Abstract Seneca sandstone is a fine-grained arkosic sandstone of dark-red coloration used primarily during the nineteenth century in Washington, DC. Several inactive Seneca sandstone quarries are located along the Potomac River 34 km NW of Washington near Poolesville, Maryland. Seneca sandstone is from part of the Poolesville Member of the Upper Triassic Manassas Formation, which is in turn a Member of the Newark Supergroup that crops out in eastern North America. Its first major public use is associated with George Washington, the first president of the Potomac Company founded in 1785 to improve the navigability of the Potomac River, with the goal of opening transportation to the west for shipping. The subsequent Chesapeake and Ohio Canal built parallel to the river made major use of Seneca sandstone in its construction and then facilitated the stone's transport to the capital for the construction industry. The most significant building for which the stone was used is the Smithsonian Institution Building or ‘Castle’ (1847–55), the first building of the Smithsonian Institution and still its administrative centre. Many churches, school buildings and homes in the city were built wholly or partially with the stone during the ‘brown decades’ of the latter half of the nineteenth century.

We present evidence of surface faulting of a poorly known first-century B.C. aqueduct in central-southern Italy. Data were acquired by means of geological, geophysical, and geodetical surveys along the surficial trace of a primary active fault (Aquae Iuliae fault). The ~30-km-long Venafrum aqueduct presents a net vertical offset of almost 4 m at the intersection with this normal fault. This fact reveals the occurrence of repeated faulting of the Roman water supply after its construction, i.e., during large historical earthquakes, the last being one of the most violent events to happen in Italy during the Middle Ages (September 1349, Mw = 6.6). We tentatively associate the remaining offset of the aqueduct to other poorly characterized earthquakes in the area, which were not previously associated with any active fault. It is a well-known fact that the recognition of ancient earthquakes on archaeological relics is a matter of debate in archaeoseismology, being difficult at all times—and often impossible—to ascertain whether the damage observed should be related to seismic shaking or other causes (i.e., wars, floods, fires, decadence, etc.). Conversely, the exceptional case represented by the faulting of an archaeological relic such as this provides certain and reliable data on the causative seismogenic source and the associated earthquakes.

Abstract The early years of the century mark a period of great activity and growth in this country, with the City of New York sharing in the building boom which required the construction of highways, subways, aqueducts, and many other utilities on a large scale. I t was at that time, almost immediately after joining the geological staff at Columbia, that Doctor Berkey became identified with this work, and his many reports are famous advisory documents, particularly in connection with tunnels used for aqueducts, transport, and other purposes. His knowledge of geologic principles, facility in critical observation, hard common sense, and ability to state a case in useful, practical and simple terms have all contributed to a unique reputation.