Editing Cape May County, New Jersey (section)

===Geology===
The oldest rocks in the county are at a depth of {{convert|5000|ft|m|abbr=on}}, formed during the [[Precambrian]] era. These [[metamorphic rock]]s include [[gneiss]], [[quartzite]], and [[schist]]. During the [[Paleozoic]] era, the region was part of a mountainous landmass that extended from the Arctic to Mexico. Erosion during the [[Triassic]] and [[Jurassic]] periods formed valleys that gathered sediment, which deposited and layered as the coastline receded and rose. In the [[Paleocene]] and [[Eocene]] epochs, as well as the later [[Miocene]] epoch, the area that is now Cape May County was under water. The coastline receded again during the [[Quaternary]] period.<ref name="geo"/>

During the [[Sangamonian]] [[interglacial]] period, melting glaciers formed rivers that carried sediment to the coast. The Bridgeton Formation deposited silt and clay through a [[fluvial]] process, while the later Cape May Formation deposited sand, silt, clay, and gravel. The [[Great Egg Harbor River]] in its formative stage produced a [[river delta|delta]] that covered much of what is now Cape May County with sediment. During the most recent ice age ([[Wisconsin glaciation]]), the sea level dropped to {{convert|430|ft|m|abbr=on}} below its current depth. Around 14,000 years ago, glaciers began melting, and the [[barrier islands]] of Cape May County formed, likely from [[spit (landform)|spits]] and lines of [[dune]]s.<ref name="geo">{{cite report|title=Geology of Cape May County in Brief|year=1976|author=Carol S. Lucey|publisher=New Jersey Department of Environmental Protection|url=http://www.state.nj.us/dep/njgs/enviroed/county-series/Cape%20May_County.pdf|access-date=January 23, 2018|archive-date=April 22, 2021|archive-url=https://web.archive.org/web/20210422191520/https://www.state.nj.us/dep/njgs/enviroed/county-series/Cape%20May_County.pdf|url-status=live}}</ref>