Dating Game: How Archaeologists Date the Biblical Past

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Since its inception, biblical archaeology has been especially concerned with dating the sites, buildings, artifacts, and written records uncovered through excavation. In many cases, assigning dates to material remains has been essential for associating them with particular events, peoples, and places mentioned in the Bible.

Accordingly, archaeologists have developed a range of methods and techniques to pinpoint when in time these remains were created, used, or destroyed. Not surprisingly, however, none of these methods is perfect, which means scholars are ever debating chronological issues and working to develop more precise dating methods.

The chronology of the Iron Age (c. 1200–586 BCE) in particular has attracted much scholarly attention and debate, because this period is most closely associated with the biblical text and its historical interpretation. The debate focuses mainly on the tenth and ninth centuries, with archaeologists generally supporting either the more traditional “high” chronology, which dates specific pottery types and monumental architecture to the time of David and Solomon in the tenth century, or the “low” chronology, which dates these same remains to the ninth century. Beyond this much-debated issue, there is also uncertainty in securely dating some archaeological remains from the eighth to the fifth centuries. In particular, radiocarbon dating for this period usually produces date ranges spanning several centuries, making it nearly impossible to date archaeological remains with any precision.

Here, I briefly review the uses (and limitations) of several dating methods, including my own specialty, archaeomagnetism, which I believe can significantly improve our understanding of Iron Age chronology.

Material culture typologies—especially of pottery found in multilayer stratified sites—allow archaeologists to establish a relative chronology of archaeological remains based on their specific forms, manufacturing techniques, and decorative styles that varied over time. Such typologies categorize pottery according to its relative age, with the youngest types of pottery found in the uppermost deposition layer, and progressively older types deposited further below the surface as excavations go deeper (see “Arch Argot: Seriation”). Many years of typological research and the comparison of pottery typologies from multiple sites have produced a high-resolution sequence of relative dates—extending from prehistory to the modern era—that is widely accepted by most archaeologists working in the southern Levant today.

Traditionally, correlating this relative dating to absolute dates has been based on connecting archaeological finds with historical information. For instance, the early Israeli archaeologist Yigael Yadin dated the Iron Age gates at Hazor, Megiddo, and Gezer to the time of Solomon based on the biblical verse that attributes the fortification of these cities to Solomon (1 Kings 9:15). Therefore, the pottery found around these gates was traditionally dated to the tenth century. As BAR readers know, however, Yadin’s hypothesis was challenged in the 1990s by Israel Finkelstein, who argued, initially also using ceramic typologies and biblical evidence (e.g., 1 Kings 21), that the archaeological contexts traditionally associated with Solomon should instead be dated to the ninth century, the time of kings Omri and Ahab of Israel.^a

ASOR PHOTO COLLECTION, PHOTO BY ILAN STULMAN

About two decades ago, the Iron Age chronology debate transformed dramatically with the increased application of radiocarbon dating to biblical archaeology. The growing use of this method has indeed improved our understanding of the absolute chronology of the period. However, this method has not yet resolved the debate, because it is contingent upon specific types of materials, namely short-lived organic remains, such as seeds, which may not always be available for analysis. Furthermore, radiocarbon analysis provides date ranges—typically on the order of several decades—that are often too large to draw historical conclusions about specific periods or events. Statistical models can help narrow these ranges, but often require the archaeologist to impose subjective considerations or limits on the data that may not be justified, leading to biased or problematic dating.

In recent years, archaeo­magnet­ism has emerged as a complementary tool to allow for a more comprehensive and reliable dating framework that enhances chronological precision. This technique measures the earth’s magnetic field as imprinted in burnt materials, such as mudbricks, hearths, and pottery, which are often abundant at archaeological sites. It takes advantage of the fact that after these materials are heated, they capture the direction and intensity of the magnetic field while they cool, effectively “locking in” a snapshot of the earth’s magnetic environment.^b This phenomenon, known as thermoremanent magnetization, enables scientists to retrieve valuable information about the past orientation and intensity of the magnetic field.

With these tools, we can determine if materials were burned and reconstruct their firing temperatures, even at relatively low temperatures starting from 200 degrees Celsius (392 degrees Fahrenheit). These tools can also determine if the burnt materials cooled in the same orientation in which archaeologists found them. This information is crucial for identifying site formation processes. For instance, burnt mudbricks in the archaeological record can be the result of their pre-firing in a kiln (prior to their use as construction material) or their firing during a destructive conflagration.

SHAI HALEVI / ISRAEL ANTIQUITIES AUTHORITY

In the City of David excavations in Jerusalem, for example, archaeomagnetic analysis shed light on a significant incident during which a monumental structure was burned and ultimately collapsed.¹ Similarly, at Tell es-Safi (Gath of the Philistines), our findings revealed that, contrary to earlier suggestions, a structure was built of sundried rather than pre-fired mudbricks that were burned only during the building’s fiery destruction.² This observation strengthens the theory that in the Levant mudbricks were not pre-fired as part of the manufacturing process during the Iron Age, a practice that likely began only during the first century BCE or later.

The magnetic data recovered from Jerusalem and Gath were used as chronological anchors for archaeomagnetic dating across much of Israel. The Jerusalem destruction layer was dated historically and archaeologically to the Babylonian destruction of 586 BCE. The destruction layer at Gath was the result of the city’s conquest by King Hazael of Aram-Damascus, mentioned in the Bible (2 Kings 12:18). This event is dated by radiocarbon and historical sources to approximately 830 BCE. Together with other chronological anchors, such as the destruction of Lachish by the Assyrian king Sennacherib in 701 BCE, the magnetic data from Jerusalem and Gath were used to create a high-precision model of the ever-changing magnetic field in the Levant.³

OLAF TAUSCH, CC BY 3.0, VIA WIKIMEDIA COMMONS

This model is now being used to date destruction layers and artifacts whose dating has been debated. Specifically, it has been shown that the destruction of Beth Shean, previously assumed to be associated with Hazael and thus dated to around 830, took place earlier, either at the end of the tenth century or at the beginning of the ninth. According to magnetic dating, this destruction likely occurred around the same time that the apiary in nearby Tel Rehov was destroyed. In the Temple of Amun at Karnak, Rehov and Beth Shean are mentioned side by side in the list of cities conquered by Pharaoh Shoshenq I (biblical Shishak) in the late tenth century. The archaeomagnetic dating of these two destruction layers could match the date of Shoshenq’s campaign, which is also mentioned in the Bible (1 Kings 14:25–26).

Each of the dating methods discussed above has its advantages and limitations. Ceramic typology is well established and enables high-resolution relative chronology. However, since changes in pottery do not occur overnight and often take place over several decades, typological methods are often unable to pinpoint periods of cultural or political transition. Furthermore, pottery styles are closely linked to specific peoples and cultures and therefore do not enable synchronization of chronologies across large areas.

Radiocarbon analysis remains the major tool for absolute dating of the early part of the Iron Age (c. 1200–800 BCE), but can be complemented by archaeomagnetic dating which can narrow its date ranges. For the eighth to the fifth centuries, archaeomagnetic dating is unique in its ability to provide high-resolution absolute dates. It can also be used to date strata where no organic remains were preserved or recorded (as was the case in many earlier excavations where only pottery was kept). Finally, unlike ceramic typology, archaeomagnetism can be used to synchronize finds unearthed hundreds of miles apart, since the magnetic field is typically uniform across large areas and regions.

Despite more than two decades of intensive radiocarbon studies, the Iron Age chronology debate has not been resolved. Instead, proponents of both the high and low chronologies rely on their own radiocarbon results and statistical models to support their respective views. In my view, only the combination of radiocarbon and archaeomagnetic dating methods applied to large chronological data sets can resolve this debate, creating a firmer and more accurate chronological framework for biblical archaeology.