Abstract
Extensive areas of northern New Jersey are underlain by carbonate rocks, ranging from Proterozoic marbles to Paleozoic limestones and dolomites. These areas include large portions of Sussex and Warren Counties, as well as smaller areas within Hunterdon, Morris, Passaic, and Somerset Counties. As part of its efforts to map the geology of the state, the New Jersey Geological and Water Survey (NJGWS) has undertaken efforts to create karst features maps of quadrangles within this area—known as the Karst Susceptibility Project Area. Through field mapping, GIS analysis, and interpretation of past data collection, NJGWS began publishing these 1:24,000-scale maps in 2023. These karst features maps utilize techniques for the automated delineation of sinkholes and closed depressions, as well as custom GIS toolboxes to assist with the identification of karst features. This is especially helpful in New Jersey, which hosts a covered karst terrain and where karst features display a muted expression and can be difficult to identify under surficial cover. The maps show the distribution of karst features by geologic formation and soil series type, as well as by thickness of surficial materials. They also include a discussion of factors impacting karstification in the map area. These include the thickness of surficial deposits, the extent of the various glaciations in New Jersey, and the location of ridges underlain by gneiss, granite, and shale adjacent to valleys underlain by carbonate rocks.
DOI
https://doi.org/10.5038/9781967518012.1036
Figure 1
Schagrin-fig.2.tif (35825 kB)
Figure 2
Schagrin-fig.3.jpg (3484 kB)
Figure 3
Schagrin-fig.4.jpg (7414 kB)
Figure 4
Schagrin-table1.tif (22415 kB)
Table 1
Schagrin-fig.5.jpg (5777 kB)
Figure 5
Schagrin-fig.6.tif (17661 kB)
Figure 6
Creating a Karst Features Map of a 7.5-Minute Quadrangle in Northern New Jersey
Extensive areas of northern New Jersey are underlain by carbonate rocks, ranging from Proterozoic marbles to Paleozoic limestones and dolomites. These areas include large portions of Sussex and Warren Counties, as well as smaller areas within Hunterdon, Morris, Passaic, and Somerset Counties. As part of its efforts to map the geology of the state, the New Jersey Geological and Water Survey (NJGWS) has undertaken efforts to create karst features maps of quadrangles within this area—known as the Karst Susceptibility Project Area. Through field mapping, GIS analysis, and interpretation of past data collection, NJGWS began publishing these 1:24,000-scale maps in 2023. These karst features maps utilize techniques for the automated delineation of sinkholes and closed depressions, as well as custom GIS toolboxes to assist with the identification of karst features. This is especially helpful in New Jersey, which hosts a covered karst terrain and where karst features display a muted expression and can be difficult to identify under surficial cover. The maps show the distribution of karst features by geologic formation and soil series type, as well as by thickness of surficial materials. They also include a discussion of factors impacting karstification in the map area. These include the thickness of surficial deposits, the extent of the various glaciations in New Jersey, and the location of ridges underlain by gneiss, granite, and shale adjacent to valleys underlain by carbonate rocks.