Fig. 1 Tectonic setting of the study area and location of samples. See Table 1. Thick lines represent major boundaries (28). Zero-milligal (0 mgal) contour (29) highlights the geodynamic continuity of the Panama arc; there are no structural breaks between the Uramita suture and the Canal Basin. (A and B) Detrital zircon ages recovered from (A) lower Miocene strata in the Canal Basin (6) and (B) Oligocene-Miocene strata in the Nuevo Mundo Syncline (18) and rivers draining the Eastern and Central cordilleras (19). (C) New U/Pb zircon ages for granitoids of the Panama arc; data point error ellipses are 68.3% confidence (see table S1).
Fig. 2 Detrital U/Pb zircon populations for all the samples recovered. (A) Middle Miocene strata; (B) Lower Miocene and Oligocene strata of the northern Andes. Data are binned insections of 10 million years (see tables S2 and S3). The youngest detrital zircon is labeled on top of the leftmost bin. See Table 1 and Fig. 1 for sample location.
Fig. 3 Paleogeographic reconstruction (28) of the Panama arc and northwestern South America during middle Miocene times (13 to 15 Ma). The first detrital loads from Panama arrived in one of two, or both, paths to the basins of northwestern South America: (i) along coastal currents transporting detritus product of the erosion of exposed plutonic rocks along the northern coast of the Panama arc and/or (ii) along fluvial channels draining emerging ranges parallel to the length of the Isthmus. The El Valle volcano, an edifice rising from sea level starting before 10 Ma (11), would only allow shallow and transient seaways between 15 and 10 Ma, as the Canal basin was connected to North America by a land bridge from Oligocene until middle Miocene times (30).
- Table 1 Sample summary.
See fig. S1 for stratigraphic location of samples.
Sample/
locality
nameDetrital zircon
sample nameLatitude
(decimal
degrees)Longitude
(decimal
degrees)Sample type Age U/Pb in detrital zircons from boreholes BH1 SI-5796 9.4699 –75.0015 Cored borehole Middle Miocene SI-6816 9.4699 –75.0015 Cored borehole Oligocene–early Miocene BH2 SI-6635 9.3651 –74.4474 Drill cuttings Oligocene–early Miocene BH3 SI-5900 9.8907 –74.6344 Drill cuttings Middle Miocene BH4 SI-6878 9.7160 –75.1124 Cored borehole Middle Miocene BH5 SI-6703 8.6716 –74.5976 Cored borehole Oligocene–early Miocene BH6 SI-6657 8.1702 –75.4761 Drill cuttings Middle Miocene SI-6672 8.1702 –75.4761 Drill cuttings Oligocene–early Miocene BH7 SI-7045 8.5168 –76.1256 Cored borehole Middle Miocene BH8 SI-6833 8.2680 –76.2033 Drill cuttings Oligocene–early Miocene U/Pb in detrital zircons from surface stratigraphic sections SMP SI-6997 8.5488 –75.6922 Hand sample Oligocene–early Miocene SA 030337-2 6.4513 –75.7403 Hand sample Oligocene–early Miocene 030337-6 6.4513 –75.7403 Hand sample Oligocene–early Miocene 030339 6.5414 –75.7754 Hand sample Oligocene–early Miocene 030357 6.4085 –75.7241 Hand sample Middle Miocene 030359 6.4166 –75.7255 Hand sample Middle Miocene 030362 6.5064 –75.8194 Hand sample Oligocene–early Miocene U/Pb in magmatic zircons from granitoid surface samples DV-165 5.7680 –76.2490 Hand sample 43.8 ± 0.8 Ma DV-167 5.7709 –76.2475 Hand sample 42.5 ± 1.3 Ma GA-001 8.5094 –77.3371 Hand sample 49.5 ± 0.9 Ma VM-001 8.4993 –77.3221 Hand sample 49.7 ± 1.6 Ma VM-003 8.4847 –77.3402 Hand sample 49.5 ± 1.1 Ma SI-860 8.8370 –77.6218 Hand sample 59.0 ± 1.9 Ma SI-900 8.6638 –77.4321 Hand sample 58.6 ± 1.6 Ma SI-1092 9.2985 –78.1047 Hand sample 58.3 ± 1.0 Ma
Supplementary Materials
www.sciencemag.org/content/348/6231/226/suppl/DC1
Materials and Methods
Supplementary Text
Figs. S1 to S3
Tables S1 to S5
References (31–42)
Additional Files
- Middle Miocene closure of the Central American Seaway
C. Montes, A. Cardona, C. Jaramillo, A. Pardo, J. C. Silva, V. Valencia, C. Ayala, L. C. Pérez-Angel, L. A. Rodriguez-Parra, V. Ramirez, H. Niño
Materials/Methods, Supplementary Text, Tables, Figures, and/or References
- Materials and Methods
- Supplementary Text
- Figs. S1 to S3
- References
- Table S1. Magmatic U/Pb data
Table S2. Detrital U/Pb data for lower Miocene strata.
Table S3. Detrital U/Pb data for lower Miocene and Oligocene strata.
Table S4. Heavy mineral data
Table S5. Petrographic data
