@article {2853,
	title = {Discovery of an Extensive Deep-Sea Fossil Serpulid Reef Associated With a Cold Seep, Santa Monica Basin, CaliforniaTable_1.docx},
	journal = {Frontiers in Marine Science},
	volume = {6},
	year = {2019},
	month = {Jul-03-2020},
	abstract = {Multibeam bathymetric mapping of the Santa Monica Basin in the eastern Pacific has revealed the existence of a number of elevated bathymetric features, or mounds, harboring cold seep communities. During 2013{\textendash}2014, mounds at \~{}600 m water depth were observed for the first time and sampled by Monterey Bay Aquarium Research Institute{\textquoteright}s ROV Doc Ricketts. Active cold seeps were found, but surprisingly one of these mounds was characterized by massive deposits composed of fossil serpulid worm tubes (Annelida: Serpulidae) exhibiting various states of mineralization by authigenic carbonate. No living serpulids with equivalent tube morphologies were found at the site; hence the mound was termed {\textquotedblleft}Fossil Hill.{\textquotedblright} In the present study, the identity of the fossil serpulids and associated fossil community, the ages of fossils and authigenic carbonates, the formation of the fossil serpulid aggregation, and the geological structure of the mound are explored. Results indicate that the tubes were most likely made by a deep-sea serpulid lineage, with radiocarbon dating suggesting that they have a very recent origin during the Late Pleistocene, specifically to the Last Glacial Maximum \~{}20,000 years ago. Additional U-Th analyses of authigenic carbonates mostly corroborate the radiocarbon dates, and also indicate that seepage was occurring while the tubes were being formed. We also document similar, older deposits along the approximate trajectory of the San Pedro Basin Fault. We suggest that the serpulid tube facies formed in situ, and that the vast aggregation of these tubes at Fossil Hill is likely due to a combination of optimal physical environmental conditions and chemosynthetic production, which may have been particularly intense as a result of sea-level lowstand during the Last Glacial Maximum.},
	doi = {10.3389/fmars.2019.00115},
	url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00115/full},
	author = {Georgieva, Magdalena N. and Paull, Charles K. and Little, Crispin T. S. and McGann, Mary and Sahy, Diana and Condon, Daniel and Lundsten, Lonny and Pewsey, Jack and Caress, David W. and Vrijenhoek, Robert C.}
}
@article {2849,
	title = {Faunal and stable isotopic analyses of benthic foraminifera from the Southeast Seep on Kimki Ridge offshore southern California, USA},
	journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
	volume = {150},
	year = {2018},
	month = {Jan-04-2018},
	pages = {92 - 117},
	abstract = {We investigated the benthic foraminiferal faunal and stable carbon and oxygen isotopic composition of a 15-cm push core (NA075-092b) obtained on a Telepresence-Enabled cruise to the Southeast Seep on Kimki Ridge offshore southern California. The seep core was taken at a depth of 973 m in the vicinity of a Beggiatoa bacterial mat and vesicomyid clams (Calyptogena) and compared to previously published data of living assemblages from ~ 714 m, four reference cores obtained at ~ 1030 m, and another one at 739 m. All of the reference sites are also from the Inner Continental Borderland but with no evidence of methane seepage.

No endemic species were found at the seep site and most of the taxa recovered there have been reported previously from other seep or low oxygen environments. Q- and R-mode cluster analyses clearly illustrated differences in the faunal assemblages of the seep and non-seep sites. The living assemblage at Southeast Seep was characterized by abundant Takayanagia delicata, Cassidulina translucens, and Spiroplectammina biformis, whereas the non-seep San Pedro Basin reference assemblage was comprised primarily of Chilostomella oolina and Globobulimina pacifica. Density and species richness were lower at the seep site compared to the non-seep site, reflecting the harsher living conditions there. The dead assemblage at the seep site was dominated by Gyroidina turgida compared to Cassidulina translucens at the ~ 1030 m non-seep site and Cassidulina translucens, Pseudoparrella pacifica, and Takayanagia delicata at the 739 m non-seep site. Density was three times lower at Southeast Seep than at the non-seep sites of comparable water depth but species richness was ~ 30\% higher. Stable carbon isotopic values were considerably depleted in the seep samples compared to the non-seep samples, with a progression from lightest to heaviest average δ13C values evident at the seep site reflecting microhabitat preference and vital effect: the deep infaunal species of Globobulimina, the shallow infaunal species Uvigerina peregrina, the epifaunal species Cibicidoides wuellerstorfi, and the shallow infaunal but aragonite-shelled species Hoeglundina elegans. The δ13C values downcore among each benthic species indicates ongoing fluid seepage through at least the last 3800 cal yr B.P. at Southeast Seep. Besides the continual local seepage, evidence from δ13C values of planktic foraminifera in the seep core suggest two pulses of methane (at 3000 and 3700 cal yr B.P.) were released that were large enough to influence much of the water column. Paired benthic and planktic foraminiferal stable oxygen isotope records provide evidence that there were no paleoenvironmental changes such as increased bottom-water temperature or changes in oxygen isotopic composition of bottom and pore waters during this 3800-year record to induce the methane releases. Instead, Southeast Seep appears to be the result of local faulting providing pathways for fluid to flow to the seafloor at a fault stepover or transpressional bend in the regional strike-slip system.},
	keywords = {Beggiatoa, benthic foraminifera, Calyptogena, Kimki Ridge, Santa Catalina Basin, Southeast Seep, Southern California, stable carbon isotopes},
	issn = {09670645},
	doi = {10.1016/j.dsr2.2018.01.011},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0967064517301509},
	author = {McGann, Mary and Conrad, James E.}
}
@article {2851,
	title = {Seafloor fluid seeps on Kimki Ridge, offshore southern California: Links to active strike-slip faulting},
	journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
	volume = {150},
	year = {2018},
	month = {Jan-04-2018},
	pages = {82 - 91},
	abstract = {The Kimki Ridge fluid seeps are located in western Catalina Basin about 60 km southwest of the southern California mainland and at a water depth of approximately 1100 m. Multichannel seismic reflection profiles collected by the U.S. Geological Survey (USGS) in 2014 show acoustic transparency within the Kimki Ridge, suggesting the possibility of fluid seeps and possible sub-seafloor fluid pathways. Subsequent multibeam bathymetric and backscatter intensity data collected during a cooperative University of Washington/USGS cruise in early 2016 show subtle seafloor buildups with high acoustic backscatter (reflectivity) in three places along Kimki Ridge, supporting the existence of fluid seepage. A Remotely Operated Vehicle (ROV) dive, conducted as part of the Nautilus Exploration Program, took place in August 2016 to confirm the presence of these previously unknown seeps and document their characteristics as well as those of any associated biological communities. Two of the three seeps were explored by ROV, and showed abundant evidence of fluid seepage, including characteristic algal mats, chemosynthetic clams, and authigenic carbonate formation. The seeps are comprised of carbonate buildups 1{\textendash}3 m thick and 300{\textendash}500 m across. Within these areas, we interpret broad crater-like depressions 30{\textendash}50 m across and 1{\textendash}2 m deep to be individual seep vents. The seep areas appear to be broad zones of diffuse seepage that support chemosynthetic biologic communities; however, active venting was not observed. Geochemical analyses of rock samples collected from the seeps indicate microbially driven anaerobic oxidation of methane at or near the sediment water interface. Seismic-reflection profiles show chimney-like fluid pathways along the limbs and in the axis of the fold forming Kimki Ridge, and evidence of methane in shallow sediments can be traced into the adjacent Catalina Basin. A system of closely spaced faults located at the axis of the Kimki Ridge anticline may serve as pathways to allow fluid flow to the seafloor. Our data are consistent with other studies that suggest that transpression is an important component in the formation and localization of fluid seeps in a strike-slip setting, implying that seep formation may be a common occurrence at fault stepovers or transpressional bends in strike-slip systems.},
	keywords = {California Inner Continental Borderland, E/V Nautilus, Faulting, methane, Seepages},
	issn = {09670645},
	doi = {10.1016/j.dsr2.2017.11.001},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0967064517301595},
	author = {Conrad, James E. and Prouty, Nancy G. and Walton, Maureen A.L. and Kluesner, Jared W. and Maier, Katherine L. and McGann, Mary and Brothers, Daniel S. and Roland, Emily C. and Dartnell, Peter}
}
@article {2852,
	title = {Investigation of Late Pleistocene and Holocene Activity in the San Gregorio Fault Zone on the Continental Slope North of Monterey Canyon, Offshore Central California},
	journal = {Bulletin of the Seismological Society of America},
	volume = {107},
	year = {2017},
	month = {Jun-06-2019},
	pages = {1094 - 1106},
	abstract = {We provide an extensive high-resolution geophysical, sediment core, and radiocarbon dataset to address late Pleistocene and Holocene fault activity of the San Gregorio fault zone (SGFZ), offshore central California. The SGFZ occurs primarily offshore in the San Andreas fault system and has been accommodating dextral strike-slip motion between the Pacific and North American plates since the mid-Miocene. Our study focuses on the SGFZ where it has been mapped through the continental slope north of Monterey Canyon. From 2009 to 2015, the Monterey Bay Aquarium Research Institute collected high-resolution multibeam bathymetry and chirp sub-bottom profiles using an autonomous underwater vehicle (AUV). Targeted samples were collected using a remotely operated vehicle (ROV) to provide radiocarbon age constraints. We integrate the high-resolution geophysical data with radiocarbon dates to reveal Pleistocene seismic horizons vertically offset less than 5 m on nearly vertical faults. These faults are buried by continuous reflections deposited after \~{}17.5  ka and likely following erosion during the last sea-level lowstand \~{}21  ka⁠, bracketing the age of faulting to \~{}32{\textendash}21  ka⁠. Clearly faulted horizons are only detected in a small area where mass wasting exhumed older strata to within \~{}25  m of the seafloor. The lack of clearly faulted Holocene deposits and possible highly distributed faulting in the study area are consistent with previous interpretations that late Pleistocene and Holocene activity along the SGFZ may decrease to the south. This study illustrates the complexity of the SGFZ, offshore central California, and demonstrates the utility of very high-resolution data from combined AUV (geophysical){\textendash}ROV (seabed sampling) surveys in offshore studies of fault activity.},
	issn = {0037-1106},
	doi = {10.1785/0120160261},
	url = {https://pubs.geoscienceworld.org/bssa/article/107/3/1094-1106/354203},
	author = {Maier, Katherine L. and Paull, Charles K. and Brothers, Daniel S. and Caress, David W. and McGann, Mary and Lundsten, Eve M. and Anderson, Krystle and Gwiazda, Roberto}
}
@article {2850,
	title = {Records of continental slope sediment flow morphodynamic responses to gradient and active faulting from integrated AUV and ROV data, offshore Palos Verdes, southern California Borderland},
	journal = {Marine Geology},
	volume = {393},
	year = {2017},
	month = {Jan-11-2017},
	pages = {47 - 66},
	abstract = {Variations in seabed gradient are widely acknowledged to influence deep-water deposition, but are often difficult to measure in sufficient detail from both modern and ancient examples. On the continental slope offshore Los Angeles, California, autonomous underwater vehicle, remotely operated vehicle, and shipboard methods were used to collect a dense grid of high-resolution multibeam bathymetry, chirp sub-bottom profiles, and targeted sediment core samples that demonstrate the influence of seafloor gradient on sediment accumulation, depositional environment, grain size of deposits, and seafloor morphology. In this setting, restraining and releasing bends along the active right-lateral Palos Verdes Fault create and maintain variations in seafloor gradient. Holocene down-slope flows appear to have been generated by slope failure, primarily on the uppermost slope (~ 100{\textendash}200 m water depth). Turbidity currents created a low relief (< 10 m) channel, up-slope migrating sediment waves (λ = ~ 100 m, h <= 2 m), and a series of depocenters that have accumulated up to 4 m of Holocene sediment. Sediment waves increase in wavelength and decrease in wave height with decreasing gradient. Integrated analysis of high-resolution datasets provides quantification of morphodynamic sensitivity to seafloor gradients acting throughout deep-water depositional systems. These results help to bridge gaps in scale between existing deep-sea and experimental datasets and may provide constraints for future numerical modeling studies.},
	keywords = {Deep-water channel, Gradient, Holocene, Sediment waves, Turbidite Fault},
	issn = {00253227},
	doi = {10.1016/j.margeo.2016.10.001},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0025322716302304},
	author = {Maier, Katherine L. and Brothers, Daniel S. and Paull, Charles K. and McGann, Mary and Caress, David W. and Conrad, James E.}
}
@article {1849,
	title = {Late Quaternary sediment-accumulation rates within the inner basins of the California Continental Borderland in support of geologic hazard evaluation},
	journal = {Geological Society of America Special Papers},
	volume = {454},
	year = {2009},
	note = {id: 1906; 10.1130/2009.2454(2.6)},
	month = {2009},
	pages = {117-139},
	abstract = {An evaluation of the geologic hazards of the inner California Borderland requires determination of the timing for faulting and mass-movement episodes during the Holocene. Our effort focused on basin slopes and turbidite systems on the basin floors for the area between Santa Barbara and San Diego, California. Dating condensed sections on slopes adjacent to fault zones provides better control on fault history where high-resolution, seismic-reflection data can be used to correlate sediment between the core site and the fault zones. This study reports and interprets 147 radiocarbon dates from 43 U.S. Geological Survey piston cores as well as 11 dates from Ocean Drilling Program Site 1015 on the floor of Santa Monica Basin. One hundred nineteen dates from 39 of the piston cores have not previously been published. Core locations were selected for hazard evaluation, but despite the nonuniform distribution of sample locations, the dates obtained for the late Quaternary deposits are useful for documenting changes in sediment-accumulation rates during the past 30 ka. Cores from basins receiving substantial sediment from rivers, i.e., Santa Monica Basin and the Gulf of Santa Catalina, show a decrease in sediment supply during the middle Holocene, but during the late Holocene after sea level had reached the current highstand condition, rates then increased partly in response to an increase in El Ni√{\textpm}o{\quotesinglbase}{\"A}{\`\i}Southern Oscillation events during the past 3.5 ka.},
	author = {Normark, William R. and McGann, Mary and Sliter, Ray W.}
}
