The reefs in the Xiannüdong Formation(Cambrian Series 2) are the oldest archaeocyathan–microbial bioconstructions in China,but the details of their microbial structures have not been previously described.However...The reefs in the Xiannüdong Formation(Cambrian Series 2) are the oldest archaeocyathan–microbial bioconstructions in China,but the details of their microbial structures have not been previously described.However,a new section at Tangjiahe site,northern Sichuan Province,contains very well-preserved microbial fabrics that provide these details,and is described in this study.The Tangjiahe section contains three levels of reefal buildups that were constructed by a consortium of archaeocyaths and calcimicrobes in varying proportions.The lowest(oldest) reefal buildup is a calcimicrobial biostrome,possibly in the form of a wide mound with a low relief(unconfirmed due to outcrop limitation),which was formed by Epiphyton with rare small archaeocyaths,and is sandwiched by flat-pebble conglomerates.The middle reefal buildup is a high-relief calcimicrobial mound,enclosed by oolites,that was built by intergrown Renalcis and Tarthinia.Archaeocyath fossils are uncommon,and were bound into the framework by microbial carbonates.The uppermost(youngest) reefal buildup is a low-relief archaeocyathan mound lacking calcimicrobes but partly having microbially-clotted textures attached on archaeocyaths.Calcimicrobes built or aided archaeocyaths to form the framework of Tangjiahe reefs.The three buildups formed in low-energy lagoons behind ooid shoals,and the environment was nutrient-rich due to terrigenous influx from adjacent lands.Tangjiahe reefs thus resemble most Early Cambrian reefs,in settings consistent with eutrophic,calm environments,and are characterized by the domination or aid of calcimicrobial components in framework construction.展开更多
To the Editor:Clinically,it is not rare for patients with bilateral non-traumatic osteonecrosis of femoral head(NONFH)first presenting to an orthopedic surgeon with one hip that requires total hip arthroplasty(THA)and...To the Editor:Clinically,it is not rare for patients with bilateral non-traumatic osteonecrosis of femoral head(NONFH)first presenting to an orthopedic surgeon with one hip that requires total hip arthroplasty(THA)and another asymptomatic or less symptomatic one that potentially needs hip preservation surgery.展开更多
基金supported by National Natural Science Foundation of China(41602166)National Scientific and Technology Major Project(2016ZX05004002-001)+2 种基金PetroChina Innovation Fund(2018D-5007-0105)Scientific Research Starting Project of SWPU(2017QHZ005)Shandong Provincial Key Laboratory of Depositional Mineralization(DMsMzO1TO35)
文摘The reefs in the Xiannüdong Formation(Cambrian Series 2) are the oldest archaeocyathan–microbial bioconstructions in China,but the details of their microbial structures have not been previously described.However,a new section at Tangjiahe site,northern Sichuan Province,contains very well-preserved microbial fabrics that provide these details,and is described in this study.The Tangjiahe section contains three levels of reefal buildups that were constructed by a consortium of archaeocyaths and calcimicrobes in varying proportions.The lowest(oldest) reefal buildup is a calcimicrobial biostrome,possibly in the form of a wide mound with a low relief(unconfirmed due to outcrop limitation),which was formed by Epiphyton with rare small archaeocyaths,and is sandwiched by flat-pebble conglomerates.The middle reefal buildup is a high-relief calcimicrobial mound,enclosed by oolites,that was built by intergrown Renalcis and Tarthinia.Archaeocyath fossils are uncommon,and were bound into the framework by microbial carbonates.The uppermost(youngest) reefal buildup is a low-relief archaeocyathan mound lacking calcimicrobes but partly having microbially-clotted textures attached on archaeocyaths.Calcimicrobes built or aided archaeocyaths to form the framework of Tangjiahe reefs.The three buildups formed in low-energy lagoons behind ooid shoals,and the environment was nutrient-rich due to terrigenous influx from adjacent lands.Tangjiahe reefs thus resemble most Early Cambrian reefs,in settings consistent with eutrophic,calm environments,and are characterized by the domination or aid of calcimicrobial components in framework construction.
基金This work was supported by grants from the National Natural Science Foundation of China(No.81703896,81673776)the Capital Health Research and Development of Special(No.2016-2-4062)+1 种基金Beijing Municipal Science and Technology Commission(No.Z 171100001017209)National Key Research and Development Program of China(No.2017YFC0108102).
文摘To the Editor:Clinically,it is not rare for patients with bilateral non-traumatic osteonecrosis of femoral head(NONFH)first presenting to an orthopedic surgeon with one hip that requires total hip arthroplasty(THA)and another asymptomatic or less symptomatic one that potentially needs hip preservation surgery.