New collections of floral and faunal remains were recovered from late Paleozoic sediments of the Mount Dall conglomerate in the Alaska Range of south-central Alaska. This isolated unit's type section is ∼1500 m thick and comprises thick to very thick conglomerate beds with interbedded sandstones and siltstones in a series of fining-upward intervals each tens of meters thick. The unit is interpreted to be a coastal braidplain deposit of Early Permian age in the upper Farewell terrane (Mystic subterrane sequence). Genus-level taxonomic composition of paleobotanical collections from lenticular mudstones to siltstones is discussed with regard to taphonomy and the interpreted lowland paleoenvironment of deposition. Poorly to moderately preserved megafossil compressions and impressions of the foliage genera Pecopteris , Zamiopteris , Rufloria , Angaropteridium , Cyclopteris , and Cordaites are consistent through several hundred meters of section and suggest a locally dense floral community. Horizons with sideritic rhizoliths indicate the presence of immature soils. The co-occurrence of these foliar and reproductive organs in the Mount Dall conglomerate suggests a mixed phytogeographic affinity to both the temperate Angaran Floristic Province of northern Pangea and the Euramerican Province of lower paleolatitudes. The brachiopod genera ? Stenoscisma and ? Schuchertella also were recovered and indicate a coastal depositional setting. These new biogeographic data complement exclusively marine zoogeographic data from the Farewell terrane's older strata and may be used to test hypotheses regarding the paleogeography of this displaced continental fragment. The paleofloral data support the placement of this terrane within a midlatitude climate belt during the Early Permian.

Carbonate speleothems are the most typical and widespread cave deposits, and the vast majority of them are considered to be inorganic. Nevertheless, the formation of a broad range of carbonate deposits in caves is intricately linked to living organisms. Although relatively unknown and largely regarded as features of limited significance, biologically mediated carbonate speleothems are diverse and numerous. They include formations such as certain dripstone and flowstone, some moonmilk and related precipitates, various subaqueous formations, rootsicles, encrusted mosses, stromatolitic speleothems, stalactitic tufa, and other deposits.