The nitty-gritty of what the lines are made of is that the lines are glyphs that were “etched” into the southern Peruvian desert floor by the removal of the darker, oxidized brown rocks, reveling the whiter rocks below. The contrast of the lighter rocks against the darker rocks is what creates the lines, which form everything from animal glyphs (boimorphs) to geometric shapes . Though the majority of geoglyps are dated to the Nasca Culture, some are even older [2, 3].
Perhaps the popularity of the lines came in the 1920s when commercial flights between Lima and Arequipa, Peru become available . Other than speculation, no real research was apparently done on the lines until a German-born teacher named Maria Reiche made the first formal surveys of the lines and figures . This was sometime after World War II and Reiche continued her surveys and conservation until her death in 1998 .
Of course Reiche had a hypothesis on what the geoglyphs represented, and in her surveys seemed to find evidence supporting it. Reiche hypothesized that the geoglyphs represented settings on an astronomical calendar . This particular and perhaps first formal hypothesis is still one of the most popular, despite being mostly discredited by modern survey and research .
One such modern survey was called The Nasca Lines Project. In which Dr. Donald A. Proulx, a Professor of Anthropology at the University of Massachusetts, participated from 1996-2000. The project was dreamed up by one David Jonson, who believed he had found a strong spatial correlation between the location of puquios (an old system of aqueducts native to the area), wells, and the geoglyphs .
He hyposhisies that :
“…trapezoids lay directly over what he calls veins, but which more accurately are zones of higher permeability materials consisting of coarser gravels associated with distributary[sic] channels in the alluvial material. Johnson claims that the width of the trapezoids defined the width of the zone capable of transmitting ground water. A zigzag pattern located along the boundary of a trapezoid indicated there was no water and defined the boundary of the water flow. Triangular geoglyphs pointed to sources of water. The last correlation that he noted was that there were always archaeological sites affiliated with geological features, puquios and wells.” 
In what was to become Johnson’s hypothesis, he and Dr. Proulx further refined it.
“These observations led to a new working hypothesis for the function of the Nasca lines that was different from any previous idea: geological faults and alluvial gravels provide pathways for ground water flow, and they transmit water as a zone of concentrated flow into the valleys. These geological features collect water in one part of the drainage and conduct it across and down the valleys to locations where it can be reached by digging puquios or wells, or to locations where the water table is high enough for springs or seepage to be present on the surface. The ancient people realized they could find a reliable source of fresh water at these locations and that is where they established their habitation sites. Johnson claims the ancient Nasca marked the flow of subterranean water with geoglyphs. He argued that there are five factors that are consistently found together: geological faults and/or higher permeability sands and gravels with the alluvial fans, archaeological sites, an aquifer, a source of fresh water (spring, seep, puquio, or well), and the geoglyphs that mark their location. Where one or more of these features are found there is a high probability the others are present.” 
In the end, after thorough investigation and evaluation of the data, there were some favorable association with particular glyphs, but no concrete association overall.
It’s important to note here that this doesn’t completely invalidate Johnson’s hypothesis, but it does show that the original needs to be reworked in light of the new evidence.
Still, even with this extensive piece of research and survey, that I recommend people read over and follow associated links, the Alien proponents still hang on. Without conclusive evidence to the contrary (and even with), those who want to believe will, as Von Daniken shows us over and over. Even with the most recent and most comprehensive research into the lines done by Johny Isla, who Von Daniken mentions by name in his newest book, and Dr. Markus Reindel.
From what I can tell, Von Daniken seems upset because Isla led a team that has produced the most concrete explanation for the lines with some very in-depth insights.
Johny Isla is the director of the Andean Institute of Archaeological Studies. Published several times and is co-director of the Nasca-Palpa Project, with Dr. Markus Reindel of the Dutch Institute of Archaeology.
Dr. Markus Reindel’s focus on the project was photogrammetric mapping of the sites using photogrammetric reconstruction. Basically, they take a whole lot of high res pictures along with GPS points and then merge the data together to produce very detailed, practically 3D images. He published his teams work in “New Technologies for Archaeology, Multidisciplinary Investigations in Palpa and Nasca, Peru” in 2009.
So, back to the Project…
The Nasca-Palpa Project: Photogrammetric Reconstruction of the Geoglyphs of Nasca and Palpa, was extremely extensive, rather than list all participants I’ll just link you to the projects page here. It’s a bit of a read, with lots of good stuff, but the best is in the results, where they not only show you the awesome pictures they produced, but their written conclusions.
First they were able to date the geoglyphs, all of them. From their data, glyph making started in the Late Paracas times at about 400 BC . At this time motifs normally engraved on rocks and boulders (petroglyphs) were transferred to the desert surface and the hillsides surrounding the valleys. These earliest figures were much smaller but still observable from far away and consisted of human shapes .
The geoglyphs continued until the end of the Nasca era (after AD 600) when the neighboring Wari empire from the eastern highlands extended its influence down the south coast. The deposition of pottery on the geoglyphs continued for a 200 years more and then ceased all together .
The project concludes that the Geoglyph complexes were probably related to kin groups who shared land rights . Members would gather on different occasions to create new geoglyphs, or remodel existing ones. During ceremony they may have walked along the geoglyphs depositing ceremonial goods like ceramic vessels containing food or beverages, field crops, textiles, Spondylus shells etc. All these goods were in some way or another related to the concepts of water and fertility which were critical to the worldview of the ancient inhabitants of Nasca .
In this way the geoglyphs become part of the cultural landscape of the valley, creating massive gathering points for kin groups for ceremony or possibly just show. They helped establish group identity and status .
The project results concludes:
“It is important to note in this context that in a common effort vast stretches of the desert were marked at large scale and thereby integrated into the cultural domain of the valley-based society. Thus, like never before or later, the hostile desert was converted into dynamic and vibrant cultural space. However, the geoglyphs bear not only integrative, but also competitive elements. Visibility studies clearly show that intervisibility was an important aspect in geoglyph placement and order. Though the geoglyphs themselves were usually not easily discernable from neighboring sites, posts erected on them and people moving around them certainly were. Geoglyph sites therefore assumed a stage-like function, and group activity upon them raised awareness of group identity among members as well as outsiders. Thus, geoglyphs played an important role in defining group status. At the same time, geoglyph-related activity was somehow independent of changing societal circumstances down in the valleys. Distribution patterns of geoglyph sites proved to be much more stable than that of settlements, cemeteries and other cultural features. All in all, geoglyphs can literally be understood as common ground for all members of Nasca society.” I highly recommend people reading over this report. I’m not sure what Von Daniken found fault in beside his paranoid ramblings about how he wasn’t allowed to walk all over the sites whenever he wanted. Besides, the technology they used to photography the areas is pretty cool.
So in my own conclusion, though you’ll never find a scientist willing to say that the Nasca lines are without a doubt simply cultural and ceremonial in nature, the research speaks for itself. Even the original hypothesis by Reiche merely suggested the glyphs were aligned with seasonal constellations and celestial activity, she never went as far as to suggest more than simple utility.
There is no need to make these lines more than what they were. They were tools, maps, and group markers made by humans to aid humans in their everyday lives. They are still amazing in their size and scope. They speak to human ingenuity and group co-ordination. Let’s not make less of our ancestors, let’s admire them more.
Hall, Stephen S
2010 Spirits in the Sand: The ancient Nasca lines of Peru
shed their secrets.
Proulx, Donald A.
The Nasca Lines Project (1996-2000)
2007 Nasca-Palpa Project: Photogrammetric Reconstruction of the
Geoglyphs of Nasca and Palpa