本文根据古地理、古生物地理、古地磙、地球化学及火山岩工作成果，提出镇安-淅川地块是早古生代自南秦岭裂离而较早缝合于北秦岭南的一小型地块、早古生代秦岭是个多岛小洋盆，具有包括镇淅地块在内的五列岛屿。由于扬子、华北板块及其间列岛的同向不等速漂移，导致了缝合过程不同于经典的板块碰撞，这是特提斯多岛洋盆缝合的一大特点，以此解释东秦岭加里东期“碰撞而不造山”的问题。

In the middle reaches of the Yangtze River, the floods have become more and more frequent, and the water level rises higher than before. The damages are becoming ever more serious. This is primarily a consequence of human activity in the river basin. Three aspeets deserve particular attention. First, destruction of vegetation has led to soil erosion in the upper reaches. In the past 30 years, the forest cover has been reduced to half, while the area exposed to severe erosion doubled in size. In the long run, this can be expected to increase flooding. Second, land reclamation and siltation has reduced lake sizes. This has resulted in decrease of the flood storage capacity. Third, the construction of levees has caused flood levels to rise due to restricted flood discharge capacity. Establishment of the Great Jinjiang levee caused silting up of the riverbed and valley in the mid-reaches of Yandtze. Consequently, the discharge capacity decreased to 60,000-68,000m3/s, which is sufficient only for ordinary floods. This article concludes that the deteriorating flood situation is the result of inappropriate human intervention in the natural environment. It is suggested that the appropriate strategy should change from “keeping the flood away” to “giving the flood way”. Related tacties and strategies under consideration are briefly summarized.

Three models for Tethys are discussed. Based on recent data from China and adjacent areas, it is concluded that an archipelagic ocean model for Tethys accords with paleomagnetic and biogeographic data that Eurasia and Gondwana were widely apart, and also accords with sedimentary data that deep ocean deposits were few, because the vast distance were filled by islands.