User:Brendon5/Guardiria Paleoindian Site

This page is a work in progress for a class project. No edits should be made to this page until my grade is received. Thanks. Brendon5 (talk) 12:52, 23 September 2009 (UTC)

Geographical Setting
The Guardiria (or Finca Guardiria) site is a poorly stratified multicomponent site located to the east of the Cordillera Central on the Reventazon River in eastern Costa Rica near the town of Turrialba. It represents the largest Paleoindian fluted point site in Central America. Paleoindian points are limited to the uppermost of three terraces of the river, with the exception of a Magellan style fishtail point and two preform tips, which were found on a lower terrace. This highest terrace has been dated to 10,000-12,000 BP. In Paleoindian times, the site would have been on an ecotone between montane oak forests and tropical rainforest. This landscape would have been attractive for prehistoric peoples, providing resources from both forest zones, as well as aquatic resources from the river. In addition, lithic materials were available in the form of cryptocrystalline river cobbles, as well as andesitic volcanic rocks from the nearby mountains. The region today receives around 4,000 mm of rainfall each year, and tropical rainforest has emerged as the natural vegetation. However, the terraces of the Reventazon River are also prime land for the cultivation of sugarcane, and modern agricultural activities have altered the landscape. Although agricultural land clearance exposed the site, repeated seasonal burning associated with sugarcane cultivation limits the potential for radiocarbon dating, and the high acidity of the soil impacts the preservation potential for organic materials. Consequently, the Guardiria site is composed of chipped stone and ceramics only, which are occasionally exposed by disc plowing.

History of Investigations
Michael J. Snarskis identified the Guardiria site in July of 1975 on the basis of lithic surface scatters upturned by sugarcane agricultural processes. Systematic surface collections and eighteen shallow test excavations were carried out by Snarskis and students in association with the National Museum of Costa Rica. Deposits were determined to be dispersed over approximately 100,000 square meters, and concentrated twenty to forty centimeters below the surface. Large quantities of chipped stone were recovered, leading to the determination that Guardiria represents a large Paleoindian quarry and workshop site with a later Ceramic Period component.

Artifacts
Around 28,000 chipped stone specimens were recovered in 1975, including eighteen whole and fragmentary fluted points. These points, with the exception of a single Magellan style point, resemble Clovis culture artifacts. A large number of other Paleoindian artifacts were found, including bifacial preforms, side scrapers, end scrapers (some exhibiting lateral spurs), snub-nosed keeled scrapers, bifacial and unifacial knives, burins, and large blades. Ceramic Period artifacts were also recovered, including 189 whole and fragmentary waisted axes, perhaps used in agricultural activities, as well as ceramic fragments. A considerable difference between lithic materials associated with the Paleoindian components and the Ceramic Period occupations was noted. The Paleoindian artifacts were produced of high quality flints, cherts, and jasper in the form of river cobbles from the nearby Reventazon River, whereas the later Ceramic Period artifacts were produced of lower quality andesitic volcanic rock and fine-grained shale not suitable for flaking.

Importance of Discoveries
Guardiria is not only one of the largest Paleoindian sites in Central America, but is also one of the few sites where three distinct Paleoindian projectile point styles have been found together. Both straight-sided and waisted projectile points representative of the Clovis culture have been found at Guardiria. These represent some of the first Clovis points to be recognized in Costa Rica. In addition, a third point style called fishtail or Magellan was also found. The co-occurrence of these three point styles at Guardiria helps shed light on multiple proposed scenarios for the development of different Paleoindian projectile point styles, with Panama and Costa Rica often considered the borderline between general spatial distributions of Clovis-like and fishtail style points. Understanding the relationships between these point styles aid in determining if Clovis and Magellan points developed in this area then diffused elsewhere, if the two point styles developed elsewhere then merged at this site as two distinct and separate migrations , or if what is represented is a gradual transition of a single point style through time. The fact that the Clovis-like materials at Guardiria were found on the oldest terrace of the Reventazon River whereas the Magellan style point was found on a lower, younger terrace allows for reconstructions of chronological sequences critical for understanding how different Paleoindian projectile point patterns are related. The findings at Guardiria solidify Costa Rica's role as a major cultural frontier even in Paleoindian times.