Panama Canal Basin Research Articles

Towards a knowledge management system for the strengthening of coffee production: A case study in the Panama Canal Basin, Panamá Oeste province

In today’s context, information and knowledge have emerged as key factors in various production processes and have become a newly discovered asset. One of these production processes is the coffee harvest. This paper presents the results of the first phase of research on the implementation of a technological knowledge management system in the coffee sector. During this initial phase, data was collected through a survey of coffee growers in the Cirigrande district, a member of CUENCAFE Acacpa, located in the province of Panamá Oeste, Panama. Several findings emerged from this survey: 84% of coffee growers are between the ages of 22 and 42, they have the ability to use digital tools, and 100% are willing to share their knowledge. In addition, to determine the internal consistency of the survey used, the Cronbach’s coefficient α was calculated, which yielded a favorable value of 0.85. In addition, Pearson’s correlation coefficient r was calculated to validate the relationship between the questionnaires. In summary, the 16-cell matrix analysis concluded that although coffee growers lack the technological means to manage knowledge, they do have rudimentary governance processes and they consider the presence of a knowledge management system to be potentially beneficial and a competitive advantage in strengthening the production of Robusta coffee (Coffea canephora).

A Ptychogastrine (Testudines, Geoemydidae) From the Early Miocene of Panama and a Review of Miocene Testudinoids From Central America

Forachelys woodi gen. et sp. nov. is described from lower Miocene (Arikareean NALMA) exposures of the upper Las Cascadas Formation (~21 Ma) in the Panama Canal Basin. It represents the latest occurrence of ptychogastrine geoemydids in North America, a group known primarily from the early Eocene to late Miocene of Europe. Forachelys woodi shares features with taxa such as Geiselemys ptychogastroides (middle Eocene, Germany) and some species of the Ptychogaster/Temnoclemmys group (late Eocene to late Miocene, Europe). The epiplastral morphology is furthermore comparable to Bridgeremys pusilla (middle Eocene of Wyoming and Utah), a taxon previously interpreted as a rhinoclemmydine ancestor. Within the Las Cascadas Formation, F. woodi co-occurred with an undescribed species of rhinoclemmydine geoemydid that represents the oldest record of Rhinoclemmys (sensu lato). The Miocene fossil record of testudinoids in Central America is reviewed and reexamined. Testudinids are diverse in the Miocene of Panama and Honduras, represented by aff. Stylemys, Caudochelys (2–3 large to giant species), and an undescribed genus and species that resembles ‘Testudo’ costarricensis. Rhinoclemmydines persisted in Panama almost continuously from the early to late Miocene, with records from the Las Cascadas (~21 Ma), upper Culebra (~20–19 Ma), Cucaracha (~19 Ma), and lower Gatun (~12–11 Ma) formations. At least two concurrent rhinoclemmydines are present in the Cucaracha Formation of Panama, and two possibly concurrent taxa in the Gracias Formation (9–6.6 Ma) of Honduras.

First North American fossil monkey and early Miocene tropical biotic interchange.

New World monkeys (platyrrhines) are a diverse part of modern tropical ecosystems in North and South America, yet their early evolutionary history in the tropics is largely unknown. Molecular divergence estimates suggest that primates arrived in tropical Central America, the southern-most extent of the North American landmass, with several dispersals from South America starting with the emergence of the Isthmus of Panama 3-4 million years ago (Ma). The complete absence of primate fossils from Central America has, however, limited our understanding of their history in the New World. Here we present the first description of a fossil monkey recovered from the North American landmass, the oldest known crown platyrrhine, from a precisely dated 20.9-Ma layer in the Las Cascadas Formation in the Panama Canal Basin, Panama. This discovery suggests that family-level diversification of extant New World monkeys occurred in the tropics, with new divergence estimates for Cebidae between 22 and 25 Ma, and provides the oldest fossil evidence for mammalian interchange between South and North America. The timing is consistent with recent tectonic reconstructions of a relatively narrow Central American Seaway in the early Miocene epoch, coincident with over-water dispersals inferred for many other groups of animals and plants. Discovery of an early Miocene primate in Panama provides evidence for a circum-Caribbean tropical distribution of New World monkeys by this time, with ocean barriers not wholly restricting their northward movements, requiring a complex set of ecological factors to explain their absence in well-sampled similarly aged localities at higher latitudes of North America.

New early Miocene protoceratids (Mammalia, Artiodactyla) from Panama

ABSTRACTAlthough Cenozoic protoceratid artiodactyls are known from throughout North America, species referred to the Miocene protoceratine Paratoceras are restricted to subtropical areas of the Gulf Coast and southern Mexico and tropical areas of Panama. Newly discovered fossils from the late Arikareean Lirio Norte Local Fauna, Panama Canal basin, include partial dentitions of a protoceratid remarkably similar to those of Paratoceras tedfordi from Mexico, suggesting a rapid early Miocene colonization of recently emerged tropical volcanic terrains (Las Cascadas Formation). Partial lower dentitions from the overlying shallow marine to transitional Culebra Formation (early Centenario Fauna) are here referred to Paratoceras orarius, sp. nov., based on relatively small size, shallow mandible anterior to p3, and narrow cheek teeth. New early Hemingfordian protoceratine fossils from the upper part of the Cucaracha Formation (late Centenario Fauna) include a partial male skull and several dentitions that, together with specimens previously referred to P. wardi (only known from the Barstovian of Texas), are here referred to Paratoceras coatesi, sp. nov., based on distinctly more gracile cranial ornamentation, relatively longer nasals, a smaller and wider lower p4 (relative to m1), and more bulbous lower premolars. Results from a cladistic analysis of 15 craniodental characters coded for 11 protoceratine species suggests that Paratoceras is a monophyletic clade with its origin in subtropical areas of Central America, spreading into the tropics of Panama during the early Miocene (Arikareean through Hemingfordian North American Land Mammal Ages [NALMAs]), and later inhabiting subtropical areas of the Gulf Coast during the middle–late Miocene (Barstovian through Clarendonian NALMAs).SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPhttp://zoobank.org/urn:lsid:zoobank.org:pub:31FFF397-6362-443C-A612-E9279FF122

A new Late Miocene chondrichthyan assemblage from the Chagres Formation, Panama

The lLate Miocene Chagres Formation from northern Panama contains the youngest outcrops of the Panama Canal Basin. Here we report two chondrichthyan assemblages that include 30 taxa from both the Rio Indio and Chagres Sandstone Members of the Chagres Formation. We report 18 new fossil records for Panama and four for tropical America, constituting the most diverse chondrichthyan association for the Cenozoic of Panama. We performed a paleobathymetry analysis based on the modern water depth preference of extant chondrichthyan taxa. The assemblage from the Rio Indio Member is characterized by taxa with neritic affinities, suggesting depths <100 m, whereas the assemblage from the Chagres Sandstone Member is dominated by taxa with oceanic affinities, suggesting 200–300 m water depths. The Chagres Sandstone Member could have accumulated at the edge of a platform–upper slope, bordered by a deep oceanic margin.

Questing Amblyomma mixtum and Haemaphysalis juxtakochi (Acari: Ixodidae) Infected with Candidatus "Rickettsia amblyommii" from the Natural Environment in Panama Canal Basin, Panama.

This work emphasizes the detection of Candidatus “Rickettsia amblyommii” in questing Haemaphysalis juxtakochi and Amblyomma mixtum. From February 2009 to December 2012, questing ticks were collected from the vegetation and leaf-litter of four protected forests and two grassy areas around the Panama Canal basin. DNA was extracted from Amblyomma mixtum, Amblyomma naponense, Amblyomma oblongoguttatum, Amblyomma pecarium, Amblyomma tapirellum, Haemaphysalis juxtakochi, and unidentified immature Amblyomma. Specific primers of citrate synthase gene gltA were used to detect and identify the rickettsiae. Amplicons with the expected band size were purified and sequenced. DNA of C. “R. amblyommii” was found in A. mixtum, H. juxtakochi and Amblyomma immatures. To our knowledge, these finding represent the first report of C. “R. amblyommii” in free-living ticks in the wilderness of Central America.

Temporal Calibration and Biochronology of the Centenario Fauna, Early Miocene of Panama

New excavations along the Panama Canal have yielded a growing Early Miocene assemblage of mammals referred to as the Centenario Fauna. Despite the area’s proximity to South America, the mammals of the Centenario Fauna have entirely North American affinities. The Centenario Fauna is distributed throughout a ∼115-m stratigraphic interval encompassing the uppermost Culebra and Cucaracha Formations within the Panama Canal basin. Previously published ages constrain the age of the lower limit of the Centenario Fauna to no younger than ∼19 Ma, but the upper limit has remained problematical. A fresh exposure of the Cucaracha tuff, a prominent marker horizon within our measured sections, has yielded two new radioisotopic determinations: (1) an 40Ar/39Ar age of 18.96 ± 0.90 Ma and (2) a U-Pb zircon age of 18.81 ± 0.30 Ma. In addition, magnetostratigraphic data indicate that the Centenario Fauna occurs within chron C5Er, from 18.78 to 19.05 Ma on the geomagnetic polarity timescale of Gee and Kent. These correlations further confirm the calibration of the latest Arikareean (Ar4) to early Hemingfordian (He1) transition in Nebraska, at the base of chron C5Er, at about 19.05 Ma. The Centenario Fauna occurs at the beginning of the Hemingfordian North American Land Mammal Age, i.e., He1. A broad faunal province existed during the early Hemingfordian that can be recognized across a north-south range of 5000 km throughout North America, with the southernmost limits defined by the Centenario Fauna of Panama.

New turtles (Chelonia) from the late Eocene through late Miocene of the Panama Canal Basin

Four distinct fossil turtle assemblages (Chelonia) are recognized from the Panama Canal Basin. The oldest, from the late Eocene–early Oligocene Gatuncillo Formation, is dominated by podocnemidid pleurodires. The early Miocene Culebra Formation includes both podocnemidids and trionychids. The early to middle Miocene Cucaracha Formation includes taxa classified in Geoemydidae (including Rhinoclemmys panamaensis n. sp.), Kinosternidae (represented by Staurotypus moschus n. sp.), large testudinids, trionychids, and podocnemidids, and finally, the late Miocene Gatun Formation records cheloniid sea turtles. These fossils include the oldest known representatives of Rhinoclemmys, the oldest record of kinosternids in Central America with a more extensive southern paleodistribution for Staurotypus and staurotypines in general, early occurrences of giant tortoises in the Neotropics, the oldest occurrence of soft-shell turtles in the tropics, the oldest late Eocene–early Oligocene Neotropical occurrences of podocnemidids. The Panamanian fossil turtles represent clades that are primarily endemic to North America, showing their very early arrival into the Neotropics prior to the complete emergence of the Isthmus of Panama, as well as their first contact with Caribbean-South American pleurodires by the early Miocene.

Age and origin of earliest adakitic-like magmatism in Panama: Implications for the tectonic evolution of the Panamanian magmatic arc system

40–20Ma marks a fundamental interval in the evolution of the 70–0Ma Panamanian magmatic arc system. During this period, there is no evidence of Panamanian magmatic arc activity to the east of the Panama Canal Basin while to the west and in localized regions to the east of the Panama Canal Basin a phase of intrusive-only activity is recorded. Fundamentally, geochemical and geochronological evidence presented herein indicate that this intrusive activity was predominantly ‘adakitic-like’ and becomes younger from west to east along an approximately W–E striking lineament. Granodiorites of the Petaquilla batholith, western Panama yield LAM-ICP-MS 206Pb/238U zircon ages of 29.0+0.7, −0.6Ma, 28.5+0.7, −0.5Ma, 28.3+0.5, −0.4Ma and 26.2+0.5, −0.9Ma. To the east of the Panama Canal Basin zircons from a hypabyssal diorite of the mainly intermediate Majé subvolcanic suite, cedes a mean 206Pb/238U age of 18.9+0.4Ma. Relative to other 70–5Ma Panamanian magmatic arc lavas and intrusives, Majé and Petaquilla intrusives yield adakitic-like major and trace element abundances (e.g., >15wt.% Al2O3, generally >3.5wt.% Na2O, >400ppm Sr, <1.9ppm Yb, <18ppm Y, Sr/Y that ranges to >120) and strongly fractionated HREE patterns. These 30–26Ma (Petaquilla) and 19Ma (Majé) suites are also compositionally similar to a subvolcanic suite of rare, circa 25Ma adakitic-like, andesitic intrusives which occur within the Panama Canal Basin midway between Petaquilla and Majé and at the same approximate latitude as Petaquilla and Majé. Collectively, the geochemical and geochronological data for the adakitic-like intrusives arc consistent with formation via partial melting of lowermost, mafic crust above a sub-horizontal slab tear that propagated from the west (Petaquilla) to the east (Majé) between 30 and 19Ma. Our new tectonic model postulates that collision between the Panamanian magmatic arc system and an ‘indentor’ (e.g., a tract of thickened buoyant, oceanic crust or plateau) occurred at about 40Ma, a time of which coincides with the initiation of left-lateral offset of the Early (i.e., 70–40Ma) Arc system. This collision resulted in the shutdown of the Early Arc system, possible steepening of the subducting Farallon slab and ultimately slab break-off and the phase of mainly adakitic-like intrusive activity. Subsequent to slab removal by ~20Ma, NE-dipping subduction jumped to the south and initiated production of the Later (i.e., post 20Ma) Arc system soon thereafter.

Lower Miocene Stratigraphy along the Panama Canal and Its Bearing on the Central American Peninsula

Before the formation of the Central American Isthmus, there was a Central American Peninsula. Here we show that southern Central America existed as a peninsula as early as 19 Ma, based on new lithostratigraphic, biostratigraphic and strontium chemostratigraphic analyses of the formations exposed along the Gaillard Cut of the Panama Canal. Land mammals found in the Miocene Cucaracha Formation have similar body sizes to conspecific taxa in North America, indicating that there existed a terrestrial connection with North America that allowed gene flow between populations during this time. How long did this peninsula last? The answer hinges on the outcome of a stratigraphic dispute: To wit, is the terrestrial Cucaracha Formation older or younger than the marine La Boca Formation? Previous stratigraphic studies of the Panama Canal Basin have suggested that the Cucaracha Formation lies stratigraphically between the shallow-marine Culebra Formation and the shallow-to-upper-bathyal La Boca Formation, the latter containing the Emperador Limestone. If the La Boca Formation is younger than the Cucaracha Formation, as many think, then the peninsula was short-lived (1–2 m.y.), having been submerged in part by the transgression represented by the overlying La Boca Formation. On the other hand, our data support the view that the La Boca Formation is older than the Cucaracha Formation. Strontium dating shows that the La Boca Formation is older (23.07 to 20.62 Ma) than both the Culebra (19.83–19.12 Ma) and Cucaracha (Hemingfordian to Barstovian North American Land Mammal Ages; 19–14 Ma) formations. The Emperador Limestone is also older (21.24–20.99 Ma) than the Culebra and Cucaracha formations. What has been called the “La Boca Formation” (with the Emperador Limestone), is re-interpreted here as being the lower part of the Culebra Formation. Our new data sets demonstrate that the main axis of the volcanic arc in southern Central America more than likely existed as a peninsula connected to northern Central America and North America for much of the Miocene, which has profound implications for our understanding of the tectonic, climatic, oceanographic and biogeographic history related to the formation of the Isthmus of Panama.

THE EMPERADOR LIMESTONE REDISCOVERED: EARLY MIOCENE CORALS FROM THE CULEBRA FORMATION, PANAMA

Caribbean reefs underwent significant biotic change during the Late Oligocene and Early Miocene. This was a critical time in the evolution of the modern Caribbean fauna characterized by increasing endemism resulting from regional extinction of lineages that survive in the modern Indo-Pacific. An understanding of the dynamics and potential causes of the Oligocene/Miocene transition, however, is hampered by the relative lack of well-preserved Oligocene to early Miocene coral faunas in the Caribbean. Here we examine new exposures in the Culebra Formation of Panama that contain a well-preserved coral fauna of Early Miocene age. Taxonomic, stratigraphic, and paleoecologic study of the Culebra Formation exposed along the Gaillard Cut of the Panama Canal allows us to infer the paleoenvironments and reef coral communities from the Panama Canal Basin during this critical interval. The Culebra Formation consists of a deepening upward sequence with shallow-lagoon sediments at the base, overlain by fringing reef facies in the middle of the section, and open-shelf to bathyal facies at the top of the section. We recovered 31 species of reef corals from a combination of new and old collections. Comparison of our collections with other Late Oligocene to Middle Miocene reef coral assemblages confirms that there was a major faunal turnover after deposition of the Upper Oligocene Antigua Formation. This turnover consisted of a large number of extinctions followed by an increased rate of first occurrences so that regional diversity did not change appreciably. Improved stratigraphic resolution at this and other Caribbean localities is required to understand fully the dynamics of change during the Oligocene/ Miocene transition.

The Geology of the Darien, Panama, and the late Miocene-Pliocene collision of the Panama arc with northwestern South America

The geology of the Darien province of eastern Panama is presented through a new geologic map and detailed biostratigraphic and paleobathymetric analysis of its Upper Cretaceous to upper Miocene sediments. The sequence of events inferred from the stratigraphic record includes the collision of the Panama arc (the southwestern margin of the Caribbean plate) and South American continent. Three tectonostratigraphic units underlie the Darien region: (1) Precollisional Upper Cretaceous–Eocene crystalline basement rocks of the San Blas Complex form a series of structurally complex topographic massifs along the northeastern and southwestern margins of the Darien province. These rocks formed part of a >20 m.y. submarine volcanic arc developed in a Pacific setting distant from the continental margin of northwestern South America. The northerly basement rocks are quartz diorites, granodiorites, and basaltic andesites, through dacites to rhyolites, indicating the presence of a magmatic arc. The southerly basement rocks are an accreted suite of diabase, pillow basalt, and radiolarian chert deposited at abyssal depths. Precollisional arc-related rocks, of Eocene to lower Miocene age, consist of 4000 m of pillow basalts and volcaniclastics, and biogenic calcareous and siliceous deep-water sediments. They consist of the Eocene-Oligocene Darien Formation, the Oligocene Porcona Formation and the lower-middle Miocene Clarita Formation. Postcollisional deposits are mostly coarse- to fine-grained siliciclastic sedimentary rocks and turbiditic sandstone of upper middle to latest Miocene age. This 3000 m thick sedimentary sequence is deformed as part of a complexly folded and faulted synclinorium that forms the central Chucunaque-Tuira Basin of the Darien. The sedimentary package reveals general shallowing of the basin from bathyal to inner neritic depths during the 12.8−7.1 Ma collision of the Panama arc with South America. The sediments are divided into the upper middle Miocene Tapaliza Formation, the lower upper Miocene Tuira and Membrillo Formations, the middle upper Miocene Yaviza Formation, and the middle to upper Miocene Chucunaque Formation. The precollisional open marine units of Late Cretaceous–middle Miocene age are separated from the overlying postcollisional sequence of middle to late Miocene age by a regional unconformity at 14.8−12.8 Ma. This unconformity marks the disappearance of radiolarians, the changeover of predominantly silica deposition from the Atlantic to the Pacific, the initiation of the uplift of the isthmus of Panama, and the onset of shallowing upward, coarser clastic deposition. This pattern is also recorded from the southern Limon Basin of Caribbean Costa Rica to the Atrato Basin of northwestern Colombia. By the middle late Miocene, neritic depths were widespread throughout the Darien region, and a regional unconformity suggests completion of the Central American arc collision with South America by 7.1 Ma. No Pliocene deposits are recorded from either the Darien or the Panama Canal Basin, and no sediments younger than 4.8 Ma have been identified in the Atrato Basin of Colombia, suggesting rapid uplift and extensive emergence of the Central American isthmus in the latest Miocene. Northward movement of the eastern segment of the Panama arc along a now quiescent Panama Canal Zone fault during Eocene-Oligocene time may have dislocated the pre-collision arc. Since collision, the portion west of this fault (Chorotega Block) has remained stable, without rotation; to the east, in the Darien region, compression has been accommodated through formation of a Panama microplate with convergent boundaries to the north (North Panama deformed belt) and south (South Panama deformed belt), and suturing with South America along the Atrato Valley. Deformation within the microplate has been accommodated in the Darien province by several major left-lateral strike-slip faults that were active until the early Pliocene, since when the plate has behaved rigidly.

Early Neogene history of the Central American arc from Bocas del Toro, western Panama

A newly discovered sequence of lower to middle Miocene rocks from the eastern Bocas del Toro archipelago, western Panama, reveals the timing and environment of the earliest stages in the rise of the Isthmus of Panama in this region. Two new formations, the Punta Alegre Formation (lower Miocene, Aquitanian to Burdigalian) and the Valiente Formation (middle Miocene, Langhian to Serravallian), are here named and formally described. The Punta Alegre Formation contains a diagnostic microfauna of benthic and planktic foraminifera and calcareous nannofossils that indicate deposition in a 2000-m-deep pre-isthmian neotropical ocean from as old as 21.5-18.3 Ma. Its lithology varies from silty mudstone to muddy foraminiferal ooze with rare thin microturbidite layers near the top. The Valiente Formation, which ranges in age from 16.4 to ca. 12.0 Ma, lies with slight angular unconformity on the Punta Alegre Formation and consists of five lithofacies: (1) columnar basalt and flow breccia, (2) pyroclastic deposits, (3) coarse-grained volcaniclastic deposits, (4) coral-reef limestone with diverse large coral colonies, and (5) marine debris-flow deposits and microturbidites. These lithofacies are interpreted to indicate that after ca. 16 Ma a volcanic arc developed in the region of Bocas del Toro and that by ca. 12 Ma an extensively emergent archipelago of volcanic islands had formed. 3 9 Ar/ 4 0 Ar dating of basalt flows associated with the fossiliferous sedimentary rocks in the upper part of the Valiente Formation strongly confirms the ages derived from planktic foraminifera and nannofossils. Paleobathymetric analysis of the two new formations in the Valiente Peninsula and Popa Island, in the Bocas del Toro archipelago, shows a general shallowing from lower- through upper-bathyal to upper-neritic and emergent laharic and fluviatile deposits from ca. 19 to 12 Ma. The overlying nonconformable Bocas del Toro Group contains a lower transgressive sequence ranging from basal nearshore sandstone to upper-bathyal mudstone (ca. 8.1-5.3 Ma) and an upper regressive sequence (5.3-3.5 Ma). A similar paleobathymetric pattern is observed from the Gatun to Chagres Formations (12-6 Ma) in the Panama Canal Basin area and in the Uscari, Rio Banana, Quebrada Chocolate, and Moin Formations (8-1.7 Ma) in the southern LimOn Basin of Costa Rica.

The late Miocene Panama isthmian strait

Miocene sediments of the Caribbean Gatun and Chagres formations, Panama Canal basin, were deposited within an archipelagic strait that connected Caribbean and Pacific waters. Shallow-water (∼ 25 m) benthic foraminifera of the Gatun Formation have a strong Caribbean affinity, indicating that a significant interoceanic, biogeographic barrier had formed at ∼ 8 Ma. However, benthic foraminifera of the overlying Chagres Formation are bathyal and markedly Pacific in affinity, indicating that at ∼ 6 Ma, waters of the Panama isthmian strait deepened to ∼ 200–500 m and Pacific bathyal waters flowed into the Caribbean. The Chagres Formation crops out at the Caribbean entrance to the Panama Canal in a large wedge of cross-laminated sandstone and coquina. The cross-laminations and coarse grain size indicate high-energy currents atypical of bathyal settings. We infer that a jet of the Pacific North Equatorial Countercurrent–Equatorial Undercurrent passed through the Panama isthmian strait to deposit these sediments on the Caribbean side. This later entry of Pacific taxa into the Caribbean had no apparent effect on the subsequent composition of Caribbean faunas.