Geography Reference
In-Depth Information
224
Figure 7.9. With five
hundred-foot cliffs of
granite capped by sand-
stone, Treves Butte stands
to the north of the main
ohio Range. Photo by
Margaret Bradshaw.
a moderate slope climbed its face to the summit. The granite cliV was also there at the
bottom, though not as high, and the rest of the mountain was built of a section of sedi-
mentary rocks several thousand feet thick. The geologists were itching to see what the
layers held, so Long, Darling, Bentley, and Jack Long hiked over to the outcrops under a
su n ny sk y.
The party followed a drift around the granite cliV and came out onto a shelf of the
sedimentary strata. Almost immediately the men found fossils—lots of them! Little ma-
rine shellfish, brachiopod bivalves, none any bigger than a quarter, but handsome, deeply
grooved teardrops, and well preserved. Discoveries are serendipitous. The party had just
discovered fossils like none other in the Transantarctic Mountains. Elsewhere, where the
basal beds above the unconformity were known, they had been laid down by rivers me-
andering across floodplains on land. Here was clear evidence of deposition at the bottom
of a shallow sea. Marine rocks like these, with fossils like these, had no counterparts.
Above the fossiliferous beds was a section of strange broken rocks, strewn through
horizons of sand. Long had never seen anything like them, but he recorded their presence
and moved higher. The section changed to mainly sandstones, which toward the top con-
tained coal beds and, in some shalelike layers, unmistakable imprints of Glossopteris, the
Permian plant fossil found previously in the Transantarctic Mountains by Scott and by
Blackburn. But trumping everything were the petrified remains of tree trunks as much as
two feet in diameter and ten feet long, littering the landscape at one horizon, looking as
if some Permian catastrophe had leveled a forest.
With such a rich assortment of fossils and rock types, Long had to be selective in
what samples the party returned to camp. From the summit, Bentley and Jack went di-
rectly back to camp, each carrying his share of rocks, while Long and Darling worked
their way slowly down the ridge, collecting as they went. The weather had been clear dur-
