摘要:At 08:02 on April 20, 2013, a Ms7.0 earthquake occurred in Lushan, Ya’an, in the Longmenshan fault zone, Sichuan. The epicenter was located between Taiping Town and Shuangshi Town, Lushan County and the maximum earthquake intensity at the epicenter reached class IX. Field investigations in the epicenter area found that, although buildings were seriously damaged, no obvious surface rupture structure was produced, only some ground fissures and sand blows and water ejection phenomena being seen. An integrated analysis of high-resolution remote sensing image interpretation, mainshock and aftershock distribution, and focal mechanism solutions indicated that this earthquake was an independent rupturing event in the southwestern segment of the Longmenshan fault zone, belonging to the thrust-type earthquake. Ruptures occurred along the south-central segment of the Shuangshi-Dachuan fault and the principal rupture plane dipped SW at 33–43°. It is inferred that the Lushan earthquake might be related to the ramp activity of the basal detachment zone (13–19 km) of the Longmenshan fault zone. Historically, there occurred at least two Ms6-6.5 earthquakes along the Shuangshi-Dachuan fault zone; thus it is thought that the Lushan earthquake, different from the Wenchuan earthquake, was a characteristic one in the southwestern segment of the Longmenshan fault zone. In-situ stress measurements indicated the Lushan earthquake was the result of stress release of the southwestern segment of the Longmenshan fault zone after the Wenchuan earthquake. This paper analyzes the tectonic setting of the seismogenic structure of this earthquake.

摘要:Geohazards induced by the Lushan Ms 7.0 earthquake on April 20, 2013 mainly have four types: collapse, landslide, slope debris flow, and sand-soil liquefaction. These geohazards mainly occurred near the epicenter, on steep slopes or below cliffs in high mountain and deep valley areas, and at or near fault ends. They have no obvious relationships to active faults, but their relationships to the weathering degree and structures of rock and rock mass are obvious. Compared with the Wenchuan Ms 8.0 earthquake on May 12, 2008, the Lushan earthquake is relatively little in the impact force and the throwing amount. All of these should be related to the magnitude of this earthquake, not very large but not very little. This character of the Lushan earthquake would make some processes uncompleted so as to bring about some concealed geohazards. Finally, in order to deal with challenges presented by such conceal geohazards, some brief recommendations are put forward.

摘要:Dongyangopelta yangyanensis gen. et sp. nov. from the Chaochuan Formation (Albian - Cenomanian) of Dongyang, Zhejiang Province, China is characterized: the convex anterior surface of the first presacral rod centrum strongly inflates laterally and slightly curves posteriorly; the fused pelvic shield composes of larger pebble-shaped bosses, defined by smaller tubercles or flat stretches of bone; most osteoderms are heavily roughened with notches and grooves for dermal attachment along the edge; domed triradiate osteoderm is present; sigmoid curvature of the dorsal surface of the ilium is present; the preacetabular process curves lateroventrally at the anterior end and has a shallow groove in the edge of the lateral and anterior ends and strong lateromedial expansion of the distal femur. The femoral head is well separated from the greater trochanter, indicating that Dongyangopelta is a nodosaurid ankylosaur, the second from southeast China. Phylogenetic analysis also positions this taxon in the Nodosauridae clade. Dongyangopelta differs from Zhejiangosaurus in the characters of presacral rod, ilium, and femur. Dongyangopelta represents the first ankylosaur outside North America and Europe that definitively possesses a pelvic shield with fused armor.

摘要:Based on the systematic study of two fossil skeleton specimens collected from the top of the third member of the marine Lower Triassic Jialingjiang Formation of Yuanan, Hubei Province, South China, a new Early Triassic primitive ichthyosaur Chaohusaurus zhangjiawanensis sp. nov. is reported and described. The beds yielding the type material are correlated with the Neospathodus homeri–N. triangularis Conodont zone. The new taxon is most similar to Chaohusaurus geishanensis Young and Dong, 1972 in the shape and configuration of the scapula, forefin, pelvic girdle and hindfin, presacral vertebral count and well-developed caudal peak, but distinguished from the latter by its larger size, the position of the pineal foramen in the centre of the parietal, the occurrence of a larger calcaneum in hindfin and the first sacral rib with distal expansion. The new species exhibits common features of primitive ichthyosaurs such as: (1) the prefrontal has an antero-dorsal shelf projecting towards the orbit; (2) the upper temporal fenestra is small; (3) the postorbital and the squamosal meet laterally to the upper temporal fenestra; and (4) cylindrical centra. However, more derived ichthyosaur characters are seen with the frontal separated from the orbital dorsal margin by the contact of the prefrontal and postfrontal, which offer new clues to the early radiation of ichthyosaurs.

摘要:A new somphospondylan sauropod (Dinosauria, Titanosauriformes): Gannansaurus sinensis gen. et sp. nov. from the Late Cretaceous Nanxiong Formation of Ganzhou Basin, Jiangxi Province of southern China is erected based on one nearly complete dorsal vertebra and a mid-caudal vertebra. It is characterized by two centroprezygapophyseal lamina fossae; large, square-shaped concavity formed by centroprezygapophyseal lamina and dorsal margin of the centrum; large infraparapophyseal fossa; three openings present within the large lateral concavity, which occupy 65% length of the centrum; the posterior centroparapophyseal lamina (PCPL) and the anterior centroparapophyseal lamina (ACPL) weakly developed; the posterior centrodiapophyseal lamina (PCDL) separated by an infradiapophyseal fossa into two branches dorsally; parapophyseal and diapophyseal laminae cross to form “K” configuration. It shares some characters with the Early Cretaceous form-Euhelopus, indicating that it is more closely related to Euhelopus rather than to other titanosauriform sauropods. This means Gannansaurus may have a close phylogenetic relationship with Euhelopus.

摘要:We describe a new species of Early Cretaceous bird from the Yixian Formation of Liaoning Province. Xinghaiornis lini gen. et sp. nov. is relatively large and characterized by a long, toothless rostrum and an elevated pedal digit I. The design of the skull and feet suggests that this bird was likely a mud-prober. This discovery provides strong support indicating that this avian trophic specialization originated at least 125 million years ago.

摘要:Lindera is a large genus of graceful, pleasantly scented and common native trees and shrubs of southern China and neighboring regions of SE Asia. There is a well-documented Cenozoic fossil record not only in these regions but also from elsewhere. A new fossil leaf record has been found in diatomite beds from the Upper Pliocene Mangbang Formation of Tuantian, Tengchong County, Yunnan. The leaves are identified and assigned to Lindera acuminatissima K. Q. Dao et B. N. Sun sp. nov., by comparing their leaf architecture and epidermal characteristics with those of 51 extant Lauraceae species and with 15 known fossil Lindera taxa. The specimens have well-preserved cuticles, with typical leaf architecture and epidermal characteristics of the Lauraceae, including entire leaf margin, intramarginal veins, basal ternate acrodromous primary veins, one-cell trichome base, paracytic stomatal apparatus, sunken guard cells, subsidiary hardly staining cells and presence of oil cells. These characteristics are consistent with Lindera sect. Daphnidium but are different from reported fossil and extant species of Lindera. The cuticles of Lindera are fragile and delicate with only three Lindera fossils reported based on this tissue. In terms of paleobiogeography, the fossil record indicates that Lindera is distributed in high- to mid-latitude regions of the Late Cretaceous to Paleocene northern hemisphere. Coincidentally, the records of Lindera located on both sides of the Bering Land Bridge possibly support the hypothesis that ancient plants extended