Developing atom probe tomography of phyllosilicates in preparation for extra-terrestrial sample return

Hydrous phyllosilicate minerals, including the serpentine subgroup, are likely to be major constituents of material that will be bought back to Earth by missions to Mars and to primitive asteroids Ryugu and Bennu. Small quantities (< 60 g) of micrometre sized, internally heterogeneous material will be available for study, requiring minimally destructive techniques. Many conventional methods are unsuitable for phyllosilicates as they are typically finely crystalline and electron beam sensitive resulting in amorphisation and dehydration. New tools will be required for nanoscale characterisation of these precious extra‐terrestrial samples. Here we test the effectiveness of atom probe tomography (APT) for this purpose. Using lizardite from the Ronda peridotite, Spain, as a terrestrial analogue, we outline an effective analytical protocol to extract nanoscale chemical and structural measurements of phyllosilicates. The potential of APT is demonstrated by the unexpected finding that the Ronda lizardite contains SiO‐rich nanophases, consistent with opaline silica that formed as a by‐product of the serpentinisation of olivine. Our new APT approach unlocks previously unobservable nanominerals and nanostructures within phyllosilicates owing to resolution limitations of more established imaging techniques. APT will provide unique insights into the processes and products of water/rock interaction on Earth, Mars and primitive asteroids

Bibliographic checklist of the marine benthic algae of Central Polynesia in the Pacific Ocean (Excluding Hawai‘i and French Polynesia)

The Polynesian algal bibliographic checklist is based on records from past references for American Samoa and Samoa (380 spp.), Cook Islands (111 spp.), Johnston Atoll (190 spp.), Line Islands (250 spp.), Niue (3 spp.), Phoenix Islands (193 spp.), Pitcairn Islands (23 spp.), Tokelau (1 sp.), Tonga (109 spp.), Wake Atoll (121 spp.) and Wallis and Futuna (191 spp.) and consists of three sections. The first section (I. Classification) provides a listing of classes, orders, and families of the 238 genera of Polynesian algae. The second section (II. Species-Reference Index) provides an alphabetized listing of the 667 named algal species under the four Phyla, i.e., Cyanobacteria (68 species), Rhodophyta (373 species), Ochrophyta (59 species) and Chlorophyta (167 species) with the applicable reference citations for each island or atoll. Brief taxonomic or nomenclatural notes are provided, when appropriate, for selected species. The third section (III. Island-Reference Index) provides a chronological listing of all published references for the respective island or atoll in each island group. The complete references for all citations in the text are provided in the Reference section

Catalog of marine benthic algae from New Caledonia

A catalog of the marine benthic algae (#Chlorophyta, Phaeophyta and #Rhodophyta) reported from New Caledonia is presented in two sections : 1. Classification; 2. Check list with references and localities. There are 35 genera, 130 species of green algae; 23 genera, 59 species of brown algae; and 79 genera, 147 species of red algae which represent a rich algal flora for the subtropics. (Résumé d'auteur

Floristic account of the marine benthic algae from Jarvis Island and Kingman Reef, Line Islands, Central Pacific

The marine benthic algae from Jarvis Island and Kingman Reef were identified from collections obtained from the Whippoorwill Expedition in 1924, the Itasca Expedition in 1935, the U.S. Coast Guard Cutter Taney in 1938, the Smithsonian Institution’s Pacific Ocean Biological Survey Program in 1964 and the U.S. National Oceanic and Atmospheric Administration’s Reef Assessment and Monitoring Program (RAMP) in 2000, 2001, 2002, 2004 and 2006. A total of 124 species, representing 8 Cyanobacteria (blue-green algae), 82 Rhodophyta (red algae), 6 Heterokontophyta (brown algae) and 28 Chlorophyta (green algae), are reported from both islands. Seventy-nine and 95 species of marine benthic algae are recorded from Jarvis Island and Kingman Reef, respectively. Of the 124 species, 77 species or 62% (4 blue-green algae, 57 red algae, 2 brown algae and 14 green algae) have never before been reported from the 11 remote reefs, atolls and low islands comprising the Line Islands in the Central Pacific