{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Daniel R. Muhs", "hasEmail": "mailto:dmuhs@usgs.gov"}, "description": "Emergent marine terraces record past periods of relatively high sea level and are common on uplifting coasts worldwide. Such landforms are extensive around the Gulf of Corinth area of Greece and along the coast of California, USA. In the Gulf of Corinth region, marine terraces record Quaternary uplift due to ongoing basin extension on the northern side of the Africa-Eurasia-Aegean Sea plate boundary. Although dating of terrace fossils has been extensive in the Perachora Peninsula part of this region, some apparent ages are much older (\u223c190 ka to \u223c150 ka) and some are much younger (\u223c91 ka to \u223c69 ka) than expected for a marine terrace that has long been hypothesized to be of last interglacial (\u223c120 ka) age. New uranium-series analyses of terrace corals from these two localities show that these corals have behaved as open systems, with back-calculated, initial 234U/238U values higher than those found in modern seawater. New and previously published U-series analyses of last-interglacial corals from San Nicolas Island, California (USA) illustrate the possible mechanisms of open-system behavior, which include both \u201cearly\u201d alpha-recoil-derived additions of 230Th and 234U, and \u201ccontinuing\u201d alpha-recoil-derived additions of these nuclides. Many corals from the Perachora Peninsula appear to have experienced the \u201ccontinuing\u201d alpha-recoil-derived open system history, which explains the apparent older ages, and permits an interpretation that all analyzed corals likely date to the last interglacial period, \u223c120 ka. If the estimated age of \u223c120 ka reported here is correct, this age, along with considerations of glacial isostatic adjustment (GIA) modeling of past sea level, indicates that the southern side of the Perachora Peninsula has experienced uplift rates ranging from \u223c0.23 m/kyr to \u223c0.57 m/kyr, increasing to the southeast, in agreement with previous work. Interpretation of the geomorphology of the northern side of the peninsula has been controversial for more than four decades. The \u201cstepped\u201d topography has been interpreted as either a series of successively higher and older marine terraces, or a marine terrace of one age that has been displaced by a series of shore-parallel, northward-dipping normal faults. Interpretation of the open-system U-series ages indicates that marine deposits at elevations of \u223c22 m and \u223c44 m both likely date to \u223c120 ka, supporting the scenario that steps in the landscape are likely fault scarps, not sea cliffs. Using the new U-series ages of \u223c120 ka, along with GIA-modeled paleo-sea level confirms another previous study that uplift rates on the northern side of the peninsula are at least as high as 0.39\u20130.46 m/kyr.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P1XTGUTQ", "description": "Landing page for access to the data", "format": "XML", "mediaType": "application/http", "title": "Digital Data"}, {"@type": "dcat:Distribution", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.689f9c6ad4be026c25c9d735.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_689f9c6ad4be026c25c9d735", "keyword": ["California", "Greece", "Perachora Peninsula", "Pleistocene", "Quaternary", "San Nicolas Island", "U-series dating", "USGS:689f9c6ad4be026c25c9d735", "faulting", "last interglacial", "marine terraces", "sea level", "tectonic uplift"], "modified": "2025-12-08T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-119.572569, 33.221298, 22.886111, 38.15", "theme": ["geospatial"], "title": "Uranium-series geochemistry and geochronology of marine terrace corals, Perachora Peninsula, Greece and San Nicolas Island, California, USA"}