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During the Cretaceous Period, the Indian Plate separated from Gondwana and drifted northwards, eventually colliding with Eurasia at the end of the period or in the early Cenozoic. This led to major changes in the composition of the flora and fauna of the region. Palynomorph assemblages from Cretaceous deposits in Gamba County, southern Xizang (Tibet), China, are analyzed herein in an attempt to determine how the vegetation of the northern margin of the Indian Plate changed. The Gamba assemblages were initially similar in composition to those from Australia but by the Santonian Stage they were more similar to those of North Africa. Differences from the former are increasingly apparent through the Albian–Cenomanian transition. The rate of evolution of the Gamba flora was about the same as that of the Australian flora prior to the Albian, somewhat slower during this stage, but faster from the Cenomanian onwards, implying that this was, to a large extent, a result of the separation of the Indian Plate from Gondwana and its northward drift during the Cretaceous Period. During the Albian, the Australian block drifted eastwards whereas the Indian Plate remained relatively static. This resulted in few changes in the Gamba palynoflora but many in palynofloras from Australia. However, the northward movement of the Indian Plate in the Late Cretaceous led to pronounced changes, with numerous inceptions of genera and species in the Gamba succession. Of these, many have an African or equatorial distribution and none has connections with Australia, indicating that the climate at this time was similar to that of North Africa and that separation from Australia was complete. The arrival of the Indian Plate in equatorial regions allowed floral exchange between its northern part and North Africa during the Santonian.

A palynostratigraphic and palynofacies study of a geological section at Cuojiangding in Zhongba County has provided a basis for discussing the palaeoenvironmental evolution of the southern continental margin of Laurasia in Xizang (Tibet) towards the end of the Cretaceous Period and during the Paleogene. It is the only record of fossil spores and pollen grains from collision- and convergence-related sediments close to the major Yarlung Zangbo Suture. Deposits of the Padana Formation at the base of the section through the Qubeiya, Quxia, and Jialazi formations to the Rujiao Zangbo Conglomerate at the top are considered to range in age from Santonian to Eocene or possibly Oligocene. During this period the India plate collided with, and continued to push against, Laurasia plate. Two spore and pollen zones and three palynofacies types are recognized. These are correlated with two transgressive–regressive cycles associated with the collision, periods of geologically rapid uplift being reflected by the molasse-like sediments of the upper Quxia Formation and the Rujiao Zangbo Conglomerate, which accumulated during the Late Paleocene and Eocene–Oligocene respectively. The first regression led to intermittent subaerial exposure and erosion of the Cuojiangding area. The second ended the marine history of the area and led first to the development of swamps in a subtropical climate, now preserved in the coal-bearing Qiuwu Formation, and later to the development of mountainous terrain, with a cooler climate at higher elevations.

Palynological analyses of two wells (Haema-1 and Kachi-1) located in two sub-basins of the Northern South Yellow Sea Basin have been carried out in order to establish a palynostratigraphic breakdown of the sedimentary succession and to determine environments of deposition. Seven assemblage zones and two assemblage subzones have been erected on the basis of frequency variations in, and occurrences of, biostratigraphically significant palynomorphs as follows: Classopollis–Ephedripites Assemblage Zone (AZ): Barremian–Albian; Alisporites–Aquilapollenites–Penetetrapites AZ, which is subdivided into an Alisporites–Rugubivesiculites Assemblage Subzone: Cenomanian–Lower Maastrichtian, and an Aquilapollenites–Penetetrapites Assemblage Subzone: Upper Maastrichtian; Momipites–Coryluspollenites AZ: Paleocene; Caryapollenites–Inaperturopollenites AZ: Lower–Middle Eocene; Quercoidites–Pinuspollenites AZ: Upper Eocene; Liquidambarpollenites–Fupingopollenites–Magnastriatites AZ: Lower–Middle Miocene; Graminidites–Persicarioipollis AZ: Pliocene. The depositional environments represented by the well sections are considered to have been generally fluvio–lacustrine, and the climate to have varied between semi-arid and wet, and subtropical and warm temperate, except during the Late Eocene and Pliocene when a cool-temperate climate prevailed. Six stages in the development of the sub-basins are recognised. These are: (1) initial stage of rift or pull-apart basin-formation during the Late Jurassic?–Cretaceous; (2) subsidence from the Paleocene to Middle Eocene; (3) alternation of uplift and subsidence in the Late Eocene; (4) synrift inversion and erosion through the Oligocene; (5) uplift during the Early Miocene; and (6) widespread subsidence from the Middle Miocene onwards apart from during the Early Pliocene when the region was subjected to uplift once more.

A single dinoflagellate cyst species occurs abundantly in nonglacial varved lacustrine deposits of the Miocene Clarkia Lake succession in northern Idaho. Previously of uncertain affinity, it is now identified as Pseudokomewuia (Pseudokomewuia) aff. granulata He 1980. The variety of other biological groups that are represented by fossils in the succession provides a basis for making observations on ecological associations and climatic conditions during the period of deposition of the sediments. The cysts do not occur in the alluvial (floodplain) and poorly laminated, early lacustrine facies that underlie the varved unit, nor in the overlying late lacustrine, oxidised, silty clay facies. They are associated only with sediment-couplets considered to reflect accumulation in temperature-stratified water approximately 8–12 m deep that overturned periodically. It is likely that the dinoflagellates inhabited the warm, epilimnic, oxygenated layer above the cool deep water in which oxygen levels were low, rendering this environment inhospitable to both animals and plants, but favouring the preservation of organic matter. Their absence from the unlaminated deposits of the early and late lacustrine facies may not mean that the motile dinoflagellates were not present in the shallower waters they represent but simply that the cysts were not preserved. These beds accumulated in oxidising environments and are palynologically barren. The land plant mega- and microfossil records suggest that the vegetation of the surrounding hills consisted of mixed deciduous–coniferous forest of a character that is typical of a moist (summer-wet) warm-temperate climate. This is also implied by some of the fauna (e.g., the salmonid fish and the gastropod Bellamya). These observations add significantly to palaeoecological conclusions drawn from the few records of nonmarine dinoflagellate cysts from Cretaceous and younger successions elsewhere, most of which have been associated with quiet lacustrine or lagoonal habitats.

Evidence is presented from nine areas in western Europe (Speeton, Yorkshire; southern North Sea; Channel and Weald Basins, southern England; Jeanne d'Arc, Lusitanian and Aquitanian Basins of the North Atlantic continental margins; Lower Saxony Basin, north Germany; the Paris Basin and southern France) for a phase of aridity which began during the Hauterivian-middle Barremian and continued to dominate the climate of the region until the mid-Aptian, although conditions during this period were not uniformly dry throughout. Criteria for recognising arid environments include the occurrence of evaporites, abundances of carbonate-rich sediments, red beds, firmgrounds, carbonate nodules and pyrite concretions, depletion of kaolinite, spore assemblages of limited morphological diversity, and the presence of numerous coniferalean and cheirolepidiacean pollen grains. The change from generally humid to dry climates during the Barremian is thought to have been linked to a lowering of sea-level. The arid phase clearly falls within the time span of the first Cretaceous Oceanic Anoxic Event.