Basin and Range

Gerelateerde afbeelding

The diabase below the contact now is a smooth and uniform hard dark rock, no tweed-its crystals too small to be discernible, having had so little time to grow in the chill zone. The contact is a straight, clear line. She rests her hand across it. The heat of the magma penetrated about a hundred feet into the shale, enough to cook it, to metamorphose it, to turn it into spotted slate. Sampling the slate with her zakelijke energie sledgehammer, she has to pound with even more persistence than before. “Some weird, wild minerals turn up in this stuff,” she comments between swings. “The metamorphic aureole of this formation is about the hardest rock in New Jersey.” She moves a few hundred feet farther on, near the end of the series of cuts. Pin oaks, sycamores, aspens, cottonwoods have come in on the wind with milkweed and wisteria to seize living space between the rock and the road, although the environment appears to be less welcoming than the center of Carson Sink. There are fossil burrows in the slate-long stringers where Triassic animals travelled through the quiet mud, not far below the surface of the shallow lake.
There is a huge rubber sandal by the road, a crate of broken eggs, three golf balls. Two are very cheap but one is an Acushnet Titleist. A soda can comes clinking down the interstate, moving ten miles an hour before the easterly winds of the traffic. The screen of trees damps the truck noise. Karen sits down to rest, to talk, with her back against a cottonwood. “Roadcuts can be a godsend. There’s a series of roadcuts near Pikeville, Kentucky-very big ones-where you can see distributary channels in a river-delta system, with natural levees, and with splay deposits going out from the levees into overbank deposits of shales and coal. It’s a face-on view of the fingers of a delta, coming zakelijke energie vergelijken at you-the Pocal1ontas delta system, shed off the Appalachians in Mississippian-Pennsylvanian time. You see river channels that migrated back and forth across a valley and were superposed vertically on one another through time. You see it all there in one series of exposures, instead of having to fit together many smaller pieces of the puzzle.”