Concentrations of the trace metals Cu, Cd, Pb, and Zn were measured in seawater, rhizosphere sediments, interstitial water, and the tissues of three tropical species of seagrasses （Thalassia hemprichii, Enhalus acoro...Concentrations of the trace metals Cu, Cd, Pb, and Zn were measured in seawater, rhizosphere sediments, interstitial water, and the tissues of three tropical species of seagrasses （Thalassia hemprichii, Enhalus acoroides and Cymodocea rotundata） from Xincun Bay of Hainan Island, South China. We analyzed different environmental compartments and the highest concentrations of Pb and Zn were found in the interstitial and seawater. The concentrations of Cd and Zn were significantly higher in blades compared with roots or rhizomes in 7＂. hemprichii and E. acoroides, respectively. A metal pollution index （MPI） demonstrated that sediment, interstitial water, and seagrasses in the sites located nearest anthropogenic sources of pollution had the most abundant metal concentrations. There was obvious seasonal variation of these metals in the three seagrasses with higher concentrations of Cu, Pb and Zn in January and Cd in July. Furthermore, the relationships between metal concentrations in seagrasses and environmental compartments were positively correlated significantly. The bioconcentration factors （BCF） demonstrated that Cd from the tissues of the three seagrasses might be absorbed from the sediment by the roots. However, for C. rotundata, Zn is likely to be derived from the seawater through its blades. Therefore, the blades of T. hemprichii, E. acoroides and C. rotundata are potential bio-indicators to Cd content in sediment, and additionally Zn content （C. rotundata only） in seawater.展开更多
Modern palms are diverse and widespread in the tropics and subtropics,especially the tropical rainforests.However,most fossil palm records have been reported from regions of relatively higher latitude.In this paper se...Modern palms are diverse and widespread in the tropics and subtropics,especially the tropical rainforests.However,most fossil palm records have been reported from regions of relatively higher latitude.In this paper seven species of coryphoid palm from the Eocene Changchang Basin of Hainan Island of South China are reported.These are Sabalites asymmetricus sp.nov.,S.robustus sp.nov.,S.tenufolius sp.nov.,S.szei Guo,S.changchagnensis Guo,Livistona sp.,and Amesoneuron sp.According to leaf morphological characteristics,they can be classified as members of the subfamily Coryphoideae.In extant flora of Hainan Island,only three species of Livistona have costapalmate leaves.These palm fossils indicate that,during the Eocene,flora in Hainan Island included a diversity of coryphoid palms,which have some bearings on the reconstruction of the palaeoclimate of South China.展开更多
On the basis of new paleontological data,the sequence and distributions of the Middle Devonian-Tournaisian rocks on Hainan Island have been sorted out for the first time.The Devonian rocks include the Middle Devonian ...On the basis of new paleontological data,the sequence and distributions of the Middle Devonian-Tournaisian rocks on Hainan Island have been sorted out for the first time.The Devonian rocks include the Middle Devonian Jinbo Formation and the Upper Devonian Changjiang Formation,which are distributed in northwestern Hainan Island.The Jinbo Formation is represented by631 m of littoral facies deposits,and was intruded by the Yanshanian granite in the base.The presence of chitinozoans Eisenackitina caster,Funsochitina pilosa,and Lagenochitina amottensis indicates the Givetian in age.The Changjiang Formation is made up of 140 m of neritic facies rocks,and contains the Famennian conodonts Palmatolepis gracilis sigmoidalis,Polygnathus germanus,and corals Cystophrentis kalaohoensis.The Devonian-Tournaisian transition beds,the lower part of the Jishi Formation,are composed of 61–129 m sandstone and siltstone,with gastropods Euomphalus spp.and brachiopods,and marked by conglomerate with the underlying Devonian rocks.The middle-upper part of the Tournaisian Jishi Formation consists of 100–251 m clastic and carbonate rocks,containing abundant corals Pseudoularinia irregularis,conodonts Siphonodella isosticha,trilobites Weberiphillipsia linguiformis,and brachiopods.On the basis of the occurrence of Xinanosprifer flabellum and Homotoma sp.,the Nanhao Formation in southern Hainan Island is now regarded as the Lower Silurian,instead of the previously designated Lower Carboniferous.It is confirmed that no Carboniferous rocks occurred in the area south to the Gancheng-Wanning Fault.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.40776086,41076069)the Pilot Project of the Knowledge Innovation Program,South China Sea Institute of Oceanology,Chinese Academy of Sciences(No.LYQY200706)the Nationa l908 Special Project(No.GD908-02-08)
文摘Concentrations of the trace metals Cu, Cd, Pb, and Zn were measured in seawater, rhizosphere sediments, interstitial water, and the tissues of three tropical species of seagrasses （Thalassia hemprichii, Enhalus acoroides and Cymodocea rotundata） from Xincun Bay of Hainan Island, South China. We analyzed different environmental compartments and the highest concentrations of Pb and Zn were found in the interstitial and seawater. The concentrations of Cd and Zn were significantly higher in blades compared with roots or rhizomes in 7＂. hemprichii and E. acoroides, respectively. A metal pollution index （MPI） demonstrated that sediment, interstitial water, and seagrasses in the sites located nearest anthropogenic sources of pollution had the most abundant metal concentrations. There was obvious seasonal variation of these metals in the three seagrasses with higher concentrations of Cu, Pb and Zn in January and Cd in July. Furthermore, the relationships between metal concentrations in seagrasses and environmental compartments were positively correlated significantly. The bioconcentration factors （BCF） demonstrated that Cd from the tissues of the three seagrasses might be absorbed from the sediment by the roots. However, for C. rotundata, Zn is likely to be derived from the seawater through its blades. Therefore, the blades of T. hemprichii, E. acoroides and C. rotundata are potential bio-indicators to Cd content in sediment, and additionally Zn content （C. rotundata only） in seawater.
基金supported by National Natural Science Foundation of China(Grant Nos.41210001,31070200and40972011)National Basic Research Program of China(Grant No.2012CB822003)+2 种基金State Key Laboratory of Palaeobiology and Stratigraphy(Nanjing Institute of Geology and Palaeontology,CAS)(Grant No.123110)Fundamental Research Funds for the Central Universities(Grant No.12LGJC04)Key Project of Sun Yat-sen University for inviting foreign teachers and the Scientific Research Fund,Hongda Zhang,Sun Yat-sen University
文摘Modern palms are diverse and widespread in the tropics and subtropics,especially the tropical rainforests.However,most fossil palm records have been reported from regions of relatively higher latitude.In this paper seven species of coryphoid palm from the Eocene Changchang Basin of Hainan Island of South China are reported.These are Sabalites asymmetricus sp.nov.,S.robustus sp.nov.,S.tenufolius sp.nov.,S.szei Guo,S.changchagnensis Guo,Livistona sp.,and Amesoneuron sp.According to leaf morphological characteristics,they can be classified as members of the subfamily Coryphoideae.In extant flora of Hainan Island,only three species of Livistona have costapalmate leaves.These palm fossils indicate that,during the Eocene,flora in Hainan Island included a diversity of coryphoid palms,which have some bearings on the reconstruction of the palaeoclimate of South China.
基金supported by National Natural Science Foundation of China(Grant Nos.40772022,41172025)China Geological Survey Project(Grant Nos.1212011120116,1212011220517)
文摘On the basis of new paleontological data,the sequence and distributions of the Middle Devonian-Tournaisian rocks on Hainan Island have been sorted out for the first time.The Devonian rocks include the Middle Devonian Jinbo Formation and the Upper Devonian Changjiang Formation,which are distributed in northwestern Hainan Island.The Jinbo Formation is represented by631 m of littoral facies deposits,and was intruded by the Yanshanian granite in the base.The presence of chitinozoans Eisenackitina caster,Funsochitina pilosa,and Lagenochitina amottensis indicates the Givetian in age.The Changjiang Formation is made up of 140 m of neritic facies rocks,and contains the Famennian conodonts Palmatolepis gracilis sigmoidalis,Polygnathus germanus,and corals Cystophrentis kalaohoensis.The Devonian-Tournaisian transition beds,the lower part of the Jishi Formation,are composed of 61–129 m sandstone and siltstone,with gastropods Euomphalus spp.and brachiopods,and marked by conglomerate with the underlying Devonian rocks.The middle-upper part of the Tournaisian Jishi Formation consists of 100–251 m clastic and carbonate rocks,containing abundant corals Pseudoularinia irregularis,conodonts Siphonodella isosticha,trilobites Weberiphillipsia linguiformis,and brachiopods.On the basis of the occurrence of Xinanosprifer flabellum and Homotoma sp.,the Nanhao Formation in southern Hainan Island is now regarded as the Lower Silurian,instead of the previously designated Lower Carboniferous.It is confirmed that no Carboniferous rocks occurred in the area south to the Gancheng-Wanning Fault.
