Earth:Höör Sandstone

Höör Sandstone
Stratigraphic range: Lower Hettangian- Late Pliensbachian
~200–184 Ma

PreЄ

Є

O

S

D

C

P

T

J

K

Pg

N

Traditionally dated as Hettangian-Sinemurian only, recent palynology show that the uppermost assemblages are almost identical that the ones recovered in the Late Pliensbachian Sorthat Formation of Bornholm^[1]
Höör Sandstone; Stratigraphic range: Lower Hettangian- Late Pliensbachian; ~200–184 Ma PreЄ Є O S D C P T J K Pg N Traditionally dated as Hettangian-Sinemurian only, recent palynology show that the uppermost assemblages are almost identical that the ones recovered in the Late Pliensbachian Sorthat Formation of Bornholm
Type	Formation
Sub-units	Stanstorp member; Vittseröd member;
Underlies	Djupadal Formation
Overlies	Hörby Formation
Thickness	Up to 50 m (160 ft)
Lithology
Primary	Sandstone
Other	Clay and Conglomerate
Location
Coordinates	[ ⚑ ] : 55°59′N 13°38′E / 55.98°N 13.63°E
Paleocoordinates	Approx. 35°N
Region	Central Skåne County
Country	Sweden
Type section
Named for	Höör, Ljungbyhed
Named by	Nilsson
Year defined	1819
	Höör Sandstone (Sweden)

Short description: Geologic formation in Sweden

The Höör Sandstone is a geologic formation in Skåne County, southern Sweden. It is Early Jurassic (Hettangian-Pliensbachian) in age.^[3] This unit outcrops in central Skane on a few isolated exposures, being traditionally subdivided into the lower “millstone” (“kvarnstenen”) and the upper “buildingstone”.^[4] The lowermost layers where also claimed to host Rhaetian strata, however latter works suggested that the layers devolved as red beds, were part of the new Hörby Formation, thus delimitating the Höör sandstone to the lower Jurassic.^[5]^[6] It has been assumed to be limited to Hettangian-Sinemurian layers, yet recent palynological analysis suggest the uppermost section is of Pliensbachian age, underlying and maybe interacting with the younger volcanic deposits.^[1] The Höör sandstone represents a mostly fluvial unit with a rich collection of fossil plants, yet also includes brackish bivalves in some layers, pointing to marine ingressions locally.^[7]

Members

Stanstorp member

This member represents the older layers of the formation, being exposed in the abandoned stanstorpsgraven quarry and in the Vittseröd area.^[8] The member is mainly composed by sandstone and has abundant plants fossils, with both Both allochthonous plant fragments and plant roots indicating vegetation in situ (palaeosols).^[8] The layers suggest several type of fluvial and/or coastal depositions, from dunes and river banks to beach deposits, where the palaeocurrent directions are clear generally from the north-east to the south-west.^[7] This section hosts abundant conglomerate intercalations, with the lower ones formed by mud fragments and the uppers with distant source material, both abundant on wood fragments, some of them up to 20 cm in diameter).^[8]

Vittseröd member

The youngest member is composed by finer-grained and much better sorted sandstones, with limited abundance of mudstones and plant fragments small and limited to a few horizons.^[8] The presence of silt and mature quartz arenites, well sorted and fairly well rounded derived from strongly altered feldspars, shows that this member hosted a high-energy environment, one where tidal currents have been invoked for the modification of fine-grained sandstones, linked with the changes of the Laurasian Seaway.^[9] The upper parts of this unit are influenced by the initial pulse of the Pliensbachian coeval vulcanism with heavy volcanic minerals in the uppermost layers.^[10]

Fauna

Ichnofossils

Lockeia siliquaria (Bivalves)^[11]
Planolites annularis (Polychaetes)^[11]
Planolites montanus (Polychaetes)^[11]
Diplichnites isp. (Xiphosurans, Insects, Arachnids)^[11]
Teichichnus isp. (Polychaetes, Echiurans, Holothurians.)^[11]
Skolithos isp. (Polychaetes, Phoronidans)^[11]
Monocraterion tentaculatum (Polychaeta, Sipuncula, Enteropneustans & Echiurans)^[11]
Rhizocorallium isp. (Polychaeta, Sipuncula, Enteropneustans & Echiurans)^[11]
Aulichnites isp. (Gastropods)^[11]
Diplocraterion parallelum (Polychaeta, Sipuncula, Enteropneustans & Echiurans)^[11]

Bivalves

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Liostrea^[7]^[12]	Liostrea hisingeri	Vittseröd	Vittseröd member	Isolated Shells	An oyster, member of Ostreidae inside Ostreida. The most common Bivalve found locally, indicator of increased salinity levels on the Hettangian layers.	Example of Liostrea specimens
Cardinia^[7]^[12]	Cardinia follini	Stanstorp Vittseröd Dagstorp	Vittseröd member	Isolated Shells	A clam, member of Cardiniidae inside Carditida. This faunal aggrupation occurs together with abundant foliar remains and are equivalent to the Brandsberga erratics, which was closer to the mouth of the bay developed in the region, as it proves the find on its sandstone of more clear marine fauna.
Avicula^[7]^[12]	Avicula inaequivalvis	Vittseröd	Vittseröd member	Isolated Shells	A Scallop, member of Pectinidae inside Pectinida. The local material assigned to this genus is now lost
Pecten^[7]^[12]	Pecten sp.	Vittseröd	Vittseröd member	Isolated Shells	A Scallop, member of Pectinidae inside Pectinida.	Example of extant Pecten

Arthropoda

Genus	Species	Location	Stratigraphic position	Material	Notes
Mesolimulus^[13]	Mesolimulus? nathorsti	Stanstorp	Vittseröd Member	SMNH Ar33179, a possible prosomal section	A horseshoe crab, member of the Limulidae inside Xiphosura. This fragment has been considered to be a Limulus or Mesolimulus prosomal shield, but due to the limited and fragmentary nature some authors referred to it as ?Chelicerata incertae sedis.^[14]
Angelinella^[15]	Angelinella angelini	Kulla Gunnarstorp	Stanstorp Member	Elytrons	A beetle, incertae sedis Archostemata inside Coleoptera.
Paracurculionites^[15]	Paracurculionites parvulus	North of Sofiero	Stanstorp Member	Elytrons	A beetle, incertae sedis Archostemata inside Coleoptera.

Flora

Genus	Species	Stratigraphic position	Member	Material	Notes	Images
Equisetites^[16]	Equisetites laevis Equisetites gracilis	Ormanäsgraven Stanstorpsgraven Per Pålssons grav	Stanstorp Member	Stems	Affinities with Equisetaceae inside Equisetales.	Example of Equisetites specimen
Todites^[16]	Todites goeppertianus	Stanstorpsgraven Ormanäsgraven Kullans stenbrott	Stanstorp Member	Isolated pinnae	Affinities with Osmundaceae inside Osmundales.
Cladophlebis^[16]	Cladophlebis svedbergii Cladophlebis scoresbyensis Cladophlebis cf. nebbensis Cladophlebis cf. spectabilis Cladophlebis arguta Cladophlebis sublobata Cladophlebis sewardii Cladophlebis divaricata	Stanstorpsgraven Ormanäsgraven Kullans stenbrott Dagstorp	Stanstorp Member	Isolated pinnae	Affinities with Osmundaceae inside Osmundales.	Cladophlebis nebbensis specimen
Dictyophyllum^[16]	Dictyophyllum exile	Stanstorpsgraven Ormanäsgraven Kullans stenbrott	Stanstorp Member	Isolated pinnae	Affinities with Dipteridaceae inside Polypodiales. Dictyophyllum is a common Dipteridacean genus of the mid-Mesozoic	Dictyophyllum nilssonii specimen
Rhizomopteris^[16]	Rhizomopteris cruciata	Stanstorpsgraven Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Isolated pinnae	Affinities with Dipteridaceae inside Polypodiales.
Hausmannia^[16]	Hausmannia forchhammeri Hausmannia dentata Hausmannia lasciniata	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Isolated pinnae	Affinities with Dipteridaceae inside Polypodiales.	Example of Hausmannia specimen
Thaumatopteris^[16]	Thaumatopteris schenkii Thaumatopteris brauniana	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Isolated pinnae	Affinities with Dipteridaceae inside Polypodiales.
Clathropteris^[16]	Clathropteris meniscioides	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Isolated pinnae	Affinities with Dipteridaceae inside Polypodiales.	Example of Clathropteris meniscioides specimen
Peltaspermum^[16]	Lepidopteris ottonis	Stanstorpsgraven Ormanäsgraven	Stanstorp Member	Isolated pinnae	Affinities with Peltaspermaceae inside Pteridospermatophyta. Indicator or reworked Rahetian layers.
Peltaspermum^[16]	Peltaspermum rotula	Stanstorpsgraven Ormanäsgraven	Stanstorp Member Vittseröd Member	Isolated pinnae	Affinities with Umkomasiaceae inside Pteridospermatophyta.
Ptilozamites^[16]	Ptilozamites blasii Ptilozamites carlsonii Ptilozamites heeri Ptilozamites nilssonii	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Isolated pinnae	Affinities with Umkomasiaceae inside Pteridospermatophyta.	Ptilozamites specimen
Sagenopteris^[16]^[17]	Sagenopteris nilssoniana Sagenopteris rhoifolia Sagenopteris undulata	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Isolated pinnae	Affinities with Caytoniaceae inside Pteridospermatophyta.	Sagenopteris specimen
Ctenis^[16]	Ctenis nilssonii Ctenis minuta Ctenis latepinnata Ctenis laxa	Vittseröd Stanstorpsgraven Per Pålssons grav	Vittseröd Member	Leaflets	Affinities with Cycadales inside Cycadopsida.	Ctenis specimen
Pseudoctenis^[16]	Pseudoctenis florinii	Vittseröd Stanstorpsgraven Per Pålssons grav	Vittseröd Member	Leaflets	Affinities with Cycadeoidaceae inside Bennettitales.
Cycadolepis^[16]	Cycadolepis giganteus Cycadolepis blomquisti	Vittseröd Stanstorpsgraven Per Pålssons grav	Vittseröd Member	Leaflets	Affinities with Cycadeoidaceae inside Bennettitales.
Nilssonia^[16]	Nilssonia münsteri Nilssonia acuminata	Vittseröd Stanstorpsgraven Per Pålssons grav	Vittseröd Member	Leaflets	Affinities with Cycadeoidaceae inside Bennettitales.	Nilssonia specimen
Wielandiella^[18]	Wielandiella punctata Wielandiella angustifolia	Stanstorpsgraven	Stanstorp Member	Female Bennetite "flower"	Affinities with Williamsoniaceae inside Bennettitales. Wielandiella may be regarded as a fossil taxon characterized by bennettitalean shrubs with branched stems and a divaricate architecture
Pterophyllum^[16]^[19]	Pterophyllum majus Pterophyllum kochii Pterophyllum aequale Pterophyllum ptilum Pterophyllum compressum	Vittseröd Stanstorpsgraven Per Pålssons grav	Vittseröd Member	Leaflets	Affinities with Williamsoniaceae inside Bennettitales. In the uppermost layers is the dominant macroflora outside Pelmastermales	Example of Pterophyllum specimen
Anomozamites^[16]^[19]	Anomozamites minor Anomozamites intermedium	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Vittseröd Member	Leaflets	Affinities with Williamsoniaceae inside Bennettitales.
Stenorachis^[16]	Stenorachis dubius	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Reproductive Organs	Affinities with Czekanowskiales inside Ginkgoales.
Ginkgoites^[16]	Ginkgoites troedsonii Ginkgoites obovatus Ginkgoites marginatus	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Leave Compressions	Affinities with Ginkgoaceae inside Ginkgoales.	Ginkgoites specimen
Schizolepis^[16]	Schizolepis hörensis	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Ovulate Strobili	Affinities with Schizolepisaceae inside Pinaceae. Associated with Pinaceae thanks to the presence of separated seen scales and bract scales.
Stachyotaxus^[16]	Stachyotaxus septentrionalis Stachyotaxus elegans	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Isolated Leaves	Affinities with Palissyaceae inside Palissyales.	Stachyotaxus specimens
Podozamites^[16]	Podozamites lanceolatus Podozamites angustifolius Podozamites cuspiformis	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Isolated Leaves	Affinities with Krassiloviaceae inside Voltziales. The local Podozamites show a rather great range of growth, reflecting tropical to subtropical conditions.	Podozamites reconstruction
Elatocladus^[16]	Elatocladus cephalotaxoides Elatocladus conferta	Vittseröd Stanstorpsgraven Per Pålssons grav Ormanäsgraven Kullans stenbrott	Stanstorp Member Vittseröd Member	Fragmentary axis compressions with preserved leaves	Affinities with Sequoioideae inside Cupressales.	Elatocladus specimen