Rifting and Rambling

4-10-07 SHORT HILLS: It is still cold today and breezy, but sunny. I need gloves to be outside for more than a few minutes. The jet stream is sagging far to the south across the eastern U.S. dragging cold, arctic air with it and draping us in it. Lots of daffodils are open around town, but none of ours have, as yet, dared to brave the cold.

Judy and I have received dozen of emails and calls about Fanny’s death. We thank all of you for the kind words and thoughts.

A bit of explanation about that last post. Those folded beds were deposited in the early Paleozoic Era, 450 million years ago; they were folded in the late Paleozoic, 300 million years ago; the rifting that split the continents began in the Mesozoic Era, 200 million years ago, and continues as the Atlantic gets a couple inches wider every year.

Speaking of rifting, our house is on the western side of a fairly steep, short hill, actually a ridge, which runs in a north-south direction for several miles. This ridge is one of several similar and parallel ridges in northern New Jersey. They are all made of basalt, the rock that lava becomes when it cools. All these ridges are volcanic. The lava poured up through weak gaps that opened up when the earth’s crust thinned and cracked right here as the continents pulled apart in the early Mesozoic Era.

I grew up in Chatham Township on top of a similar ridge that parallels the western bank of the Passaic River. Where we now live, the ridge parallels the eastern bank of the Passaic. Judy grew up in South Orange on the eastern side of the ridge adjacent to the one on which we now live, together they are the Orange Mountains, that one is First Mt, and this one Second Mt. In the seventies, after we were married, we lived in West Orange again on the eastern side of First Mt.

The basalt, a fine-grained, extrusive igneous rock, is usually black and contains a lot of iron rich minerals. As the surface weathers it turns rust colored due to the oxidation of the iron and forms the reddish soil that underlies our yard. Volcanic soils, rich in minerals, are prized by farmers. This is why there are always villages clustered around volcanoes in what would seem to be a hazardous place to live.

In our yard the red soil should be capped by an organic layer of black loamy stuff made of decomposed leaves, twigs and other plant material like what you see on the forest floor. Trees grow in the topsoil and the roots reach down to the undersoil for the minerals. Most of our topsoil is gone. Our steep hillside has seen a proliferation of streets, houses, driveways, patios and other impervious surfaces that don’t absorb rainwater and that replaced the native deciduous forest which did. In the forest, the trees soak up a lot of rain leaving little runoff. Grasslands absorb less drainage than forests and asphalt none. The resulting heavy runoff has caused us to lose topsoil to erosion. Leaves and grass clippings, if left in place, would ultimately decompose and replace some of the lost organic layer. Leaving the fallen leaves ungathered and unremoved will be my experiment in land reclamation.

Here is a pic of the contact between reddish sandstones and a black basaltic eruption. The picture is from a beach in Nova Scotia, which experienced rifting of the same kind as New Jersey had at the same time and for the same reasons.