@article {Ludwig2011,
	title = {{U-Th systematics and ages of carbonate chimneys at the Lost City Hydrothermal Field}},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {75},
	number = {7},
	year = {2011},
	pages = {1869{\textendash}1888},
	abstract = {The Lost City Hydrothermal Field (LCHF) is a serpentinite-hosted vent field located 15~km west of the spreading axis of the Mid-Atlantic Ridge. In this study, uranium{\textendash}thorium (U{\textendash}Th) geochronological techniques have been used to examine the U{\textendash}Th systematics of hydrothermal fluids and the 230Th ages of hydrothermally-precipitated carbonate chimneys at the LCHF. Fluid sample analyses indicate that endmember fluids likely contain only 0.0073~ng/g U or less compared to 3.28~{\textpm}~0.03~ng/g of U in ambient seawater. For fluid samples containing only 2{\textendash}21{\%} ambient seawater (1.1{\textendash}11~mmol/kg~Mg), Th concentration is 0.11{\textendash}0.13~pg/g and surrounding seawater concentrations average 0.133~{\textpm}~0.016~pg/g. The 230Th/232Th atomic ratios of the vent fluids range from 1 ({\textpm}10)~{\texttimes}~10-6 to 11 ({\textpm}5)~{\texttimes}~10-6, are less than those of seawater, and indicate that the vent fluids may contribute a minor amount of non-radiogenic 230Th to the LCHF carbonate chimney deposits. Chimney 238U concentrations range from 1 to 10~$μ$g/g and the average chimney corrected initial $δ$234U is 147.2~{\textpm}~0.8, which is not significantly different from the ambient seawater value of 146.5~{\textpm}~0.6. Carbonate 232Th concentrations range broadly from 0.0038~{\textpm}~0.0003 to 125~{\textpm}~16~ng/g and 230Th/232Th atomic ratios vary from near seawater values of 43 ({\textpm}8)~{\texttimes}~10-6 up to 530 ({\textpm}25)~{\texttimes}~10-3. Chimney ages, corrected for initial 230Th, range from 17~{\textpm}~6~yrs to 120~{\textpm}~13~kyrs. The youngest chimneys are at the intersection of two active, steeply-dipping normal faults that cut the Atlantis Massif; the oldest chimneys are located in the southwest portion of the field. Vent deposits on a steep, fault-bounded wall on the east side of the field are all Th, range from 17~{\textpm}~6~yrs to 120~{\textpm}~13~kyrs. The youngest chimneys are at the intersection of two active, steeply-dipping normal faults that cut the Atlantis Massif; the oldest chimneys are located in the southwest portion of the field. Vent deposits on a steep, fault-bounded wall on the east side of the field are all},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0016-7037},
	doi = {10.1016/j.gca.2011.01.008},
	url = {http://dx.doi.org/10.1016/j.gca.2011.01.008},
	author = {Ludwig, K A and Shen, C C and Kelley, D S and Cheng, H and Edwards, R L}
}
@article {Brazelton2010,
	title = {{Archaea and bacteria with surprising microdiversity show shifts in dominance over 1,000-year time scales in hydrothermal chimneys}},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {107},
	number = {4},
	year = {2010},
	pages = {1612{\textendash}1617},
	abstract = {The Lost City Hydrothermal Field, an ultramafic-hosted system located 15 km west of the Mid-Atlantic Ridge, has experienced at least 30,000 years of hydrothermal activity. Previous studies have shown that its carbonate chimneys form by mixing of \~{}90 {\textdegree}C, pH 9{\textendash}11 hydrothermal fluids and cold seawater. Flow of methane and hydrogen-rich hydrothermal fluids in the porous interior chimney walls supports archaeal biofilm communities dominated by a single phylotype of Methanosarcinales. In this study, we have extensively sampled the carbonate-hosted archaeal and bacterial communities by obtaining sequences of {\textgreater}200,000 amplicons of the 16S rRNA V6 region and correlated the results with isotopic (230Th) ages of the chimneys over a 1,200-year period. Rare sequences in young chimneys were commonly more abundant in older chimneys, indicating that members of the rare biosphere can become dominant members of the ecosystem when environmental conditions change. These results suggest that a long history of selection over many cycles of chimney growth has resulted in numerous closely related species at Lost City, each of which is preadapted to a particular set of reoccurring environmental conditions. Because of the unique characteristics of the Lost City Hydrothermal Field, these data offer an unprecedented opportunity to study the dynamics of a microbial ecosystem{\textquoteright}s rare biosphere over a thousand-year time scale.},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0027-8424},
	doi = {10.1073/pnas.0905369107},
	url = {http://dx.doi.org/10.1073/pnas.0905369107},
	author = {Brazelton, W J and Ludwig, K A and Sogin, M L and Andreishcheva, E N and Kelley, D S and Shen, C C and Edwards, R L and Baross, J A}
}
@article {Kelley2007,
	title = {{The Lost City Hydrothermal Field revisited}},
	journal = {Oceanography},
	volume = {20},
	number = {4},
	year = {2007},
	pages = {90{\textendash}99},
	keywords = {AUV ABE (Autonomous Benthic Explorer), HOV Alvin (Human Occupied Vehicle)},
	issn = {1042-8275},
	doi = {10.5670/oceanog.2007.09},
	author = {Kelley, D S and Fruh-Green, G L and Karson, J A and Ludwig, K A}
}
@article {Ludwig2006,
	title = {{Formation and evolution of carbonate chimneys at the Lost City Hydrothermal Field}},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {70},
	number = {14},
	year = {2006},
	pages = {3625{\textendash}3645},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0016-7037},
	doi = {10.1016/j.gca.2006.04.016},
	url = {http://dx.doi.org/10.1016/j.gca.2006.04.016},
	author = {Ludwig, K A and Kelley, D S and Butterfield, D A and Nelson, B K and Fruh-Green, G L}
}
@article {Kelley2005a,
	title = {{A serpentinite-hosted ecosystem: The lost city hydrothermal field}},
	journal = {Science},
	volume = {307},
	number = {5714},
	year = {2005},
	pages = {1428{\textendash}1434},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0036-8075},
	doi = {10.1126/science.1102556},
	url = {http://dx.doi.org/10.1126/science.1102556},
	author = {Kelley, D S and Karson, J A and Fruh-Green, G L and Yoerger, D R and Shank, T M and Butterfield, D A and Hayes, J M and Schrenk, M O and Olson, E J and Proskurowski, G and Jakuba, M V and Bradley, A M and Larson, B I and Ludwig, K A and Glickson, D A and Buckman, K and Bradley, A S and Brazelton, W J and Roe, K and Elend, M J and Delacour, A and Bernasconi, S M and Lilley, M D and Baross, J A and Summons, R T and Sylva, S P}
}
@article {Fruh-Green2003,
	title = {{30,000 years of hydrothermal activity at the Lost City vent field}},
	journal = {Science},
	volume = {301},
	number = {5632},
	year = {2003},
	pages = {495{\textendash}498},
	issn = {0036-8075},
	doi = {10.1126/science.1085582},
	url = {http://dx.doi.org/10.1126/science.1085582},
	author = {Fruh-Green, G L and Kelley, D S and Bernasconi, S M and Karson, J A and Ludwig, K A and Butterfield, D A and Boschi, C and Proskurowski, G}
}
