The Ordovician Craighead Limestone Formation of southwest Scotland was formed on a carbonate platform on the eastern tropical margin of the Laurentia palaeocontinent during the early Katian (c. 456 Ma). It yields the most diverse and well-preserved ostracod fauna yet recovered from the Scottish Ordovician succession, with some 25 species divisible into two distinct marine biotopes comprising shallow lagoonal and deeper platform margin settings, respectively. The ostracods show strong biogeographic links at species-level with Sandbian and early Katian faunas of North America, including Krausella arcuata, Steusloffina cuneata, Monoceratella teres and species of Levisulculus and Platybolbina. However, many of the ostracod genera that characterize the Craighead Limestone Formation have earlier origins in the Baltica palaeocontinent, suggesting enhanced migration of species from mid- (Baltica about 30° S) to low (Laurentia) latitudes in the late Sandbian and early Katian interval. Such Baltica-origin genera include Distobolbina, Kiesowia and Platybolbina. Notable is the wide biogeographic occurrence of Steusloffina cuneata, extending from warm tropical Laurentia to cooler high-latitude Gondwana, an enormous latitudinal range for a shelf-dwelling marine species. The possible Tvaerenellidae taxon Duoarcus levigatus gen. et sp. nov. is described.

Late Cretaceous sandstone succession of the Pab Formation in western Sulaiman Fold Thrust belt Pakistan was investigated for petrology and bulk rock chemistry to determine its source terrain, paleo-weathering and tectonic setting. The formation is mainly comprised of sandstone with reddish to maroon color shale and arenaceous limestone. Texturally, the sandstone is fine to coarse grained, sub-angular to well-rounded and moderately to well sorted. The sandstone is petrologically and geochemically classified as quartz arenite to sub lithic arenite. The detritus was mainly derived from plutonic acidic source. QtFL and QmFLt suggests that recycled orogeny and Craton Interior setting were major sources of sediments. Geochemical models support that the detritus was derived from quartzose sedimentary source terrain, suggest deposition in a passive continental margin setting. Average values of chemical indices are CIA 59% CIW  67% and CIV 12.70%, which suggest moderate to high degree of chemical weathering in source area, that may reflect humid climate condition in the source area. The petrographic study and geochemical models demonstrate that the Pab Formation is mostly composed of mature sandstone from acidic plutonic and low-grade metamorphic rocks terrain in recycled and Craton Interior setting deposited on western passive margin of Indian plate in Tethys Ocean.