Investigator's Glossary

A technique of stone construction where visible surfaces are dressed to fit together like a jigsaw puzzle, often without mortar. Most famously associated with Inca architecture (Sacsayhuamán) and pre-Roman walls in Italy.

A period of rapid cooling in the late Pleistocene, 12,900 to 11,700 years ago. It marks a sudden return to glacial conditions and is central to theories regarding lost civilizations and the extinction of North American megafauna.

Light Detection and Ranging. A remote sensing method that uses light in the form of a pulsed laser to measure ranges to the Earth. It enables archaeologists to 'see' through dense jungle canopy to reveal hidden structures.

An old dump for domestic waste which may consist of animal bone, human excrement, botanical material, mollusc shells, sherds, lithics, and other artifacts associated with past human occupation.

An artifact of historical, archaeological, or paleontological interest found in a very unusual or seemingly impossible context that challenges conventional historical chronology.

A type of stonework found in Mycenaean architecture, built with massive limestone boulders, roughly fitted together with minimal clearance between stones and no use of mortar.

The slow, continuous change in the orientation of an astronomical body's rotational axis. The full cycle takes approximately 25,772 years, a period often encoded in ancient mythological numbers.

The process by which stone walls are fused together by intense heat, turning the rock into glass. Found in ancient hill forts in Scotland and elsewhere, the method of heating remains a subject of debate.

A relatively barren and soil-free landscape in eastern Washington, eroded by cataclysmic floods (the Missoula Floods) that swept across the region at the end of the last Ice Age.

A large stone that has been used to construct a structure or monument, either alone or together with other stones. Derived from the Ancient Greek 'megas' (great) and 'lithos' (stone).

A theoretical classification of materials (similar to concrete) proposed by Joseph Davidovits, suggesting that the blocks of the Great Pyramid of Giza were cast in place rather than quarried and moved.

An extinct species or subspecies of archaic human that ranged across Asia during the Lower and Middle Paleolithic. Their DNA suggests interbreeding with Homo Sapiens and significant technological capability.

Literally 'before the flood.' In alternative history, this refers to the era or civilizations existing prior to the major cataclysms of the Younger Dryas period.

Distinctive concave depressions found on granite obelisks and walls (e.g., Aswan Quarry), suggesting a method of stone removal that defies the conventional explanation of pounding with dolerite balls.

A type of single-chamber megalithic tomb, usually consisting of two or more vertical megaliths supporting a large flat horizontal capstone or 'table'.

A branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks.

Evidence of ancient machining where a hollow drill was used to cut through hard stone like granite, leaving a central core. The feed rates implied by the striations often rival modern diamond drills.

The now-challenged theory that the Clovis culture were the first inhabitants of the Americas, arriving via the Bering Land Bridge approximately 13,000 years ago.

The study of how people in the past understood the phenomena in the sky, how they used these phenomena in their cultures, and what role the sky played in their architecture.

Small, knob-like protrusions often left on the face of polygonal stone blocks. Their purpose is debated, ranging from lifting aids to celestial representations or acoustic functions.

Precision-cut andesite blocks found at Puma Punku in Bolivia. Their complex geometric shape and identical dimensions suggest a form of mass production or pre-fabrication.

A period of rapid sea-level rise that occurred between 11,500 and 11,200 years ago, coinciding with the end of the Younger Dryas and potentially submerging coastal civilizations.

A type of very dark, fertile anthropogenic soil found in the Amazon Basin, evidence of a large, settled agrarian civilization in a region previously thought incapable of supporting one.

A Neolithic archaeological site in Turkey dating to c. 9500 BCE. Its massive T-shaped pillars predate the invention of pottery and agriculture, challenging the timeline of civilization.

A stone pillar, typically having a square or rectangular cross section and a pyramidal top, set up as a monument or landmark. Moving the largest examples (1000+ tons) remains an engineering mystery.

A sacred stone that was supposedly endowed with life, or gave access to a deity. Meteorites were often venerated as baetyli in the ancient world.

A method for determining the age of an object containing organic material. It is limited in that it cannot date stone directly, only organic matter found in or near the stone.

A layer of carbon-rich soil found across North America dating to the onset of the Younger Dryas. It contains nanodiamonds and iridium, suggesting an extraterrestrial impact event.

An underground temple or tomb. The Hypogeum of Ħal Saflieni in Malta is famous for its acoustic properties, where sounds made in certain rooms resonate at 110Hz.

A clamp shape (often hourglass or T-shaped) cut into two adjoining stones. Metal clamps were poured into these cuts to hold the stones together during earthquakes.

A construction technique where stones are fitted and stacked without mortar or binding agents. The stability relies on precise shaping, weight distribution, and friction between stones. Found in cultures worldwide from ancient walls to modern stone fences.

A dating method that measures when quartz or feldspar grains were last exposed to sunlight. As sediment is buried, radiation accumulates in mineral grains. By measuring this stored energy, researchers can determine burial age.

Natural fractures in rock that form at right angles to each other, creating a three-dimensional grid pattern. Common in cooling igneous rock (like granite) where thermal contraction causes the rock to crack along perpendicular planes.

A weathering process where rock breaks off in sheets or slabs parallel to the surface. Caused by pressure release as overlying material erodes away. Creates the appearance of stacked layers that can resemble constructed masonry.

A natural rock formation created by differential weathering and erosion. Underground water and chemistry rot softer rock into sand while leaving harder core stones intact. Later erosion exposes these blocks, sometimes stacked in ways that appear intentional.

Fragmented material produced by a volcanic eruption, including ash, cinders, pumice, and volcanic bombs. Tephra layers are useful for dating archaeological sites because volcanic eruptions occur at specific moments in time, creating time markers in the geological record.

An extinct genus of large camel that lived in North America during the Pleistocene epoch. Camelops hesternus stood about 7 feet tall at the shoulder and roamed the western United States until approximately 10,000 years ago, disappearing during the late Pleistocene megafaunal extinction.

A complex, pre-Columbian Native American civilization that flourished across the American Midwest and Northeast from approximately 100 BC to AD 400. They are known for constructing massive, precise geometric earthworks and maintaining an extensive trade network known as the Hopewell Interaction Sphere.