Evaluating the Shinumo-Sespe drainage connection: Arguments against the “old” (70–17 Ma) Grand Canyon models for Colorado Plateau drainage evolution

The provocative hypothesis that the Shinumo Sandstone in the depths of Grand Canyon was the source for clasts of orthoquartzite in conglomerate of the Sespe Formation of coastal California, if verified, would indicate that a major river system flowed southwest from the Colorado Plateau to the Pacific Ocean prior to opening of the Gulf of California, and would imply that Grand Canyon had been carved to within a few hundred meters of its modern depth at the time of this drainage connection. The proposed Eocene Shinumo-Sespe connection, however, is not supported by detrital zircon nor paleomagnetic-inclination data and is refuted by thermochronology that shows that the Shinumo Sandstone of eastern Grand Canyon was >60 °C (∼1.8 km deep) and hence not incised at this time. A proposed 20 Ma (Miocene) Shinumo-Sespe drainage connection based on clasts in the Sespe Formation is also refuted. We point out numerous caveats and non-unique interpretations of paleomagnetic data from clasts. Further, our detrital zircon analysis requires diverse sources for Sespe clasts, with better statistical matches for the four “most-Shinumo-like” Sespe clasts with quartzites of the Big Bear Group and Ontario Ridge metasedimentary succession of the Transverse Ranges, Horse Thief Springs Formation from Death Valley, and Troy Quartzite of central Arizona. Diverse thermochronologic and geologic data also refute a Miocene river pathway through western Grand Canyon and Grand Wash trough. Thus, Sespe clasts do not require a drainage connection from Grand Canyon or the Colorado Plateau and provide no constraints for the history of carving of Grand Canyon. Instead, abundant evidence refutes the “old” (70–17 Ma) Grand Canyon models and supports a <6 Ma Grand Canyon.

Supplemental Material: Evaluating the Shinumo-Sespe drainage connection: Arguments against the “old” (70–17 Ma) Grand Canyon models for Colorado Plateau drainage evolution

Table S1: Rotations of measured paleomagnetic paleopoles to test the error introduced by measuring inclinations relative to cross bedding of different orientations instead of horizontal bedding. Table S2: Detrital zircon data used in this study. Table S3: Quantitative comparison results from DZstats.

Supplemental Material: Evaluating the Shinumo-Sespe drainage connection: Arguments against the “old” (70–17 Ma) Grand Canyon models for Colorado Plateau drainage evolution

Table S1: Rotations of measured paleomagnetic paleopoles to test the error introduced by measuring inclinations relative to cross bedding of different orientations instead of horizontal bedding. Table S2: Detrital zircon data used in this study. Table S3: Quantitative comparison results from DZstats.

Performance Evaluation of Corporators and Authorities based on Public Grievances Redressal

People in their day-to-day life face many general problems like damaged street lights, irregular water supply, blocked drainage connection etc. In these situations they complain to the concerned authority. If the complaint is unsolved, they complain to their areas representatives i.e. corporator. But in majority of the cases complainants dont get timely delivery of the solutions to their complaint and moreover authorities and corporators are neither made accountable nor answerable for it. Hence public grievances redressal is a major issue. Another important issue is that there are no quantitative measures representing a politician. If there would be any such metrics it would assist people in selecting suitable candidate in election and would also guide political parties in selecting suitable contestant for contesting in election. There are also no quantitative measures of government employees, which if exist would be used in providing promotions and increments. This work addresses these two major issues and provides solution for it. Android app is developed which evaluates Authorities and Corporators based on whether they have solved peoples complaint and if solved how early it is solved. It provides evaluation in terms of score and rank. It also provides performance graph and statistical graphs.

Phylogeographic Diversity of the Lower Central American Cichlid Andinoacara coeruleopunctatus (Cichlidae)

It is well appreciated that historical and ecological processes are important determinates of freshwater biogeographic assemblages. Phylogeography can potentially lend important insights into the relative contribution of historical processes in biogeography. However, the extent that phylogeography reflects historical patterns of drainage connection may depend in large part on the dispersal capability of the species. Here, we test the hypothesis that due to their relatively greater dispersal capabilities, the neotropical cichlid species Andinoacara coeruleopunctatus will display a phylogeographic pattern that differs from previously described biogeographic assemblages in this important region. Based on an analysis of 318 individuals using mtDNA ATPase 6/8 sequence and restriction fragment length polymorphism data, we found eight distinct clades that are closely associated with biogeographic patterns. The branching patterns among the clades and a Bayesian clock analysis suggest a relatively rapid colonization and diversification among drainages in the emergent Isthmus of Panama followed by the coalescing of some drainages due to historical connections. We also present evidence for extensive cross-cordillera sharing of clades in central Panama and the Canal region. Our results suggest that contemporary phylogeographic patterns and diversification in Lower Central American fishes reflect an interaction of historical drainage connections, dispersal, and demographic processes.

Protection of in-stream biota from urban impacts: minimise catchment imperviousness or improve drainage design?

Urbanisation is a looming global threat to in-stream biodiversity, but the best approaches to mitigation are unclear. This paper asks if the protection of in-stream biota, in particular macroinvertebrate assemblages, is dependent on the sequestration of catchments from urbanisation, or if protection in urbanised catchments can be achieved through better drainage design. In-stream macroinvertebrate assemblage composition was assessed for 16 catchments spanning a rural–urban gradient. Catchment imperviousness and drainage connection (the proportion of impervious area directly connected to streams by stormwater pipes), together with other possible driving factors, were assessed as explanatory variables of macroinvertebrate assemblage composition. The proportion of variance explained independently and jointly by each variable was assessed by hierarchical partitioning. Assemblage composition was strongly explained by the gradient of urban density (i.e. a large proportion of variance was jointly explained by variables correlated with the urban gradient; imperviousness, connection, longitude and elevation). However, drainage connection was the strongest independent correlate. Most sensitive taxa were absent from sites with >20% connection. Thus the connection of impervious surfaces to streams by pipes is a more likely determinant of taxa loss than the impervious areas themselves. Low-impact urban design approaches that reduce drainage connection are postulated as the most effective management solution to the protection of stream biota in urban catchments.

Links between short-term velocity variations and the subglacial hydrology of a predominantly cold polythermal glacier

The surface velocity of a predominantly cold polythermal glacier (John Evans Glacier, Ellesmere Island, Canada) varies significantly on both seasonal and shorter time-scales. Seasonal variations reflect the penetration of supraglacial water to the glacier bed through significant thicknesses of cold ice. Shorter-term events are associated with periods of rapidly increasing water inputs to the subglacial drainage system. Early-season short-term events immediately follow the establishment of a drainage connection between glacier surface and glacier bed, and coincide with the onset of subglacial outflow at the terminus. A mid-season short-term event occurred as surface melting resumed following cold weather, and may have been facilitated by partial closure of subglacial channels during this cold period. There is a close association between the timing and spatial distribution of horizontal and vertical velocity anomalies, the temporal pattern of surface water input to the glacier, and the formation, seasonal evolution and distribution of subglacial drainage pathways. These factors presumably control the occurrence of highwater-pressure events and water storage at the glacier bed. The observed coupling between surface water inputs and glacier velocity may allow predominantly cold polythermal glaciers to respond rapidly to climate-induced changes in surface melting.