Anatomy, Evolution, and Paleoenvironmental Interpretation of an Ancient Coastal Plain: Integrated Paleopedology and Palynology from the Upper Cretaceous (Maastrichtian) Prince Creek Formation, North Slope, Alaska, USA

Reconstructing the paleohydrology of a cretaceous Alaskan paleopolar coastal plain from stable isotopes of bivalves

“…Based on 0.5 and 35 ppt end-members, N. percrassa lived in a maximum freshwater to marine water mixture of 78% to 22% and a minimum freshwater mixture of 50% to 50% mixture. This is consistent with the interpretation of Flaig et al (2013) that suggests that the clams and surrounding sediment are deposited in distal lacustrine or nearshore lagoonal or of estuarine environment near the mouth of a distributary channel that emptied into the Cretaceous Arctic Ocean. This is also consistent with the surrounding fossils and sedimentary structures such as root traces and freshwater ostracodes.…”

“…This study highlights the importance of using a multi-taxa approach to accurately reconstruct the climate and environmental dynamics of ancient Arctic systems if we are to use such ancient systems to predict future Arctic climate/environmental conditions as we approach a greenhouse world. Flaig et al, 2013) including the isotopic composition of various bodies of water. The isotopic composition of Arctic marine water is estimated at~−3‰ (Zhou et al, 2008), mixed marine-freshwater is estimated at −14.41.7‰ to −16.23‰ (average data from bivalves at a maximum of 12.5°C and a minimum of 4.5°C, this study), meteoric water is estimated at~−22.3 to −20.8‰ (data from pedogenic siderite and dinosaurs, Suarez et al, 2013) and river water is estimated at −22.3 to −28.7‰ (data from dinosaurs, Suarez et al, 2013).…”

“…By combining this data with data from Suarez et al, 2013 andFlaig et al (2013), we gain additional insight into the paleohydrology present across the Cretaceous Alaskan coastal plain along a transect from the ancestral Brooks Range to the arctic Alaskan coast (Fig. 6).…”

“…Flaig et al (2011) examine the facies and alluvial architecture of the PCF and determined that the PCF represents a poorly drained coastal plain to lower deltaic plain heavily influenced by marine waters influx with flashy seasonal flooding likely driven by from snowmelt in the ancestral Brooks Range. This likely contributes to the preservation of dinosaurs entombed in these seasonal flash flood deposits (Fiorillo et al, 2010;Flaig et al, 2011Flaig et al, , 2013Flaig and Fiorillo, 2015). Since stable isotopes of ancient minerals like carbonates and phosphate record the isotopic composition of the water from which it precipitated from, and since the isotopic composition of water is indicative of its source (marine, meteoric, and snowmelt) we will test these interpretations using isotopic composition of bivalves associated with the isotopic composition of phosphate and siderite from a study by Suarez et al (2013).…”

“…By combining new data from powder X-ray diffraction, cathodoluminescence, thin section petrography, and stable carbon and oxygen isotopes of Cretaceous bivalves with the paleoevironmental and paleohydrologic reconstructions of the ancient terrestrial ecosystem on the Alaskan coastal plain originally described by Flaig et al (2011Flaig et al ( , 2013 and Suarez et al (2013), we can get both a regional and a global perspective on this ancient Arctic ecosystem.…”