel from Pinar del Rio to Santa Clara. Visit outcrops of passive margin sedimentary rocks of the Placetas belt, Santa Clara mélange, and ophiolites.

Day 4 (April 15)

Exploration of ophiolitic mélanges in Santa Clara.

Day 5 (April 16)

Study of Cretaceous Volcanic Arc, volcano-sedimentary packages, and the Upper Cretaceous Manicaragua batholith.

Day 6 (April 17)

Visits to amphibolite and granitic rocks of the Mabujina complex and the Escambray metamorphic massif. Overnight in Trinidad.

Day 7 (April 18)

Return to Havana after breakfast.