Manhattan Schists and Schisms (Rock encounters now and then)
Saint Nicholas Avenue in Harlem follows an old Lenape trail which runs obliquely north-south from 111th Street to 193rd Street, breaking the grid. In a section near 131st Street, across from the row of tenement housing, Manhattan Schist lifts up. Like the City, which is constantly changing through the process of demolition and construction, this rock is metamorphic. Folded in steep anticlines and synclines, Manhattan Schist contrasts with the orthogonal nature of the urban grid.
Walking north toward 113rd street, Saint Nicholas Avenue suddenly becomes a canyon. The rocks rise 4-stories tall, a reminder of wilder times when continents collided, melted, and rose. Today, a landscape of basketball courts sits amid these tall grey rocks. Geos in Greek is “non-life;” geology speaks of inanimate things. Yet today’s manmade transformations of the earth call into question this distinction. In Harlem, we confront an entangled existence with the “natural;” summertime basketballs and barbecues merge into one smoky, continuous, moving scene with the rocks. As Robert Smithson points out, “the manifestations of technology are at times less an extension of man than they are aggregates of elements. Even the most advanced tools and machines are made of the raw matter of the earth.” 
A geologic continuum of old and new chemicals and minerals is present here: rocks, oil, gas, rocks. Each element possesses different forms, shapes, and sizes, like the chemically altered minerals in the Schist. The smell of burning coal, another sedimentary rock, emerges from iron minerals of the steel grill. The butyl rubber of basketballs, formed from either the thermal cracking of natural gas or lighter fractions of crude oil, bounce against the hot bitumen blacktop. Some elements come in manmade and some in natural formations. Water streams digest polystyrene Orangina-filled cups. Disposable barbeque trays from extracted aluminum accommodate the burned flesh of cattle. As Elizabeth Povinelli remarks in Geontologies “rather than focusing on the difference between Life and Nonlife…let’s rethink the link between the geochemistry of Earth and the biochemistry of Life.” We will never witness the rock transformations of the great supercontinent Pangea. But here at West 133rd Street, through the summer afternoon smoke, we can catch a glimpse of new types of earthy transformations at play.
Manhattan Schist is a wrinkly, majestic bedrock. When Pangea was formed, the East Coast of North America collided with the floor of the Atlantic Ocean, pushing a layer of shale—a rock of clay and sand—into the earth’s molten core. The result was Manhattan Schist, formed by heat, pressure, and chemical reactions in the water. In this rock, you find feldspar, hornblende, shiny slivers of quartz, and mica. These minerals point to the depths and degree of pressure from which this rock emerged. During heat transformations, minerals grow in sizes and shapes, and shift orientations. When fluids flowing through the rocks carry away or add elements, chemical compositions also change. These rocks, as still as they seem now, have a far-from-static life.
With the emergence of geology as a scientific discipline in the 17th century, rocks, minerals, and fossils were the means to reconstruct natural history and time. For the naturalist Georges Cuvier, “…man, to whom has been accorded only an instant on earth, would have the glory of reconstructing the history of the thousands of ages that preceded his existence, and of the thousands of beings that have not been his contemporaries!” 
In his fascinating dissertation from 1914, “The Manhattan Schist of Southeastern New York State and its Associated Igneous Rocks,” geologist Charles Reinhard Fettke uncovers the history of Manhattan’s geological knowledge, stating “the region underlain by the Manhattan Schist was explored and settled long before the science of geology had begun to attract any attention in this country.” Earliest geological references  to Manhattan Schist appeared in 1816, five years after the 1811 imposition of a grid upon all of Manhattan’s terrain irrespective of topography. The intense construction of the City brought accidental knowledge of its ground. Today, in the Manhattan landmass, the Rock only appears in certain moments —in an outcropping in Central Park or other peculiar instances anchored in the urban fabric.
Basketballs and barbecues, bodies and their sweat, cooked flesh and minerals, portable speakers, smoke and music fuse together with these metamorphic rocks into one new assemblage of the Wild.
 Smithson, Robert, Jack D Flam, and Nancy Holt. Robert Smithson: The Collected Writings. [Revised and Expanded ed.]. The Writings of Robert Smithson. Berkeley [etc.]: University of California Press, 1996: 101
 Povinelli, Elizabeth A. Geontologies: A Requiem to Late Liberalism. Durham: Duke University Press, 2016: 43.
 Rudwick, Martin J.S. Bursting the Limits of Time: The Reconstruction of Geohistory in the Age of Revolution. Chicago: University of Chicago Press, 2005: 509.
 Fettke, Charles R. “The Manhattan Schist of Southeastern New York State and Its Asso-ciated Igneous Rocks,” Annals of the New York Academy of Sciences. v. 23, Pp. 193-260. New York: New York Academy of Sciences, 1914: 197.
 Wilson, W.E. (1994) “The history of mineral collecting 1530-1799”. Mineralogical Record, 25.