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Early Permian fusulinids from both northern and southern parts of the Baoshan Block (western Yunnan, Southwest China) are illustrated and compared with coeval fusulinid faunas from other northern peri-Gondwana areas to disclose paleogeographic information. Systematic study of collected fusulinid materials and examination of published data from the Dingjiazhai area, northern Baoshan Block, show that fusulinids there includeEoparafusulina pseudosimplexandPseudofusulina macilenta.Fusulinids from the Aluotian Section, southern Baoshan Block, consist ofP. minitumidisculan. sp.,P. macilenta, P. tumidiscula, E. pseudo simplex, E.aff.E. laudoni, andE.sp. Early Permian fusulinids from both northern and southern Baoshan Blocks are dominated byPseudofusulinaandEoparafusulinaspecies and they are similar to those from Central Pamir, South Afghanistan, East-Central Iran, Central Oman, East Hindu Kush and northern Karakorum, revealing a Sakmarian to Artinskian age. Moreover, detailed comparison shows that the Early Permian fusulinid assemblage from the Baoshan Block is more similar to those from East-Central Iran, Central Pamir and South Afghanistan. This implies that the Baoshan Block may have been near those areas during the Early Permian.

The middle Permian Cryptospirifer fauna (brachiopod) has hitherto been found in more than 30 localities in the Yangtze Platform, South China. Examination of data from various localities shows that it occurs stratigraphically in three intervals in the range from the upper Kungurian to Wordian. In the Baoshan block in western Yunnan the fauna occurs in the basal part of the Daaozi Formation and is of possibly an early Wordian age. Outside China the Cryptospirifer fauna has been reported from central and northwest Iran and central Turkey, where the fauna may have an age around the Wordian\Capitanian boundary. Rapid global warming since the late Early Permian and possession of other suitable environmental factors such as proper substrate, clastic input and water depth enabled the Gondwana-derived Baoshan Block and related tectono-stratigraphic units in Iran and Turkey to host the Cryptospirifer fauna, a fauna evolved in the Yangtze Platform that is a type area of the Cathaysian province.

There is a large ductile shear zone, 2 km wide and more than 350 km long, in the South Qilian Mountains, western China. It is composed of volcanic, granitic and calcareous mylonites. The microstructures of the ductile shear zone show nearly E-W extending subvertical foliation, horizontal and oblique stretching lineations, shearing sense from sinistral to oblique sinistral strike-slip from east to west, “A” type folds and abundant granitic veins. Measured lattice preferred orientations (LPOs) of the mylonitic and recrystallized quartz of the granitic mylonite in the west segment suggest a strong LPO characterized by the dominant slip systems {10times10} formed at high temperature (>650°C). K-feldspar of the mylonite shows an 39Ar/40Ar high-temperature plateau age of 243.3±1.3 Ma, and biotite, 250.5±0.5 Ma, which represent the formation age of the ductile shear zone. The 39Ar/40Ar plateau ages of 169.7±0.3 Ma and 160.6±0.1 Ma and the 39Ar/40Ar isochron ages of 166.99±2.37 Ma and 160.6±0.1 Ma of biotites in the mylonite represent the subsequent deformation age. These ages indicate that this ductile shear zone is similar to the Altun and South Kunlun sinistral ductile shear zones in its ages of movement, formation, reactivation and duration.

Fossil materials of Shanita and Hemigordius from a section northeast of the Woniusi (the Woniu Temple) of Baoshan, western Yunnan are described and figured in this paper. Field investigation indicates that fossils of these two foraminifer genera are extremely abundant and form a typical Shanita-Hemigordius assemblage in the so-called "Cracked Limestone" in the Baoshan area. Preliminary study has revealed that the features of this assemblage, which includes Shanita amosi, S. chagouensis, Hemigordius renzi and H. biconcavus, are similar not only to the Shanita fauna previously reported from the Shazipo Formation in the Zhengkang area, west Yunnan, but also to those from the Permian of Burma, Thailand, Iran and Turkey.

Phanerozoic strata are distributed in several north-south trending zones in the central part of the Changning-Menglian Belt. Four types of Devonian to Triassic stratigraphic successions can be identified: (1) clastics with limestone lenses in the mid-section, changing up-section into alternations of fine clastics and cherts; (2) clastics with chert intercalations and limestone lenses, and topped by Permian basic volcanics; (3) clastics-basic volcanics—carbonates—clastics; and (4) limestones, dolomitic limestones—dark gray thin-bedded limestones, argillaceous limestones, mudstones and siliceous mudstones. Devonian to Triassic cherts occur in different horizons and different zones from east to west. These cherts are usually transitional to their neighboring clastics. There is no continuous Devonian to Middle Triassic chert sequence in the central zone of the Changning-Menglian Belt as Liu et al. (1991, 1993) reported. Volcanics and the overlying carbonates described by some workers as “seamount” sequences are more likely to have formed in a marine environment on continental crust. Succession (4) is newly recognized in the area from Menglai to Yong'an in Cangyuan County and further north to Padi of Gengma County. Basalts, cherts and clastics also appear in this area. Mid-Triassic (very probably Ladinian) radiolarians extracted from bedded cherts in the Ganzhejidi section indicate that they are in higher stratigraphic positions. The change from bedded cherts via siltstones to thick-bedded sandstones with thin-bedded fine intercalations in the Ganzhejidi section and (some other outcrops along the road from Cangyuan to Gengma) suggests a fundamental change of sedimentary environment caused by a rapid increase of a large quantity of detritus supply. These siliciclastic sediments are possibly syn-orogenic deposits.

Studies in the past decade have proven the Shanita fauna to be an excellent marker of the northern peri-Gondwana tectonic blocks. Thus, a study of the Shanita fauna from the Baoshan area in western Yunnan Province, China, could provide pivotal paleontological evidence for the paleogeographic reconstruction of the Baoshan block. We systematically analyzed the composition and the age of the Shanita fauna from the Permian Da’aozi Formation in Woniusi Section of the Baoshan area. Results suggested that the characteristic genera Shanita and Hemigordiopsis in this fauna comprised eight species (including two new species), and ten genera of other nonfusulinid foraminifera were also recognized from this fauna. Further comparative study showed that the Shanita fauna from the Baoshan area were probably late Maokouan (Lengwuan) to Wuchiapingian in age. In general composition, this fauna is comparable to those Shanita faunas from Shan State of Burma, Peninsular Thailand, and Nagri of Tibet, China. However, the relatively low generic diversity and occurrence of some endemic species, as well as the absence of fusulinids, indicate certain regional features of the Shanita fauna from the Baoshan area.

The Rabeignathus bucaramangus fauna was recently found from the limestone beds of the top part of the clastics-dominated Dingjiazhai Formation in the Aluotian section, southern Baoshan Block, western Yunnan. With Rabeignathus bucaramangus as the dominant species, this fauna includes Rabeignathus bucaramangus (Rabe), Homeoiranognathus huecoensis (Ritter), Sweetognathus inornatus Ritter, Sweetognathus whitei (Rhodes), Mesogondolella cf. bisselli (Clark and Behnken) and a few of ramiform elements. The characteristics of the fauna suggest that it can be correlated with the upper part of the Sweetognathus whitei Zone and assigned to the Middle Artinskian.

In southwest China Permo-Carboniferous depositional sequences of Gondwana affinity were first discovered in the Himalayan region by the expedition team of Acadimia Sinica in 1975. By 1983, Gondwana-affinity Permo-Carboniferous sequences had been identified also in the Lhasa Block, the south Qiangtang Block in Tibet, and the Tengchong and Baoshan blocks in Yunnan. These sequences are characterised by the presence of successions, which are interpreted as glacio-marine deposits and by the presence of Gondwana-affinity biota. The distribution of Gondwana-affinity Permo-Carboniferous indicates that basins whose remnants are now represented by the Yarlung–Zangbo Suture and the Bangong–Nujiang Suture did not exist at that time, and the vast area south of the Lungmu–Shuanghu–Jinshajiang Zone in Tibet and west of the Changning–Menglian Belt in Yunnan formed a part of the northern margin of Gondwana.