Editing Shadow marks (section)

== Description ==
[[File:SIX_88DB623E-A768-403D-BDF0-1250EBC6DFCC.jpg|thumb|The formation mechanism of shadow marks demonstrates that the appearance of shadows on the ground is closely related to the angle of the sun.]]
Shadow marks are surface-visible patterns that emerge due to minor variations in terrain elevation when sunlight strikes at a low angle.<ref name=":0" /> These differences in elevation cast elongated shadows, allowing subtle [[Topography|topographic]] irregularities—such as ancient walls, [[Ditch|ditches]], or mounds—to be visualized from above.<ref name=":5" /> Unlike [[Cropmark|crop marks]], which result from vegetation stress, or [[Soil mark|soil marks]], which emerge from changes in soil texture or color, shadow marks rely primarily on physical relief and light geometry.<ref name=":3" /><ref name=":0" /> As such, they serve as a valuable indicator of buried or eroded archaeological features that are not detectable at ground level.<ref name=":0" />

The visibility of shadow marks is highly sensitive to lighting conditions.<ref name=":0" /> Early morning and late afternoon are ideal times for observation, as the sun is low on the horizon and shadows are longer, enhancing the contrast between elevations.<ref name=":0" /> Even slight undulations in terrain can become apparent under such lighting, particularly in winter months when vegetation is sparse and light angles are optimal.<ref name=":0" /> Archaeologists frequently capture [[Aerial photography|aerial photographs]] during these times to take advantage of the enhanced shadow definition. In flat landscapes, where surface features are often minimal, the interplay between light and surface texture can exaggerate minor topographic variations, making shadow marks particularly effective.<ref name=":1" />

However, the clarity of shadow marks can be influenced by various surface conditions.<ref name=":2" /> [[Vegetation]] cover, ploughed fields, [[soil moisture]], and cloud shadows all affect how light interacts with the ground and, consequently, the visibility of these marks.<ref name=":2" /><ref name=":8" /><ref name=":1" /> For this reason, shadow mark detection often requires repeated aerial surveys under differing environmental and seasonal conditions. In lowland or arid zones, temporary surface features or infrastructure may complicate interpretation, requiring careful visual analysis.<ref name=":2" />

Despite their sensitivity to environmental factors, shadow marks remain a crucial tool for [[archaeological prospection]]. Their topographic basis complements other remote sensing techniques, enabling the detection of features that may not produce biological or chemical contrasts.<ref name=":1" /> When integrated with additional methods, shadow marks help form a composite view of subsurface landscapes and have proven especially useful in revealing long-buried cultural features and terrain modifications.<ref name=":0" />