Project

Project Start Date: 2005.

Research Question: The probable one-to-one relationship between changes in the natural environment and those in the sociocultural environment in the southwest of the Iberian Peninsula during the Recent Prehistory, when the area knew at least two complex archaic sociopolitical formations: one in the 3rd millennium BCE (Southern and Western Chalcolithic) and another in the first half of the 1st millennium BCE (the Kingdom of Tartessus). We aim to test this relationship and determine to what extent it occurred, in what forms, and with what effects over the course of those three thousand years.

Rationale and Objectives::

Originally launched (in 2005) to test in the field the hypothesis put forward by W. Wickboldt and R. W. Kühne regarding settlement and cultural development in the Guadalquivir marshes during the Recent Prehistory, since 2009 this interdisciplinary project has focused on the following immediate areas of study: (1) the transformations of the Atlantic coastline of the southwestern Iberian Peninsula during the Holocene and (2) cultural manifestations in the southwestern quadrant of the Peninsula from the Neolithic period through the Roman era, whose material remains suggest at least two periods of relatively complex institutional organization, one in the 3rd millennium BCE and the other in the 1st millennium BCE. The research is conducted on the assumption that these transformations and cultural manifestations were closely interrelated.

From a broader comparative perspective, in the fields of paleogeomorphology and historical political anthropology, the Project is relevant to a theory or model concerning the origin and structural dynamics of social inequality and the state in the cultural evolution of humanity: a theory already well-established through comparable cases from the prehistory and ancient history of Western European countries, the Mediterranean basin, and the Near East, as well as from the ethnohistory and archaeology of Indigenous America.

Until the creation of Doñana National Park in the Lower Guadalquivir region in the 1960s, this area was known to have been inhabited for centuries by a human community that had adapted to making use of the many resources—both fixed and mobile—provided by the marshlands and the nearby coastline. In the early 20th century, the construction of the Marismilla Palace, near the mouth of the Guadalquivir River, led to the unexpected discovery of the remains of an even older human settlement: the archaeological site of El Cerro del Trigo, dating from the 2nd to the 6th century CE. A few years later, in the 1920s, the Anglo-French archaeologist George Bonsor and the German philologist Adolf Schulten excavated this site, believing that beneath the Roman remains they would find those of the capital of the kingdom of Tartessus, famous in antiquity. Although the excavations did not uncover this city, they revealed a significant settlement in Doñana during the Roman period and would inspire comparable archaeological projects on Tartessus in the lower Guadalquivir basin. Furthermore, Schulten and Bonsor’s project revealed evidence of an even earlier human settlement, dating back to prehistoric times, as well as signs of widespread land subsidence near the river’s mouth.

The hypothesis put forward by Wickboldt and Kühne, published between 2003 and 2006, brought Bonsor and Schulten’s objective back into the spotlight after decades in which studies on Tartessus had focused on other objectives and other areas of the southwestern Iberian Peninsula, relying almost exclusively on archaeology as a source of information. Wickboldt and Kühne identified large-scale geometric shapes in satellite images of the Guadalquivir marshes, which they interpreted as traces left by a significant archaeological site: hypothetically, that of the city of Tartessus, in light of references by Greek and Roman authors to this ancient peninsular kingdom that Schulten and Bonsor had already pointed out. For Wickboldt and Kühne, as for Schulten (though not for Bonsor), such references would be equivalent to those made by the philosopher Plato regarding the political and religious center of the island or peninsula of Atlantis in his dialogues Timaeus and Critias, since, according to these researchers, both sets of references belong to parallel oral and historiographical traditions.

The hypothesis, which was reported by the prestigious British journal Antiquity in 2004, was met with skepticism, if not outright rejection, by the vast majority of archaeologists and historians familiar with Doñana; primarily because of the hypothesis’s reference to Atlantis —a highly controversial topic in and of itself—and because the hypothesis contradicted the dominant model among those same scholars regarding the formation of the Guadalquivir marshes and the current landscape of the Doñana Natural Park: a uniformitarian geological model dating back to the research of the German O. Jessen and the Spaniard Juan Gavala y Laborde in the 1920s and 1930s. According to this model, the surface of Doñana would have been continuously flooded from the time of the maximum transgression reached by the Atlantic Ocean in the southwest of the Iberian Peninsula during the Holocene (about 6,000 years ago) until medieval times, either because it was part of the ancient Guadalquivir estuary or because it contained a large lake or lagoon: the so-called Lacus Ligustinus, as named by the 4th-century CE Roman author Rufus Festus Avienus.

The research by Jessen and Gavala, however, predates our understanding of climatic fluctuations during the Holocene (and their effects on sea level and other factors influencing coastal change), carbon-14 dating, and the formulation of the theory of plate tectonics. Furthermore, since the 1970s, studies of the geological evolution of the southwestern Iberian coastline during the Quaternary have begun to reveal a complex and relatively rapid dynamic of interrelated variables (marine erosion and sedimentation, fluvial sediment input, terrain topography, neotectonic stresses causing earthquakes and tsunamis, etc.), with effects of varying durations. These new findings necessitated a substantial revision and modification of the uniformitarian model.

Such advances in geology—along with the identification of additional geometric shapes by the Hinojos Project team; shapes that suggest archaeological remains in images of the Marisma distinct from those examined by Wickboldt and Kühne—prompted a preliminary field test of these two researchers’ hypothesis: a test that would rule out the possibility that these shapes resulted from nothing other than the changing natural geomorphology of the ancient Guadalquivir estuary, in accordance with the model proposed by Jessen and Gavala. That first phase of the Hinojos Project revealed surface archaeological remains and anomalous sedimentation in the subsoil, indicating that—contrary to what the model posits—a significant portion of the ancient estuary may have been above sea level—as it is today—during one or more prehistoric periods following the peak of the ocean transgression. Pollen was also found indicating human occupation dedicated to agriculture, livestock farming, and herding during those same periods.

In a second phase, between 2009 and 2020, the project’s main objective was to test the uniformitarian model itself as an adequate explanation for the formation of the Guadalquivir marshes during the Holocene. During this second phase, the researchers conducted new surface surveys and a greater number of geophysical soundings and electromagnetic surveys of the subsurface, as well as a comparative study of additional images and maps of the area, further pollen analyses, and archaeological excavations. The results obtained are consistent with those of the aforementioned previous geological investigations, as well as with those of archaeological surface surveys conducted west of the Doñana Natural Park in the 1990s and with findings of scattered remains from the Neolithic and Chalcolithic periods within the park itself dating back to the 1920s. These various results point to widespread destruction that occurred in the area around 2000 BCE, caused by a cataclysmic event of oceanic origin (likely a tsunami). The effect of this event, combined with significant land subsidence, would have been the burial of the remains of the human settlement that had existed up to that point and an extensive marine transgression across the entire territory of the ancient Guadalquivir estuary, restoring the landscape to the appearance it had some 2,000 years earlier, at the peak of the Atlantic transgression during the Holocene.

Although such destruction is accounted for in Wickboldt and Kühne’s hypothesis, the research conducted rules out a connection between this event and the geometric shapes in the Hinojos Marsh that the two German researchers observed in the satellite images. The same can be said of the shapes that researchers from the Hinojos Project in turn identified in other satellite images and aerial photographs: shapes that, paradoxically, are at the origin of the hypothesis. Although these figures—or most of them—appear to be traces of structures built by people, they date back no further than the Al-Andalus period (712–1262 CE), during which much of what is now Doñana was devoted to livestock farming and grazing, just as it is today. gentes del entorno, datarían de no más allá de la época andalusí (712-1262 EC), de la que se sabe que buena parte de lo que es hoy Doñana se dedicaba a la ganadería y el pastoreo, como en la actualidad.

Two new cataclysms, with the resulting acceleration of land subsidence, are believed to have affected the same area around 1550 and 1150 BCE, respectively. The event that occurred around 1150 BCE, of a magnitude comparable to that of the event around 2000 BCE, is thought to have brought an end to a new phase of cultural development in Doñana: that of the Middle Bronze Age, following a period of demographic and cultural decline that lasted for most of the second millennium BCE.

Land subsidence is thought to have continued, albeit at a slower rate, up to the present day, causing a total continental area estimated at about 5,000 hectares to eventually disappear below sea level. Consequently, all of Doñana’s geomorphology that is visible today is believed to be the result of sedimentation over the last 2,000 years at most. At least two additional oceanic episodes—one in the 6th century BCE and another in the 2nd or 3rd century CE—must have accelerated this subsidence process during those periods. Over the last five thousand years, the cycle of rapid and violent marine transgression episodes (likely tsunamis) would therefore have lasted between 400 and 800 years. The sustained subsidence and the resulting loss of land area above sea level must have had a very significant impact on settlement patterns, their distribution throughout the lower Guadalquivir basin, and the ways in which communities were organized.

The findings of the Hinojos Project were featured in the U.S. National Geographic Society documentary Finding Atlantis, which aired in 2011. Although this documentary was the result of a collaboration between the project’s directors and American archaeologist Richard Freund of the University of Hartford, it does not accurately reflect those findings, nor does it convey the reasons behind the project.

In a third phase, from 2020 to the present, the project has focused primarily on the reciprocal relationship between the natural environment and human or cultural order in the lower Guadalquivir basin during the 1st millennium BCE—a time period that historically encompasses the Tartessian period, followed by the post-Tartessian (or Turdetanian) period, the Carthaginian period, and the Roman Republican period. To date, four field studies have been conducted: (1) a study of the geological composition of the La Algaida coastal spit, (2) an analysis of sedimentation on and around the spit, (3) a reconstruction of the network of river channels, floodplains, levees, lagoons, estuaries, and tidal arms in the basin for the 1st millennium BCE, and (4) the comparison of the resulting landscape with the paleogeographic (natural and human) information provided by ancient authors.

The La Algaida coastal spit has been found to be largely unaffected by the basin subsidence process that began c. 2000 BCE, as it contains, just a few meters below the surface, a prominent Pliocene and Pleistocene paleorelief that forms part of the upper edge of the fault series which, at that point, marks the boundary between the Baetic mountain system and the Hercynian massif of the Iberian Peninsula. In the first millennium BCE, far removed from the alluvial silting observed today, what is now a coastal spit was an island located a short distance from the mouth of the Guadalquivir River, which consequently divided the river into two estuaries. The impact on this island and the river’s double estuary at that time of the probable 6th-century BCE tsunami—traces of which have been detected at points farther away in the lower basin, as well as in the Bay of Cádiz and the Huelva estuary—remains to be elucidated.

Following the violent transgression of the ocean around 1150 BCE, the onset of a new phase of progradation of the Doñana coastal spit and new fluvial contributions to the filling of the lower basin—from both the Guadalquivir and converging rivers—had the long-term effect of reshaping the network of river channels, levees, channels, lagoons, and tidal inlets in the basin. The progressive growth of the Doñana spit led to a narrowing of the Guadalquivir’s estuary and the isolation of the basin from the ocean; this process—further driven by the sustained subsidence of a large part of the basin—resulted in the accumulation of river flows in the form of a large coastal lagoon.

Around the middle of the first millennium BCE, but before the 6th-century tsunami, this paleogeography—shaped by the interaction of rivers, the ocean, and active neotectonic processes in the region—appears to correspond to a significant degree with the ancient written accounts from the area that have survived to the present day, especially those found in the works of Pseudo-Scymnus, Strabo, Pomponius Mela, Pliny the Elder, and Avienus. These writings state, for example, that the Guadalquivir River (called “Betis” at the time) had two mouths, both of which originated from “a large lake” (called “Lacus Ligustinus” by Avienus) near the coast.