Carboniferous Provenance Evolution In The Hugoton Embayment,midcontinent,USA And Implication On The Provenance Analysis In The Pearl River Mouth Basin,China

Late Mississippian to Pennsylvanian was a critical time interval with major changes in global tectonics,climate,glacier activities and eustacy.Hugoton Embayment located in the southwestern Kansas in center of the US.developed two sandstone systems in the late Mississippian and early Pennsylvanian respectively under the environment of shallow-water shelf with dominate carbonate deposition in Carboniferous.The development of the two systems are coeval with the culmination of Appalachian orogeny in the east margin of Laurentia and the Ancestral Rocky Mountains deformation in the midwestern Laurentia.Due to the spatial and temporal feature,the two systems play an important role in both understanding the influences of the two mentioned regional tectonic events on the sedimentation of the interior of Laurentia craton and testing the transcontinental sediment dispersal pattern proposed by Gehrels et al.,(2011).Study based on 3-D seismic,wireline log and core data suggests obvious difference between the late Mississippian Chester and Early Pennsylvanian Morrow system.The Chester incised valley filling system shows decreasing fluvial and increasing marine and tidal influences from north to south which is interpreted as a tide-dominated estuary.The Morrow system is characterized by earlier fluvial and later extensive deposition by marine transgression.Both Chester and Morrow systems underwent substantial uplift and erosion resulted in preservation as residual and isolated sedimentary bodies with provenance difficult to determine.Systematic sampling and detrital zircon U-Pb dating has been conducted to the sand-rich core intervals from the boreholes which drilled with Chester and Morrow system which shows crucial variation on age distribution of them.The Chester system is characterized by bimodal pattern with peaks corresponding to Greenville(900-1300Ma)and Tocnic-Acadia orogenies(500-350Ma)while Morrow system shows two other major age clusters corresponding to Yavapai-Mazatzal Province(1600-1800Ma)and Midcontinent Granite-Rhyolite Province,(1300-1550Ma)Based on the understanding of the main age provinces in central North America that may have provided sediment for Carboniferous strata of the Hugoton Embayment and the characterization of the Appalachian orogen using proxy of Paleozoic strata from its foreland basin,the comparative result suggests the source area of the Chester system point to Appalachian orogen.The absence or rareness of grains with Archean ages which make up a major peak in most of the early Paleozoic sandstones precludes the possibility that the sandstones as the major sources for the Chester system.We also compiled the Paleozoic data from Illinois Basin and conducted new analysis for the coeval strata deposited in the Arkoma Shelf which might located in the dispersal pathway.The results shows similar bimodal pattern change started from Mississippian in the two areas supports the Chester system in the Hugoton Embayment is part of the transcontinental sediment dispersal pattern.Comparison between both Chester and Morrow system,and Hugoton and Grand Canyon shows the significant role of the Ancestral Rocky Mountains deformation in the early Pennsylvanian.Double dating of the zircon grains with Y-M and G-R provenance ages shows the timing of deformation is close to the boundary of Mississippian and Pennsylvanian at about 326 Ma.Based on the geo-thermochronology of the two sandstone systems and geological background,we build the Carboniferous provenance system and evolution and relationship with the regional tectonic evolution in the midcontinent represented by the Hugoton Embayment.The Late Mississippian is characterized by flat and broad shelf,detritus produced by the Allegheny orogeny caused by collision of Laurentia and Gondwana in the east margin were transported by transcontinental river systems from east to west and filled the incised valley system in the Embayment.Till Early Pennsylvanian,the deformation of the Ancestral Rocky Mountains blocked the sediment dispersal from the east and provide significant material from the basement uplifts.The provenance system provide a new method for stratigraphic correlation and has been tested in the Kinsler and Lexington field.The study in the Hugoton Embayment shed important light on the provenance analysis in offshore basin of China.Take Pearl River Mouth basin as an example,enlighten by the idea of characterizing the age distribution of Appalachian orogeny through proxy of the strata in its foreland basin,we compile published detrital zircon U-Pb ages from major rivers across the Cathaysia Block,to better understand spatial differences in sediment source regions in southeastern China and suggest the sediments of late Oligocene Zhuhai Formation and Enping Formation in the northern part of the basin is similar to the northeastern Pearl River,narrowing this region as the source;Enlighten by the idea of provenance analysis though both spatial and temporal comparison of Pennsylvania system,we shows the major provenance of the intrabasinal basement uplift to Wenchang and southern Enping samples through temporal comparison of Wenchang to Zhuhai Formation and spatial comparison between CB and Pearl River Mouth basin basement and suggest a 110-125 Ma age-group diagnostic of intrabasinal sediment sources.