Strike–slip origin of Cretaceous Mazhan Basin, Tan-Lu Fault Zone, Shandong, east China

The Mazhan Basin, Shandong Province, China, is located between the main faults, F₃ and F₄, of the Tan-Lu Fault Zone. It is an elongated basin more than 60 km in length and 8 km in width and contains a series of typical continental sediments (the Upper Cretaceous Wangshi Group). This series was divided into three sedimentary facies associations: conglomerate facies association; sandstone facies association of alluvial fan to lake margin environment; and siltstone facies association of lacustrine origins. Their zonal distribution pattern may represent a contemporaneous heterotopic facies due to a lateral facies change from margins to axis of the basin. Their stratigraphic sequence becomes younger northward along the boundary faults. This suggests that the depocenter of the fan–lake system tends to migrate northward along F₃. From the asymmetric features (i.e. basin shape, lithofacies distribution, facies change) the Mazhan Basin can be explained by progressive subsidence at the Tangwu releasing bend of F₃ with sinistral strike–slip movement. Judging from the fission track (FT) ages from the Wangshi Group, it was concluded that a sinistral strike–slip movement along the main fault, F₃ of the Tan-Lu Fault in Shandong, has lasted until the Late Cretaceous. Its displacement is estimated to be larger than the migrated distance, 60 km, of the depocenter of the Mazhan Basin.     

山东海阳所麻粒岩向过渡榴辉岩转化的变质动力学过程及其构造意义

在山东半岛东南端的乳山海阳所,角闪岩和长英质片麻岩呈互层产出,在某些角闪岩层的中心残留有弱变形的麻粒岩和强变形的过渡榴辉岩（斜长石榴辉岩）团块,在弱变形的麻粒岩团块中发育有窄的（〈１ｃｍ）剪切条带,沿着这些剪切条带和强变形过渡榴辉岩团块中,原麻粒岩被转化为含斜长石的过渡榴辉岩。变形和流体在这一转化过程中加速了元素扩散和迁移的速度,在变形强和有流体加入的部位麻粒岩向榴辉岩转化的程度明显增强,麻粒岩相     

Paleomagnetism of Cretaceous Red beds from Eastern Part of South China Block

INTRODUCTIONCollisionofIndiawithAsiaappearstohavebroughtaboutlargetectonicdeformationofAsia,especiallyEastAsia(Tapponnieretal.,1986).Post-Cretaceousdeformation(translationand/orrotation)ofSimaoandIndochinablocks,whicharelocatedatthesouthernsideofRedRiverfault(RRF),hasbeenreportedfromCretaceouspaleomagneticin-vestigations(Yangetal.,l995;HuangandOpdyke,l993IYangandBesse,1993).AlsoinSouthChinablock(SCB)locatedatnorthsideoftheRRF,localdeformationofsomeregionsneartheRRFhasbeendocum…