CARBONATE VS SILICICLASTIC DEPOSITIONAL SYSTEMS: A FIELD TRIP GUIDE TO MODERN SEDIMENTARY ENVIRONMENTS AND THE GEOLOGY OF BOCAS DEL TORO, PANAMA Luis Ignacio Quiroz, Jaime Escobar, Cindy GonzalEs, Edward Salazar, Carlos Jaramillo, Camilo Montes, AlEjandro Machado, Austin HEndy INSTITUTO COLOMBIANO DEL PETROLEO-ECOPETROL FiEld trip GuidE DEcEmbEr 9 – 14 of 2011 Bocas dEl Toro Panama CARBONATE VS SILICICLASTIC DEPOSITIONAL SYSTEMS: A FIELD TRIP GUIDE TO MODERN SEDIMENTARY ENVIRONMENTS AND THE GEOLOGY OF BOCAS DEL TORO, PANAMA Luis Ignacio Quiroz University of SaskatchEwan Canada Jaime Escobar Universidad Jorge TadEo Lozano Bogotá Cindy GonzalEs Edward Salazar Carlos Jaramillo Camilo Montes AlEjandro Machado Austin HEndy Smithsonian Tropical REsEarch institute Panamá PURPOSE OF FIELD TRIP The main goal of this field trip is to study modern siliciclastic to carbonate depositional environments. The Bocas del Toro Archipelago with its protected lagoons, mangrove belts, swamps, sandy beaches and coral reef formations, provides an excellent setting to observe a wide range of modern sedimentary environments from open-water, typical Caribbean reef formations, to humid, tropical swamp environments. The research station of the Smithsonian Tropical Research Institute, located in the middle of this archipelago, is equipped with all the laboratory space and logistical equipment to concentrate in the study of these environments. INTRODUCTION The course will take place at the Bocas del Toro Research Station. At Colon Island in Panama 's Bocas del Toro region in the Caribbean, STRI has established a site for educa- tion and research, providing scientists and students with access to an extraordinary di- versity of marine and terrestrial biota. This station is situated among areas of undisturbed forest, a remarkable coastal lagoon system, and numerous islands and reefs. The STRI Bocas del Toro Research Station is located just outside the town of Bocas del Toro on Isla Colon, in Bocas del Toro Province, Panama. Isla Colon, a 61 sq km island, is situated in the Archipielago de Bocas del Toro along the Caribbean coast just 35 km from Panama ’s boarder with Costa Rica and is part of an archipelago of more than 68 islands and numer- ous mangrove keys. The lab is within easy reach of a wide variety of marine and ter- restrial habitats. Unlike the locations of many marine laboratories in the Caribbean the STRI lab is situated in an area of relatively high productivity and high terrestrial input, resulting in a diversity of habitats within a 5 to 15 minute boat ride from the station. These include seagrass meadows (with Thalassia, Syringodium, Halodule, and Halophila species), corals, mangroves and sandy beaches. STRI researchers and visiting marine sci- entists have been studying such diverse topics as mass coral spawning, turtle nesting, the impact of fisheries on conch and sea cucumbers, chemosymbiotic clams, and mangrove productivity. The station is fully equipped with several boats, diving facilities, micro- scopes, aquaria, and several laboratories and dormitories for both students and research- ers. 1. GEOLOGICAL SETTING The Caribbean Plate is located in between two major continental plates, the North and South American plates (Figure 1). Pindell et al. (2006) reviewed the general tectonic history of the Caribbean. According to their model, the Caribbean Plate was formed in the Pacific, slightly south of the present day Central America Volcanic Arc, and was transported to the east between the North and South American plates. Figure 1: The Caribbean in the Plate Tectonic context. Image source http://www.ig.utexas.edu/research/projects/plates/pt.info.htm Igneous and metamorphic rocks along the circum-Caribbean orogenic belt date the onset of westward-dipping subduction at the eastern margin of the Caribbean Plate at 120 Ma, and allow tracking in time the location of the leading edge of the Caribbean Plate until its present position at the Lesser Antilles Volcanic Arc (Figure 2; Pindell et al., 2006). The western margin of the Caribbean Plate is defined by the Chorotega and Panama- Choco blocks (Fig. 3), which are located at the complex junction between NaZca, Cocos, Caribbean and South American plates (Molnar and Sykes, 1969). FIELD TRIP INTINERARY DAY 1: ALMIRANTE BAY Stop 1.1: Bocas REsEarch Station-STRI Point - Mangrove and Seagrass environments - Fringing Reef along the leeside of the Colon Island Stop 1.2: ThE EnsEnada GrandE, SouthErn Almirante Bay - Reefs affected by sedimentation near Almirante City - Dos Hermanas Island patch reef and mangrove - Punta Pond sock patch reef Stop 1.3: PastorEs Island fringing rEEf - Panoramic view along the fringing reef surrounding the Pastores Island Stop 1.4: Cayo Coral patch rEEf - Delicate branching corals at Cayo Coral DAY 2: THE NORTHERN PART OF THE ARCHIPELAGO Stop 2.1: Long BEach - High energy upper shoreface and foreshore environments at Long Beach Stop 2.2: Zapatilla Cays Patch REEf - Reef Flat environments - Back reef lagoon with seagrass meadows and sandy blowouts that cut erosively through the seagrasses - Low-energy foreshore at the Island’s beach Stop 2.3: ThE southEastern margin of thE Bastimentos Island (Salt CrEEk) - Patch reefs with healthy Acropora palmata corals DAY 3: CHANGUINOLA SWAMP/STRANDPLAIN COMPLEX Stop 3.1: ThE Changuinola Swamp - Walk though different zones of vegetation along the swamp Stop 3.2: Strandplain ComplEx - RecogniZing of the main morphological elements of the strandplain complex - Trench in the back shore area and description of sedimentary structures Stop 3.3: ThE southEastern transgrEssive margin of thE Changuinola Swamp - RecogniZing the transgressive margin of the swamp near Canal Viejo - Erosive margin of the swamp in Bocas del Drago DAY 4: CHIRIQUI LAGOON/CRICAMOLA DELTA Stop 4.1: ThE Cricamola DElta Plain/Swamp - Mangrove Creeks - Damani Swamp Stop 4.2: DElta front rEworkEd by waves (sand spit) - Sand spit east of the mouth of the Cricamola River Stop 4.3: Cricamola River Point Bar - Morphology and sedimentary structures in a point bar DAY 5: GEOLOGY OF PUNTA VALIENTE AND PLEISTOCENE LIMESTONE NEAR COLON ISLAND Stop 5.1: Punta ValiEnte - Contact between the Deep Marine Punta Alegre Formation and the overlying Valiente Formation - RecogniZing of the different facies of the Valiente Formation - Tobobe Sandstone and Nancy Point formations at Finger island Stop 5.2: Cayo dE Agua Island - Shallow marine deposists of the Cayo de Agua Formation Stop 5.3: Hill Point - Pleistocene reef limestone and backreef grainstone Stop 5.4: Swan KEy Island - Pleistocene fore reef limestone Stop 5.5: Solarte Island - Wave- and storm-dominated lower shoreface and offshore deposits of the Old Bank Formation.