User:Field studies/sandbox: Difference between revisions
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Today Cueva Fell joins most of southern Argentina in what is known as the Fuego-Patagonia steppe environment. The area receives less than 400mm annual precipitation (typical for the Patagonia region but much drier than neighbouring coastal or mountain terrains) and is dominated by bunch grasses from the genuses ''Festuca'' and ''Stipa'', along with a variety of herbaceous vegetation(Markgraf 1993:56). |
Today Cueva Fell joins most of southern Argentina in what is known as the Fuego-Patagonia steppe environment. The area receives less than 400mm annual precipitation (typical for the Patagonia region but much drier than neighbouring coastal or mountain terrains) and is dominated by bunch grasses from the genuses ''Festuca'' and ''Stipa'', along with a variety of herbaceous vegetation(Markgraf 1993:56). |
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===Flora & Fauna=== |
===Flora & Fauna=== |
Revision as of 05:21, 15 March 2012
Template:Infobox Pre-Columbian site
Cueva Fell is a natural cave and archaeological site in southern Patagonia.[1] Cueva Fell is in proximity to the Pali Aike Crater, another significant archaeological site. Cueva Fell combined with the nearby Pali Aike site have been submitted to UNESCO as a possible World Heritage Site.[2]
Site Discovery
Fell's Cave was discovered by Junius Bird. It came to his attention because arrow points and flakes were found on the surface. The cave was originally called the Río Chico shelter, but was later renamed by Bird to Fell's Cave in honour of the Fell family who owned the Estancia Brazo Norte, the North Arm Station, where the cave is located (Bird 1). Excavation of the site began in 1936.
Site Formation
Fell's Cave is located in the Río Chico canyon, Chile, near the Straits of Magellan and the Argentina border. This area is known as the southeastern Patagonian basalt plateaus (Markgraf via Bird 1988:196). Situated on the southeast side of what was once a river bank, it is more accurately described as a shelter. It was formed by river water wearing away at the sandstone bank, leaving behind a canopy of lava conglomerate and thus creating a shelter/cave 28 feet deep and 38 feet wide. The erosion formed a smooth floor of hard clay (Bird 1998:134). Remnants of sandstone still clinging to the conglomerate roof eventually fell to the floor, forming a sterile layer that later separated human occupation periods (Bird 1988:134).
Stratigraphy
Junius Bird labelled the occupational layers of the site from top to bottom, thus the layer directly under the surface is I, and the oldest layer is V.
Surface
The surface material of the site is composed of dirt, rocks, and hard-packed sheep manure. The surface layer ranges from 18 to 24 inches in thickness (Bird 1).
Layer I
The youngest stratigraphic layer of Fell’s Cave is a dark earth layer, reaching approximately 10 inches in thickness (Bird 1). This component dates from c. 700 years BP to the present (Roosevelt 1). According to conventional radiocarbon dating, the layer dates to 1265 A.D. +-90 (Bird 1).
Layer II
The division between Layer I and Layer II is relatively indistinguishable as the sediments are of similar dark earth, and also reach about 10 inches or more in thickness (Bird 1). This layer dates to c. 6,500 years BP (Roosevelt 1).
Layer III
This layer dates to c. 8,500-6,500 BP (Roosevelt 1).The earth consistency between Layers II and III marking a notable distinction between the two. Layer III is approximately 12-15 inches thick of compacted dark earth (Bird 1).
Layer IV
The thickness of this layer varies from 13-17 inches and consists of firmly packed dark earth (Bird 1). This layer dates from c. 10,000 to 8,500 BP (Roosevelt 1).
Sterile Layer
After the earliest layer, Layer V, had accumulated, sandstone slabs fell from the roof of the cave and sealed it off. This layer is 15 to 20 inches thick (Bird 1).
Layer V
A refuse soft clay soil varying in thickness from 3 to 9 inches composes the oldest occupation level at the site (Bird 1). The site dates from 11,000 RCYBP +-170 top 10,080 RCYBP +-160 according to conventional radiocarbon dating (Bird 1).
Chronology
![Artist's rendition of Cueva Fell exterior](http://178.128.105.246/cars-http-upload.wikimedia.org/wikipedia/commons/thumb/9/90/Cueva_Fell_Painting.jpg/220px-Cueva_Fell_Painting.jpg)
Bird named the periods from earliest to latest, thus Period I is the oldest and is associated with Layer V, while Period V is the latest and is associated with Layer I.
Period V
This period (layer I) is typified by a tool assemblage containing small arrow points and various bone tools, as well as such cultural materials as combs and beads (Roosevelt 1). Based on the style of the arrow points, it is likely that this period is associated with the Ona Indians (Roosevelt 1). The faunal assemblage of this period is dominated by guanaco bone fragments (Bird 1).
Period IV
Period IV is characterized by the presence of stone tools such as stemmed or legged stone points, knives, and small thumb-nail scrapers as well as a bone tool assemblage (Roosevelt 1). Large bolas, and various beads and other ornaments are also present (Roosevelt 1). This Period can also be distinguished by the building of structures including extended burials and rock cairns (Roosevelt 1). Again, the faunal assemblage is dominated by guanaco (Bird 1).
Period III
Present in this layer are bone awls, stone scrapers, and triangular stone points with rounded bases (Roosevelt 1). Also, bolas of notably smaller size than the subsequent later period, period IV (Roosevelt 1). It has been suggested that these small stone bolas may have been used in procurement of birds (Roosevelt 1). Guanaco and fox bone fragments dominate the faunal assemblage (Bird 1).
Period II
This layers consists mainly of bone points and awls, and stone scrapes (Roosevelt 1). Junius Bird notes in Travels and Archaeology in South Chile that this layer contained significantly more sediment in relation to artifact distribution (1).
Period I
The oldest cultural occupation at this site belongs to the Fell’s Tradition (Dillehay et al. 1). Thus, Fell’s Cave is the type site for the Fell’s Tradition. This tradition is characterized most notably by fishtail points as well as various stone scrapers, choppers, stone discs and bone tools (Roosevelt 1). Four small hearths were also uncovered within this period. They contained stone flakes and burnt bone, and later proved to be partially cremated human burials (Roosevelt 1).
Geology
Ecology
Climate
In the Late Pleistocene, prior to 12,500ka BP, the area surrounding Cueva Fell was dominated by high winds, year-round freezing temperatures, and annual precipitation under 300mm. This heathland environment was replaced by a treeless, xeric, herbaceous steppe environment through 11ka BP, as the freezing temperatures and winds began to abate (Borrero 1999-2:341; Markgraf 1993:53). This is the climate and terrain that most closely predated the first human inhabitants in the area.
The earliest occupation dates suggested by the finds in Layer V—c. 11-10 ka BP—correspond to a period of stadial cooling. In what has been described as a possible South American equivalent to the Younger Dryas, the Patagonian region experienced a period of low temperatures and high precipitation as well as advancing glaciers (Borrero 1999:93-98). This was followed in 10-9 ka BP by a warming trend. These two thousand years in question marked a fitful end to the last ice age, one marked by high environmental variability. While this produced significant changes in some taxa, humans, at this time, were already becoming adept at adjusting to new environments and appear not to have been deleteriously affected by the changeable and unpredictable climate (Markgraf 1993:62-63).
As the Holocene warming trend persisted, so the environment of southern Patagonia continued to change. The archaeology of Fell’s Cave provides evidence for the regular occurrence of summer droughts in the area—droughts that, combined with increasing summer storm activity, may have led to wildfires. The decrease in water availability combined with the evident (through pollen analysis) dramatic change in grazing flora species, are proposed as contributing factors to the evident faunal extinction (Markgraf 1993:63; Paez 1999:73).
The period of 9000 to 6000 BP saw less remarkable shifts in climate, with a general trend away from xeric taxa and, it is then presumed, an increase in precipitation. There is insufficient radiocarbon control at the site to determine local climate conditions post-6000 BP, however regional ecology suggests a slight shift towards more aridity (Markgraf via Bird 1988:199-200).
Today Cueva Fell joins most of southern Argentina in what is known as the Fuego-Patagonia steppe environment. The area receives less than 400mm annual precipitation (typical for the Patagonia region but much drier than neighbouring coastal or mountain terrains) and is dominated by bunch grasses from the genuses Festuca and Stipa, along with a variety of herbaceous vegetation (Markgraf 1993:56).
Flora & Fauna
Cueva Fell is notable for the range of now-extinct faunal finds excavated from within it. Notable among these are the giant sloth and the horse. The horse was to become extinct and absent in the Americas through most of the Holocene until it was imported by Europeans (Birds 1970:207). In fact the evidence of the ancient horse Cueva Fell was the first proof that horses occupied the Americas before being (re)introduced from the Old World. The stratified remains of both human and animals provides evidence that human occupation of the area actually preceded the extinction of both the native horse (Parahipparium saldasi) and the ground sloth (Mylodon listai). This same evidence suggested that ancient horse was hunted and eaten (Bird 1988:153). However humans weren’t the sole predators in the area. Bone remains of the horse, lama and ground sloth all display puncture marks, most likely made by the Patagonia panther (Borrero 1999-2:342).
The Early Holocene taxa change—the extinction of mostly herbivorous animals—was initially attributed to human overhunting, as were the megafaunal extinctions in North America. Pollen analysis extracted from Cueva Fell suggested a substantial reduction in grassland taking place in southern Patagonia in the period just preceding these extinctions, and was an early piece of evidence in the mounting argument against hunting as the primary cause of species collapse (Markgraf via Bird 1988:196). Large quantities of guanaco (lama) were also found in the older depositional layers. Where other large grazing fauna died out in the early Holocene, guanaco appear to have survived as a result of their less specialized plant diet, adapting to change in vegetation that accompanied the warming Holocene. Guanaco population sizes initially dipped along with other grazing species, but eventually recovered (Markgraf via Bird 1988:200-201).
Analysis of canine remains found in all five human occupation levels of the cave initially suggested they were those of domestic dog (Canis familiaris). This would have been remarkable as the earliest evidence for the domestic dog in the Americas. However subsequent analyses suggest the skull and teeth remains to have been from two wild species: Pseudalopex griseus (South American gray fox) and Canix avus (a small fox or wolf-life canine, particular to South America in the late Pleistocene period) (Clutton-Brock via Bird 1988:189-94). Other faunal bone remains include hawks and falcons (Borrero 1999-2:342).
Artifacts
The first excavation of Fell’s cave in 1936 yielded 511 artifacts. These included hafted implements, knives, scrapers, bolas, a couple of circular rubbing stones, and bone tools.[3]
Group | Category | Surface Layer | Layer I | Layer II | Layer III | Layer IV | Layer V |
---|---|---|---|---|---|---|---|
Hafted Implements | Ona-type arrow point | - | 13 | 2 | - | - | - |
Patagonian-type arrow point | 1 | 11 | 5 | 1 | - | - | |
Small, triangular arrow point | - | 2 | - | 1 | - | - | |
Small, rudimentary stem | - | 1 | - | - | - | - | |
Old-type, triangular point | - | - | 2 | 20 | 2 | - | |
Triangular, concave base | - | 1 | 1 | 2 | - | 1 | |
Fishtail point | - | - | - | - | - | 15 | |
Hafted knife | - | 12 | 5 | 2 | - | - | |
Hafted knife, questionable | - | 5 | 2 | - | - | - | |
Knives | Thin, single-edge | - | 1 | - | 2 | - | - |
3-sided | - | - | possibly 2 | 1 | 1 | - | |
?, concave base, broad, thin | - | - | 1 | - | - | - | |
Fragment (uncertain) | - | - | - | - | - | 3 | |
Combination knife-scraper | - | - | 1 | 2 | - | - | |
Scrapers | Single-edge, rough flake | 11 | 45 | 59 | 36 | 25 | 26 |
2-edge, large | 3 | 2 | 2 | - | 2 | 1 | |
2-edge, narrow | - | 4 | 11 | 1 | 6 | - | |
2 points | - | - | - | - | - | 2 | |
Large, rough, circular edge | - | - | 1 | 2 | 2 | 6 | |
Reversed-edge | - | 1 | - | - | - | 1 | |
End | - | - | - | - | - | 6 | |
Small, hafted | 13 | 26 | 51 | 9 | - | - | |
Unfinished blank | - | 1 | - | 6 | 1 | - | |
Bolas | Deep groove, flat ends | - | 1 | - | - | - | - |
Unfinished | - | - | - | 1 | - | - | |
Spherical, fragment | - | 1 | - | - | - | - | |
Lemon-shaped, fragment | - | - | 1 | - | - | - | |
Circular rubbing stone | - | - | - | - | - | 2 | |
Bone Implements | Chipping tool | - | 12 | 6 | - | - | - |
Bird bone awl | - | - | 1 | - | - | - | |
Solid bone awl | - | 1 | - | - | - | - | |
Lance point | - | - | - | - | 1 | - | |
Bead | - | 1 | - | - | - | - | |
Totals | 28 | 141 | 153 | 86 | 40 | 63 |
Perhaps the most significant find in the 1936 excavation was the fishtail projectile point. All of the fishtail points were associated with large mammal, including extinct horses, giant ground sloths, and guanacos. The oldest fishtail has been radiocarbon dated to ca. 11,000 years.[5] (to be continued)
Discoidal stones, referred in the chart as circular rubbing stones, were also found. Bird notes in a 1970 journal article that “stone artifacts shaped by pecking and grinding are so generally absent among Paleo-Indian finds that exceptions are noteworthy”. [6]
See also
Line notes
References
- Junius B. Bird (1988) Travels and Archaeology in South Chile, Published by University of Iowa Press, 246 pages ISBN 0-87745-202-4
- Calvin J. Heusser (2003) Ice Age Southern Andes: A Chronicle of Paleoecological Events, Published by Elsevier, 240 pages ISBN 0444514783