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We present a time series of coastline change for the Irrawaddy delta region of Myanmar using the earliest available navigation chart from 1850, and a set of topographic maps and satellite imagery dating from 1913 to 2006. Despite the large sediment load delivered annually to the gulf by the Irrawaddy and Salween Rivers, the coastline has been largely stable for 156 years, advancing at an average rate of no more than 0.34 km per century since 1925. The long-term average rate of increase in land area across the study area between 1925 and 2006 is 4.2 k[m.sup.2]/year, but this masks a period of more rapid accumulation between 1925 and 1989 (8.7 k[m.sup.2]/year), followed by a period of net erosion at a rate of 13 k[m.sup.2]/year until 2006. Less than 9% of the sediment load delivered to the study region by the Irrawaddy, Salween and Sittoung Rivers has contributed to the observed progradation, with the remainder being exported into the Gulf of Martaban to depths below low tide level, or filling any accommodation space created due to subsidence or sea level rise. In contrast to many deltas worldwide, we suggest that the coastline encompassing the Irrawaddy delta and the Salween River is more or less in equilibrium, and that sediment deposition currently balances subsidence and sea level rise. Myanmar has fewer large dams relative to its Asian neighbours, and the Salween is currently undammed. This is forecast to change in the next 5-10 years with extensive damming projects on the mainstem of the Salween under consideration or construction, and the sediment retention will cause losses in sediment supply to the Gulf of Martaban, and retreat of the delta. This could impact the densely populated delta region and Yangon, and further exacerbate the impacts of extreme events such as Cyclone Nargis in 2008. KEY WORD: Burma, Irrawaddy delta, Salween, sediment flux, coastal sedimentation

A seismic stratigraphic analysis of Miocene deposits in the Baltimore Canyon region (offshore New Jersey) reveals tremendous three-dimensional complexity and challenges traditional approaches to sequence stratigraphic interpretation. Individual sequences vary dramatically in along-strike thickness, revealing the locations of the sediment sources. Within sequences, the low-stand wedge thins dramatically along strike (tens to hundreds of meters) and is interpreted to record variable paleobathymetry along strike. As indicated by sequence thickness distributions, shelf break positions, lithologic composition, and stratigraphic relationships, sequences record sediment migration and progradation across the basin through time. As a result of these depositional complexities, relative sea-level curves, interpreted from parallel dip lines, vary in magnitude and amplitude across the basin. Development of Neogene stratal patterns within the Baltimore Canyon region has been closely linked to glacioeustatic change. Our reconstructions of delta switching and progradation emphasize that Miocene stratal patterns were greatly influenced by autocyclic depositional processes.

The Carboniferous Pottsville Formation of eastern Pennsylvania in the central Appalachian foreland basin is considered a classic orogenic molasse, typical of other Acadian-Alleghanian clastic wedges along the eastern margin of Laurentia. Although the Pottsville conglomerates are thought to be derived entirely from early Alleghanian highlands, we have documented an unrecognized dramatic change in the sediment-dispersal pattern within the formation; northwest-directed paleocurrent indicators in older units (implying an orogenic provenance) are superseded abruptly by southwestward-directed paleocurrent indicators (implying a cratonal provenance). This alteration in the sediment-dispersal pattern is attributed to basin reorganization during Early Pennsylvanian time as tectonic loads migrated southward during orogenesis. The paleocurrent data warrant a revision of Early Pennsylvanian paleogeography and demonstrate that molasse facies can record a complex interplay between sediment dispersal systems along both active and cratonal margins of a foreland basin.

Examines the Carboniferous Pottsville Formation of eastern Pennsylvania. Carboniferous Pottsville Formation as a classic orogenic molasse; Derivation of the Pottsville conglomerates from early Alleghanian highlands; Basin reorganization during the Early Pennsylvanian time as tectonic loads migrated southward during orogenesis.