1. Introduction
We appreciate this opportunity for further discussion of the Brazos, Texas, K-T boundary sequences and their timing with respect to the Chicxulub impact. Keller et al. [1] used a multidisciplinary approach to document the stratigraphy, paleontology, mineralogy and geochemistry of the newly drilled Mullinax-1 core and a new outcrop sequence. Based on this multi-proxy dataset very strong evidence was presented that reveals that the Chicxulub impact predates the K-T mass extinction [1]. Schulte et al. take issue with this approach and our findings largely because they believe (1)that the Chicxulub impact caused the K-T mass extinction and therefore the K-T boundary must be placed at the impact spherule layer [2-4]. We welcome this opportunity to clarify misunderstandings, misconceptions and misinterpretations of the K-T record in Texas and elsewhere.   At the heart of our disagreements is the decades old controversy about the cause of the end-Cretaceous mass extinction. Schulte and collaborators have long argued that the sandstone complex, or event deposit, with impact spherules at the base in NE Mexico and Texas mark Chicxulub impact-generated tsunami deposits at the K-T boundary [3-7]. Keller and others have documented that these sandstone complexes were deposited over a long time period, that the K-T boundary is above these deposits and the original Chicxulub impact layer is in late Maastrichtian sediments predating the K-T mass extinction by about 300 ky [8-12] (2). With the stratigraphic sequences in Mexico and Texas in direct conflict(3) with the Chicxulub as K-T impact scenario, Schulte and collaborators now consider these sequences as too complex to reveal the K-T and Chicxulub impact history. Instead, they favor condensed deep-sea(4) and terrestrial sections(5) as the ultimate support for the Chicxulub K-T age claim because they juxtapose the spherule layer and early Danian sediments [13-15]. But the ultimate test for any historical sequence of events lies in the expanded records of continental shelf and slope areas (7) where high sedimentation rates reveal stratigraphic separation and normal sedimentation(8) between events, such as we documented for Texas [1](6). We stand by our published data and interpretations and present new data and graphics to clarify their misconceptions and misrepresentations on the placement of the K-T boundary.