Unravelling the Gordian Knot: Integrating Advanced Portable Technologies into the Analysis of Rock-Art Superimposition

几千年来，在全球范围内，人类在洞穴和其他石头表面上作画。一些画过的地方后来被人们重新参观，在旧的上面添加了新的画。这些遗址可能是色彩丰富、复杂的画作组合，一幅一幅地堆叠在另一幅上，以至于很难在很长一段时间内辨别出画作的顺序。虽然考古学家已经发展出许多复杂的理论来解释这些画作，并且掉落的画作碎片可能会在实验室中进行分析，但直到最近，当画作仍然留在岩石表面时，使用强大的科学设备来分析这些画作是非常困难的。然而，技术的进步已经生产出了小型的可移动设备，现在可以在不损害画作的情况下进行详细的现场分析。这些非破坏性便携式技术可以对洞穴、岩石表面和绘画进行三维扫描；可以使用x射线技术来确定用于制作绘画颜料的化学元素；用激光仪器识别画作的有机成分；并且可以使用便携式数码摄影来揭示通常人眼难以察觉的隐藏层。解开戈地结项目将运用所有这些方法来分析在美国加利福尼亚州发现的名为Pleito的遗址上壮观而多彩的绘画。普雷托是世界上最复杂的绘画遗址之一。它有数百幅不同颜色的独立画作，包括不同色调的红、黑、白、黄、橙、绿和蓝。这是北美任何已知遗址中最宽的调色板，重要的是，它有多个面板，绘画被放置在早期的绘画上。这种被称为叠加的复涂，对试图理解在风景中发现的绘画艺术的岩石艺术研究人员提出了最大的挑战。尽管如此复杂的绘画具有挑战性，但它们为能够解开顺序的考古学家提供了了解绘画随时间发展的最大机会。在Pleito遗址内，一个被研究人员称为“戈甸结”的面板是在那里发现的最精致的面板，使其成为世界上发现的最复杂的史前面板之一。这个项目的名字来源于这个面板，因此Pleito及其以各种颜色执行的复杂复涂序列是解开绘画事件历史的理想案例。所采用的方法将集成一系列便携式技术，包括便携式x射线荧光、便携式拉曼光谱、高光反射变换、dStretch数字摄影和便携式数字激光扫描，以解开构成世界上最复杂遗址之一的绘画序列。这些技术将有助于解决有关颜料使用传统的问题，并深入了解艺术在土著社会中的作用。该项目包括一个最先进的3d娱乐网站，位于海峡群岛的加州州立大学，提供了一种替代现场参观的方式，作为一种体验现场的方式，而不会有破坏古代绘画的风险。此外，一项新的条件评估将把遗址的退化情况与2003年的基线报告进行比较，以了解最近有多少画作被侵蚀。最后，一系列将不同颜料与不同类型的粘合剂结合在一起的实验将为我们提供材料，用于实验室和便携式设备的测试，以创建一个光谱数据库。这将为我们提供一系列不同的化学读数，以便与实际画作进行比较，并允许世界各地的研究人员将他们的发现结果与戈迪亚结光谱数据库进行比较

For thousands of years and across the globe, humans have painted images in caves and on other stone surfaces. Some painted sites were later revisited by people who added new paintings on top of the older. Such sites can be very colourful, complex assemblages of paintings placed one on top the other, so much so that it can be very difficult to discern the sequence of painting over very long periods of time. While archaeologists have developed many sophisticated theories to interpret these paintings, and pieces of the paintings that have fallen off may be recovered to analyze in a laboratory, until recently it has been very difficult to analyse the paintings using powerful scientific equipment while the paintings remain on the rock surface. However, technolgoical advances have produced small transportable devices which now allow for detailed on site analyses that do not harm the paintings. These non-destructive portable technologies can scan the cave, rock-surface, and paintings in 3-Dimensions; can use X-ray technology to determine the chemical elements used to make the pigment that makes the painting; laser instruments to identify organic components of the paintings; and can use portable digital photography to reveal hidden layers normally barely perceptible to the human eye. Unravelling the Gordian Knot Project will apply all of these methods to analyze the spectacular and colourful paintings at the site called Pleito, found in California, USA. Pleito is one of the most complex painted sites in the world. It has hundreds of individual paintings with many colours, including different shades of red, black, white, yellow, orange, green, and blue. This is the widest colour palette of any known site in North American and, importantly, it has multiple panels where paintings have been placed over earlier ones. This kind of overpainting, known as superimposition, presents the greatest challenge to rock-art researchers in their attempts to understand painted art found in the landscape. Even though such complex paintings are challenging, they offer to the archaeologist who can unravel the sequence the greatest chance of understanding the development of paintings through time. Within the site of Pleito, a panel known to researchers as the 'Gordian Knot' is the most elaborate panel found there, making it one of the most complex prehistoric panels found anywhere in the world. The name of this project is derived from this panel, and so Pleito and its complex sequences of overpainting executed in various colours is an ideal case to disentangle the history of painting events. The method employed will integrate a range of portable technologies including portable X-Ray Fluorescence, portable Raman Spectroscopy, Highlight Reflectance Transformation, dStretch digital photography, and portable digital laser scanning to unravel the sequence of painting that makes up one of the most complex sites found anywhere in the world. These techniques will help address questions concerning traditions of pigment use and give insights into the role of the art within Native society. The project includes a state-of-the-art website with a 3-D recreation to be housed at the California State University, Channel Islands, offering an alternative to site visitation as a means to experience the site without risk of damaging the ancient paintings. Also, a new conditional assessment will compare degradation of the site to a 2003 baseline report to see how much of the paintings have recently eroded away: finally, a series of experiments combining different pigments with different types of binding agents will give us material to test with both lab based and portable equipment in the creation of a spectral database: this will give us a series of different chemical readings to compare with the actual paintings and allow researchers across the world to compare results from their discoveries with the Gordian Knot Spectral Databasee