BARSTOVIANA
Newsletter of Weird Stuff in the Mojave Desert Near Barstow, California

The Barstovian Mystery Excreta (identified as amberat: a packrat midden) was discovered in a cavity in a boulder on the northwest rim of Rainbow Basin (near Barstow, California). The boulder is located beside a small dry stream bed, just on the cusp from which the stream plummets 50 feet and becomes the main northeastern channel of Rainbow Basin, a steep canyon of green and red mudstones of the Barstow Formation (15 mya).

The boulder is a coarse conglomerate of 6"-18" pieces of granite breccia in a matrix of coarse sand and decomposed granite. (Probably Pickhandle breccia, 25 mya[?], broken granite cliff fragments fallen into mountain streams, buried by volcanoes. This boulder locally transported, up to half a mile downhill from the crest of the Mud Hills).

Several chunks of granite and much matrix have fallen away from the boulder to expose the excreta mass. The excreta cavity is on the north (upstream) side of the boulder. About 2 cubic feet of excreta are exposed; more may lie in the rock behind and above.

On close inspection the excreta mass was found to be disgusting. It comprises about 30% small mouse turds (50-mm gauge), 40% straw, 10% seeds (2-mm yellow spherical), and 20% hard brown/black material (urine?) that looks like violin rosin. These ingredients occur in horizontal layers, somewhat mixed.

The black/brown material is a hardened liquid. It is found throughout the mass, cementing it all together. It is most dense on lower and lateral surfaces. It forms a hard coating on lower surfaces of the mass, with "droplets" up to 1/4". The mass is very firmly cemented, and the black/brown stuff is extremely hard and brittle (cannot be cut with a sharp knife; crumbles without noticeable planar flaking).

Chunks of fallen excreta mass were also discovered lying below the rockbound mass itself, 2-inch thick by 5-inch wide by 6-inch long slabs, broken off at straw/turd interfaces. Lots of recent mouse poops were observed in the bottom of the cavity and on the ground around it, and some year-old coyote scat lay very nearby.

The distal (south, canyonward) side of the boulder (not pictured) has a ledge just above the excreta mass, with a rodent hole and a few poops but no exposed excreta mass, and below this a shallow cavity on the same level as the excreta mass but devoid of holes or poops or exposed excreta.

This is apparently be a packrat midden, and years of it.

For an account of how the Manly Expedition ate amberat, click here.

BARSTOVIAN BYWAYS

Tubes: What's Up With Them?
Fragments like the one show were found lying plentifully on the surface of the south slope of a sand dune on the ridge between Rainbow Basin and Owl Canyon, in the location shown on the map. Soils on these ridges and hills are not part of the Barstow Formation, but less than 1 million years old--from the pluvial lake period. Manix Lake lay south and east of here. The quantity of pieces seemed to indicate that they had sifted out of the upper dune, which had blown away. But they were not so many as to have been very dense if not sifted, soI did not prosepect below the surface (also because it's an official National Scenic Wonder).

Most pieces are not branched like the one shown, but are single stems of similar size (1 to 2 inches). Most pieces are slightly thinner than this, but a few are half again as thick (and not as round in cross-section). This piece has an unusual lot of large yellow crystals on the exterior. The crystals are on the surface only; the inside is very fine-grained and powders easily. The surface crust is brittle.

Some pieces show vague concentric rings on the broken ends; most do not. Some seem to have thin outer white shells. Some show planar (or cylindrical?) flaking as in bone or wood, but most do not. All resembled twigs. Two small fragments were hollow tubes. In the rest, the interior is a fine-grained tan-colored material that powders easily, uniform and without a central core.

Both surface and interior are finely but densely porous, and fizz in acid. The pieces are quite light, hard, and brittle, and tinkle brightly when shaken together.

If you think you know what this might be, e-mail me.

What's That?
Lights in the sky over Daggett.
Click the photo to find out!

Photo Courtesy of The Route 66 Collection--www.wemweb.com