We stop to watch the hippopotami wallowing in a concrete pool, in front of the 1500 year old Huaca 32.
“So have you been able to date the tumis?” Alla asks, wiping some lucuma ice cream off her nose.
“ I have an answer, but it is neither a yes nor a no.”
“Clarify, por favor!”
“I thought I could categorise the drawings on one panel by brightness, and perhaps relate that to age. But there are no tumis on that panel. There is one white mark above the heart, that could be a tumi, but it is not well drawn. It appears to be recent.”
How recent. 1750, the date of the Huarochiri rebellion?”
“It could be, plus or minus one hundred years. There is a clearer tumi to the left of the main panel, with a double ring handle. And on the opposite face of that rock there is a large handled tumi. Based on brightness, all three of them appear to be older than the heart, but more recent than the dot track,.”
“You mean they were made sometime between the Spanish invasion and the present? Then its the rebellion!”
“Its not that simple. On the north-facing panel I have only one calibration point, JMJR’s initials. There is one large, bright tumi, but there are many poorly drawn T-shapes, which are a good deal fainter. That rock face does not have a shiny black surface, and there is little variation in brightness.“
“What does that mean. Tell me simply.”
“On the main front panel, there is a wide range of image brightness, the drawings appear to be darkening with time. But to the side of that panel, and higher up, and on the opposite face, we don`t see that. Maybe even older images remain bright. I am saying that I can`t tell.”
“So that`s the end of my exciting image of the rebels crossing the river, calling on the gods to bless their knives before they march on Lima?”
“You can still believe that, but without a tumi on the main panel, I can not support it. And there`s more.”
I pull out my phone and run through some of the photographs of the rocks.
“Here, we have seven tumis, with curved blades, all drawn together on one panel. The shape, the styles are similar. They are drawn smoothly, fluidly, but lightly, sketched on the surface of the stone.”
I pull up another image.
“Here, on another rock, we have these five thick, round-ended blades, and the shaft is much wider. These are fully drawn, worked deep into the rock.”
And I open up a third and fourth photograph on the screen.
“And these are the rough drawn T-shapes, twenty or thirty of them on another two panels of two more rocks.”
“So not all tumis are alike.”
“You have just shown me that two platform mounds, side by side, can be separated by five hundred years or more. To see the difference, we have to look at the adobitos. I am saying that these tumis too, can be differentiated by shape, by the manner in which they were drawn, by choice of rock panel and by brightness. Even without detailed analysis the tumis can be put into five groups; apparent tumis being held by humans would be a sixth category. Maybe the tumis too span different cultures and hundreds of years.”
We had reached the sea lions’ enclosure, which stank of fish. Several herons had descended onto the rocks to stand watch over the pool.
“An image is drawn onto these rocks eighty or a hundred times, and yes, the image is drawn in different styles and forms, but people are drawing the same object are they not? A tumi, a ceremonial sacrificial knife, surely? And this image repeated so many times is specific to this site. It is not a llama or a serpent, which we see at every petroglyph site from north to south. This must tell us something!”
“I have another idea…”0