Pecora Escarpment Main Icefields Area
The Pecora Escarpment (85º38'S 68º42'W) is an isolated series of nunataks trending SW-NE situated between the Thiel Mountains and the Patuxent Range. Extensive bare ice areas of approximately 120 square kilometers occur both on the upstream and downstream sides of the escarpment in the immediate vicinity of the nunataks. Numerous smaller ice patches are present within a 40 kilometer radius of the Pecora Escarpment. PCA20-Figure 1 (35 KB JPEG) is an aerial view of the Pecora Escarpment Main Icefields area looking southward. PCA20-Figure 2 (58 KB JPEG) is an enlarged portion of the U.S.G.S. 1:250000 scale Pecora Escarpment quadrangle.
Meteorites have been recovered from nearly all of the bare ice areas surrounding the Pecora Escarpment. Informal names have been given to local basins and ice patches for the purposes of referring to the areas in the field. Numerous smaller isolated and geographically distinct icefields are present in the immediate region, and meteorites have been recovered from some of these during reconnaissance searches.
The icefields at the Pecora Escarpment were first searched for meteorites during a reconnaissance traverse from the Thiel Mountains, some 160 km to the west, in the 1982-1983 field season (Schutt et al., 1983 and Schutt, 1985). A significant meteorite concentration was discovered and 32 meteorites were collected. During the 1991-1992 season an ANSMET team systematically searched much of the most promising icefields and conducted reconnaissance searches of some of the nearby icefields (Harvey and Schutt, 1992). A total of 490 numbered meteorite specimens were recovered. During the 2001 season a non-governmental expedition visited the area and recovered 33 specimens (Sipera, P. et. al. 2002).
PCA20-Table 1 is a tabulation of the various meteorite types recovered from the Pecora Escarpment Main Icefield.
The locations of the meteorites from the 1982-1983 season were surveyed from base stations on bedrock using the snowmobile odometer or pacing for distance and a compass for relative bearings or triangulation. The locations of the 1991-1992 specimens were determined using a combination of GPS and traditional theodolite/EDM surveying methods. Most of the meteorites surveyed using GPS were determined by differential GPS techniques.
No exact location information is available for PCA 82515, PCA 82523, PCA 82524, PCA 82527. These four meteorites were found on one of the isolated ice areas approximately 16 kilometers east of Lulow Rock. No location information was recorded for PCA 82521. During the 1991-1992 season an icefield about 40 kilometers north of the Pecora Escarpment, referred to as the North Forty Icefield, was briefly visited and meteorites were found there. Three meteorites were recovered there (PCA 91235, PCA 91253, and PCA 91248). Follow the link to traverse to the North Forty Icefield. Another specimen, PCA 91020, was found on a small ice patch called the Halfway Icefield which is located approximately 16 kilometers northwest from the Pecora Escarpment. The locations of these four specimens, determined by using a GPS receiver, are available in the database and are indicated on PCA20-Figure 2 (58 KB JPEG).
A large meteorite fragment, PCA 91009, was found with many additional paired fragments scattered about in close proximity, and along a path at least 400 meters downwind. Many of these fragments were mapped. The following meteorites found within the strewn field are probably paired with PCA 91009, but were not mapped: PCA 91047, PCA 91386, PCA 91432, PCA 91370, PCA 91367, PCA 91368, PCA 91361, PCA 91360. No exact location information is available for PCA 91074, PCA 91431, and PCA 91264, but PCA 91074 is known to have been found in the general area of PCA 91102 and PCA 91026 at the south end of the NE Steppes icefield area. PCA 91431 was found within 1/2 kilometer of PCA 91118 on the Main Icefield.
Acknowledgments; Richard Crane, Urs Krähenbuhl, Louis Rancitelli, and John Schutt were involved in the field work in the 1982-1983 field season. Francisco Anguita, Ralph Harvey, Alex Krot, John Schutt, Peter Wasilewski, and Michael Zolensky were members of the 1991-1992 ANSMET field party.
Traverse to the Pecora Escarpment Meteorite Listing (34 KB - Last updated 4/19/05)
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