Geospatial Analysis of Green Pond “Puddingstone” as Building Stone, Morris County, New Jersey, USA

Abstract

Green Pond Conglomerate “puddingstone”, a maroon colored quartzite with white quartz pebbles, forms a bedrock ridge in the Paleozoic Green Pond Outlier, extending northeast from Morris County into Passaic County, New Jersey, then into Orange County, New York. Throughout Morris County, rounded boulders of the puddingstone are common in the Pleistocene glacial sediments. Our previous research finds the puddingstone boulders along with other fieldstones in buildings, retaining walls, and field fences. However, there are several instances of structures completely faced with the durable and attractive puddingstone, in and around the cities of Morristown and Madison, mostly limited to affluent houses and one prominent church of the mid- to late-19th century. In these cases, puddingstone boulders were partially dressed, in rubble stone fashion, a labor-intensive effort. We believe the only source for the puddingstone building material is from the glacial boulders.

The objective of this study is to derive the spatial attributes of the Green Pond puddingstone, its distribution as glacial boulders, and the unique clustering of affluent buildings in central Morris County. The ArcGIS Spatial Analyst tool is used to derive the distance-decay distribution from the parent bedrock, as well as the heterogeneity in the deposition, influenced by topography. We determined the degree of clustering of the puddingstone-constructed buildings and glacial boulder deposits by applying hot spot analysis. These results highlight the geographic uniqueness of this building stone, and enhanced justification toward historic preservation.