Were these images created before the Nasca lines?
Survey near the town of Palpa, Peru, has revealed a wealth of geoglyphs that appear to be older than their celebrated neighbours at Nasca. Luis Jaime Castillo, Johny Isla, Fabrizio Serván, and Karla Patroni reveal what has been found, and why these images seem to have been aimed at a very different audience to the Nasca lines.
The extraordinary lines and animal motifs populating the Nasca plateau in Peru are world-famous. Just to the north, though, a wealth of rather different images can be found in the environs of the modern city of Palpa. These compositions usually feature human figures or creatures, and are generally believed to be the handiwork of the Paracas culture, which lasted from c.800 BC to AD 1. If so, the Palpa figures were probably created before their celebrated neighbours, which are attributed to the Nasca culture, lasting from c.1 to 650 AD. The presence of these two distinct geoglyph styles provides an opportunity to compare and contrast creation techniques and image styles.
Between November 2017 and April 2018, we conducted extensive aerial surveys of the mountain slopes around the city of Palpa, to locate and document geoglyphs. This work was conducted in collaboration with the Ministry of Culture, in order to identify archaeological features and thus help to protect them. Our survey was partially funded by the National Geographic Society as a component of the GlobalXplorer’s programme, which aims to test findings by amateur archaeologists. As well as examining such sites, our surveys successfully discovered several new examples of Palpa figures.
Finding the Palpa figures
Fieldwork was conducted by a team of Peruvian archaeologists led by Luis Jaime Castillo, from the Catholic University in Lima, and by Johny Isla, from the Peruvian Ministry of Culture, and included Fabrizio Serván and Karla Patroni from the Pontifical Catholic University of Peru (PUCP). Examining this vast region of low mesas – flat-topped and steep-sided hills – and mountain slopes required subjecting it to systematic aerial survey for the first time. Drones were flown at low altitudes and took thousands of photos that were then processed through photogrammetry software. This approach created highly detailed and accurate 3D models and 2D orthophotos – that is, images presented at a uniform scale – of the slopes, which faithfully capture even the slightest crease in the surface. Just like the neighbouring Nasca region, Palpa’s climate is extremely arid. Indeed, it receives almost no rain, so modifications to the surface can remain visible for millennia. The creation of both the Palpa figures and the seemingly later Nasca lines relied on a common technique, which involved removing the dark-coloured stones that carpet the ground, to expose lighter soil underneath. Fortunately, altering the surface in this manner means that the handiwork of the people creating the Palpa figures can still be detected using both 2D images and 3D models.
Surveys and aerial documentation were conducted using small, fully automated drones flying at altitudes of 20m to 50m. Drones ranged over extensive areas of 100 to 884ha, tasked with capturing a tight grid of photographs. Their flightpath was preset using autopilot software that controlled altitude, speed, camera position, photograph overlap, and so on. Such coverage is in stark contrast to previous drone sorties targeting geoglyphs in this region, which mostly served to verify previously located figures or achieve a detailed visual record of a single composition. Previous projects by Markus Reindel and Johny Isla, from the German Archaeological Institute, and Masato Sakai, from the University of Yamagata, have located and documented figures with drones, but rather than just seeking out known or suspected Palpa imagery, our project harnessed the capability of drones to survey sizeable tranches of the landscape, presenting an opportunity to examine areas even when we had no prior indication that figures were present within them. Consequently, most of the figures detected during our work were identified in the lab, while the photos were being processed and studied, rather than on site. In this regard, the project was really a proof-of-concept aimed at demonstrating that extensive drone survey can serve as an effective means to prospect for previously unsuspected archaeological features.
A massive advantage with amassing so much information is that it allows us to recognise distributional patterns, with the Paracas people clearly favouring certain kinds of setting and particular stone and soil colours when crafting their figures. Establishing this made the task of identifying further figures a bit easier: most of the Palpa figures occupy specific locations in the landscape, notably slopes and the sides of mesas. Naturally, these are also areas where, because of the steepness of the terrain and the remoteness of the location, there has been very little circulation of animals and people, thus contributing to their preservation. Usually, the ground surface takes the form of an even mantle of dark oxidised stones, with a lighter underlying subsoil. Of course, imagery executed on such a surface by the simple method of moving the stones could easily be erased by rainwater draining off the flat-topped mesas. Fortunately, there is so little rain in this hyper-arid environment – certainly not enough to create flowing water – that even though millennia have passed since the figures were created, very little water erosion is visible. Instead, the greatest enemies of this imagery have been the wind – which can blow fiercely, stripping away the soil and exposing a darker layer of underlying stones – and, inevitably, human encroachment.
All images: San José de Moro Archaeological Program Photo Archive