OCR Text |
Show ( alluvial fan accretion) resulted in bathymetric closure that today is nowhere more than a few meters deep. In other words, during its very late Quaternary history, Utah Lake has never been much more than a wide to very wide place in a plexus of converging rivers, including the Spanish Fork, Provo, and American Fork rivers. In earliest post- Bonneville time, the floor of Utah Valley was a NW- draining alluvial plain, in effect a braided outwash plain. Notes Pertaining to Travel Segments and to Discussion Stops En route from Salt Lake City to Stop [ 1]. Our route crosses ( transversely) the deltaic/ paleodeltaic depocenter of the Jordan River. Near- surface stratigraphic packages and surficial paleochannels of very late Pleistocene and Holocene ages will be discussed briefly. ( Hovingh on the Great Salt Lake subbasin) The amphibians Rana pipiens and Bufo woodhousii were historically found west of the Salt Lake City airport to the shores of Great Salt Lake. They have never been collected in the Tooele subbasin. This suggests that Great Salt Lake mesic- adapted amphibians were associated with Jordan River drainage patterns and never migrated west of the Wasatch Line. Stop [ 1]. The main purposes of this stop are to discuss three things: tectonic elements of the Great Salt Lake structural basin ( some of which are outlined in a GBASH poster on " Limneotectonics of Great Salt Lake, Utah"), salient features of Quaternary offshore stratigraphy, and 20th century biological and chemical limnology ( selected aspects of which are summarized on the next three pages). En route from Stop [ 1] to Stop [ 2]. ( Hovingh on the Puddle Valley subbasin and the definition of xeric- adaptive amphibians) The spadefoot toad Spea intermontanus has bred in a man- made water source 15 km from the nearest other man- made water source, suggesting movement over arid environments. In the Bonneville basin, 57% of their breeding locations are man- made- water troughs, catchment reservoirs, and reservoirs associated with springs. Their preferred habitat consists of ephemeral waters without aquatic vegetation, below 1500 m elevation. During Lake Bonneville times, the spadefoot toad may have occupied habitats in the Lynndyl Dunes, 140 km S of Puddle Valley ( the geomorphic history of the Lynndyl Dunes is summarized in Dorothy Sack's masters thesis). Stop [ 2], The main purposes of this stop are to observe and discuss the spectacular inflow bar at the N end of Puddle Valley. The Puddle Valley inflow bar is the subject of documentation provided by Dorothy Sack, starting four pages hence. |