The Acre cores arrived at August 6th. The science team is busy splitting, imaging, describing and sampling the cores at CSD facilities at University of Minnesota.
Due to maintenance in the early hours, it took us a bit longer to reach the 678m mark. The first core was retrieved in the evening, and the team was thrilled to get back to work!
Both science teams did enjoy the Sunday of maintenance to meet at the beach of Bagre. The repairs on the drilling streams are almost done at night, the well closed the last 70 meters and we are drilling to reach the 678 m again.
GEOSOL started drilling the cement and found contaminations at 546 meters. Unfortunately, the cable failed during the operation. GEOSOL is still drilling the cement and we expect to get new cores on August 8th from depths below 680 meters.
The new generator arrived on the island and the operation will come back as soon as possible. The GEOSOL took advantage of the cement drying to install the BOP (Blowout Preventer) in the well.
The science team checked the deposit and stored some cores while we waited for the drilling team to give us a position. The drilling team decided to cement the well between 560 and 600 meters.
At about 650 m depth we found this beautiful sample of a very cemented and poorly sorted material with chalcopyrite/pyrite between the mudstones leves.
Today we conducted an inspection with Marcelo Augusto Moreno da Silva Alves, member of the environmental agency from Pará (SEMAS). He visited the whole operation, updated with information from the drill rig and the science goals.
Team on site, led by Angela, did a sampling in superficial soil for microbiology analysis with hand auger. This data will be compared with results from the cores.
With new data acquired from yesterday's trip, we found the rocks at low tide (around 11am). The rock is mostly sandstone cemented with Fe-Mg oxides, with a few shells (upper left sample), probably from bivalves. Below the sandstone, sparse layers of unconsolidated grey clay may be found, similar to some cores. Fun fact: because of those clays' ability to become hard once they dry, some people describe its use as cement.
Today William and Angela had a field trip to "Bosque da Água" (Water's grove), looking for a first view of rocks described for the locals. Unfortunately, the tide was too high.
As the drill rig finished undergoing maintenance, the drilling resumed through poorly cemented fine sandstone. So far, the lithology varied between very well cemented mudstone, shale, beds of coal and now sandstone
As we say farewell to Isaac, Dayane, Alessandro and Rain, we got some help from a local professor to handle the cores. We need all the help we can get when the team gets shorter. After Isaac gets some rest, he will work on the cores from the first drill site in Acre, in Minnesota
After changing the drill bit, we welcomed new members of the team. William will put his sedimentology and mdis knowledge to the test, while Caio will get to know and experience the drilling project for the first time.
In between very well cemented mudstones and sandy siltstones, the night shift team recovered some shale samples. We have been seeing a cementation increase along every other core.
While the cores were coming out, the team was visited by some of the local professors. A big part of the project is to spread scientific knowledge to the local community, teaching about the evolution of the Amazonian rainforest for those curious enough to listen.
Even while the drill rig was undergoing some safety maneuvers, the science team didn't stop working. During the day, the team repaired one of the tents with some extra core liners.
The greenish shale cored at 506m depth will tell an interesting history.
The drilling continues during the day shift. During the night shift, the science activities will be stopped to perform the well and maintenance on the drill rig.
