The Holzmer Collection: The Potential of Submerged Prehistoric Sites on the Jersey Shore


By: Richard Adamczyk

Along the beaches of New Jersey, some interesting treasures can wash ashore. In August 2014, a Paleoindian projectile point, dated to 10,000 years ago, was discovered by a 10 year-old boy on Long Beach Island. A month later, an 11 year-old girl found another prehistoric point in Long Branch. Finds like these are incredible, rare gems that let beachgoers and tourists contribute one small piece to the archaeological record. Or in the case of Mr. Allyn Holzmer, you can spend a lifetime collecting an entire site’s worth of prehistoric artifacts.

Select artifacts from the Holzmer collection, NJSM accession AE2016.4.

Mr. Holzmer spent almost 50 years walking the same quarter-mile swath of beach on the bay side of Cape May, where the Delaware feeds into the Atlantic Ocean. In that time, he has collected buckets of projectile points, scrapers, drills, ceramics, and other prehistoric artifacts. Mr. Holmer has recently donated his collection to the New Jersey State Museum (NJSM).

The dense concentration of artifacts in one location would suggest the location of a significant archaeological site just offshore. But why are there prehistoric Native American sites located underwater on the Jersey coast in the first place?

Around 12,000 years ago, humans first migrated into the region we now call New Jersey. This was the end of the geologic age called the Pleistocene, which lasted from 2.6 million years ago to about 11,700 years ago. This time period is commonly referred to as the last “Ice Age,” although technically the era experienced the rise and fall of many ice ages. The Pleistocene in North America was characterized by the existence of two enormous expanses of ice, covering most of modern Canada and some of the Northern United States. The massive ice sheets to the north stored an incredible amount of water, and the ocean levels were much lower than they are today. As the ice sheets melted, the shoreline crept closer and closer inland, submerging existing coastal sites. Today, these prehistoric archaeological sites remain buried beneath the ocean floor, and many are located just off the Jersey coast. The occasional artifact drifts ashore from time to time, a remnant from ages past.


Approximate location of Pleistocene ice sheets at their largest. (From “Physical Geology” by Steven Earle used under a CC-BY 4.0 international license.)
Approximate location of the eastern coastline 21,000 years ago. (Figure 9 from “Ground Water in Freshwater-Saltwater Environments of the Atlantic Coast” by Paul M. Barlow, USGS Circular 1262.)

What kind of people were living in New Jersey before Europeans arrived? Archaeologists divide the state’s prehistoric past into three general periods: the Paleoindian, the Archaic, and the Woodland periods. Lasting from 12-10,000 years ago, the Paleoindian period consisted of small, mobile bands of hunter-gatherers utilizing distinct fluted projectile points. The Archaic period lasted from 10,000 years ago to 3,000 years ago, and is subdivided into the Early, Middle, and Late Archaic. This period demonstrates an increase in small settlements, a more diverse toolkit, evidence of fishing activity, soapstone bowls, and the beginnings of agriculture. The Woodland period, which lasted from 3,000 years ago to European contact, marked a greater increase in sedentary lifestyles (living in one place for extended periods), more dependence on agriculture, the use of ceramic pots, and the introduction of bow-and-arrow technology. The Native Americans that lived in this region were the ancestors of the Lenape (also called Delaware Indians). Today, there are three federally recognized Lenape tribes in the United States: the Delaware Tribe of Indians and the Delaware Nation currently reside in Oklahoma, and the Stockbridge-Munsee Community live in Wisconsin. The Ramapough Lenape Nation, Powhatan Renape Nation, and the Nanticoke Lenni-Lenape still live in the region and are recognized by the State. Groups such as the New Jersey Sand Hill Band of Indians also claim Lenape descent.

Understanding the age of an archaeological site can tell us a great deal about the people that lived there. So how old is the Holzmer site? To answer this question, we need to determine which prehistoric time period the site reflects. The collection consists only of artifacts that were removed from their archaeological context by the Delaware Bay, and they can no longer be dated by studying the soil layers they were originally deposited in (artifacts in the deepest layers are the oldest, with each level closer to the surface representing a more recent archaeological deposit). Without any soil context or associated organic remains for carbon dating, these artifacts can only be dated through the examination of their shape and comparing them to established artifact typologies with known date ranges. This is a common method used by archaeologists. By defining certain types of artifacts, mainly projectile points and pottery styles, archaeologists can more easily compare artifacts between different sites for dating purposes or the analysis of cultural features. For example, this is a projectile point found by Mr. Holzmer:

Rossville Point. NJSM# AE2016.4.276.

Without any context, it would be difficult to date this point. However, other archaeologists have found numerous points that are shaped the same way. This particular type is called a Rossville point. Named after a neighborhood in Staten Island and commonly seen along the East Coast, Rossville points are recognized by their contracting stem, the bottom portion of the tool that tapers to a point.

rossville comparison
Left: Point from Holzmer collection, Right: Typical Rossville shape (after

Since numerous Rossville points have been found within datable contexts, we know that they are typically made and used during the Late Archaic period. By looking at all the artifacts with known types and date ranges, we can estimate dates for the Holzmer site. It should be noted that the Holzmer collection is still being processed, and many artifacts have not been identified or cataloged yet. Therefore, this is a preliminary analysis based on a sample of the site’s artifacts. However, most of the artifacts with identifiable and datable types are reflected here, so it can be considered a fair representation of the site’s age.

The following table outlines the currently identified and cataloged diagnostic artifacts in the Holzmer collection. Diagnostic artifacts are artifacts with associated types and date ranges.

Holzmer Point table

As demonstrated in the table above, the collection heavily represents a larger quantity and greater diversity of projectile points associated with the Late Archaic period. This would suggest that the height of this site’s occupation occurred during this time, possibly into the Early Woodland as well. Prominent in the collection is a significant quantity of Late Archaic points such as the Rossville and Bare Island points, pictured below:

Pictured top-left to bottom-right: NJSM#s AE2016.4.111, 109, 108, 97, 112, 105, 125, 95, 107, 106.

The Archaic period demonstrates Native American groups adapting to new, post-Pleistocene environments with diverse toolkits, exploiting the resource-rich environmental zones that appeared. The Late Archaic saw an increase in seasonal and permanent settlements, the introduction of soapstone bowls, and early agriculture. A few ceramics also start to appear as the Archaic transitions into the Woodland. The Holzmer collection represents the diversity of stone tools that Late Archaic peoples used, such as stone points, scrapers, drills, gravers, and even sherds of pottery. Although not mentioned in the table above, most of the lithics appear to be made from local stones, such as argillite, cherts, jaspers, and quartzites. The site was most likely a Late Archaic settlement that was able to adapt to its environment and make use of local materials rather than relying heavily on long distance trade, as exotic materials like copper are not represented. Due to the site’s location, it is probable that these people utilized river resources supplemented with terrestrial hunting. Resources like fish and freshwater mussels would have been consumed by the people of this settlement. Late Archaic peoples are also known to have used artifacts like net sinkers to aid fishing, and at least one has been identified in the collection. Archaic cultures are known to establish settlement patterns with procurement sites and base camps, where small settlements would lie on the periphery of a group’s territory and gather resources to send back to the central settlement. Sometimes Archaic settlements were seasonally occupied, where central base camps were typically occupied during the summer, while fall camps extended outward and spring camps were located on the coast. It is possible that the Holzmer site was a seasonally occupied procurement site that made use of the location’s access to ocean and inland resources. However, this is merely speculation; without a true archaeological excavation, it can be difficult to find data to support this besides the assortment of lithics. Post-holes from semi-permanent structures, charred plant and food remains, animal remains, pollen and soil samples, etc. are all missing pieces of information that might provide more context. Another potential for research is to analyze nearby prehistoric sites to try and map out larger settlement patterns; archaeologists do not only look at sites individually, but also as part of a larger network. Prehistoric people moved, communicated, and traded among multiple settlements just like we do today.

Collections like the Holzmer artifacts can be frustrating for archaeologists; they present us with a great deal of cultural material but with little context to help piece together information about the site. When writing about artifacts from the continental shelf, NJ archaeologists Charles Bello and Jack Cresson have said that “there is little we can do to piece the puzzle together again” (Bello and Cresson 1995:55). We can obtain as much information as we can from the artifacts themselves, however, without a true excavation that records archaeological context, the information stops there. It is possible to conduct archaeology out on the continental shelf, through the use of scientific diving techniques and underwater archaeology. However, locating the site offshore and excavating it underwater can be difficult. Future research should look at using underwater elevation datacalled bathymetry, to map the seafloor and predict possible prehistoric site locations based on identified features, such as depressions that may have once been riverbeds or terraces. Archaeologists can predict where prehistoric sites may be located by examining proximity to water sources, how flat an area is, etc. By studying the ocean floor, these features can be identified underwater and used to predict site locations. There are many factors that need to be considered; it is possible that the site is not directly offshore, and the artifacts washed up after being affected by waves, currents, tidal action, and other processes that could have carried the artifacts from elsewhere. This particular site is located on the bay side of Cape May, which means the artifacts could have also been affected by bay processes such as subtidal circulation, through which surface water and bottom water move in different directions around the Delaware Bay, affecting currents and carving channels into the bay floor.

Funding is also a major concern; most archaeological work done in New Jersey is part of cultural resource management, which protects archaeological sites when federally-funded construction and development threatens them. Cultural resource management is rarely done offshore, with the exceptions of wind farms and oil rig construction. This research would most likely have to be funded by a university or institution with an academic interest. Underwater archaeology is expensive and requires costly equipment and trained specialists.


Despite these setbacks, this type of work can yield useful information and may be worthwhile to conduct. Underwater environments are often anaerobic (lacking oxygen) which can result in better preservation of organic materials. The small organisms that consume organic material cannot survive in anaerobic environments. Underwater sites have yielded organic artifacts such as bone tools and plant food remains. For example, in 2009, the Tudsehage Submerged Settlements Project in Skaelskor, Denmark studied a similar site that had been submerged by rising sea levels, dating to around 7,500 to 8,500 years ago. After diving on the site, they had excavated a preserved wooden stake, cut firewood, and hazelnuts. All of these discoveries were made possible due to the great potential that underwater sites provide for artifact preservation. Pursuing research of prehistoric sites on the continental shelf may lead to discoveries that are not possible on land. If the Holzmer site’s physical location was discovered and excavated, it could lead to a greater understanding of our prehistoric past.

Adovasio, J. M. and C. Andrew Hemmings.
2012 Underwater Archaeological Excavation Techniques. NOAA Ocean Explorer (website). 

Bailey, Geoffrey N., and Nicolas C. Flemming.  

2008 Archaeology of the continental shelf: Marine resources, submerged landscapes and underwater archaeology.” Quaternary Science Reviews 27: 2153-165. 

Bello, Charles, and Jack Cresson.

1995 “A Fluted Point from Island Beach State Park.” Bulletin of the Archaeological Society of New Jersey 50: 53-55.

Cotter, Kelly-Jane.

2014 Boy finds 10,000-year-old artifact on LBI.Asbury Park Press. 

Cotter, Kelly-Jane.

2014 Girl finds prehistoric projectile point on beach.” Asbury Park Press. 

Kraft, Herbert C., and R. Alan Mounier.

1982 “The Archaic Period in New Jersey.” 

Larsen, Brandon (editor).

Rossville. Projectile Point Identification Guide. 

Meltzer, David.

2009 First Peoples in a New World. University of California Press, Los Angeles.

Merwin, Daria E.

2003 “The Potential for Submerged Prehistoric Archaeological Sites off Sandy Hook.” Bulletin of the Archaeological Society of New Jersey 57: 1-10. 

Pape, Edwin H., and Richard W. Garvine

1982 The subtidal circulation in Delaware Bay and adjacent shelf waters.” Journal of Geophysical Research 87(C10): 7955. 

Robinson, David S.

Archaeological Approaches to Identifying Submerged Cultural Landscapes and Ancient Native American Archaeological Sites in Southern New England. Electronic document.

Veit, Richard.

2012 “Setting the Stage: Archaeology and the Delaware Indians, a 12,000-Year Odyssey.” In New Jersey: A History of the Garden State, pp. 6-32. Rutgers University Press, New Brunswick.

Weiss, Cindy.
2009 Grad Student Finding Clues to Early History in Submerged SitesUConn Today. University of Connecticut, October 7.

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